Subsequent leukaemia in autoimmune disease patients

Previous studies have shown that patients diagnosed with some autoimmune (AI) diseases are at an increased risk of leukaemia but limited data are available on survival. We systematically analysed the risks (standardized incidence ratio, SIR) and survival (hazard ratio, HR) in nine types of leukaemia among 402462 patients hospitalized for any of 33 AI diseases and compared to persons not hospitalized for AI diseases. Risk for all leukaemia was increased after 13 AI diseases and survival was decreased after six AI diseases. SIRs were increased after all AI diseases for seven types of leukaemia, including SIR 1 center dot 69 (95% confidence interval (CI): 1 center dot 292 center dot 19) for acute lymphoblastic leukaemia (ALL), 1 center dot 85 (95% CI: 1 center dot 652 center dot 07) for acute myeloid leukaemia, 1 center dot 68 (95% CI: 1 center dot 372 center dot 04) for chronic myeloid leukaemia, 2 center dot 20 (95% CI: 1 center dot 692 center dot 81) for other myeloid leukaemia', 2 center dot 45 (95% 1 center dot 992 center dot 98) for other and unspecified leukaemia', 1 center dot 81 (95% CI: 1 center dot 112 center dot 81) for monocytic leukaemia, and 1 center dot 36 (95% CI: 1 center dot 081 center dot 69) for myelofibrosis. The HRs were increased for four types of leukaemia, most for myelofibrosis (1 center dot 74, 95% CI: 1 center dot 332 center dot 29) and ALL (1 center dot 42, 95% CI: 1 center dot 031 center dot 95). Some AI diseases, including rheumatoid arthritis, were associated with increased SIRs and HRs in many types of leukaemia. The present data showed increases in risk and decreases in survival for many types of leukaemia after various AI diseases. Leukaemia is a rare complication in AI disease but findings about this comorbidity at the time of leukaemia diagnosis may help to optimize the treatment and improve survival.