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

  • JL Vaughan
  • J Fourie
  • S Naidoo
  • N Subramony
  • T Wiggill
  • N Alli

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 × 109/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 × 109/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 × 109/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.

Published
2015-07-31
Section
Articles

Journal Identifiers


eISSN: 0256-95749
print ISSN: 2078-5135