[Relations between the principal classes of serum immunoglobulins and serodiagnostic tests in viroses. I. Influenza infection].

The relationship between the main serum immunoglobulin classes (IgM, IgG) and the positive diagnostic serologic tests (hemagglutination-inhibition and complement fixation) followed up in 30 paired serum samples from patients in the course of a primary influenza infection with B virus strain, before and after treatment with 2-ME, showed actual participation of the IgM molecules sensitive to 2-ME in the CF test. HI with the serum fractions of patients and convalescents of influenza B, in the presence of virus strains A and B, that had circulated earlier in the area, showed anamnestic responses by the presence of IgG and IgA antibodies in the patients' sera; HI and CF with the same serum fractions in the presence of virus B/Iaşi/74 of the epidemic, showed the presence of IgM, IgG and IgA in the convalescent sera, as also demonstrated by immunoprecipitation in agar gel with specific IgM, and IgA antisera and by treatment with 2-ME. Separation of these sera on a Sephadex G-200 column revealed filtration of IgM antibodies at the same peak as the IgG and IgA antibodies, possessing a closely resembling molecular weight (7S) and probably being IgM subunits with an immunologic behaviour similar to that of the intact molecule sensitive to 2-ME.