The use of immature platelet fraction to predict time to platelet recovery in patients with dengue infection.

Background: In dengue infection, knowing time to platelet recovery is essential for optimal management.Aims: To determine a predictor for platelet recovery in patients with dengue infection.Methods: Platelet count and immature platelet fraction (IPF) from daily blood samples of patients with dengue infection during hospitalisation and 1-4 weeks after discharge were retrospectively analysed. The levels of patients' IPF were compared with normal controls recruited from healthy children with normal platelet counts.Results: A total of 244 EDTA blood samples were collected daily from 64 patients (45 males) with dengue infection (36 dengue fever, 28 dengue haemorrhagic fever) during hospitalisation and after discharge from the hospital. They did not receive any platelet concentrate transfusion. The median IPF among normal children was 3.6% with a 95 percentile of 9.9%. In dengue patients, an IPF of ≥10.0% after defervescence was associated with a subsequent platelet count of ≥60 × 109/L within 72 hours.Conclusion: In patients with dengue infection, IPF ≥10.0% after defervescence is a predictor of subsequent platelet recovery to a haemostatic level ≥60 × 109/L within 72 hours.