破骨细胞在强直性脊柱炎滑膜组织中的分化及其在外周关节骨质破坏病理机制中的作用

目的检测破骨细胞在强直性脊柱炎（AS）外周关节滑膜组织中的分化情况，了解破骨细胞的分化与AS患者外周关节骨质破坏病理改变的相关性。方法应用单克隆抗体，通过免疫组织化学及酶组织化学染色的方法检测13例AS、16例类风湿关节炎（RA）、17例骨关节炎（OA）及6例健康对照关节滑膜组织中CD68蛋白表达及TRAP染色阳性滑膜细胞的分布状况，并通过计算机辅助图像分析系统和半定量分析方法确定CD68分子表达水平及TRAP染色阳性细胞在各研究组滑膜组织中的差异性。结果滑膜组织中均有CD68阳性细胞，AS和RA组CD68表达水平较OA组和健康对照组显著增高（P〈0．05），其阳性细胞主要分布于滑膜衬里层，衬里下层也见少量表达；OA和健康者滑膜中仅有少量CD68阳性细胞分布。TRAP染色阳性细胞位于滑膜组织衬里层、淋巴细胞聚集区及滑膜软骨交界区，其中AS组阳性细胞百分数显著低于RA组，OA及正常对照组阳性细胞少见。RA组阳性细胞百分数与RANKL表达水平呈正相关（r=0．442，P=0．043）。结论炎症关节滑膜组织中表达CD68分子及TRAP染色阳性滑膜细胞数量的增加为破骨细胞的分化、成熟提供了充足的细胞数量基础，破骨细胞数量和活性上调是造成强直性脊柱炎外周关节骨质破坏的重要前提。

The differentiation of osteoclast in the synovium and its role in the pathogenesis of peripheral joint bone destruction in ankylosing spondylitis

Objective To compare expression and distribution of CD68 protein and TRAP positive protein in ankylosing spondylitis (AS), rheumatoid arthritis (RA), osteoarthritis (OA), and normal synovial tissues to study the differentiation of osteoclast in synovial tissues obtained from AS patients and its role in the pathogenesis of bone destruction in AS. Methods Immunohistochemical analysis was performed using CD68 monoclonal antibody to detect CD68 expression, and the distribution of TRAP positive cells in the synovial tissues was examined by enzyme histochemistry in 13 AS, 16 RA, 17 OA patients and 6 healthy controls. The above two variables were quantified in the labeled sections by digital image analysis and semiquantitative analysis to compare the expression of CD68 positive cells in different patient groups and normal subjects. Results Positive CD68 staining was seen in synovial cells from all the patients with AS, RA, OA and normal subjects, and the expression levels of CD68 from patients with AS and RA were higher than those from OA patients and healthy subjects. The CD68 positive cells were abundant mainly in lining layer. In areas where elevated RANKL expression levels were present, the number of TRAP positive cells was found significantly increased in AS and RA synovium. TRAP positive cells were rarely observed in synovium from OA patients and normal controls. There was positive correlation between the number of TRAP positive cells and the RANKL expression (r=0.442, P=0.043) in RA patients. Conclusions An obvious increase in the number of CD68 positive cells and TRAP positive cells in synovium may provide a main source of osteoclastogenesis in AS patients. The up-regulation of activity and quantity of osteoclast may have an important role in peripheral articular destruction in patients with AS.