Usefulness of immature platelet fraction for the clinical evaluation of myelodysplastic syndromes.

Ratios of young platelets or reticulated platelets can be routinely obtained as an immature platelet fraction (IPF) with the XE-2100 automated hematology analyzer (Sysmex, Kobe, Japan). We combined IPF analysis of 31 patients with myelodysplastic syndrome (MDS) with a complete blood count, a bone marrow examination, and a chromosome analysis. The patients with >40 x 10(9)/L platelets were classified as group A, and those with > or =40 x 10(9)/L were placed in group B. The 2 groups were subclassified as A1 or B1 for patients with an IPF of <10% and as A2 or B2 for those with an IPF > or =10%. Categories A1, A2, B1, and B2 comprised 12 patients, 6 patients, 7 patients, and 6 patients, respectively. Patients with a relatively high IPF (>10%) (category A2 or B2) showed distinctive characteristics. Group B2 showed a higher frequency of chromosomal abnormalities than B1 (P = .029), and group A2 tended to show a higher incidence of clinical improvement than A1 (P = .08). IPF determination may be clinically useful for the assessment of prognosis for MDS patients.