Departamento de Biología Molecular y Genómica, Instituto de Investigación en Reumatología y del Sistema Músculo Esquelético, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Guadalajara, Jalisco, CP 44340, México.
Arthritis Res Ther. 2010;12(1):R6. doi: 10.1186/ar2905. Epub 2010 Jan 8.
Autoantibodies to RNA helicase A (RHA) were reported as a new serological marker of systemic lupus erythematosus (SLE) associated with early stage of the disease. Anti-RHA and other autoantibodies in Mexican SLE patients and their correlation with clinical and immunological features were examined.
Autoantibodies in sera from 62 Mexican SLE patients were tested by immunoprecipitation of 35S-labeled K562 cell extract and enzyme-linked immunosorbent assay (anti-U1RNP/Sm, ribosomal P, beta2GPI, and dsDNA). Anti-RHA was screened based on the immunoprecipitation of the 140-kDa protein, the identity of which was verified by Western blot using rabbit anti-RHA serum. Clinical and immunological characteristics of anti-RHA-positive patients were analyzed.
Anti-RHA was detected in 23% (14/62) of patients, a prevalence higher than that of anti-Sm (13%, 8/62). Prevalence and levels of various autoantibodies were not clearly different between anti-RHA (+) vs. (-) cases, although there was a trend of higher levels of anti-RHA antibodies in patients without anti-U1RNP/Sm (P = 0.07). Both anti-RHA and -Sm were common in cases within one year of diagnosis; however, the prevalence and levels of anti-RHA in patients years after diagnosis did not reduce dramatically, unlike a previous report in American patients. This suggests that the high prevalence of anti-RHA in Mexican patients may be due to relatively stable production of anti-RHA.
Anti-RHA was detected at high prevalence in Mexican SLE patients. Detection of anti-RHA in races in which anti-Sm is not common should be clinically useful. Racial difference in the clinical significance of anti-RHA should be clarified in future studies.
抗 RNA 解旋酶 A（RHA）抗体被报道为与疾病早期相关的系统性红斑狼疮（SLE）的新的血清学标志物。本研究检测了墨西哥 SLE 患者的抗 RHA 及其他自身抗体，并分析了它们与临床和免疫特征的相关性。
采用放射性免疫沉淀法和酶联免疫吸附试验（抗 U1RNP/Sm、核糖体 P、β2GPI 和 dsDNA）检测 62 例墨西哥 SLE 患者血清中的自身抗体。基于对 140kDa 蛋白的免疫沉淀筛选抗 RHA，并用兔抗 RHA 血清通过 Western blot 验证其身份。分析抗 RHA 阳性患者的临床和免疫特征。
在 62 例患者中，有 23%（14/62）检测到抗 RHA，其阳性率高于抗 Sm（13%，8/62）。抗 RHA（+）与（-）病例之间各种自身抗体的阳性率和水平无明显差异，尽管在无抗 U1RNP/Sm 的患者中抗 RHA 抗体水平有升高趋势（P=0.07）。在诊断后 1 年内，抗 RHA 和抗 Sm 均常见，但与美国患者的既往报道不同，在诊断后数年，抗 RHA 的阳性率和水平并未显著降低。这表明，抗 RHA 在墨西哥患者中的高阳性率可能是由于其相对稳定地产生抗 RHA。
在墨西哥 SLE 患者中，抗 RHA 的检出率较高。在抗 Sm 不常见的种族中检测抗 RHA 可能具有临床意义。在未来的研究中应阐明抗 RHA 在种族差异中的临床意义。
