Pathology - PathCare
Transcription
Pathology - PathCare
Pathology Vol. 1 No. 2 I know but one freedom and that is the freedom of the mind - Antoine de Saint-Exupery The mind is not a vessel to be filled, but a fire to be ignited That is what learning is. - Plutarch You suddenly understand something you've understood all your life, but in a new way. - Doris Lessing You cannot teach a man anything; you can only help him find it within himself - Galileo Galilei The Academy for Tr aining & Development 11 Beyond the borders Microangiopathic haemolytic anaemia 3 14 Anaemia of chronic disease The coeliac iceberg 5 16 Clinical implications of GFR estimation by MDRD equation Diagnosis of smear negative pulmonary and extrapulmonary tuberculosis 7 17 Oral epithelial precursor lesions Learners benefit from PathCare gift 9 18 The PathCare Academy for Training and Development PathCare snippets Education is the most powerful weapon which you can use to change the world - Nelson Mandela June 2006 2 pathology forum x Editorial Team Editor Dr Dawie de Beer Production Dr Ross Millin Elandi Bishop Design and Layout Adéle Borton, Hannes Vosloo, Mark Calvert, Brent Davids From the Editor Private medical groups in South Africa have entered markets overseas in recent times. Life Healthcare (formerly Afrox Healthcare) has been involved for the past few years in the Partnership Health Group (PHG) in Britain while Medi-Clinic and Netcare, recently announced acquisitions in private hospital groups in the United Arab Emirates and Britain respectively These actions come as no surprise to us at PathCare. We have been involved in expanding beyond our borders for more than a decade. This edition of the PathCare Pathology Forum opens with an overview by the CEO of PathCare, Bruce Dietrich, on these developments. Recently PathCare announced the opening of the PathCare Academy of Training and Development at N1 City, conceived to address the skills shortage at certain levels in pathology in South Africa. This venture is headed by Eric Spencer and his article on the Academy graces our middle pages. The previous edition of the PathCare Pathology Forum carried an article by chemical pathologist Esmé Hitchcock at the reference laboratory at N1 City on formulas to estimate the glomerular filtration rate. In this edition she has follows on with a discussion on the interpretation of GFR as calculated by die MDRD-equation. Other esteemed contributors are Vince Phillips, professor in oral pathology at the dental faculty at the University of the Western Cape, Cor Aalbers chemical pathologist and Alicia Els, haematologist, both at our reference laboratory, Engela le Roux and Teresa Nel, haematologists at PathCare in Bloemfontein and Kas Kasongo, pathologist at PathCare in Port Elizabeth. Features e-mail news@pathcare.co.za Beyond the borders 2 Management Anaemia of chronic disease 3 CEO Dr Bruce Dietrich Clinical implications of GFR estimation by MDRD equation 5 Oral epithelial precursor lesions 7 The PathCare Academy for Training and Development 9 Microangiopathic haemolytic anaemia 11 The coeliac iceberg 14 Diagnosis of smear negative pulmonary and extrapulmonary tuberculosis 16 Learners benefit from PathCare gift 17 PathCare snippets 18 Director Pathology Operations Dr John Douglass Director Operations Africa Dr Nasser Mia Director Special Operations Dr Johan van Wyk Chief Systems Officer Dr Clive Prior Chief Financial Officer Ms Julie Buissinne Human Resources Director Vacant A list of PathCare Pathologists is available on our website at www.pathcare.co.za Pathologist contact email clients@pathcare.co.za Published June 2006 by: PathCare Business Centre • PathCare Park Drs Dietrich, Voigt, Mia & Partners Neels Bothma Street • N1 City • Goodwood • 7460 Private Bag X107 • N1 City • Goodwood • 7463 Tel : (021) 596 3400 • Fax : (021) 596 3726 S A N A S ACCREDITED LABORATORY ISO / IEC 17025 / 15189 pathology forum beyond the borders During the early 1990's the partners in the practice of Dietrich, Street and Partners (DSP) concluded that future changing circumstances in the country could pose threats not only to private medical practice overall but specifically also to private pathology. Based on the premise that threats should be viewed as opportunities, DSP developed strategies to deal with these potential threats to ensure a more secure future. At that time private pathology in South Africa was fragmented and consisted of practices of varying size, each operating independently, and characterised by a limited bargaining power and an inability to fully maximise benefits from economies of scale. As cost-effective practice of pathology is largely volume driven, the management and partners of DSP saw value in consolidation through associations and mergers with other practices in the region. This approach eventually led to the formation of the PathCare Group of pathology practices, currently one of the three large laboratory groups in private pathology in South Africa. The burgeoning Group also endeavoured early to expand beyond our national borders. As a first step the Group merged with the private pathology practice of Dr Jamie van Zyl in Windhoek, Namibia, in 1992. The practice in Windhoek has since grown considerably and now performs the majority of private pathology work in that country. During the early 1990's the Group decided to open facilities in the United Kingdom (UK). Rotation of South African staff through these gives them the opportunity to gain wider experience and bring increased skills back to South Africa. With the collapse of the rand during the nineties, the Group experienced additional pressure to broaden its base as almost all the reagents and equipment were bought in dollars, pounds or yen. Expansion into the UK enabled the Group to earn pounds which proved very helpful in financing foreign purchases of reagents and equipment. Automated Line Cape Town A recent development has been the drive in the UK towards privatisation of certain sectors of the National Health Service. This gave impetus to the formation of PathCare International Limited (PIL) which is a UK company fully owned by PathCare in South Africa. PIL is involved in joint ventures with the New Victoria Hospital in Kingston-on-Thames and Doublesure Diagnosis in Devon. It also fully owns laboratories which provide laboratory services to the Partnership Health Group Independent Sector Treatment Centres in Plymouth and Barlborough Links. The Group has expanded further into Africa in response to the Nepad initiative. PathCare is a minor shareholder in laboratories in Kenya and Nigeria. These laboratories are internationally accredited. A depot has been established in Dubai. Overflow work from the Emirates Airline Clinic in Dubai as well as specimens from other doctors, clinics and hospitals in the United Arab Emirates and surrounding countries are collected there and flown to Cape Town for processing. Similar working relationships have been established with laboratories in Mauritius, Ethiopia and Ghana. Burj Al Arab Hotel Dubai Nigeria Processing this overflow work in Cape Town increases the volumes of specialized tests in the laboratory. This allows PathCare to increase the number of South Africans employed locally and to develop high-technology laboratories with skilled staff and the opportunity to train South African citizens in these fields. This also results in an inflow of revenue to South Africa. It is clear that by a process of association and amalgamation PathCare has formed a consolidated base from which to extend into the international arena thereby not only bringing benefits to itself but also to South African pathology in general. 