[Islet cell cytoplasmic antibodies (ICA) and complement-fixing islet cell cytoplasmic antibodies (CF-ICA) in patients with newly detected type 1 diabetes mellitus of short duration].

Cytoplasmic islet cell antibodies and endogenous insulin secretion were studied in 60 children and adolescents having insulindependent (Type I) diabetes mellitus. The age of the subjects was 2-34 years. Thirty-nine patients were investigated at the time of diagnosis, in the group of 21 patients duration of disease was shorter than 2 years. Islet cell antibodies were analysed by indirect immunofluorescence for both conventional (ICA) and complement-fixing (CF-ICA) antibodies using cryostat sections of fresh frozen human pancreas. ICA were observed in 53% of patients. At the time of diagnosis 76% of children and 14% of adults were positive for ICA. In the remaining group of patients ICA were observed in 40% of children and 64% of adults. CF-ICA were present only in the ICA positive sera (47%). ICA titres were 1:1-1:128, CF-ICA titres were 1:1-1:8. There was no linkage between ICA and CF-ICA titres. The residual beta cell function was measured by serum C-peptide. There was no association between presence of ICA and residual beta cell function. The patients having CF-ICA had a significantly higher endogenous insulin secretion in comparison with the patients who were ICA negative.