Tsuruha Jun-Ichiro, Masuko-Hongo Kayo, Kato Tomohiro, Sakata Masahiro, Nakamura Hiroshi, Sekine Taichi, Takigawa Masaharu, Nishioka Kusuki
Rheumatology, Immunology and Genetics Program, Institute of Medical Science, St Marianna University School of Medicine, Kawasaki, Japan.
J Rheumatol. 2002 Jul;29(7):1459-66.
Our previous study revealed that some patients with rheumatoid arthritis (RA) possessed autoantibodies to YKL-39, a cartilage related protein. We investigated whether patients with osteoarthritis (OA) also displayed autoimmunity to YKL-39.
Autoantibodies to recombinant YKL-39 as well as human cartilage glycoprotein-39 were detected by ELISA and Western blotting. The tested serum samples were derived from 117 patients with OA, 94 patients with RA, and 2 groups of 50 arthropathy-free healthy donors who matched the OA and RA groups for age and sex. We determined autoepitopes on YKL-39 using 3 overlapping fragments of YKL-39 (designated F1, F2, F3). T cell proliferation response to YKL-39 was analyzed using the 3H-thymidine incorporation assay.
Autoantibodies to YKL-39 were detected in 13 (11.1%) patients with OA and 11 (11.8%) with RA. In the epitope mapping, all the 3 fragments of YKL-39 were found to carry autoepitopes, but F1 was recognized most frequently. Proliferative responses of peripheral blood mononuclear cells against YKL-39 were detected in 6 (46%) of the 13 OA patients who were positive for the anti-YKL-39 autoantibodies and in 2 (17%) of the 11 antibody positive RA patients.
These results show that autoimmunity to YKL-39 in patients with OA was present at equal or somewhat higher frequency than in patients with RA. The cellular and humoral immune responses to YKL-39 may be involved in the pathological process of OA as well as RA.
我们之前的研究表明，一些类风湿关节炎（RA）患者拥有针对软骨相关蛋白YKL-39的自身抗体。我们调查了骨关节炎（OA）患者是否也对YKL-39表现出自身免疫性。
采用酶联免疫吸附测定（ELISA）和蛋白质印迹法检测重组YKL-39以及人软骨糖蛋白-39的自身抗体。检测的血清样本来自117例OA患者、94例RA患者以及两组各50名无关节病的健康供者，这两组健康供者在年龄和性别上与OA组和RA组相匹配。我们使用YKL-39的3个重叠片段（命名为F1、F2、F3）确定YKL-39上的自身抗原表位。采用3H-胸腺嘧啶核苷掺入法分析T细胞对YKL-39的增殖反应。
在13例（11.1%）OA患者和11例（11.8%）RA患者中检测到YKL-39自身抗体。在抗原表位定位中，发现YKL-39的所有3个片段都带有自身抗原表位，但F1被识别的频率最高。在13例抗YKL-39自身抗体阳性的OA患者中有6例（46%）检测到外周血单个核细胞对YKL-39的增殖反应，在11例抗体阳性的RA患者中有2例（17%）检测到该反应。
这些结果表明，OA患者中对YKL-39的自身免疫性出现的频率与RA患者相当或略高。对YKL-39的细胞免疫和体液免疫反应可能参与了OA以及RA的病理过程。