2 Nigeria Laboratory Dr Bruce Dietrich pathology forum anaemia of chronic disease Causes of anaemia of chronic disease The three main causes of ACD, infection, inflammation and neoplasia, are responsible for about 75% of cases (see table). Although the chronic diseases that cause ACD are mostly easily identified, this is not always the case and therefore occult disease should be considered in all cases of unexplained anaemia. Characteristics of anaemia of chronic disease • • • • Anaemia of chronic disease (ACD) is the commonest anaemia in hospitalised patients and is the second most common anaemia, after iron deficiency anaemia, outside the hospital. ACD occurs in patients with acute and chronic immune activation and is therefore often referred to as anaemia of inflammation. Moderate anaemia-normochromic normocytic to hypochromic microcytic Hypoferraemia (decreased serum iron) Raised tissue iron stores. Decreased red cell production Pathophysiology The immune system is the driving force behind ACD, with cytokines (eg. interleukin 1, interferon gamma and tumour necrosis factor) and cells of the reticulo-endothelial system (RES) playing a central role. A determining change in ACS is dysregulation of iron homeostasis, causing an increased uptake and retention of iron in the cells of the RES. Iron is diverted out of the circulation to the stores with a resultant decrease in iron available to the erythroid precursors which in turn leads to ironrestricted erythropoiesis. Hepcidin, released by the liver in response to inflammation, is an important mediator of the process as it supresses iron absorption and iron release from stores. Figure 1 Erythrocytes in ACD Figure 2 Iron (blue) in bone marrow particle Other pathophysiological factors are: • • • a curtailed proliferation of erythroid precursors as a result of direct inhibitory effects of cytokines; insufficient erythropoietin (EPO) response for the degree of anaemia; and moderately decreased red cell survival resulting from increased erythrophagocytosis. Erythropoiesis can also be suppressed through infiltration of the bone marrow by tumour cells or microorganisms. Factors which may aggravate the anaemia include episodes of blood loss, vitamin deficiencies (eg vitamin B12 and folate), hypersplenism, autoimmune haemolytic anaemia, renal insufficiency and radio- and chemotherapy. Dr Alicia Els 3 pathology forum Chronic renal disease Anaemia of chronic renal disease shares features with ACD, although the decreased production of EPO as a result of renal insufficiency and the antiproliferative effects of uraemic toxins contribute significantly to the pathophysiology. It is important to note that in patients with end stage renal disease, chronic activation of the immune system can develop from contact activation by dialysis membranes or as a result of repeated infections. Laboratory evaluation of ACD • • • • • Serum iron and transferrin saturation is decreased (hypoferraemia). Serum transferrin is decreased and serum ferritin is increased as part of the acute phase response, or normal. Soluble transferrin receptor levels are normal in pure ACD and may be useful to recognise true iron deficiency in patients with ACD. The bone marrow shows increased iron in macrophages but reduced iron transfer to sideroblasts. Determination of erythropoietin levels is only useful in patients with a haemoglobin level less than 10g/L and interpretation should consider the degree of anaemia. Treatment of ACD Treatment is indicated as the anaemia itself has adverse effects and also because anaemia often indicates a poorer prognosis in a variety of conditions. It is important to correct a moderate anaemia in patients older than 65 years, in patients with additional risk factors (eg coronary vascular disease, lung disease and chronic renal disease) and in patients receiving chemotherapy or dialysis. Treatment of the underlying disorder, if possible, is most important. Alternatives include red cell transfusion and recombinant EPO in selected patients. CAUSES OF ACD Infection Neoplasia Inflammatory • • • • • • • • • • • Viral infections, including HIV Bacteria Parasites Fungi Haematological malignancies Solid tumours RA, SLE and other connective tissue diseases Vasculitis Sarcoidosis Inflammatory bowel disease Chronic rejection after transplantation Chronic renal disease 4 pathology forum clinical implications of GFR estimation by MDRD equation Why do many normal individuals have decreased MDRD calculated GFR values? An important limitation of the GFR estimation equations is decreased accuracy at higher levels of GFR. It has been shown that GFR estimates by MDRD calculations are indeed more accurate in patients with chronic renal disease, than in healthy subjects. These findings are also reflected in our laboratory data. MDRD calculated GFR results <60 ml/min show a closer correlation with creatinine clearance results, than MDRD calculated GFR results >60 ml/min (see figure). R 2 = 0.77 y = 0.5998x + 7.6519 The National Kidney Foundation (US) and the UK Chronic Kidney Disease Guidelines Group have recommended that all serum creatinine concentrations now be reported with an estimated glomerular filtration rate (GFR), calculated by the abbreviated MDRD equation * (MDRD calculated GFR). This has been implemented at PathCare. An overview of the GFR prediction equations was presented in the previous issue of the Pathology Forum. In this article, we discuss some practical implications of the MDRD calculation. 