Organ-specific antibodies in healthy and diabetic children and young adults.

160 children and young adults (aged 7-21 years) and 84 diabetics (aged 2-19 years) were screened for thyroglobulin (TgA), thyroid microsomal (MsA), smooth muscle (SMA), parietal cell (PCA), reticulin (RA), glomerular (GIA) and mitochondrial (MA) antibodies. The diabetics were also screened for islet cell antibodies (ICA). The overall incidence of other antibodies than ICA at the lowest serum titre studied was 18.1 percent for healthy children and 30.9% for diabetic children. The elevation in diabetics is significant (p less than 0.01). Females were overrepresented in both groups and had the highest titres of antibodies. The age group 10-14 years was observed to be a special time at which antibody titres became positive. As compared with the controls, diabetics exhibited an increased incidence of MsA (4.4 and 11.9% respectively, p less than 0.001), PCA (5.0 and 10.7% respectively, p less than 0.05) and RA (3.8 and 9.5% respectively, p less than 0.05). The presence of ICA or the duration of diabetes showed no correlation with other autoantibodies. The results indicate that autoantibodies at a low titre are a common phenomenon. Diabetics seem to be susceptible to react against their own tissue, which is probably associated with their increased frequency of autoimmune diseases.