Islet autoantibodies in cord blood from children who developed Type I (insulin-dependent) diabetes mellitus before 15 years of age

Islet autoantibodies are early markers for Type I (insulin-dependent) diabe tes mellitus. The aim of this study was to establish whether islet autoanti bodies were present at birth in children who developed Type I diabetes befo re 15 years of age. Cord blood sera from 81 children who developed Type I d iabetes between 10 months and 14.9 years of age were tested for glutamic ac id decarboxylase autoantibodies (GAD65Ab), islet cell antigen 512 autoantib odies (ICA512Ab), insulin autoantibodies (IAA) all by quantitative radiolig and binding assays and islet cell autoantibodies (ICA) by indirect immunofl uorescence. Cord blood sera from 320 randomly selected matched children wer e controls. The children who developed Type I diabetes had an increased fre quency of cord blood islet autoantibodies compared with control subjects: G lutamic acid decarboxylase autoantibodies were detected in 6% (5/81) patien ts and 2% (5/320) control subjects (p = 0.03); islet cell antigen 512 autoa ntibodies in 5% (4/73) patients and 1% (4/288) control subjects (p = 0.06); insulin autoantibodies (IAA) in 0% (0/79) patients and 0.3% (1/320) contro l subjects (p = 0.36); and islet cell autoantibodies in 10% (8/81) patients compared with 0.6% (2/320) control subjects (p = 0.0001). Taken together, 17% (14/81) patients had one or more islet autoantibody compared with 4% (1 2/320) control subjects (p = 0.0001). Whereas none of the control children had more than one antibody, 4% (3/81) children who later developed Type I d iabetes were double positive (p = 0.002). Although glutamic acid decarboxyl ase autoantibodies' concentrations in cord-blood correlated to those in the mothers' blood at the time of delivery, no corresponding correlation was f ound for the other two types of autoantibodies. The increased frequency of cord blood islet autoantibodies suggests that the Type I diabetes process c ould already be initiated in utero.