Autoimmune/autoinflammatory disease co-existence in patients with myelodysplastic syndrome and chronic myelomonocytic leukemia

Objective: The aim of this study is to evaluate the coexistence of autoimmune and autoinflammatory diseases in patients diagnosed with Myelodysplastic Syndrome (MDS) and Chronic Myelomonocytic Leukemia (CMML) who were followed up and treated as inpatients or outpatients at our institution. Materials and Methods: This retrospective study included patients diagnosed with MDS or CMML between 2014 and 2024 at the Hematology outpatient clinic and inpatient wards of Karadeniz Technical University Faculty of Medicine. Demographic characteristics, laboratory parameters at the time of diagnosis, bone marrow aspiration and biopsy findings, cytogenetic analyses for MDS diagnosis, clinical features, diagnostic and therapeutic approaches, presence of autoimmune/autoinflammatory diseases, and their treatments were reviewed retrospectively. Results: A total of 319 patients were included, comprising 277 with MDS and 42 with CMML. Of the patients, 44.8% were female and 55.2% male, with a mean age at diagnosis of 69.4 years. At diagnosis, 73.4% (n=237) were classified as low-risk, and 25.7% (n=82) as high-risk. Autoimmune/autoinflammatory diseases were identified in 16.9% (n=54) of the patients. The most frequently observed conditions were connective tissue diseases and Hashimoto's thyroiditis. Patients with autoimmune/autoinflammatory diseases had significantly lower lymphocyte counts compared to those without such conditions. Additionally, this group had a lower rate of leukemic transformation and a higher overall survival rate. The mean survival time after diagnosis for the entire cohort was 52.9 months. In univariate analysis, female sex, absence of leukemic transformation, lower disease risk, fewer cytopenias, presence of autoimmune disease, use of corticosteroids and conventional synthetic DMARDs, higher leukocyte, neutrophil, platelet, and albumin levels, as well as lower lymphocyte count, CRP level, and ferritin level, were all associated with longer survival. In multivariate analysis, absence of leukemic transformation, fewer cytopenias, higher platelet and albumin levels, and lower ferritin levels were identified as independent favorable prognostic factors for survival. Conclusion: This study suggests that alterations in the adaptive immune system may play a significant role in the course and prognosis of MDS and CMML. Specifically, lymphocyte count may serve as a prognostic biomarker. Moreover, inflammatory markers such as CRP, albumin, and ferritin may provide valuable insights into prognosis assessment. While these findings appear to carry prognostic significance, further studies and validation in different cohorts are required for their integration into current international prognostic scoring systems. Keywords: Myelodysplastic Syndrome, Chronic Myelomonocytic Leukemia, Autoimmune Disease, Autoinflammatory Disease, International Prognostic Scoring System (IPSS)