Autoimmunity and inflammation in myelodysplastic syndromes

Autoimmune and inflammatory conditions (AICs) are encountered in up to 25%of patients with myelodysplastic syndromes (MDS). A wide range of AICs have been reported in association with MDS and can range from limited clinical manifestations to systemic diseases affecting multiple organs. Vasculitides, connective tissue diseases, and inflammatory arthritis are frequently reported in different studies; noninfectious fever and constitutional symptoms at presentation are common. Associations between AICs and specific MDS characteristics vary by study, but the available data suggest that AICs cluster more often in younger patients with higher-risk MDS. In general, AICs do not seem to confer worse survival, although certain AICs may be associated with adverse outcome (e.g. vasculitis) or progression of MDS (Sweet's syndrome). Nonetheless, these complications may have a significant impact on quality of life and affect the timing and type of MDS-directed therapy. The mainstay of management of these complications in the short term relies on immunosuppressive drugs. Increasing evidence suggests that hypomethylating agents may be effective in treating these complications and reduce steroid dependence. While the pathogenesis of AICs is incompletely understood, growing appreciation of cellular immune deregulation, cytokine hypersecretion, and the genetic heterogeneity underlying MDS may improve our understanding of common pathways linking MDS, inflammation, and autoimmunity.