A close association of autoimmune-mediated processes and autoimmune disorders with chronic myelomonocytic leukemia: observation from a single institution.

Chronic myelomonocytic leukemia (CMML), a clonal hematopoietic stem cell disease, may be linked to immune-mediated processes and/or autoimmune disorders (AID), although the exact pathogens are still elusive. We retrospectively analyzed 123 CMML patients in our institution. Twenty-four CMML patients (19.5%) had at least one immune-mediated disorder, most commonly idiopathic thrombocytopenic purpura, gout and psoriasis. Four of these 24 patients (15%) had more than one AID. We found that, in contrast to the general population with a prevalence rate of 3.2-5.2%, newly diagnosed CMML patients demonstrated a high prevalence and variety of immune-mediated processes and/or AID. When we compared the results with those of myelodysplastic syndromes published in the literature, the prevalence of AID in these two groups of patients is similar. Our results also showed that the presence of cytogenetic abnormalities was less in CMML patients with AID (6 of 21; 28.6%) than in those without AID (37 of 94; 39.4%), although there was no statistical significance (p = 0.334). A multicenter large cohort study of CMML with AID is recommended to illustrate the molecular relationship between the two distinct groups.