Dörner T, Feist E, Held C, Conrad K, Burmester G R, Hiepe F
Department of Medicine III, Charité Medical School, Humboldt University of Berlin, Germany.
Hepatology. 1996 Dec;24(6):1404-7. doi: 10.1002/hep.510240616.
Antibodies against the 52-kd Ro(SS-A) protein are significantly associated with the primary Sjogren's syndrome (pSS). A small proportion of patients suffering from primary biliary cirrhosis (PBC) with secondary Sjogren's syndrome (PBC/SS) who are serologically characterized by antimitochondrial type 2 antibodies also express anti-52-kd Ro(SS-A) antibodies. The primary B-cell-derived antigenic responses by autoimmune sera were analyzed in both entities using truncated recombinant proteins to examine whether different epitopes are associated with these diseases. Sera were collected from 25 patients with pSS and 9 anti-52-kd Ro(SS-A)-positive patients suffering from PBC/SS. B-cell epitope mapping was performed using different 52-kd Ro(SS-A) fusion proteins in enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Sera from patients with pSS showed the broadest reactivity against antigenic epitopes at AA 153-245 compared to the significantly limited reactivity against AA 228-245 of sera from patients with PBC. B-cell epitopes within AA 190-245 represent immunodominant epitopes recognized by pSS sera in a significantly higher degree than by PBC sera, which react predominantly with AA 228-245 (P < .0001). Anti-La(SS-B) antibodies were significantly associated with anti-52-kd Ro(SS-A) in sera from patients with pSS compared with PBC patients (P < .025). Thus, the antibody response to 52-kd Ro(SS-A) in PBC appears to be induced differently than in pSS. Although a limited immune response to 52-kd Ro(SS-A) occurs in PBC/SS patients, a more extended epitope spreading is evident in patients with pSS.
抗52-kd Ro(SS-A)蛋白抗体与原发性干燥综合征（pSS）显著相关。一小部分患有继发性干燥综合征（PBC/SS）的原发性胆汁性肝硬化（PBC）患者，其血清学特征为抗线粒体2型抗体，也表达抗52-kd Ro(SS-A)抗体。在这两种疾病中，使用截短的重组蛋白分析自身免疫血清的原发性B细胞衍生抗原反应，以检查不同表位是否与这些疾病相关。收集了25例pSS患者和9例抗52-kd Ro(SS-A)阳性的PBC/SS患者的血清。在酶联免疫吸附测定（ELISA）和免疫印迹中，使用不同的52-kd Ro(SS-A)融合蛋白进行B细胞表位图谱分析。与PBC患者血清对228-245氨基酸区域的显著有限反应性相比，pSS患者血清对153-245氨基酸区域的抗原表位具有最广泛的反应性。190-245氨基酸区域内的B细胞表位代表了pSS血清比PBC血清更显著识别的免疫显性表位，PBC血清主要与228-245氨基酸区域反应（P <.0001）。与PBC患者相比，pSS患者血清中的抗La(SS-B)抗体与抗52-kd Ro(SS-A)显著相关（P <.025）。因此，PBC中对52-kd Ro(SS-A)的抗体反应似乎与pSS中的诱导方式不同。虽然PBC/SS患者对52-kd Ro(SS-A)发生有限的免疫反应，但在pSS患者中明显存在更广泛的表位扩散。
