Abstract
Autoimmunity and an antecendant viral infection may play important roles in the occurrence of insulin-dependent diabetes mellitus (IDDM). Although there have been many immunological studies of adult IDDM, no such report on a sufficient number of children with this disorder has been made in Japan.
One hundred and forty children in Hokkaido with IDDM of which the onset was at less than 15 years of age were studied for their HLA antigens and the presence or absence of islet cell antibody (ICA), antimicrosomal antibody (AMA) and of antithyroglobulin antibody (ATA).
Among the HLA antigens studied, Bw 54, DR 4 and MT 3 were significantly higher in frequency in patients than in controls while the frequencies of B 5 and DR 2 in patients were lower than in controls. In particular, MT 3 was most often found in patients (97.1%). These findings suggest the positive linkage of a HLA haplotype Bw 54-DR 4-MT 3 and the negative linkage of B 5 and DR 2 antigens to IDDM.
Twenty-two (44.0 %) of 50 patients studied had ICA within 12 months from the onset of diabetes, but the ICA-positive patients tended to decrease in number thereafter.
AMA/ATA was positive in 23 (26.7%) of 86 patients. However, there was no difference as to the frequencies of HLA antigens and the AMA/ATA positive rate between the patients having ICA persistently for five or more years and those whose ICA had disappeared by the fourth year from the onset.
The findings in the present study indicate that (1) MT 3 antigen would be associated with IDDM, (2) autoimmunity is not the only etiological mechanism for the disease, and (3) the persistent presence of ICA does not mainly correlate to autoimmunity
