抗酿酒酵母抗体和抗中性粒细胞胞质抗体对炎症性肠病的诊断价值

The value of anti-saccharomyces cerevisiae and antineutrophil cytoplasmic antibodies in diagnosing inflammatory bowel disease

目的了解抗酿酒酵母抗体（ASCA）和核周型抗中性粒细胞胞质抗体（pANCA）的分布，观察其在炎症性肠病（1BD）诊断及鉴别诊断中的意义。方法选择2002年9月至2007年7月在北京协和医院就诊并行ASCA、pANCA检查的IBD患者175例，其中克罗恩病（CD）62例、溃疡性结肠炎（UC）97例、未定型16例。另取对照者167例。采用酶联免疫吸附法测定血清ASCA水平，间接免疫荧光法测定血清pANCA水平。结果在CD、UC、未定型者、对照者中，ASCA的阳性率分别为45．2％、14．4％、11／16、29．3％，pANCA的阳性率分别为4．8％、56．7％、1／16、4．8％。对照者中，ASCA在恶性肿瘤、嗜酸性粒细胞增多症、自身免疫性肝病、弥漫性结缔组织病及肠结核中的阳性率较高（分别为42．1％、2／5、4／10、4／19、4／14）。ASCA诊断CD的敏感性、特异性及阳性预测值分别为45．2％、85．6％、66．7％。pANCA诊断UC的敏感性、特异性及阳性预测值分别为56．7％、95．2％、94．8％。联合检测ASCA＋／pANCA-诊断CD的敏感性、特异性及阳性预测值分别为41．9％、93．8％、81．3％。联合检测ASCA-／pANCA＋诊断UC的敏感性、特异性和阳性预测值分别为48．5％、98．4％、97．9％。结论ASCA和pANCA不适于作为IBD筛查指标，联合检测有利于UC与CD的鉴别诊断。

Objective To assess the distribution of anti-saccharomyces cerevisiae antibodies （ASCA） and perinuclear antineutrophil cytoplasmic antibody （ pANCA ） in order to investigate their values in diagnosing inflammatory bowel disease （IBD）. Methods Serum samples were collected from 175 patients with IBD including 62 with Crohn＇s disease （CD）, 97 with ulcerative colitis （UC） and 16 with indeterminate type between Sept. 2002 to July 2007. One hundred and sixty-seven patients were served as controls. Immunofluorescence technique and ELISA were used to detect pANCA and ASCA, respectively. Results The positive rate of ASCA in CD patients （45.2%） was statistically higher than that in UC patients （14. 4%） and controls （29. 3%） （P〈0. 05）. The positive rate of pANCA was significantly higher in UC patients （56. 7%） compared with CD patients （4.8%） and controls （4.8%） （P〈0.05）. The positive rate of ASCA in control patients with malignant disease, autoimmune hepatic diseases, diffuse connective tissue diseases and intestinal tuberculosis was 42.1%, 4/10, 4/19, and 4/14 respectively. The sensitivity, specificity and positive predictive value of positive ASCA combined with negative pANCA in diagnosing CD was 41. 9%, 93. 8% and 81. 3%, respectively, while combined negative ASCA with positive pANCA in diagnosing UC was 48.5%, 98.4% and 97. 9%, respectively. Conclusions Neither ASCA nor pANCA can be used as a screening marker for IBD, while combination of pANCA with ASCA may be helpful in differentiating UC from CD.