Is presence of islet autoantibodies at birth associated with development of persistent islet autoimmunity? The Diabetes Autoimmunity Study in the Young (DAISY)

OBJECTIVE - To determine whether the presence of islet auto,antibodies in the umbilical cord blood is predictive of subsequent development of islet autoimmunity. RESEARCH DESIGN AND METHODS - Cord blood sera from 1,118 subjects from the Diabetes Autoimmunity Study in the Young (DAISY) cohort, as well as their venous blood samples taken at follow-up clinic visits, were tested for GAD65 autoantibodies (GAAs), insulin autoantibodies (IAAs), and IA-2 autoantibodies (IA-2As). Venous blood samples taken from mothers of cord blood autoantibody-positive children were analyzed for the same autoantibodies. RESULTS - At least one of three islet autoantibodies was present in 42 (3.7%) of the cord blood samples tested. The presence, of cord blood autoantibodies did not predict the subsequent development of islet autoimmunity (adjusted hazard ratio = 0.73 [0.09, 5.88]). Discordance between cord blood and corresponding maternal autoantibodies was seen in 3 of 36 infants. A strong correlation between levels of autoantibody in cord blood and maternal circulation was found for GAA (r(2) = 0.93, P < 0.001) and IAA (r(2) = .0.89, P < 0.001) but not IA-2A (r(2) = 0.05, P = 0.19). Cord blood autoantibodies in all but one subject disappeared by 9 months of age. CONCLUSIONS - The presence of cord blood autoantibodies is not predictive of subsequent development of islet autoimmunity. The majority of cord blood autoantibodies appear to result from maternal transmission.