Fehr K, Artmann G, Velvart M, Böni A
Arthritis Rheum. 1977 Jul-Aug;20(6):1240-8. doi: 10.1002/art.1780200613.
Tissue culture methods demonstrated the production of agglutinators against the cathepsin D site in IgG (CDA) and a neutral protease site in IgG (NPA) by rheumatoid synovial tissue. Seven of 11 specimens from seropositive and 2 of 7 specimens from seronegative RA patients were positive for CDA, whereas 2 of 11 specimens from seropositive and 1 of 7 specimens from seronegative patients were positive for NPA. None of the 6 control specimens was positive for both types of agglutinators. Chromatography of two synovial tissue incubates showed that the CDA were of the IgG type. By the immunofluorescence technique, plasma cells containing CDA were demonstrated in rheumatoid synovial tissue and draining lymph nodes of rheumatoid joints. The staining for CDA in the synovium was different from the staining for pepsin agglutinators in adjacent sections. Phagolysosomes containing CDA were found in synovial exudate cells from rheumatoid patients as well as in phagocytosing lining cells and macrophages of the sublining layer of rheumatoid synovial tissue. These findings suggest that antibodies directed at hidden antigenic sites in IgG revealed by endogenous proteolysis take part in the immune reaction and in the inflammation of rheumatoid joints.
组织培养方法表明，类风湿性滑膜组织可产生针对IgG中组织蛋白酶D位点（CDA）和IgG中中性蛋白酶位点（NPA）的凝集素。血清阳性RA患者的11份标本中有7份、血清阴性RA患者的7份标本中有2份CDA呈阳性，而血清阳性患者的11份标本中有2份、血清阴性患者的7份标本中有1份NPA呈阳性。6份对照标本中两种凝集素均无阳性。对两份滑膜组织培养液进行色谱分析表明，CDA属于IgG类型。通过免疫荧光技术，在类风湿性滑膜组织及类风湿关节引流淋巴结中发现了含有CDA的浆细胞。滑膜中CDA的染色与相邻切片中胃蛋白酶凝集素的染色不同。在类风湿患者的滑膜渗出细胞以及类风湿性滑膜组织衬里下层的吞噬衬里细胞和巨噬细胞中发现了含有CDA的吞噬溶酶体。这些发现表明，针对内源性蛋白水解所揭示的IgG中隐藏抗原位点的抗体参与了免疫反应和类风湿关节的炎症反应。
