Clinical course of patients with aplastic anemia or myelodysplastic syndrome associated with persistent neutropenia

Patients with aplastic anemia (AA) or myelodysplastic syndrome (MDS) often have persistent severe neutropenia and are susceptible to infectious complications. We retrospectively reviewed the clinical course of patients with AA or MDS who had neutropenia (neutrophil count<500/μl) for more than 25days. A total of 46 patients, 11 with AA and 35 with MDS, were included. Twenty-three patients had infectious events (IE), and the cumulative incidence of IE was 30% at 6months and 51% at 1year. The cumulative incidence of IE was 67% at 1year in 30 patients who experienced very severe neutropenia of less than 200/μl. Overall survival in all patients was 76% at 6months and 65% at 1year. In a multivariate analysis, male sex, underlying diseases, and a neutrophil count of less than 200/μl as a time-dependent covariate significantly affected IE. In analyses that excluded patients with AA, male sex was the only factor. In conclusion, severe neutropenia was significantly associated with IE in patients with AA or MDS, and IE might be lethal. When we only considered patients with MDS, the neutrophil count alone could not be used to predict the prognosis.