An incidence peak of juvenile diabetes. Relation to Coxsackie B virus immune response.

All new cases of insulin dependent diabetes mellitus (IDDM) in children below 15 years of age were recorded prospectively during a 21-year period 1964-1984 in a defined uptake area with a relatively constant child population. The total number of children recorded was 222-111 boys and 111 girls. The number of new cases varied between 4 cases in 1968 and 20 in 1984; in 1983 seventeen new cases were recorded. Specific IgM antibodies against Coxsackie B virus (CBV), types 1-5 were measured by a reverse radioimmunoassay (RIA) technique in 24 consecutive patients collected during the period March 1982-January 1984, some of whom represented the recent period of a very high incidence of diabetes. Sixteen patients (67%) exhibited CBV IgM responses, strongly suggesting a current or recent CBV infection. The titres declined during the first few months of diabetes and seemed to be absent after the first half-year period. Among age-matched non-diabetic children scheduled for elective procedures during the same period, no cases with CBV-IgM antibodies were detected. Only three of the 16 IgM-RIA-positive patients showed a significant rise in the neutralising antibody titre against the same Coxsackie B type. It is concluded that CBV may play a pathogenetic role in induction of IDDM, and possibly more frequently so during periods with a high incidence of diabetes, at least in children below 15 years of age.