Walker R C, Ruane P J, Rosenblatt J E, Lyerly D M, Gleaves C A, Smith T F, Pierce P F, Wilkins T D
Diagn Microbiol Infect Dis. 1986 May;5(1):61-9. doi: 10.1016/0732-8893(86)90092-1.
Clostridium difficile culture, test tube, and microtiter cytotoxicity assays, and enzyme-linked immunosorbent assays (ELISAs) for toxin A and toxin B, were simultaneously performed on 113 fresh diarrheal stool specimens randomly selected from those submitted to our clinical laboratory for routine C. difficile testing. The performance of these tests in diagnosing C. difficile-related enteric disease (CDRED) was based on a clinical assessment of the likelihood of CDRED as determined by a systematic review of case histories blinded from the test results. Among 61 antibiotic recipients, both the microtiter cytotoxicity assay and the toxin A ELISA were highly specific for CDRED (95% and 100%, respectively). Specificities for the other procedures were much lower (tube cytotoxicity assay, 79%; culture, 74%; and toxin B ELISA, 56%). The high sensitivities of the culture (89%) and toxin B ELISA (83%) were somewhat negated by their low specificities. The only test that was both specific and had acceptable sensitivity (78%) was the microtiter cytotoxicity assay. This study indicates that ELISAs for detection of C. difficile toxins are not as reliable as the cytotoxicity assay in the laboratory diagnosis of CDRED, and that clinical correlation is essential in the evaluation of any new test for CDRED.
对随机选自提交至我们临床实验室进行艰难梭菌常规检测的113份新鲜腹泻粪便标本，同时进行了艰难梭菌培养、试管及微量滴定板细胞毒性测定，以及毒素A和毒素B的酶联免疫吸附测定（ELISA）。这些检测在诊断艰难梭菌相关性肠道疾病（CDRED）中的表现，基于对病例史进行系统回顾（对检测结果不知情）所确定的CDRED可能性的临床评估。在61名接受抗生素治疗的患者中，微量滴定板细胞毒性测定和毒素A ELISA对CDRED均具有高度特异性（分别为95%和100%）。其他检测方法的特异性则低得多（试管细胞毒性测定为79%；培养为74%；毒素B ELISA为56%）。培养（89%）和毒素B ELISA（83%）的高灵敏度在一定程度上因其低特异性而被抵消。唯一既具有特异性又具有可接受灵敏度（78%）的检测是微量滴定板细胞毒性测定。本研究表明，在CDRED的实验室诊断中，用于检测艰难梭菌毒素的ELISA不如细胞毒性测定可靠，并且在评估任何用于CDRED的新检测时，临床相关性至关重要。