90 80 70 MDRD 60 50 40 30 20 10 0 -10 0 20 40 MDRD <60 60 80 100 120 CrCl y = 0.4853x + 34.509 R 2 = 0.43 180 160 MDRD 140 120 100 80 60 40 20 20 MDRD >60 Dr Esmé Hitchcock 5 70 120 CrCl 170 220 pathology forum How should we interpret decreased MDRD calculated GFR results? Reasons for the relatively inferior performance of the MDRD equation in people with normal or near-normal renal function are: • A GFR <60 ml/min suggests chronic renal disease. A GFR >60 ml/min, with markers of kidney damage, such as proteinuria, also suggests chronic renal disease. Individuals with a GFR 60-90 ml/min, with no markers of kidney damage, but with risk factors for kidney disease, such as hypertension, diabetes mellitus, family history of renal disease and autoimmune disease, should be evaluated further. Selection bias: The equation was developed in a population with chronic renal disease (mean GFR 40 ml/min). • The use of regression analysis, by its very nature of best fit to the observed mean, decreases the accuracy of the estimate in populations with different ranges of GFR. If applied to individuals with higher ranges of GFR, the GFR will be underestimated. • The relationship between serum creatinine and GFR may differ fundamentally in populations with and without renal disease. At the same serum creatinine level, age, and sex, GFR is on average 26% higher in healthy persons than in patients with chronic renal disease. A greater muscle mass and higher dietary protein intake in healthy persons may account for this difference. Can MDRD calculations be used in acute renal failure? No, the MDRD GFR estimate should not be used during acute renal failure. Due to a more complex association between serum creatinine and rapidly changing renal function, the GFR estimation equations are not applicable during acute renal failure. Other possible causes for unreliable MDRD calculated GFR results were listed in the previous issue of the PathCare Pathology Forum. Conclusion Figure 1 Interdigitating secondary processes of podocytes on the outer surface of a capillary in the renal glomerulus. GFR estimation by the MDRD equation is not accurate in the higher ranges of GFR. It can, however, detect impaired renal function much earlier than serum creatinine alone and a MDRD calculated GFR result between 60-90 ml/min should be evaluated further in patients at risk for chronic renal disease. The MDRD equation currently provides the most useful estimate of GFR in adults and is the marker of choice for monitoring renal function in chronic renal disease. Figure 2 Diabetic nephropathy, thickening of glomerular capillaries Variability of serum creatinine levels in healthy persons could be mainly attributed to muscle mass and dietary protein intake, A 50% higher serum creatinine level is associated with an 18% lower GFR. In chronic renal disease patients, a 50% higher serum creatinine level is associated with a 41% lower GFR, possibly reflecting that here the GFR may have the dominant effect on serum creatinine variability rather than muscle mass and protein intake. It also reflects the increasing role of tubular secretion of creatinine on serum creatinine levels as GFR declines. • * Calibration bias: The serum creatinine results from the MDRD study laboratory may differ from those obtained in other laboratories. A constant calibration bias between laboratories causes greater inaccuracies in estimated GFR for persons with a normal serum creatinine level, than for those with an elevated serum creatinine level. In cases where the serum urea and albumin values are also available, the original MDRD equation is used. Input by Dr. Julian Jacobs is gratefully acknowledged. If the MDRD calculated GFR results in the higher range are not accurate, why do we report them? The MDRD calculated GFR is nonetheless a more sensitive index of decreased GFR than serum creatinine alone. It is well known that the GFR has reduced by approximately 50% before the serum creatinine rises above the reference range. Reporting serum creatinine alone, may therefore lead to delays in diagnosis and treatment of chronic renal disease. Sources: 1. Ann Intern Med. 2004;141:929-37 2. Ann Intern Med. 2003;139:137-47 6 pathology forum oral epithelial precursor lesions Precursor lesions are defined as altered epithelium with an increased likelihood of progression to squamous carcinoma (SCC). The altered epithelium shows a variety of cytological and architectural changes that have traditionally been grouped under the term dysplasia¹. Atypia is not considered synonymous with dysplasia and has been used in the context of inflammatory and regenerative changes particularly referring to cytological features. Atypia refers to cytological changes that may or may not be pre-malignant. Dysplasia refers to architectural disturbance accompanied by cytological atypia. The principal precursor lesions of the oral and oropharyngeal region are white patches (leukoplakia) (Fig 1) and red patches (erythroplakia) (Fig 2) or mixed red and white lesions (speckled leukoplakia Fig. 3). Histopathology Precursor lesions in the oral cavity can be thick or atrophic. By definition there is no invasion of the lamina propria. The magnitude of the surface keratinisation is of no importance and is often misleading. Hyperplasia describes the increase in cell numbers that may occur in the spinous layer or in the basal-parabasal cell layers (basal cell hyperplasia). The architecture shows regular stratification without cellular atypia. Dysplasia is architectural disturbance with cytological atypia. There is a challenge in the recognition of the earliest manifestations of dysplasia and no single combination of the features in Table 1 allow for consistent distinction between hyperplasia and the earliest stages of dysplasia. Dysplasia is a spectrum of cytological features and no rigid criteria exist to precisely delineate this spectrum into specific categories. However, the features listed in Tables 1 and 2 can be applied to broadly distinguish mild, moderate and severe dysplasia. Mild dysplasia Architectural disturbance is limited to the lower third of the epithelium and accompanied by cytological atypia. (minimum criteria for dysplasia) There is often a change in the keratin pattern in the area i.e. from para-keratin to orthokeratin (Fig.4 and 5). Moderate dysplasia The architectural disturbance in moderate dysplasia extends from the basal layer up into the middel third of the epithelium, but on the degree of atypia may be more severe. Severe dysplasia Architectural disturbance extending more than two thirds of the epithelium with associated cytological atypia. The oral epithelium can be atrophic and the severe atypical changes may be located in the basal cell region (Fig. 7). WHO CLASSIFICATION (2005) SQUAMOUS INTRAEPITHELIAL NEOPLASIA (SIN) Mild dysplasia Basal/parabasal cell hyperplasia SIN 1 Moderate dysplasia Atypical hyperplasia (risky epithelium) SIN 2 Carcinoma in-situ Severe dysplasia / carcinoma in-situ > two thirds of the epithelial thickness shows atypical dysplasia SIN 3 The theoretical concept is that malignant transformation has occurred but invasion is not present. Pronounced cytological atypia is present and extends the full thickness of the epithelium. Atypical mitotic figures and abnormal superficial mitoses are