Floyd M, Tesar J T
Clin Exp Immunol. 1979 Apr;36(1):165-74.
The effect of IgM rhematoid factor (RF) on reversepassive cutaneous Arthus reaction in rats was studied. The RF was obtained from the serum cryoglobulin of a patient with symptoms of purpura, arthralgia and digital gangrene. The cryoglobulins was of IgG-IgM type and when given i.v it induced a prompt hypocomplementaemia in experimental animals. The purified RF also induced low serum complement levels when injected i.v. along with complexes of non-complement-fixing, aggregated IgG. A reverse passive Arthus reaction was induced by intradermal injection of IgG anti-bovine serum albumin (BSA), followed by an i.v. dose of antigen (Ag). The cutaneous inflammatory reaction was aggravated by simultaneous administration of IgM RF intradermally, but not by IgM without antibody (Ab) properties. Intradermal injection of low concentrations of non-complement-fixing IgG anti-BSA, along with normal human IgM, followed by i.v. injection of BSA, resulted in a complete lack of cutaneous inflammation. At higher Ab concentrations there was only a mild inflammation. However, when IgM RF was substituted for normal IgM and injected with non-complement-fixing anti-BSA, an effective reverse passive cutaneous Arthus reaction and vasculitis was induced. The inflammatory response was greatly suppressed by decomplementation of animals by cobra venom factor. This study provides evidence favouring an inflammatory, complement-dependent role for RF in vasculitis.
研究了IgM类风湿因子（RF）对大鼠被动反向皮肤Arthus反应的影响。RF取自一名有紫癜、关节痛和手指坏疽症状患者的血清冷球蛋白。该冷球蛋白为IgG-IgM型，静脉注射时可使实验动物迅速出现补体血症。纯化的RF与非补体结合的聚集IgG复合物静脉注射时，也可导致血清补体水平降低。通过皮内注射IgG抗牛血清白蛋白（BSA），然后静脉注射抗原（Ag）诱导被动反向Arthus反应。皮内同时给予IgM RF可加重皮肤炎症反应，但给予无抗体（Ab）特性的IgM则无此作用。皮内注射低浓度非补体结合的IgG抗BSA与正常人IgM，随后静脉注射BSA，可完全不出现皮肤炎症。抗体浓度较高时，仅有轻度炎症。然而，用IgM RF替代正常IgM并与非补体结合的抗BSA一起注射时，可诱导有效的被动反向皮肤Arthus反应和血管炎。用眼镜蛇毒因子使动物补体耗竭可大大抑制炎症反应。本研究提供了证据，支持RF在血管炎中具有炎症性、补体依赖性作用。
