LAUSR

People with type 1 diabetes (T1D) are at increased risk for comorbid autoimmune disease (CAID). The TrialNet Pathway to Prevention (PTP) Study screens relatives of people with T1D for islet autoantibodies (Ab) to determine T1D risk. PTP Ab+ participants self-reported (Y vs. N) whether or not they had CAIDs at the start of monitoring. Outside of celiac disease, CAID has not been examined in Ab+ participants. Of the 5,740 Ab+ participants, 586 (10.2%; 95% CI: 9.4 - 11.0%) reported having a CAID. Of those with a single confirmed Ab+, GADA+ participants had a higher prevalence of CAID (230/1709=13.5%) vs. those who were IA-2A+ (8/88=9.1%) or mIAA+ (40/592=6.8%; p In conclusion, the reported prevalence rates of CAID is high in Ab+ relatives of people with T1D, inversely correlated with the number of Ab present, and related to DR3 and DR4/DQ8 haplotypes. The change in the direction of association of CAID with Ab number after an adjustment for HLA status suggests that DR3 and DR4/DQ8 could contribute to both CAID and Ab development. Disclosure K. Simmons: None. S. Geyer: None. D.K. Wherrett: None. H.M. Ismail: None. M. Lundgren: None. L.E. Bocchino: None. J.M. Sosenko: None. C. Greenbaum: Research Support; Self; Janssen Research & Development. A. Steck: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (5U01DK0855095, K12DK094712-08)