commonly seen. The Table 2. Classification scheme showing histological features The majority of leukoplakias will not show dysplasia and are as a result of hyperplasia. The majority of leukoplakias will not undergo malignant change and may even regress if the aetiological agent is removed. Red and mixed lesions (speckled leukoplakia) show a high frequency of dysplasia and are often of a high grade. Figure 1 Leukoplakia of the under surface of the tongue with a verrucous or wart-like appearance. Prof Vince Phillips 7 Figure 2 Erythroplakia of the right pillar of the fauces Figure 3 Speckled leukoplakia of the cheek mucosa. pathology forum atrophic oral epithelium may show these signs limited to the basal and parabasal layers and be covered by a layer of keratin². ARCHITECTURE Abnormal variation in epithelial size Loss of polarity of basal cells Abnormal variation in nuclear shape (nuclear pleomorphism) Drop-shaped rete ridges Abnormal variation in cell size Increased number of mitotic figures Abnormal variation in cell shape (cellular pleomorphism) Abnormally superficial mitoses (mitoses above the basal cell layer) Increased nuclear-cytoplasmic ratio Premature keratinisation in single cells (dyskeratosis) Increased nuclear size Keratin pearls within rete pegs Atypical mitotic figures Increased number and size of nucleoli Hyperchromasia Discussion Squamous epithelium that is reactive, regenerative or reparative in response to trauma, inflammation, irradiation or ulceration may manifest architectural disturbance and a degree of cytological atypia. Nutritional deficiencies of iron, folate and vitamin B12 can simulate dysplasia. These lesions are not considered precursor lesions and should be distinguished from them. Severe dysplasia is associated with a greater likelihood of progression to malignancy. The dysplastic changes are as a result of genetic changes within the epithelium. The mutations are regarded to be a result of carcinogenic agents like tobacco and alcohol usage as well as susceptible epithelial cells. There are no genetic markers that reliably predict malignant transformation. Table 1. Criteria used for diagnosing dysplasia The clinical appearance of the oral mucosa in precursor lesions can vary from a thick white plaque to an erosive red area, but the clinical appearance only hints at the changes that are present microscopically. Traditionally the dysplastic lesions seen in the uterine cervix are graded according to the extent of the atypical changes within the architecture of the epithelium. Thus a severely dysplastic epithelium would show full thickness atypia. In the oral mucosa, however, the clinical appearance often belies the atypical features seen histologically. The surface retains a parakeratin or orthokeratin layer but the basal cell and para-basal cell layers may show moderate to severe atypia (Figs.6 and 7) or even early infiltrating carcinoma. The WHO² states that most leukoplakias are benign but that 4 - 8% of them will become malignant. However, 30% of erythroplakias are either carcinoma insitu or infiltrating carcinoma at the first examination. When the patient first presents with a white or red oral lesion, a biopsy of the area is essential to establish the histological degree of dysplasia of the epithelium. A patient with a mild or moderately dysplastic leukoplakia should be encouraged to quit the carcinogenic habit and be followed up on a regular basis. These patients should be examined at least once a year and if any change Figure 4 Hyperkeratosis with basal cell proliferation(hyperplasia) and “drop-shaped” retepegs Figure 5 Mild dysplasia. Cellular pleomorphism of the basal cells and prominent nucleoli. CYTOLOGY Irregular epithelial stratification has occurred in the clinical appearance i.e the lesions has become bigger or has developed red areas, a biopsy should be mandatory. Those patients with severe dysplasia should be referred to an oncologist. Sources: 1. Gale N, Pilch BZ, Sidransky, Westra WH, Califano J. (2005) Epithelial precursor lesions. Tumours of the hypopharynx, larynx and trachea. Pathology & Genetics. Head and Neck Tumours. WHO Classification of Tumours. WHO Press. P140-3. 2. Gale N, Pilch BZ, Sidransky, Westra WH, Califano J Johnson N, MacDonald DG. (2005) Epithelial precursor lesions. Tumours of the oral cavity and oropharynx. Pathology & Genetics. Head and Neck Tumours. WHO Classification of Tumours. WHO Press. P177-9. Figure 6 Moderate dysplasia showing pleomorphism of cells, mitotic figures above the basal cell layer, abnormal mitotic figures and basal cells with some nuclei showing more than one prominent nucleolus. 8 Figure 7 Severe dysplasia (squamous intraepithelial neoplasia) showing hyperchromatism and atypical features. Abnormal mitotic figures in the lower layers of the epithelium, but a relatively undisturbed surface layer. The Academy for Tr aining & Development the PathCare Academy for training and development PathCare is pleased to introduce our newest division - the PathCare Academy for Training and Development. The Academy opened its doors near our core reference laboratory at N1 City in Cape Town on the 1st of February 2006. The Academy was established by the PathCare Chief Executive Officer, Dr Bruce Dietrich, and his Executive Committee. The new initiative is part of a strategy to help address the South African skills shortage in general and shortages in the pathology sector, and in PathCare, in particular. The Academy is built upon three developmental pillars, namely: Development of Technical Expertise, Quality Service, and Business Capacity. The first major programmes, which commenced between February and April 2006, are primarily focused on the technical field to supply skilled professional and associate professional technical staff for the future. New and upgraded programmes in the quality service and business capacity fields commenced with the April 2006 to March 2007 training year. The Development of Technical Expertise Over the past six years PathCare has been a leader in skills development in the pathology sector. The first three learnerships proposed for the sector were spearheaded by PathCare through its early involvement in the interim steering committee and the first Board of the Health and Welfare Sector Education and Training Authority (HWSETA). PathCare also spearheaded the establishment of Standards Generating Bodies for new and / or updated qualifications to be placed on the National Qualifications Framework (NQF) of the South African Qualifications Authority (SAQA). PathCare has worked closely with the Professional Board of Medical Technology of the Health Professions Council of South Africa (HPCSA) to ensure that students receive quality training and that they are able to be registered with the Council in order to practice. Eric Spencer The new