The Elevation of Red Blood Cell Distribution Width is an Independent Prognostic Factor for Juvenile Myelomonocytic Leukemia

Abstract Juvenile myelomonocytic leukemia (JMML) is an overlapping myeloproliferative and myelodysplastic disorder of infants and early childhood. With heterogeneous genetic background across patients, the existing clinical and laboratory prognostic features are inadequate to predict outcome, posing an urgent need to identify new prognostic indicators. Red cell distribution width (RDW) is a critical parameter reflecting the heterogeneity of erythrocyte size. Recent studies highlighted RDW elevation as a valuable indicator for poor outcomes in various diseases. However, the prognostic role of RDW in JMML remains unclear. From the retrospective analysis of our single-center JMML cohort incorporating a total of 77 patients, we discovered RDW elevation as an independent adverse factor for children with JMML. Multivariate cox proportional hazard models showed that patients with red cell distribution width standard deviation (RDW-SD) >51.65 fl at diagnosis were susceptible to much worse overall survival rate (HR = 5.22, CI = 1.50-18.21, P=0.010). Besides, the combination of RDW elevation and protein phosphatase non-receptor type 11 (PTPN11) mutation was likely to predicted a subgroup with the worst outcomesin our cohort.