Rockford Orthopedic Associates, 324 Roxbury Rd, Rockford, IL 61107, USA.
Arthritis Res Ther. 2009;11(6):R177. doi: 10.1186/ar2866. Epub 2009 Nov 23.
Ankylosing spondylitis (AS) and inflammatory bowel disease (IBD) share similarities and are classified as spondyloarthropathies. In IBD, anti-Saccharomyces cerevisiae antibody (ASCA), anti-I2 (associated with anti-Pseudomonas activity), anti-Escherichia coli outer membrane porin C (anti-OmpC), anti-flagellin (anti-CBir1), and antineutrophil cytoplasmic antibodies (ANCA) possess clinical significance. Because of the overlap between the two conditions, a pilot study was designed to compare the frequency of these antibodies in AS patients compared to normal controls.
Serum stored from 80 AS patients and 80 control subjects was available for analysis. ASCA, anti-I2, anti-OmpC, anti-CBir1, and ANCA studies were completed on all serum samples using Enzyme-Linked Immunosorbent Assay (ELISA) methodology. The following analyses were performed: comparison of positivity based on the established values in IBD, median values, the number of subjects in each serology in the 4th quartile of a normal distribution, and the mean quartile sum of all the antibodies.
There was no difference in positivity rates between AS and control groups with the established IBD values. The median anti-I2 response was significantly higher in AS than in controls (11.78 vs 7.86, p = 0.017). Significantly more AS patients had quartile scores of 4 for the following antibody responses: ASCA IgG (26% vs 13%, p = 0.016, OR = 2.49, CI 1.168 - 5.313), ASCA IgG and IgA (27% vs 12%, p = 0.006, OR = 2.9, CI: 1.342 - 6.264), and anti - I2 (25% vs 14%, p = 0.0424, OR = 2.15, CI: 1.018 - 4.538). The mean quartile sum of the antibody responses was elevated in AS patients when ANCA was excluded (10.526 vs 9.519, p = 0.03). When ANCA was included, this difference lost significance.
The data from this pilot study points towards mucosal dysregulation as an important pathway in AS. We were able to demonstrate that anti-I2 could play a pathologic role in AS. The elevated mean total antibody response being significant only with ANCA exclusion is consistent with the histopathological evidence that intestinal inflammation in AS is similar to Crohn's disease. To better define the roles of these antibodies in AS, larger studies with more precisely defined patient characteristics are required.
强直性脊柱炎（AS）和炎症性肠病（IBD）具有相似之处，被归类为脊柱关节病。在 IBD 中，抗酿酒酵母抗体（ASCA）、抗 I2（与抗假单胞菌活性相关）、抗大肠埃希菌外膜孔蛋白 C（抗-OmpC）、抗鞭毛蛋白（抗-CBir1）和抗中性粒细胞胞质抗体（ANCA）具有临床意义。由于这两种疾病之间存在重叠，因此设计了一项初步研究，以比较 AS 患者与正常对照组之间这些抗体的频率。
对 80 例 AS 患者和 80 例对照者的储存血清进行了分析。使用酶联免疫吸附试验（ELISA）方法对所有血清样本进行了 ASCA、抗 I2、抗-OmpC、抗-CBir1 和 ANCA 研究。进行了以下分析：基于 IBD 中既定值、中位数、正态分布第 4 四分位数的每个血清学中的受试者数量以及所有抗体的四分位数总和的阳性率比较。
AS 组和对照组之间的阳性率无差异，使用既定的 IBD 值。AS 患者的抗 I2 反应中位数明显高于对照组（11.78 对 7.86，p = 0.017）。AS 患者具有以下抗体反应的四分位数评分 4 的比例显著更高：ASCA IgG（26% 对 13%，p = 0.016，OR = 2.49，CI 1.168 - 5.313）、ASCA IgG 和 IgA（27% 对 12%，p = 0.006，OR = 2.9，CI：1.342 - 6.264）和抗-I2（25% 对 14%，p = 0.0424，OR = 2.15，CI：1.018 - 4.538）。排除 ANCA 后，AS 患者的抗体反应四分位数总和升高（10.526 对 9.519，p = 0.03）。当包括 ANCA 时，这种差异失去了意义。
这项初步研究的数据表明，黏膜失调是 AS 的一个重要途径。我们能够证明抗 I2 可能在 AS 中发挥病理性作用。仅在排除 ANCA 时升高的平均总抗体反应具有统计学意义，这与 AS 中肠道炎症类似于克罗恩病的组织病理学证据一致。为了更好地定义这些抗体在 AS 中的作用，需要进行具有更精确患者特征的更大规模研究。
