Lee Scott D, Turgeon David K, Ko Cynthia W, Fritsche Thomas R, Surawicz Christina M
Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
Am J Gastroenterol. 2003 Jul;98(7):1569-72. doi: 10.1111/j.1572-0241.2003.07482.x.
The aim of the present study was to assess the correlation of Triage Micro Clostridium difficile Panel and toxin B cytotoxicity assay with the clinical diagnosis of C. difficile diarrhea.
The subjects evaluated were 98 patients with diarrhea for whom stool was submitted for testing for C. difficile. Clinical symptoms prompting evaluation, laboratory values, comorbid illness, and treatment outcomes that provided clinical insight into the etiology of the diarrhea were recorded. These data were then reviewed by two experienced clinical gastroenterologists who were blinded to the results of the Triage enzyme immunoassay and cytotoxin B assay. The final diagnosis of C. difficile diarrhea was based on the patient's clinical evaluation and symptoms, treatment, and subsequent outcome.
Of 98 patients evaluated, 33 were diagnosed with C. difficile diarrhea by clinical criteria. The toxin B assay displayed 88% sensitivity and 100% specificity and positive predictive value. The toxin A component of the Triage Panel displayed 45% sensitivity but 98% specificity and 94% positive predictive value. The common antigen had 97% sensitivity and 95% negative predictive value. Among the 45 patients with only a common antigen detected, the most common diagnoses for diarrhea were chemotherapy-related, antibiotic-related diarrhea, and graft versus host disease.
Our data show that both the Triage Micro C. difficile Panel and cytotoxin B for C. difficile have a high positive predictive value and negative predictive value for C. difficile diarrhea. The Triage Micro C. difficile Panel provides a reasonable alternative to the cytotoxin B assay in the assessment of clinically relevant C. difficile. The Triage Micro C. difficile Panel is less labor intensive and less expensive than cytotoxin B assay. The panel approach improves on the individual assay performances by increasing sensitivity and negative predictive value. When both common antigen and toxin A are positive, the likelihood of C. difficile diarrhea is high; conversely, when both results are negative, the likelihood of C. difficile diarrhea is low.
本研究旨在评估艰难梭菌分诊微板检测法和毒素B细胞毒性测定与艰难梭菌腹泻临床诊断之间的相关性。
评估对象为98例腹泻患者，其粪便被送检以检测艰难梭菌。记录促使进行评估的临床症状、实验室检查值、合并症以及能为腹泻病因提供临床见解的治疗结果。然后由两位经验丰富的临床胃肠病学家对这些数据进行回顾，他们对分诊酶免疫测定和细胞毒素B测定的结果不知情。艰难梭菌腹泻的最终诊断基于患者的临床评估、症状、治疗及后续结果。
在98例接受评估的患者中，33例根据临床标准被诊断为艰难梭菌腹泻。毒素B测定显示出88%的敏感性、100%的特异性和阳性预测值。分诊微板检测法的毒素A成分显示出45%的敏感性，但特异性为98%，阳性预测值为94%。共同抗原的敏感性为97%，阴性预测值为95%。在仅检测到共同抗原的45例患者中，腹泻最常见的诊断为化疗相关、抗生素相关性腹泻和移植物抗宿主病。
我们的数据表明，艰难梭菌分诊微板检测法和艰难梭菌细胞毒素B检测法对艰难梭菌腹泻均具有较高的阳性预测值和阴性预测值。在评估临床相关的艰难梭菌时，艰难梭菌分诊微板检测法为细胞毒素B检测提供了合理的替代方法。艰难梭菌分诊微板检测法比细胞毒素B检测法劳动强度更低且成本更低。该微板检测法通过提高敏感性和阴性预测值，改进了单个检测方法的性能。当共同抗原和毒素A均为阳性时，艰难梭菌腹泻的可能性很高；相反，当两者结果均为阴性时，艰难梭菌腹泻的可能性很低。
