IMMATURE PLATELET FRACTION MEASURED USING THE AUTOMATED HEMATOLOGY ANALYZER XE-2100: A POSSIBLE PREDICTIVE MARKER FOR PLATELET RECOVERY AFTER CHEMOTHERAPY AND HEMATOPOIETIC STEM CELL TRANSPLANTATION

Background and Purpose: The ability to predict platelet recovery after chemotherapy allows for a more reasonable approach to platelet transfusion. We assessed the clinical utility of monitoring the percentage of immature platelet fraction (IPF%) using the XE-2100 automated hematology analyzer to predict platelet recovery. Patients and Methods: The IPF% of 130 healthy volunteers and 100 patients was measured using the XE-2100. Further, IPF% was serially monitored in 19 cancer patients who received 35 courses of chemotherapy and hematopoietic stem cell transplantation (HSCT), and data were then retrospectively analyzed. Results: The IPF% in 130 healthy volunteers was 2.8±1.4% and inversely correlated with platelet count (r=0.319). In cancer patients undergoing chemotherapy and HSCT, a transient increase in IPF% (IPF% peak) was observed prior to recovery of the platelet count to more than 30×109/l within 1 to 11 days. In cases undergoing chemotherapy with more than 10% of the IPF% peak value, platelet recovery (>30×109/l) occurred significantly earlier than in those with less than 10% of the IPF% peak value (3 and 5 days, respectively; p=0.0164). In one case undergoing autologous HSCT with more than 10% of the IPF% peak value, platelet recovery occurred earlier than in cases undergoing allogeneic HSCT with less than 10% of the IPF% peak value (2 days and 4-11 days, respectively). Conclusion: Findings in the present study suggest that IPF% is a useful parameter for predicting platelet recovery after chemotherapy and HSCT, as well as has the potential to facilitate optimal platelet transfusion.