Pretreatment Immature Platelet Fraction as a Surrogate of Reticulated Platelets Predicts the Response to Corticosteroids in Adults with Immune Thrombocytopenia.

OBJECTIVES

Reticulated platelets circulating in the blood reflect megakaryopoietic activity and platelet turnover and can be automatically and low-invasively measured as the immature platelet fraction (IPF) using a Sysmex XN hematocytometer. The present study retrospectively investigated whether or not the IPF can predict the treatment response to corticosteroids in adult patients with primary immune thrombocytopenia (ITP).

METHODS

Forty-six patients who had been newly diagnosed with primary treatment-naïve ITP and started treatment with corticosteroids were analyzed.

RESULTS

Among the 46 primary ITP patients, 33 (72%) responded to the treatment and 13 (28%) did not. The percentage of IPF (IPF%) among the nonresponders was significantly lower than that of the responders (6.6 vs. 16.0%; p < 0.001). In the receiver operating characteristics analysis, the optimum IPF% cut-off value for predicting the treatment response was 12%, with a specificity of 85% and a sensitivity of 76%.

CONCLUSIONS

Our findings thus suggest that measuring the IPF% as a surrogate of reticulated platelets is useful to identify patients likely to respond to corticosteroids.