Abnormal immunoglobulin and rheumatoid factor synthesis by blood lymphocytes in patients with primary Sjögren's syndrome.
Peripheral blood B lymphocytes from patients with primary Sjögren's syndrome showed significantly higher spontaneous synthesis of IgG, IgM, and IgM rheumatoid factor in vitro, compared with B lymphocytes from healthy controls. Lymphocytes from patients also showed higher IgM rheumatoid factor production after mitogen stimulation. Patients had competent suppressor activity for IgG, but not for IgM synthesis. Pre-irradiation of T cells, but not depletion of OKT8+ cells, markedly enhanced IgG synthesis in cocultures with autologous B cells; therefore, the T lymphocyte responsible for this effect is radiosensitive and is not identified by OKT8. OKT8+ lymphocytes from patients did not suppress Ig synthesis by autologous B plus T cell cocultures. However, OKT8+ cells from normal controls down-regulated Ig synthesis by B plus T cells from patients. The abnormal proportion of helper and suppressor cells suggests that there is altered redistribution of regulatory subpopulations in peripheral blood from Sjögren's syndrome patients.
D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000378:metabolism; D001773:Blood Cells / Q000378:metabolism*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis; D007136:Immunoglobulins / Q000096:biosynthesis*; D008214:Lymphocytes / Q000145:classification / Q000378:metabolism*; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D012217:Rheumatoid Factor / Q000032:analysis / Q000096:biosynthesis*; D012859:Sjogren's Syndrome / Q000378:metabolism*; D013601:T-Lymphocytes / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology; D050378:T-Lymphocytes, Regulatory / Q000502:physiology
D007075:Immunoglobulin M; D007136:Immunoglobulins; D008934:Mitogens; D012217:Rheumatoid Factor