programmes in the technical category include the following: Learnerships for Phlebotomy Technicians This new learnership provides learners from previously disadvantaged backgrounds with an opportunity to acquire one of the newest nationally recognised qualifications in South Africa. In keeping with international trends, phlebotomy technicians develop specialised skills for the collection of specimens in the pathology and blood transfusion sectors. The qualification is designed to also strategically help relieve the shortage of qualified nursing staff in the country. The new PathCare Academy commenced with South Africa's first phlebotomy learners in a programme which is run with the support and co-operation of the HWSETA, SAQA, HPCSA, Western Province Blood Transfusion Services, and Cape Peninsula University of Technology (CPUT). Medical Laboratory Technicians The training of medical laboratory technicians is not yet in the form of a registered learnership. Yet PathCare has dramatically increased its number of student technicians and is training them through the Academy and in our accredited training laboratories in a programme as similar to that of a learnership as is possible at this time. Upon completion of the programme, students write an exam set by the professional board of the HPCSA and when successful are registered with the Council. For the first time, PathCare has recruited additional numbers of previously disadvantaged individuals from the general public (previously only existing staff trained as technicians) to undergo this Academy programme. Bursaries for Medical Technology Students Through co-operation with the CPUT, the Academy has also introduced new bursary schemes for students of bio-medical technology. The first bursaries have been awarded for 2006. These students will complete their experiential learning and internships in PathCare laboratories throughout South Africa and will provide a new pool of qualified medical technologists from previously disadvantaged backgrounds for the organisation. Bridging course from Medical Technician to Medical Technologist The Academy is sponsoring a number of existing PathCare staff to attend part-time instruction through the CPUT in order to again increase the number of qualified professionals in the organisation. Education is the most powerful weapon In addition to the above which you can use to change the world programmes, various other - Nelson Mandela technical short courses are to be offered by the Academy for existing staff in order to ensure that the knowledge and skills of our technical and professional personnel are continuously developed. The Development of Service Quality and Business Capacity Various new short courses and certificate programmes in the service quality and business capacity categories will be introduced at the Academy in the 2006-2007 training year. These programmes, like those in the pillar of technical expertise, run with the national SETA training year. Our Workplace Skills Plans and Annual Training Reports have been fully approved by the HWSETA every year since the inception of the Skills Development Act. Through a combination of internal programmes and programmes outsourced to accredited providers nationally, the Academy will help to ensure that PathCare's service delivery is constantly enhanced through the continuous development of all of our staff. Courses to be offered in the Academy prospectus for the year include programmes in customer care, quality assurance, occupational health and safety, diversity awareness, coaching, industrial relations, conflict management, human resources, financial skills, change management, various computer skills, and general management skills, among others. Particular emphasis is also being placed on the skills development of previously disadvantaged individuals in general, and the development of existing managers and new managers for the future. Recently, a HWSETA supported initiative saw previously disadvantaged staff members attend management development programmes through the University of Stellenbosch Business School; further such programmes will be provided by and / or outsourced by the Academy in the 2006-2007 training year. By providing these learnerships, certificate and diploma programmes, bursaries, and short courses through the three developmental pillars of of technical expertise, quality service, and business capacity, the new PathCare Academy for Training and Development will contribute towards the broader skills revolution in South Africa and will help ensure that PathCare offers a continuously improving service to our valued supporters and patients. PathCare is proud of this new initiative and we trust that it will grow from strength to strength. pathology forum microangiopathic haemolytic anaemia Erythrocyte (or red cell) fragmentation syndromes are characterised by the presence of red cell fragments (schistocytes) in the blood film. These are usually accompanied by intravascular haemolysis (fragmentation haemolysis). There are many causes of fragmentation haemolysis. Some common causes are summarised in Table 1. This article will concentrate on microangiopathic haemolytic anaemia (MAHA). CATEGORY MODE OF HAEMOLYSIS 1. Microangiopathic haemolytic anaemia 2. Other physical trauma such as: • Thermal injury (burns) Physical damage to erythrocytes by microthrombi Thermal damage to cell membrane proteins • Cardiac trauma (e.g. prosthetic valve) Physical trauma to erythrocytes • March haemoglobinuria (e.g. marathon runners) Excessive force on the erythrocytes as they pass through the microcapillaries Table 1: Causes of fragmentation haemolysis Damage to the endothelial lining of the small vessels Leucocytosis may be present Platelet activation with the formation of fibrin strands and microthrombi Thrombocytopenia due to the consumption of platelets Fibrinolysis Red cell fragmentation Splenic sequestration MAHA is a term that describes a haemolytic process caused by microcirculatory lesions. Damage to the endothelial lining of the small vessels results in deposits of fibrin within these vessels. As erythrocytes (red blood cells) are forced through the fibrin strands, their cell membranes may be sliced open. This leads to schistocytes (red cell fragments) in the peripheral blood film and is reported as fragmentation haemolysis. Dr Engela le Roux and Dr Teresa Nel Intravascular haemolysis Anaemia Increase in the number of reticulocytes Haemoglobinaemia é in serum LDH and AST é in serum unconjugated bilirubin Haemoglobinuria ê in serum haptoglobin ( this is seen with chronic haemolysis) Figure 1 : Pathogenesis of microangiopathic haemolytic anaemia (MAHA) 11 pathology forum 1. 2. 3. 4. 5. 