Pseudothrombocytopenia – frequency, causes, and evaluation in a clinical lab.

Abstract

Objective: To find out frequency, different causes of pseudothrombocytopenia and
their further evaluation to reach a final diagnosis
Methodology: This cross-sectional study was conducted at Muhammad Medical
Hospital, Mirpurkhas between October 2021 to January 2022. All patients who had
an automated platelet count less than 100 were included in the study. While patients with a known cause of thrombocytopenia were excluded. Data was collected
with the help of designed proforma. Complete blood count was performed by an
automated hematology analyzer. The samples with platelet count less than 100
(flag on platelet counts) were selected for peripheral blood smear review for manual counting to ascertain the cause of thrombocytopenia.
Results: A total of 1800 blood samples were analyzed. 95 patients (5.27%) had isolated platelet count < 100 with no previous history. Peripheral blood smear review
was done, 84 patients (88%) had true thrombocytopenia that is low platelet count
by both automated and manual techniques. The incidence rate of pseudothrombocytopenia was 0.61%. Clumping due to EDTA was found in 0.27% cases followed by
platelet satellitism in 0.05% cases.
Conclusion: Our study reported an incidence of pseudothrombocytopenia to be
0.61%. Further breakdown revealed clumping due to EDTA to be the most common
cause. Platelet Satellitism was found to be the cause of pseudothrombocytopenia in
0.05% cases.

Keywords: pseudothrombocytopenia, PTCP, spurious, thrombocytopenia.