Reverse radioimmunoassays of IgM and IgG antibodies to Coxsackie B viruses in patients with acute myopericarditis.

A reverse radioimmunoassay (RIA) of antibodies to enteroviruses, previously developed for the detection of IgM antibodies to Coxsackie B1 (CB1) and B3 (CB3) and to Echo 11 (E11) and 30 (E30) viruses, was extended in the present study for the detection of IgM antibodies to Coxsackie B2 (CB2), B4 (CB4), and B5 (CB5) viruses and of IgG antibodies to CB1-CB5, E11, and E30 viruses. After standardisation of the assays and application to a collection of serum specimens from patients with proven enterovirus infections, specimens from patients with diagnosed or suspected acute myo- and/or pericarditis (myopericarditis group), and control specimens from patients with nonenterovirus infections, were studied, as well as from apparently healthy subjects. Of the patients with enterovirus infections, 29 of 30 (97%) were positive in the IgM RIA and 19 of 25 (76%) in the IgG RIA. In the myopericarditis group, 18 of 37 (49%) patients showed Coxsackie B (CB) virus-specific IgM titres and 9 of 37 (24%) CB virus-specific IgG titres. In the control specimens very few positive responses were detected. The RIAs appeared to be type specific or at least predominantly type specific, provided that the amount of labeled virus was carefully standardised. The sensitivity of the RIAs seemed to be rather high for IgM but low for IgG. In the neutralisation (NT) test no significant rise or fall in titre against CB viruses was demonstrated in the myopericarditis group. It is concluded that the reverse IgM RIA may be valuable for studies of the role of CB viruses in acute myo- and/or pericarditis.