Pseudothrombocytopenia Unveiled: Navigating Frequency and Causes in a Tertiary Care Hospital

Abstract

Objective: To determine the proportion and laboratory-identified mechanisms of pseudothrombocytopenia among patients with automated platelet counts <100 × 10⁹/L in a tertiary care hospital.
Study Design: Descriptive Cross-sectional study
Place and Duration of Study: This study was conducted in the Department of Pathology, Fauji Foundation Hospital Rawalpindi, from January 01, 2025, to June 30, 2025.
Materials and Methods: All patients undergoing complete blood count analysis during the study period with an automated platelet count below 100 × 10⁹/L were included. Peripheral blood smears were examined to classify the subtypes of thrombocytopenia into true thrombocytopenia and pseudothrombocytopenia, including platelet clumping, giant platelets, and abnormal platelet distribution. Data was analyzed using SPSS Statistics version 29.0. Chi-square test was applied for categorical variables, and p-value < 0.05 which is considered
statistically significant.
Results: Out of total 755 blood samples, morphologically consistent with true thrombocytopenia (absence of smear artefacts) accounted for the majority of cases (70.7%). Among the 221 cases of pseudothrombocytopenia (29.3%), platelet clumping was the most frequent cause (19.7%), followed by giant platelets (7.9%) and abnormal platelet distribution (1.6%).
Conclusion: Pseudothrombocytopenia remains a frequent laboratory artefact in patients with low automated platelet counts. Accurate classification through systematic peripheral blood smear evaluation is essential to differentiate pseudothrombocytopenia from true thrombocytopenia. Implementation of standardized laboratory verification practices supports reliable platelet count reporting and enhances patient safety.