Diagnostic Accuracy of Immature Platelet Fraction (IPF) to Differentiate Between Thrombocytopenia due to Peripheral Destruction versus Bone Marrow Failure.

Objective: To analyse the predictive value of immature platelet fraction (IPF) as an independent diagnostic marker to differentiate between hyperdestructive and hypoproductive thrombocytopenia.

Study Design: Cross-sectional observational study. Place and Duration of the Study: Armed Forces Institute of Pathology Rawalpindi, from February to July 2022.

Methodology: A total of 164 samples were included in the study by non-probability consecutive sampling. Among these, 80 were obtained from normal individuals serving as control; 43 were obtained from patients having hyperdestructive thrombocytopenia (idiopathic thrombocytopenia, thrombotic thrombocytopenic purpura, disseminated intravascular coagulation); and 41 were obtained from those hypoproductive thrombocytopenia (acute leukaemia, aplastic anaemia, chemotherapy). Sysmex automated haematology analyzer, XN-3000 was used to determine the immature platelet fraction (IPF) of the patients. ROC curves analysis was done to ascertain area under curve.

Results: Immature platelet fraction (IPF %) was significantly higher in consumptive / hyperdestructive thrombocytopenia group i.e. median (IQR), 21% (14.4-26.2) as compared to 6.5% (4.6-8.9) in hypoproductive thrombocytopenia, and 2.6% (1.3-4.1) in normal control group (p <0.001). Cut-off value with the highest sensitivity and specificity for IPF vs. normal population was 7.95% with sensitivity of 97.7% and specificity of 86%.

Conclusion: Immature platelet fraction (IPF of 7.95%) possesses high diagnostic accuracy, sensitivity and specificity for differentiation between hyperdestructive vs. hypoproductive thrombocytopenia. It can be used as a reliable marker to differentiate between the two entities.

Key Words: Immature platelet fraction, Thrombocytopenia, Bone marrow failure, Peripheral destruction.