Serum levels of secretory IgA and in vitro production of IgA in rheumatoid arthritis.
Twenty-three per cent of rheumatoid arthritis (RA) patients show an increase of serum IgA concentrations. To determine the role of mucous-associated lymphoid tissue (MALT) in the elevation of serum IgA in RA, we studied the serum secretory-IgA (s-IgA) in 63 RA patients and in 30 healthy controls. We also analysed the secretion of circulating B cells producing IgA, which is known to reflect mucous tissue activity, in a subgroup of 15 patients with increased serum IgA concentrations, and in control patients. The mean s-IgA in the RA patients was 0.046 mg/ml +/- 0.064, versus 0.002 +/- 0.004 mg/ml in controls (not significant). Active disease defined by clinical criteria was associated with an increase in serum s-IgA (p < 0.001). Furthermore, in a subgroup of RA patients with high serum IgA levels, we found an increase in in vitro IgA production by circulating blood lymphocytes (17.39 +/- 15.2 micrograms/ml), versus RA patients with normal serum IgA levels or controls (p < 0.001). These results were not modified by LPS or PWM. Our results further support the hypothesis of primary MALT activation following environmental antigenic stimulation in RA patients.
Jorgensen
C
C
Department of Immuno-Rheumatology, Centre Gui-de-Chauliac, Montpellier, France.
Bologna
C
C
Gutierrez
M
M
Anaya
J M
JM
Reme
T
T
Sany
J
J
D000328:Adult; D000368:Aged; D000941:Antigens; D001172:Arthritis, Rheumatoid / Q000209:etiology / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007071:Immunoglobulin A, Secretory / Q000097:blood*; D066298:In Vitro Techniques; D008221:Lymphoid Tissue / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009092:Mucous Membrane / Q000276:immunology
D000941:Antigens; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory