Olsen N, Ziff M, Jasin H E
Rheumatol Int. 1982;2(2):59-66. doi: 10.1007/BF00541247.
In vitro synthesis of IgG, IgM and IgM-rheumatoid factor (IgM-RF) was investigated in unstimulated and pokeweed mitogen (PWM)-stimulated 7-day cultures of blood mononuclear cells (BMC) from 28 seropositive patients with active rheumatoid arthritis (RA), in a second group of 13-day cultures from 94 unselected rheumatoid patients, and in 21 healthy controls. Both normal and rheumatoid BMC cultures synthesized IgM-RF in response to PWM stimulation. Mitogen-induced stimulation was shown to be dependent on the presence of T-lymphocytes. PWM-induced IgM and IgM-RF synthesis were reduced in BMC from rheumatoid patients in comparison with healthy controls. However, the fraction of IgM-RF in the total IgM synthesized was significantly higher in the RA supernatants than in the controls, suggesting the presence of a larger precursor B-cell population committed to IgM-RF synthesis in those cultures. BMC from 44 of the 94 patients demonstrated spontaneous synthesis of IgM-RF, and this was positively correlated with disease activity and rheumatoid factor titer. Spontaneous production was shown to reside in the T-lymphocyte depleted, adherent cell-depleted, B-cell subpopulation. It is concluded that in active RA there is a specific activation and expansion of the circulating B-cell subpopulation committed to IgM-RF synthesis, possibly due to abnormal immunoregulatory mechanisms modulating synthesis of this antibody.
在来自28例血清阳性的活动性类风湿关节炎（RA）患者的血液单核细胞（BMC）的未刺激和经商陆有丝分裂原（PWM）刺激的7天培养物中，在来自94例未选择的类风湿患者的第二组13天培养物中，以及在21例健康对照中，研究了IgG、IgM和IgM类风湿因子（IgM-RF）的体外合成。正常和类风湿BMC培养物在PWM刺激下均合成IgM-RF。有丝分裂原诱导的刺激显示依赖于T淋巴细胞的存在。与健康对照相比，类风湿患者的BMC中PWM诱导的IgM和IgM-RF合成减少。然而，RA上清液中合成的总IgM中IgM-RF的比例显著高于对照，表明在那些培养物中存在更大的致力于IgM-RF合成的前体B细胞群体。94例患者中有44例的BMC表现出IgM-RF的自发合成，且这与疾病活动度和类风湿因子滴度呈正相关。自发产生显示存在于T淋巴细胞耗竭、黏附细胞耗竭的B细胞亚群中。得出的结论是，在活动性RA中，致力于IgM-RF合成的循环B细胞亚群存在特异性激活和扩增，这可能是由于调节该抗体合成的异常免疫调节机制所致。
