There are few data regarding the association of autoimmune and inflammatory diseases (AID) with Philadelphia negative myeloproliferative neoplasms (MPN). In this retrospective study, we describe the prevalence, clinical and biological features and outcome of AID association in MPN. A total of 1541 MPN patients were included, encompassing 95 (6%) patients with AID. Female patients were predominant within the AID group (65% versus 54%, p=0.03). A total of 103 AID diagnoses were reported in 95 patients, including 48 organ-specific AID, 13 inflammatory arthritis, 9 connective tissue diseases, 9 dermatosis, 6 systemic vasculitis and 18 unclassified AID. The prevalence of TET2 mutations was higher in the AID cohort (32% versus 22%), although not statistically significant (p=0.08). In subgroup analysis of patients with myelofibrosis, TET2 mutations were more prevalent in AID group (p=0.025). The prevalence of driver and other additional mutations did not differ between the 2 groups. The association with AID did not impact overall survival (p=0.67), transformation-free survival (p=0.37) or secondary myelofibrosis-free survival (p=0.91). Our data suggest that the prevalence of AID is similar in MPN patients to that of the general population. TET2 mutations are highly prevalent in MPN patients with AID potentially suggesting a shared physiopathology.
