ISSN:
1437-160X
Keywords:
Rheumatoid arthritis
;
IgM-rheumatoid factor
;
Ia+ T cells
;
Pokeweed mitogen
;
Helper T cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In peripheral blood and synovial fluid of patients with rheumatoid arthritis (RA), increased levels of Ia antigen-positive (Ia+) T cells have been demonstrated. Therefore, we examined these Ia+ T cells in vitro to identify their role in the production of rheumatoid factor (RF) and to study the immunologic abnormalities of RA. When Ia+ T cells from peripheral blood of RA patients were added to pokeweed mitogen (PWM)-non-stimulated autologous B cells, the amount of IgM-RF production was 25.8±6.4 (mean±SE) (p〈0.001) as compared to 16.0±4.6 ng/ml (mean±SE) in the presence of Ia− T cells. When Ia− OKT4+ cell fractions, obtained by excluding Ia+ T cells from OKT4+ cells, were added to B cells, the increase in IgM-RF production was markedly lower than that obtained with the OKT4+ cell fraction. These results indicate that the helper T cells which induce the production of IgM-RF may derive from the Ia+ OKT4+ cell fraction. B cells from rheumatoid synovial fluid produced IgM-RF levels as high as 102.7±19.2 ng/ml (mean±SE) even without stimulation. When T cells from autologous synovial fluid were added, IgM-RF production was not increased. These data suggest that B cells from RA synovial fluid had already been activated. When synovial fluid T cells were added to B cells from autologous peripheral blood, larger amounts of IgM-RF were produced as compared to experiments in which T cells from peripheral blood were added, suggesting that T cells from synovial fluid induce an enhanced IgM-RF production by B cells. The presence or absence of Ia antigen on the surface of synovial fluid T cells did not affect the level of IgM-RF production. Our results indicate that Ia+ T cells from the peripheral blood of RA patients induce the production of IgM-RF by autologous B cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00270657
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