Krause I, Blank M, Cervera R, Font J, Matthias T, Pfeiffer S, Wies I, Fraser A, Shoenfeld Y
Department of Medicine E, Rabin Medical Center Beilinson Campus, Tel Aviv University, Tel Aviv, Israel.
Ann N Y Acad Sci. 2007 Jun;1108:481-8. doi: 10.1196/annals.1422.051.
Anti-Saccharomyces cerevisiae antibodies (ASCA), directed against the phosphopeptidomannan (PPM) part of the cell wall of the yeast, have been identified as an important and specific serological marker for Crohn's disease. We evaluated the prevalence and properties of ASCA in APS patients. Thirty-one out of 155 APS patients tested positive for ASCA (20.0%), compared to 5.0% in healthy controls (P < 0.05). The presence of ASCA was not associated with any specific manifestation of APS. The ASCA found to be the population of anti-beta2GPI antibodies (Abs). Affinity purified anti-beta2GPI from ASCA-positive sera on a beta2GPI column, bound specifically the PPM, as shown by direct binding and competition assays (95-98%). The PPM inhibited differentially the anti-beta2GPI binding to beta2GPI. Since the anti-beta2GPI anti-PPM could bind only native form of beta2GPI and not the recombinant form, we assume that these specific anti-beta2GPI subpopulations of Abs are directed to the glycosylated site of the molecule. In conclusion, a subpopulation of anti-beta2GPI is specific to the glycosylated site of the beta2GPI molecule that cross-reacts with PPM.
抗酿酒酵母抗体（ASCA），针对酵母细胞壁的磷酸肽甘露聚糖（PPM）部分，已被确定为克罗恩病的一种重要且特异性的血清学标志物。我们评估了抗磷脂综合征（APS）患者中ASCA的患病率和特性。155例APS患者中有31例ASCA检测呈阳性（20.0%），而健康对照者中的比例为5.0%（P<0.05）。ASCA的存在与APS的任何特定表现均无关联。发现ASCA为抗β2糖蛋白I抗体（Abs）群体。通过直接结合和竞争试验表明（95 - 98%），在β2糖蛋白I柱上从ASCA阳性血清中亲和纯化的抗β2糖蛋白I能特异性结合PPM。PPM可不同程度地抑制抗β2糖蛋白I与β2糖蛋白I的结合。由于抗β2糖蛋白I抗PPM只能结合天然形式的β2糖蛋白I，而不能结合重组形式的β2糖蛋白I，我们推测这些特异性抗β2糖蛋白I亚群的Abs是针对该分子的糖基化位点。总之，抗β2糖蛋白I的一个亚群对β2糖蛋白I分子的糖基化位点具有特异性，且与PPM发生交叉反应。
