An Immunofluorescence Study of Rheumatoid Factor.

The rheumatoid factor group of macroglobulins is a characteristic concomitant of rheumatoid arthritis and can be detected readily in the serum of most rheumatoid patients by a variety of serological techniques employing as reactant either human gamma globulin (Heller, Jacobson, Kolodny, and Kammerer, 1954; Singer and Plotz, 1956; Epstein, Johnson, and Ragan, 1956) or erythrocytes sensitized with rabbit antibody (Waaler, 1940; Rose, Ragan, Pearce, and Lipman, 1948). Various workers applying the immunofluorescence technique of Coons and Kaplan (1950) have studied the distribution of rheumatoid factor in the tissues of rheumatoid patients (Kaplan and Vaughan, 1959; Mellors, Heimer, Corcos, and Korngold, 1959; Kaplan, Suchy, and Meyeserian, 1960; Mellors, Nowoslawski, Korngold, and Sengson, 1961b; Mellors, Nowoslawski, and Korngold, 1961a). Employing aggregated human gamma globulin and rabbit immune complexes labelled with fluorescent tracers and known to react with rheumatoid factor in serological studies (Edelman, Kunkel, and Franklin, 1958; Christian, 1958), Mellors and his associates located rheumatoid factor reactive with both types of reagent in plasma cells in synovium and lymph nodes as well as in the intrinsic cells of germinal centres in lymphoid follicles. From the results of their mixed staining experiments with contrastingly labelled reagents (1961b), they concluded that there were at least two types of cellular rheumatoid factor which occur separately or simultaneously in individual plasma cells, but that only one or the other was present in germinal centres. Kaplan and his colleagues reported that rabbit gamma globulin as well as aggregated human gamma globulin reacted with plasma cells and germinal centre cells in rheumatoid lymph nodes (Kaplan and others, 1960) and that rabbit gamma