ABSTRACT
BACKGROUND: Immature platelet fraction (IPF) is the percentage of reticulated platelet (RP) of total platelet count. We measured an IPF reference range using XE-2100 blood cell counter with upgraded software (Sysmex, Japan) and evaluated the clinical utility of this parameter for the laboratory diagnosis of thrombocytopenia due to an increase in peripheral platelet destruction. METHODS: Peripheral blood samples collected into K2 EDTA (Beckton Dickinson, USA) were analyzed at Chonbuk National University Hospital. One hundred forty-two samples from apparently healthy adults (all routine full blood count parameters including platelets within the healthy reference range) were used to establish a normal reference range for IPF. The patients were classified into 3 groups including hypoplastic (consisted of 22 patients undergoing chemotherapy with falling platelet counts and 14 with aplastic anemia), cirrhotic (40 with cirrhosis of liver), and idiopathic thrombocytopenic purpura (ITP) (14 with ITP) groups. RESULTS: An IPF reference range in healthy individuals was established as 0.4-5.4%, with a mean of 1.7%. A significant increase in IPF values was found in the ITP patient group. The cut-off value of IPF was 6.1% and its sensitivity and specificity were 92.9%, and 82.9% respectively. Reproducibility was good. CONCLUSIONS: A rapid, inexpensive automated method for measuring IPF is feasible and should become a standard parameter in evaluating thrombocytopenic patients.