Mononuclear phagocyte system Fc-receptor function in patients with seropositive rheumatoid arthritis.
Mononuclear phagocyte system (MPS) Fc-receptor function in 20 patients with seropositive rheumatoid arthritis (RA) was investigated using radiolabelled autologous erythrocytes coated with an average of 5,800 molecules of anti-rhesus IgG (E. IgG). Although clearance times (T1/2) of E. IgG tended to be longer in RA patients than those in healthy controls (46 +/- 6 min vs 38 +/- 5 min, mean +/- s.e.m., P = 0.38), this did not reach statistical significance. Liver spleen uptake ratios (LS ratios) were increased in patients with RA (13/100 +/- 1/100 vs 7/100 +/- 1/100, P less than 0.05). There was no correlation of T1/2 or LS ratios with articular disease activity, vasculitis, ESR, IgM containing immune complex levels or Clq-binding immune complex levels. Although Clq-binding immune complex levels were significantly higher in patients with vasculitis than in those without (P less than 0.01), T1/2 and LS ratios did not differ in these two groups of patients. The T1/2 and LS ratios of E.IgG did not reveal a defect in MPS Fc-receptor function and did not correlate with one of the above-mentioned clinical and immunological parameters. We suggest that in order to establish a possible defect in Fc-receptor function correlating with disease activity and immune complex levels in RA patients, soluble immune complexes or immune complex-like material should be used as probes.
D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007518:Isoantibodies / Q000502:physiology; D008099:Liver / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010586:Phagocytes / Q000276:immunology*; D011961:Receptors, Fc / Q000276:immunology*; D012204:Rh-Hr Blood-Group System / Q000276:immunology; D013154:Spleen / Q000276:immunology
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007518:Isoantibodies; D011961:Receptors, Fc; D012204:Rh-Hr Blood-Group System