ESPE Abstracts

Background: The assignment to type 1 diabetes mellitus (T1DM) can be confirmed by the determination of diabetes-specific autoantibodies. Five different antibodies can be determined. The determination of several antibodies is more expensive than the determination of a single antibody. In times of scarce resources, the sequential determination of antibodies could save costs. The aim of this study was to determine the frequency of antibodies and their age and gender distribution.

Methods: In 200 children and adolescents with T1DM (85 female, age 0.9 to 16.6 years), islet cell antibodies (ICA), glutamate decarboxylase AK (GADA), tyrosine phosphatase IA-2 Ak (IA-2A) and insulin autoantibodies (IAA) were determined at onset. The zinc transporter 8 antibody (A-ZT8-A) was only determined in a few patients and is therefore not included.

Results: ICA was positive most frequently in 176 (88%) patients. IA-2A was the second most frequent positive antibody (74.5 %). GADA were positive in 70 %, IAA in 49.5 %. Of the 24 ICA-negative patients, 14 were positive for IA-2A and 10 for GADA, of which 7 were only GADA positive. In one patient only, IAA were detected and 3 were negative of all 4 antibodies. Significant gender differences were only found in the 0-5 year age-group. In this group, ICA and IA-2A were equally common in males (both 81%) and ICA was most common in females (92%). In this age group, GADA was the second most common antibody in girls, while IAA was the third most common antibody in boys and girls.

Conclusion: In the overall group, the determination of ICA identifies 88% of patients with T1DM. The additional determination of IA-2A identifies 95% and the further determination of GADA identifies 98.5% of patients with T1DM. In the youngest age group, the first antibody in girls and boys should be ICA, the second antibody GADA in girls and IA-2A in boys. The third antibody should be IAA. Sequential determination can appropriately confirm the autoimmune genesis of existing diabetes while saving costs. The additional determination of A-ZT8-A could identify further children who were previously considered seronegative.