Female and preserved platelet count subgroups of myelodysplastic syndrome patients benefit from standard-dose azacitidine.

BACKGROUND: Hypomethylating agents, including azacytidine (AZA), are standard therapeutics for patients with high-risk myelodysplastic syndromes (MDS), a group of myeloid neoplasms. However, treatment schedules are not unified in real-world practice; in addition to the standard 7-day (standard-dose) schedule, shortened (reduced-dose) schedules are also used. AIMS: The aim of this study was to discover the patient group(s) which show differential efficacy between standard-and reduced-dose AZA to MDS. METHODS AND RESULTS: The outcome of different AZA doses in a cohort of 151 MDS patients were retrospectively analyzed. Overall survival (OS) was not significantly different between standard- and reduced-dose AZA groups by multivariate analysis. However, an interaction was found between either the sex (female vs. male), the platelet counts (< 40 × 103 /µl vs. ≥ 40 × 103 /µl), or the karyotype risk (< poor vs. ≥ poor) and standard-dose AZA for longer OS. Subgroup analyses revealed better OS with standard- over reduced-dose AZA in female patients (HR, 0.27 [95% CI, 0.090-0.79]; p = 0.011), and those with platelet counts ≥ 40 × 103 /µl (HR, 0.51 [95% CI, 0.26-0.99]; p = 0.041). The union of female and preserved platelet count subgroups also benefited from standard-dose AZA. With this as a test cohort, we next analyzed patients registered in the JALSG MDS212 study, for whom 7-day and 5-day AZA treatment strategies were prospectively compared, as a validation cohort (N = 172). That cohort showed the same tendency as the retrospective results. CONCLUSION: We identified the union of female and preserved platelet count subgroups which benefited from standard-dose AZA, imparting crucial information to physicians planning treatment regimens in MDS patients.

[Acquired platelet dysfunction with severe bleeding tendency in triple-negative myelofibrosis].

A 50-year-old man demonstrated markedly increased number of white blood cells, anemia, severe splenomegaly, and bleeding tendency. Bone marrow analysis revealed remarkable hypercellularity; dysplasia in multilineage cells, including megakaryocytes; and fibrosis. He was eventually diagnosed with triple-negative myelofibrosis. A massive hematoma developed at the bone marrow biopsy site. A similar episode recurred after the second bone marrow biopsy. The von Willebrand factor and other coagulation factor activities were within normal ranges. Platelet aggregation analyses demonstrated highly impaired aggregation induced by ADP, collagen, and epinephrine. Treatment with hydroxyurea and ruxolitinib, a JAK inhibitor, was ineffective, and he eventually died on day 144 after hospitalization. Acquired platelet dysfunction uncommonly occurs in patients with myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN), without precise elucidation of the frequency and underlying mechanism. The onset of bleeding tendency in the current patient suggested that platelet dysfunction may be caused by somatic genetic events. Here, we discuss the mechanisms of acquired platelet dysfunction in MDS or MPN with a literature review.