HLA-DR Antigen Positive Cells in the RA Synovium. -Their Significant Role Concerning in the Continuation of Chronic Inflammation of RA.

类风湿性关节炎滑膜细胞的特征将类风湿性关节炎滑膜上增殖明显的subblining D细胞分为D(F)细胞和D(M)细胞两种类型。在培养过程中，D(F)细胞在多种细胞因子的作用下表现出较高的增殖活性，并能很容易地改变其形态和功能特征。另一方面，D(M)细胞增殖非常缓慢，它们在其表面连续且强烈表达HLA-DR抗原。这些结果提示，D(F)细胞在RA滑膜炎组织病理变化的形成中起重要作用，D(M)细胞在很大程度上与RA的免疫活性有关。我们对早期RA滑膜炎进行了免疫组化研究，发现RA早期在毛细血管周围可见HLA-DR阳性细胞，随后出现T淋巴细胞，后期出现B淋巴细胞聚集。部分早期RA患者经免疫调节药物（CCA）治疗后病情有所改善，但滑膜HLA-DR阳性细胞未见明显定性和定量变化。这些发现提示RA滑膜炎发展过程中细胞相互作用的复杂性。4滑膜细胞与类风湿结节细胞的比较类风湿结节中大部分细胞的特征与类风湿滑膜炎中的D细胞非常相似。临床类风湿滑膜炎的特点是其进行性和破坏性与类风湿结节相反。类风湿结节组织病理学上淋巴细胞浸润不明显。这些发现提示淋巴细胞浸润对RA滑膜炎慢性破坏性炎症的持续至关重要。

1 Characteristics of RA synovial cells The sublining D cells which were remarkably proliferating in the rheumatoid synovial membrane were divided into two type cells, D(F) cells and D(M) cells immunohistochemically. In culture, D(F) cells showed high proliferative activity and easily transformed their morphological and functional character under the effects of variable cytokines. On the other hand, D(M) cells proliferated very slowly, and they contiguously and strongly expressed HLA-DR antigen on their surface. These findings suggest that D(F) cell plays an important role in formation of histopathological variety of RA synovitis and D(M) cell is largely concerned in the immunological activity of RA. 2 Histopathological study of early stage of synovial lesion We investigated the early stage of RA synovitis immunohistochemically and from this study it become clear that in very early of RA, HLA-DR positive cells were found in pericapillary region and following them T lymphocytes appeared and B lymphocytes appeared to aggregate in later. 3 The effects of drugs on RA synovitis Some patients with early stage RA showed improvement of condition of disease after treatment with immunomodulating drug (CCA), but no apparent qualitative and quantitative changes of HLA-DR positive cells in synovium were observed. These findings suggest the complexity of cellular interaction in development of RA synovitis. 4 Comparison of synovial cells with cells in rheumatoid nodule The characteristics of majority of cells in rheumatoid nodule were quite similar to that of D cells in rheumatoid synovitis. Clinically rheumatoid synovitis is characterized by its progressive and destructive nature in contrast to rheumatoid nodule. Histopathologically in the rheumatoid nodule the lymphocyte infiltration was less conspicuous. These findings suggest that lymphocyte infiltration is essential for the continuation of chronic destructive inflammation of RA synovitis.