6. It is important to identify the underlying disease or condition responsible for the MAHA and to start with effective treatment and supportive care immediately. The clinical symptoms, age group and target organs affected and laboratory tests may help to make the correct diagnosis. See Table 2 for diseases and conditions associated with MAHA. Disseminated Intravascular Coagulation (DIC) Haemolytic Uraemic Syndrome (HUS) Thrombotic Thrombocytopaenic Purpura (TTP) Disseminated Carcinoma Malignant Hypertension HELLP Syndrome Table 2: Diseases and conditions associated with MAHA. Because of the similarity in clinical manifestations there has been considerable ongoing debate as to whether TTP and HUS are simply different clinical expressions of the same disease. However, TTP occurs most often in young adults and the variety of manifestations present in TTP reflects damage to multiple organs. The neurologic symptoms of TTP are more prominent and the condition carries a higher mortality rate than HUS. There is an increase in the prevalence of HIV associated TTP and the central nervous system (CNS) abnormalities are more severe in HIV cases. The CNS abnormalities of TTP include headaches, confusion, seizures and coma. Drugs associated with TTP include mitomycin, ticlopidine, clopidogrel, cyclosporin and quinine. Fragmentation Haemolysis Child Pregnant woman Male or pregnant female without pre-eclampsia DIC screen + Acute renal failure Pre - eclampsia DIC Consider HUS DIC screen - CNS symptoms ++ Consider HELLP Clinical history: Eg Hypertension Prosthetic valve Carcinoma, etc. Consider TTP HELLP syndrome is a severe form of preeclampsia manifesting with hemolysis, elevated liver enzymes and low platelets. Figure 2: An approach to MAHA Laboratory tests Abnormalities in coagualation tests help to distinguish between DIC and TTP/HUS. Abnormal coagulation tests with DIC include: • Prolonged PT, PTT and thrombin time • Increased fibrin degradation products (FDP) and D-dimers • Decreased fibrinogen levels • Decreased antithrombin III levels These abnormalities are absent in TTP/HUS. 12 pathology forum Summary: • If faced with a patient with MAHA treat as TTP until proven otherwise. • The clinical symptoms, age group affected, organs involved and laboratory tests may assist in establishing the correct diagnosis. • DIC coagulation screening helps to distinguish DIC from TTP/HUS • The haematologist plays an important role in the diagnosis of MAHA through the morphological evaluation of the peripheral blood smear and the identification of fragmentation haemolysis. • MAHA is a fragmentation haemolytic process due to endothelial lining damage of the small vessels resulting in fibrin deposits within the vessel. • MAHA is a medical emergency and early diagnosis, supportive care and correct treatment will reduce the mortality rate. CATEGORY ASSOCIATED CONDITION AGE CHARACTERISTICS PATHOPHYSIOLOGY TREATMENT Microthrombi form with an increased consumption of platelets and coagulation proteins. Patient develops bleeding tendencies. Treat the underlying cause. Fresh Frozen Plasma Cryoprecipitate Blood products (red cell concentrate and platelets as is appropriate) Heparin is controversial can be considered if liver function is normal. DIC Infections Complications of pregnancy Neoplasm (e.g. AML-M3) Massive tissue injury Vascular injury Miscellaneous e.g. snake bite Any age HUS (D+ or D-) Classically D+ (with diarrhoea) or occasionally D- ( without diarrhoea) > 90% of cases are due to verocytotoxin-secreting bacteria such as S. dysenteriae or E. coli 0157:H7 <5 year (occasional reports MAHA of adult cases) Thrombocytopaenia Acute renal failure Mild CNS symptoms DIC screen is negative Previously healthy child Toxin induces damage to the colonic mucosa. This allows for the toxin to enter the circulation which leads to endothelial damage which is most prevalent in the glomerular capillaries. Peritoneal dialysis in the anuric phase Transfusions Treat the hypertension Treat the water and electrolyte imbalances. Fresh frozen plasma exchange can also be considered. TTP 40% of cases are associated with infection of which HIV is a major component. 10-25% of cases are associated with pregnancy or oral contraception. Other causes include drugs, systemic lupus erythematosus, lymphoma, carcinoma, etc. 20-50 years old Females are affected more than males MAHA Thrombocytopaenia Renal dysfunction Severe CNS symptoms Fever DIC screen is negative. Lack of von Willebrand factor cleaving protease enzyme. This leads to elevated levels of large von Willebrand multimers. Fresh Frozen plasma Fresh Frozen plasma exchange IV steroids with or without vincristine Cryosupernatant (NOT cryoprecipitate ) Anti-platelet agents Splenectomy can be considered for those patients that develop the chronic relapsing type of TTP. CONTRA - INDICATIONS: Platelet transfusion as this increases thrombi formation. HELLP syndrome 10% of pregnancies with eclampsia develop HELLP syndrome Pregnant women MAHA Thrombocytopaenia Elevated liver enzymes Pre-eclampsia The precipitating factor is unknown. Deliver the foetus. Steroid therapy (lung maturation; reduces cell destruction and eliminates platelet transfusion demands in the mother). Malignant hypertension Underlying severe hypertension Mainly adults MAHA Thrombocytopaenia Severe hypertension Unknown Possibly fibrinoid necrosis of the arterioles Lower blood pressure. Disseminated cancer Underlying carcinoma with extensive metastases (especially mucin secreting tumours such as adenocarcinoma) Mainly adults MAHA Thrombocytopaenia Underlying carcinoma Endothelial damage Chemotherapy and supportive care. Table 3 : Sumary of diseases and conditions associated with MAHA 13 MAHA Thrombocytopaenia DIC screen is positive pathology forum the coeliac iceberg Introduction Coeliac disease (coeliac sprue) or gluten sensitive enteropathy is characterized by an inflammatory response in the mucosa of the small intestine after the ingestion of wheat gluten, resulting in malabsorption. Untill recently it was suspected that this is primarily a disease of infants, but with more sensitive and specific laboratory tests, the diagnosis is now being made more frequently in adults. In fact it has been reported that up to 20% of new diagnoses are made in patients over the age of 60. Previously it was thought that the incidence is about 1:3000, but with recent emerging evidence it is estimated to be 1:100 to 1:300, depending on the country. Pathophysiology The pathogenesis of coeliac disease (CD) is based on the presentation of gluten in the small bowel in a genetically predisposed person, eliciting an inappropriate T-cell response. There is a 10% prevalence of CD in first degree relatives with CD. malabsorption. Currently the most common presenting feature in adults is anaemia. Extra-intestinal symptoms include osteoporosis, short stature, dental enamel defects, arthritis and arthralgias as well as neurological