Immune thrombocytopenia at Chris Hani Baragwanath Academic Hospital

Abstract

Immune thrombocytopenia (ITP) is an auto-­‐antibody mediated platelet disorder associated with thrombocytopenia with/without the presence of mucocutaneous bleeding. Primary ITP is a diagnosis of exclusion. A variety of identifiable causes of ITP contribute to the increasing number of patients with secondary ITP. The management of ITP includes identification and removal of any secondary cause/s and institution of therapy for symptomatic patients (evidence of bleeding), who generally have a platelet count of < 30 X 109/l. After stabilization, treatment with corticosteroids is the initial therapy of choice, with clearly defined indications for other treatments including splenectomy, rituximab, thrombopoietin mimetics and other agents. There is a paucity of data with regard to ITP in South Africa and this study attempts to address this gap and define the changing pattern of ITP in a series of public sector patients diagnosed and managed at a large tertiary hospital over a 25 year period. Patients and Methods This study is a retrospective review of adult patients seen at the Clinical Haematology Unit, Department of Internal Medicine at Chris Hani Baragwanath Academic Hospital during the period 01/01/1987 to 31/12/2011. The aim of the study was to determine the profile of patients with ITP, in particular to assess the demographics, clinical presentation, aetiology and management of patients with ITP. In addition, the presentation and outcome of HIV positive versus HIV negative patients was assessed. Results and Discussion A total of 243 adult patients with a diagnosis of ITP who presented to the Clinical Haematology Unit, Department of Medicine, CHBAH, during the period 01/01/87 – 31/12/11 were analysed. The median age at presentation was 32 years, with female to male ratio of 4.2:1. The median platelet count at presentation was 10 X 9/l, with a median of 14 days to platelet recovery of 100 X 109/l. Primary and secondary ITP was responsible for 48% and 50% of the patients respectively. Secondary ITP increased over the years with important contributions from HIV (40%) and pregnancy (16,8%). Mucocutaneous bleeding remained the predominant clinical manifestation. Twenty percent of the patients in the study were HIV positive with a female predominance of 3:1. The average CD4 count was 145/ul, with 33% of patients on cART at the time of diagnosis. It was demonstrated that 61.3% of the patients achieved a complete response following initial treatment with corticosteroids and antiretroviral therapy. In general, the response to treatment was greater in HIV negative patients versus HIV positive patients and HIV positive patients took a longer time to achieve a complete response. Splenectomy was performed in 19% of the patients. 69% of these patients had primary ITP and the remainder (i.e. 31%) had secondary ITP. The most common post surgical morbidity was sepsis. There was no significant differences in outcomes between primary and secondary ITP. conclusion ITP in South Africa is predominantly a disease of young females. Over the years, there has been a paradigm shift, with an increase in secondary ITP. HIV is the most important defined secondary cause. The presentation in our patients is with severe symptomatic thrombocytopenia (median platelet count of 10 X 109/l), with mucocutaneous bleeding requiring immediate therapeutic intervention. Oral corticosteroids are the mainstay of initial treatment. However, a significant number of patients require ongoing long term steroid therapy to maintain the platelet count in a safe range without bleeding. HIV seropositivity was associated with a lower response rate and a longer time to platelet recovery, compared to HIV seronegativity. Splenectomy was performed in approximately one fifth of the patients. It is the most definitive and only curative therapy in ITP. The response rate to splenectomy was 84% (62% CR and 22% PR). Splenectomy is feasible in both primary and secondary ITP, including patients with HIV. After corticosteroids, azathioprine is the most commonly used agent in our patients. Very few patients received rituximab and thrombopoietin mimetics were not used in view of their prohibitive cost. Overall, the outcome in our patients is similar to that described in the literature.