IgG, IgA, IgM, and IgD antiglobulins in juvenile rheumatoid arthritis.

Usual techniques for the detection of antigammaglobulin factors (DAT, SCAT, HEAT, Latex FII) are based upon agglutination reactions and are therefore useful when IgM antibodies are involved. It is well known that antiglobulins also belong to IgG and IgA classes. In our experience, 50 per cent. of patients with JRA are persistently seronegative when sera are tested only with conventional agglutination techniques (Garcia Morteo, Hubscher, and Arana, 1970). Recent papers reported elevated IgG antiglobulins in seronegative RA and JRA demonstrated by means of immunoadsorption techniques employing human, horse, and rabbit gammaglobulin rendered insoluble either with glutaraldehyde or with bisdiazobenzidine. These adsorbents had non-specific elution of immunoglobulins (Torrigiani and Roitt, 1967; Torrigiani, Ansell, Chown, and Roitt, 1969; Torrigiani, Roitt, Lloyd, and Corbett, 1970; Bianco, Panush, Stillman, and Schur, 1970). The purpose of this work was to evaluate antigammaglobulin factors in seronegative JRA using a quantitative immunoadsorption technique which would have no non-specific elution of immunoglobulins.