The B cell repertoire in rheumatoid arthritis. III. Preferential homing of rheumatoid factor-producing B cell precursors in the synovial fluid.
OBJECTIVE
We sought to compare the frequencies of precursors producing IgM rheumatoid factors (IgM-RFs) in synovial fluid and peripheral blood B cells from patients with rheumatoid arthritis (RA).


METHODS
We used limiting-dilution analysis of Epstein-Barr virus-activated B cells from seropositive and seronegative patients. B cell precursors producing IgM against insulin, an irrelevant autoantigen, were also assessed for comparison.


RESULTS
On average, IgM-RF-producing precursors were 15-fold higher in the synovial fluid than in the peripheral blood of seropositive RA patients, but not in seronegative RA patients. The frequency of B cell precursors producing IgM against insulin was lower in the synovial fluid than in the peripheral blood of both the seropositive and the seronegative patient groups; moreover, the concentrations were similar in both groups.


CONCLUSIONS
The findings provide evidence against a nonspecific accumulation of IgM-producing cells in the synovial fluid, and suggest that there is an active attraction of the RF-producing B cell precursors toward sites of inflammation in RA.
Moynier
M
M
INSERM U291, Montpellier, France.
Abderrazik
M
M
Didry
C
C
Sany
J
J
Brochier
J
J
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000378:metabolism / Q000473:pathology*; D001323:Autoantibodies / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D001772:Blood Cell Count; D002465:Cell Movement / Q000502:physiology; D005260:Female; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D004854:Herpesvirus 4, Human / Q000502:physiology; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007330:Insulin Antibodies / Q000276:immunology; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000378:metabolism*; D013582:Synovial Fluid / Q000166:cytology* / Q000378:metabolism
D001323:Autoantibodies; D007075:Immunoglobulin M; D007330:Insulin Antibodies; D012217:Rheumatoid Factor