Kappa:lambda light chain ratio in IgG eluted from rheumatoid arthritis synovium

The light chain ratio in IgG eluted from rheumatoid arthritis synovial membrane was studied using quantitative immunodiffusion. The ratio obtained in synovial IgG was different from that of IgG in peripheral blood. In several instances a marked domination of one type light chain was noted in the eluted IgG, which also showed a limited electrophoretic dispersion on immunoelectrophoresis. This suggests that synovial IgG in rheumatoid arthritis is antibody, and not derived non-specifically from the immunoglobulin pool. Lambda type light chains dominated over kappa type in most eluates, suggesting preferential involvement of cells producing lambda type molecules.

Fibrinolytic and fibrin stabilizing activity of synovial membranes

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Immune complexes in rheumatoid synovitis: a mixed staining immunofluorescence study

Complexes of IgG—rheumatoid factor (RF) and IgG—β_1C were demonstrated in the synovial membrane obtained from patients with rheumatoid arthritis (RA) by a mixed immunofluorescence method that shows simultaneously the two components of the complex.

IgG—RF was found only in the synovia of cases with circulating RF, while IgG—β_1C deposits could be detected in both seropositive and seronegative cases.

These findings are discussed in connection with the pathogenesis of rheumatoid synovitis in the light of the immune complex pathogenetic mechanism.

Lymph node iron in rheumatoid arthritis. Histology, ultrastructure, and chemical concentration

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Synovial membrane in experimentally-produced chronic haemarthrosis

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Immunofluorescent demonstration of an IgG-B1C complex in synovial lining cells of rheumatoid synovial membrane

Synovial tissues obtained at arthrotomy or by needle biopsy were digested with trypsin, and suspensions of synovial cells isolated. Immunofluorescent staining of these cells has shown the simultaneous presence of immunoglobulin G (IgG) and the β_1C component of complement in the cytoplasm of most of the phagocytic lining cells of fifteen of seventeen synovia obtained from both seropositive and seronegative patients with rheumatoid arthritis. This staining pattern was not found in synovial cells obtained from patients with other inflammatory or non-inflammatory arthritides. Discrete cytoplasmic inclusions composed of: (1) IgG and α_1C, and (2) IgG and rheumatoid factor were also observed, but only in synovial cells from seropositive rheumatoid patients. The significance of the presence of an apparent IgG–β_1C complex in the synovial lining cells of most patients with rheumatoid arthritis is discussed.

Localization of hyaluronic acid in synovial cells by radioautography

Cultured human synovial cells secrete hyaluronic acid (HA) into the culture medium. Glucosamine-6-(3)H was shown to be a direct and relatively specific precursor of HA-(3)H by the following observations: the susceptibility of nondialyzable radioactivity in the medium to hyaluronidase, its migration with hexuronic acid on zone electrophoresis in polyvinyl chloride, its exclusion from Sephadex G-200, and the localization of radioactivity to glucosamine after hydrolysis of the labeled polysaccharide. The presence of intracellular HA-(3)H was established by sequential extraction of labeled cells and by radioautography of synovial cell cultures digested with hyaluronidase in situ. When cells were exposed to medium lacking glucose, glucosamine-(3)H-uptake was enhanced; and this made possible electron microscopic radioautographic studies. These studies demonstrate the early and continued presence of HA-(3)H within the Golgi apparatus.

Iron in the synovial membrane in rheumatoid arthritis and other joint diseases

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Synovial cell synthesis of a substance immunologically like cartilage proteinpolysaccharide

Fluids from joints contain a substance that reacts immunologically like one of two known antigenic components of articular cartilage proteinpolysaccharide. This newly recognized substance occurs in the lining cells of synovial membranes as shown by indirect immunofluorescence. The localization of this substance in tissue culture cells derived from synovial membranes and its identification in the culture medium supports the suggestion that it is synthesized by lining cells. Rheumatoid synovial cells contain less of this substance.

Rheumatoid factor in synovial effusions: local production and consumption

The ratio of synovial fluid γM-type rheumatoid factor (RF) to serum RF was compared with the ratio for two other γM-antibodies (trypsin- and periodate agglutinin) and total γM-globulin content in thirteen patients with rheumatoid arthritis.

In one case, the ratio for RF was higher than the ratios for the other γM-globulins and declined after synovectomy, indicating that a significant amount of RF in the synovial fluid was derived from locally produced RF. In three cases, the ratio for RF was lower than the other γM-globulin ratios, indicating local consumption or inhibition of RF in the joint. It was postulated that this phenomenon was due to some form of aggregated γG-globulin. In nine cases, the ratio for RF was equal or almost equal to the ratios for the other γM-globulins, indicating that the synovial fluid RF in these cases was mainly delivered from the circulation.