symptoms like peripheral neuropathy, cerebellar ataxia, epilepsy and migraine. Over 95% of CD patients express the HLA-DQ2 and -DQ8 molecules. These molecules bind the gliadin fraction of gluten, present it to the T-helper cells to activate tissue transglutaminases, which in turn deaminate glutamine of the gliadin peptide to glutamic acid. This elicits a stronger T-cell response. These lymphocytes activate other lymphocytes with the release of cytokines and TNF-α which result in villous atrophy. The gold standard for the diagnosis of CD remains a small bowel biopsy demonstrating villous atrophy while the patient is still consuming a gluten containing diet (four slices of bread daily for six weeks), followed by improvement after institution of a gluten free diet (GFD). When a patient is suspected of suffering from CD, there is a range of laboratory tests that can be performed: a full blood count to establish anaemia or abnormal red cell morphology, tests for the diagnosis of diabetes and thyroid disease as well as tests for diagnosing malabsorption, like folate, ferritin, calcium or alkaline phosphatase levels. The enzyme, tissue transglutaminase, is one of the targets of the autoimmune response in CD. It has been noted that autoimmune diseases occur more commonly in patients with CD. These include diabetes mellitus and autoimmune thyroiditis. Unexpected episodes of hypoglycaemia or diarrhoea should alert the clinician to the possibility of CD. Diagnosis Classically the diagnosis of CD is made on infants between the ages of four months and two years presenting with small bowel symptoms like vomiting, diarrhoea, abdominal distension and impaired growth. Older children may present with short stature, delayed puberty, anaemia and rickets. Atypical CD may present with no features of malabsorption, but only with abdominal pain, persistently elevated transaminase levels, recurrent aphthous stomatitis, arthralgia and defects in dental enamel. Children may even present with behavioural disturbances, irritability, depression and poor performance at school. Until recently the tests available for the diagnosis of CD were the small bowel biopsy and the IgA and IgG antigliadin antibodies. The latter tests had moderate sensitivity but far less specificity than the more current IgA anti-endomysial antibodies and the IgA antitransglutaminase antibodies. Older patients may have more atypical symptoms presenting them to various specialities before the diagnosis is made. These may vary from being tired all the time, to persistent anaemia or gynaecological problems like infertility, recurrent miscarriages or orthopaedic problems like fractures. The absence of diarrhoea does not exclude CD. Common signs and symptoms include abdominal pain, frequency of bowel movement, weight loss, bone disease, chronic anaemia, or severe anaemia during pregnancy, fatigue and biochemical evidence of 14 Dr Cor Aalbers pathology forum The latter two newer tests have proven to be far superior to the former two and are now the tests of choice. From a diagnostic point of view they perform equally well and as the IgA transglutaminase antibody test is easier to perform than the IgA antiendomysial antibody test, the transglutaminase test is the test of choice. The possibility of false positive results are rare, but should be suspected in IgA myeloma and in liver cirrhosis, while false negative results are primarily seen in IgA deficient individuals. It should also be noted that if the patient has been on a GFD the test results will also become negative. This feature is used to monitor the patient's compliance with his diet. Treatment The management of a patient with a confirmed CD, is a life time commitment to label reading and a GFD. Therefore there is no place for a therapeutic trial as a firm diagnosis has to be made first before this commitment can be expected of the patient. Once the GFD has been instituted in a patient with confirmed CD, 70% of patients have symptomatic improvement within two weeks. Rebiopsy results will only improve after about three months. If no improvement is noted on a GFD, other causes should be considered like irritable bowel syndrome, lactose intolerance, microscopic colitis or pancreatic insufficiency. COMMON FEATURES LESS COMMON FEATURES Adults Iron deficiency Diarrhoea General Short stature Delayed puberty Children Diarrhoea Failure to thrive Abdominal distension Gastrointestinal Recurrent aphthous stomatitis Recurrent abdominal pain Steatorrhea Extraintestinal features Folate deficiency anaemia Osteopenia/osteoporosis Dental enamel problems Hypertransaminasaemia Thrombocytosis Arthralgia/arthropathy Polyneuropathy Ataxia Epilepsy Infertility Recurrent abortions Anxiety and depression Follicular keratosis Alopecia ASSOCIATED CONDITIONS Definitive associations Dermatitis herpetiformis IgA deficiency Type I DM Autoimmune thyroiditis Sjögren's syndrome Microscopic colitis Rheumatoid arthritis Down's syndrome IgA nephropathy COMPLICATIONS Refractory sprue Enteropathy-associated T-cell lymphoma Ca of the oropharynx, oesophagus and small bowel Ulcerative jejunoileitis Collagenous sprue Possible associations Congenital heart disease Recurrent pericarditis Sarcoidosis Cystic fibrosis Fibrosing alveolitis Lung cavities Pulmonary hemosiderosis Inflammatory bowel disease Autoimmune hepatitis Primary biliary cirrhosis Addison's disease SLE Vasculitis Polymyositis Myasthenia gravis Schizophrenia Clinical presentations of coeliac disease Sources 1. Farrell, RJ and Kelly, CP. Current concepts: Celiac Sprue. N Engl J Med, 2002 Vol. 346, No 3; 180-188. 2. Hill, PG and McMillan, SA. Anti-tissue transglutaminase antibodies and their role in the investigation of coeliac disease. Ann Clin Biochem 2006; 43: 105-117 Photos of figures 2 & 3: Dr Stephen Price Figure 1 Normal villi in small intestine Figure 2 Atrophic villi and lymphocytic infiltrate in small intestine in coeliac disease Figure 3 CD3+ T-lymphocyte infiltrate in mucosa and epithelium of small intestine in coeliac disease pathology forum diagnosis of smear negative pulmonary and extra pulmonary tuberculosis The increase in smear-negative cases of tuberculosis (TB) in HIV-infected individuals dramatically erodes the predictive value of traditional methods of TB diagnosis (microscopy and chest X-ray). Sputum smear positivity rates in TB/HIV patients depend on the degree of immune deficiency. As the CD4 count declines, the likelihood of both extrapulmonary TB and smear-negative TB increases. Figure 1 Acid- and alcoholfast bacilli with Ziehl-Neelsen stain Definition of Smear-Negative Pulmonary TB: • At least two negative sputum specimens for TB, and • radiographic abnormalities consistent with active TB, and • decision by a clinician to treat with a full course of anti-TB chemotherapy, or • patients with a TB