Prevalence and causes of thrombocytopenia in an academic state-sector laboratory in Soweto, Johannesburg, South Africa

Abstract

Background. Causes of thrombocytopenia range from laboratory errors to life-threatening pathological conditions. To establish the cause, appropriate laboratory investigation is required. Objectives. To determine the prevalence and causes of platelet counts <100 × 10 9 /L in state health facilities in Johannesburg, South Africa, as well as the quality of the subsequent laboratory work-up in this setting. Methods. Full blood counts (FBCs) performed on 7 randomly selected days at the National Health Laboratory Service laboratory at Chris Hani Baragwanath Academic Hospital were retrospectively reviewed. Samples with platelet counts <100 × 10 9 /L were identified, and pertinent information was extracted from the laboratory database. Results. Of 4 456 FBCs included, 381 (8.6%) had a platelet count of <100 × 10 9 /L. Thrombocytopenia prevalence rates were high in haematology/oncology wards (34.4%), intensive care units (20.5%) and medical wards (18.7%) and among neonatal inpatients (16.5%), and were lowest in outpatient clinics (1-2%). A cause was apparent in ~60% of patients, the commonest causes being chemotherapy and sepsis (each comprising >20% of the recognised causes). Spurious thrombocytopenia, disseminated tuberculosis, aplastic anaemia, immune thrombocytopenia and malignant marrow infiltration each accounted for 5-10% of the causes, while malaria, thrombotic thrombocytopenic purpura, HIV effect and liver disease were each identified in <5% of cases. HIV status was documented in ~70% of the patients, of whom ~50% tested positive. The quality of the laboratory work-up showed differences between specialties within the hospital setting, and was poorest in the primary healthcare clinic sector. Conclusion. Thrombocytopenia is common in hospitalised patients in the Johannesburg academic state sector. Differences in the quality of the laboratory work-up emphasise the need for a standardised approach to thrombocytopenia investigation and increased awareness among clinicians.

Liver function tests and fibrosis scores in a rural population in Africa: a cross-sectional study to estimate the burden of disease and associated risk factors

“…However, diagnostic accuracy is not well established in sSA and can be influenced by the population being assessed and the nature of underlying liver disease. [10][11][12][13][14][15] GPR has recently been reported as an independent predictor of significant fibrosis in naive Gambian patients with chronic hepatitis B (CHB) infection, 13 while the usefulness of cut-off values for APRI scores in CHB has been questioned. 16 However, further studies are needed to determine the specificity and sensitivity of different scores in different settings.…”

Prevalence and aetiology of moderate and severe thrombocytopenia in a tertiary and quaternary centre in KwaZulu-Natal

“…However misdiagnosis of thrombocytopenia also occurs, and could be the result of artefactual laboratory errors. 3 , 4 A full blood count and peripheral blood smear are mandatory as an initial test in patients with thrombocytopenia. 1 , 5 Although there have been advances in the automation of haematology analysers, the peripheral blood smear still remains an important diagnostic tool.…”

“… 1 , 7 Another aetiology of thrombocytopenia is increased peripheral destruction of platelets that may occur following disseminated intravascular coagulation, thrombotic microangiopathy and increased platelet sequestration due to hypersplenism. 4 , 8 …”

Liver function tests and fibrosis scores in a rural population in Africa: estimation of the burden of disease and associated risk factors

“…However diagnostic accuracy is not well established in sSA and can be influenced by the population being assessed and the nature of underlying liver disease (9)(10)(11)(12)(13)(14). GPR has recently been reported as an independent predictor of significant fibrosis in treatment naïve Gambian patients with chronic hepatitis B (CHB) infection (12).…”