Fehr K, Baici A, Velvart M, Knöpfel M, Rauber M, Sommermeyer G, Salgam P, Cohen G, Böni A
Bull Schweiz Akad Med Wiss. 1979 Sep;35(4-6):317-27.
The synovial fluid (SF) of RA patients contains large amounts of PMN which are well equipped with neutral enzymes to degrade articular cartilage: elastase and cathepsin G, which both destroy proteoglycans and native collagen, as well as 2 types of collagenoases. Indirect evidence suggests that PMN might be important in the destruction of RA articular cartilage. In 19 SF of RA patients no free elastase or collagenase was found. Using immune histochemical methods, we observed that PMN and macrophages of SF contain both elastase and alpha 1-anti-trypsin and alpha 2-macroglobulin. Peripheral PMN - but not monocytes - contain elastase, however both types of cells lack alpha 1-antitrypsin and alpha 2-macroglobulin. Elastase is demonstratable in the superficial layer of pannus free RA articular cartilage. These findings suggest that neutral proteinases from PMN in RA SF are generally neutralized by physiologic inhibitors and removed by phagocytes. The enzyme-inhibitor interaction might be bypassed during "frustrated phagocytosis" so that enzymes like PMN elastase can damage RA articular cartilage.
类风湿关节炎（RA）患者的滑液（SF）中含有大量的中性粒细胞（PMN），这些细胞富含降解关节软骨的中性酶：弹性蛋白酶和组织蛋白酶G，它们均可破坏蛋白聚糖和天然胶原蛋白，此外还有2种胶原酶。间接证据表明，PMN可能在RA关节软骨破坏中起重要作用。在19例RA患者的滑液中未发现游离的弹性蛋白酶或胶原酶。采用免疫组织化学方法，我们观察到滑液中的PMN和巨噬细胞同时含有弹性蛋白酶、α1-抗胰蛋白酶和α2-巨球蛋白。外周血PMN（而非单核细胞）含有弹性蛋白酶，然而这两种细胞均缺乏α1-抗胰蛋白酶和α2-巨球蛋白。在无血管翳的RA关节软骨表层可检测到弹性蛋白酶。这些发现提示，RA滑液中PMN产生的中性蛋白酶通常被生理抑制剂中和并被吞噬细胞清除。在“吞噬受挫”过程中，酶-抑制剂相互作用可能被绕过，从而使PMN弹性蛋白酶等酶能够损伤RA关节软骨。
