Presence and persistence of islet cell antibodies in children with type I diabetes mellitus

Abstract

It is wellknown that immune responses play a major role in the development of type I insulin dependent diabetes mellitus (IDDM). This mixed crosssectional and longitudinal study was undertaken to evaluate the presence of islet cell antibodies (ICA) in diabetic children in relation to age and to duration of diabetes. Cytoplasmic ICA were determined by immunofluorescence in 72 patients (40 boys and 32 girls) aged 9 months to 17 years, with IDDM. ICA were measured only once in 54 patients and at regular intervals in 18, amounting to a total of 95 samples collected. ICA were present in 10 out of 11 patients at the time of diagnosis of IDDM. They were still found in 10 out of 61 patients in whom IDDM lasted for at least 2 years (persistent ICA). In the other patients ICA were not detected or disappeared within a 2 years duration of diabetes (non persistent ICA). HLA-DR3 type was found in all patients with persistent ICA for at least 2 years and in 65% of the others; HLA-DR4 was found in both groups of patients at an incidence of 70% and 62% respectively. None of the 21 children who became diabetic before the age of 5 years, had persistent ICA whereas 25% of the patients becoming diabetic after that age had persistent ICA. These data clearly show the importance of genetic factors and of age at onset of diabetes in the development and persistence of ICA in infancy and childhood.