Autoimmune cytopenias associated with inflammatory bowel diseases: Insights from a multicenter retrospective cohort

Abstract Introduction Autoimmune cytopenias (AIC) including autoimmune hemolytic anemia (AIHA) and immunologic thrombocytopenia (ITP) are rare immunologic disorders, scarcely reported in inflammatory bowel diseases (IBD). We conducted a multicentric retrospective study, including a case-control analysis, that aimed to describe the characteristics and outcomes of patients affected by AIC and IBD. Method Forty cases were recruited from 4 IBD centers and 2 AIC tertiary centers. Controls were recruited from the MICISTA registry. Results From the MICISTA registry, incidences were estimated at 4.1/100,000 patient-years and 12.5/100,000 patient-years after IBD diagnosis for AIHA and ITP, respectively. All AIHA patients (n = 14) had colonic involvement (13/14 with UC), whereas CD (52%) and UC (48%) diagnoses were evenly distributed among ITP patients. Compared to control IBD patients, cases were characterized by a higher frequency of extra-intestinal manifestations (37.5% vs 17%, p  Conclusion Although low, incidence of AIC appears higher in IBD patients compared to the general population. The association seems to be mainly non-fortuitous, especially for colitis-associated AIHA.