title: Genetic, immunologic, and environmental heterogeneity of IDDM. Incidence and 12-mo follow-up of an Italian population.
abstract: The 1-yr incidence of insulin-dependent diabetes mellitus (IDDM) in a population of the Piedmont and Aosta Valley area of Italy was recorded. Anti-virus antibodies (e.g., Coxsackie B1-6, mumps, cytomegalovirus), islet cell antibodies (ICAs), and HLA-A, -B, -C, and -DR were determined in 74 IDDM patients (38 males, 36 females) and in controls. Total IDDM incidence was 5.0/100,000, and the incidence for those less than 20 yr of age was 11.6/100,000. Anti-virus antibody frequency was not different in IDDM patients and controls. ICAs were present in 58% of IDDM patients at onset and in 30% after 12 mo, and complement-fixing ICAs were found in 39 and 17%, respectively. IDDM was significantly and positively associated with DR3/DR4 and negatively associated with DR2 and DR5. ICA frequency was significantly higher in DR3/DR4 heterozygote patients than in patients without DR3 and DR4. These results suggest that in this IDDM population viral etiology is not evident, ICAs offer only a partial pathogenetic explanation, and genetic and immunologic heterogeneity is evident.
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D003710:Demography; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D004777:Environment; D005260:Female; D005500:Follow-Up Studies; D006680:HLA Antigens / Q000032:analysis*; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D007558:Italy; D008297:Male; D010641:Phenotype
chemical_list: D000914:Antibodies, Viral; D006680:HLA Antigens; D006684:HLA-DR Antigens