smear-negative sputum which is culture-positive for Mycobacterium tuberculosis. Indications for drug susceptibility testing: • Smear positive at 2-3 months • Smear positive patients at the end of treatment • Re-treatment cases • MDR contacts WHO revised diagnostic algorithms: The WHO recently revised their diagnostic algorithms for the diagnosis of TB in ambulant and seriously ill patients. They can be viewed at http://www.who.int/tb/smear_neg_tb_callforcomments/en/ Additional techniques that can reduce diagnostic delay in HIVinfected patients: • Biopsy of peripheral lymph nodes - fine needle aspirate: diagnostic yield of up to 75% - core or excision biopsy: yield of up to 85% • Induced sputum • TB blood cultures and early morning urine for TB culture • Bone marrow biopsy particularly in pancytopaenic patients • Z-N stain and culture of gastric aspirations ( children) When to request TB culture: • Extra-pulmonary TB • Smear-negative cases • Suspected multiple drug resistance (MDR) • Suspected mycobacteria other than tuberculosis (MOTT) • Gastric aspirations (for PTB in children) Sources: 1. WHO Shop TB Department Expert Consultation Meeting ,Sept. 2005 2. Saranchuk P et al: The Diagnosis of Smear-negative TB in HIV-infected patients. 2nd South African AIDS Conference, Durban, Abstract 573,2005 16 Kas Kasongo pathology forum learners benefit from pathcare gift Carl Sagan (1934-1996), the celebrated astronomer, author, critical thinker and populariser of science once commented: “As a result of the rapid social and technological changes over the last few centuries, the world is not working well. The solution is to teach people to think, not only analitically, but creatively and conceptually as well”. Dr Ruth Rabinowitz, a medical doctor and scientist, has produced a teacher's handbook, Working with Wonder, which echoes Sagan's sentiments, and in her own words, '..develops critical thinking, creative individuals and a love of learning. It also makes learning fun.' The book demonstrates '..how teachers can make any subject matter interesting and relevant, part of a world perspective, a springboard for communication and creativity..' according to Dr Rabinowitz. The book has been warmly and enthusiastically received in educational circles. Professor Kader Asmal, the then Minister of Education, states in his foreword: 'This is a book that strives to develop skills that learners need to collect, analyze, organize and critically evaluate information.' The book has also been endorsed by a variety of public and private educational institutions including the departments of education in the Western Cape, North West Province and Gauteng, the Jane Goodall Institute and the Endangered Wildlife Trust. Unfortunately owing to the nature of the book, it cannot be purchased by schools through the usual tendering process. While some private schools and large business groups that have outreach programs have purchased the book, most schools can only obtain the book through donation. PathCare, as part of our Social Responsibility Programme, indentified 200 primary schools in the Western Cape with English and isiXhosa as medium of instruction and donated a copy of the book to each of these schools. 17 pathology forum pathcare snippets The practice of Drs Voigt and Partners with its main laboratory in Bloemfontein and part of the PathCare Group recently celebrated its 44th anniversary. Dr Willie van Rijswijk, head of Accreditation and Quality Assurance at PathCare, recently attended the Clinical Pathology Accreditation Annual Conference at the Royal Society of Medicine in London. He delivered a lecture on automation in pathology with reference to the automated line at the new PathCare Reference Laboratory at N1 City. His lecture was well received and afterwards he was assailed with questions. Dr George Röhm joined the PathCare laboratory in Welkom as clinical pathologist at the beginning of April 2006. Dr Röhm was a partner at PathCare for many years but decided after his retirement recently that he wanted to remain active and therefore took the opportunity to join the Welkom laboratory when the need arose there for an additional pathologist. PathCare's peripheral laboratory at Medpark, next to the N1 City Hospital, has been moved to the nearby Reference Laboratory and equipped as a new urgent laboratory. All pathology work for PathCare from N1 City Hospital will be performed in this new laboratory. A dedicated courier will ensure that specimens are urgently delivered to the new facility. Our nursing service in the N1 City Hospital and the services at the Medpark depot remain the same. Dr Tertius Gouws head of the Veterinary Laboratory at N1 City, Mr. Louis Birch of our Occupational Health Department and staff of PathCare's Client Service Departments in Bloemfontein, Bethlehem, Klerksdorp and Welkom recently attended the Nampo Agricultural Week and Harvest Festival at Bothaville. The extent of the show was enormous with more than 600 exhibitors and 70 000 visitors. PathCare's exhibit attracted much attention. 18 Oshakati Namibia Otjiwarongo WINDHOEK Swakopmund Walvis Bay Springbok Kuruman Upington Vryburg VEREENIGING Harrismith BETHLEHEM Parys Vanderbijlpark Sasolburg Kroonstad Potchefstroom WELKOM KLERKSDORP Mafikeng Kathu KIMBERLEY Lesotho Maseru PORT ELIZABETH Uitenhage EAST LONDON Queenstown BLOEMFONTEIN Knysna Oudtshoorn Plettenberg Bay Jeffreys Bay Republic of South Africa WORCESTER PAARL Stellenbosch Vredendal Vredenburg Durbanville BELLVILLE Milnerton Cape Town SOMERSET GEORGE WEST Mossel Bay Hermanus Visit our website www.pathcare.co.za for further information Laboratories CAPE TOWN PathCare Reference Laboratory PathCare Park, N1 City Tel : (021) 596 3400 Fax : (021) 596 3727 WORCESTER Tel : (023) 347 1021 Fax : (023) 342 8723 Practice No. 5200539 Drs Izak Loftus, Linda Steyn SOMERSET WEST Tel : (021) 852 3144 Fax : (021) 851 6240 PAARL Tel : (021) 872 5158 Fax : (021) 872 5393 Practice No. 5200539 Drs Laing, Soldin & Venter GEORGE Tel : (044) 803 8200 Fax : (044) 874 6525 Drs Hofmeyr, Kasongo Practice No. 5200539 PORT ELIZABETH Tel : (041) 391 5700 Fax : (041) 391 5702 Practice No. 052 000 000 6238 Drs Burger, Venter, Van Greunen & Partners WINDHOEK Tel : 09264 (61) 283 6000 Fax : 09264 (61) 283 6020 VEREENIGING Tel : (016) 440 6300 / 79 Fax : (016) 455 5749 Practice No. 052 000 001 9356 Drs de Beer, van Zijl, Mattana & Louw KLERKSDORP Tel : (018) 468 9000 Fax : (018) 468 9010 Dr M Crause Practice No. 052 000 001 9356 BETHLEHEM Tel : (058) 303 4961 Fax : (058) 303 7687 BLOEMFONTEIN Tel : (051) 401 4600 Fax : (051) 401 4613 WELKOM Tel : (057) 391 0400 Fax : (057) 352 5916 Practice No. 5200539 Dr Dotti von Ulmenstein KIMBERLEY Tel : (053) 830 8960 Fax : (053) 831 2398 Practice No. 5200539 Dr R.P. Mulligan EAST LONDON Tel : (043) 701 5900 Fax : (043) 701 5950