比較兩種分生法用於快速診斷結核病

Comparison of Two Molecular Methods for Rapid Diagnosis of Tuberculosi

結核病仍是全球盛行的傳染病且已成為台灣嚴重的公衛問題。本研究的目地即是評估利用real-time PCR的COBAS assay （Roche COBAS TaqMan MTB Test）及運用cross-priming amplification技術的 MP assay （MP FASTSURE TB DNA Rapid Test）兩者對於鑑定結核菌的臨床表現。我們將2011年1 月至12月這段期間收集的210個檢體分別操作上述兩種方法並將結果與傳統生化試驗鑑定結果相 比較。MP assay對於144個臨床檢體的敏感性、特異性、陽性（陰性）預測值分別為92.75, 98.67, 98.46 及93.67%。COBAS assay的結果則為91.30, 89.33, 100及93.06%。而且，MP assay對於50個BACTEC MGIT 960培養陽性檢體的敏感性、特異性、陽性（陰性）預測值得到令人滿意的結果（分別為100, 100, 100及100%）。COBAS assay的結果則為100, 52.94, 100及100%。此外，MP assay對於16個L-J培養 陽性檢體的敏感性、特異性、陽性（陰性）預測值亦得到令人滿意的結果（分別為100, 100, 100及 100%）。COBAS assay的結果則為50, 16.67, 100及100%。MP assay對於210個各類別檢體的敏感性 及特異性為95.28%及99.04%。COBAS assay的結果則為92.45%及75%。我們的結果亦顯示MP assay既便宜又省時，適合應用於臨床鑑定結核菌。

Tuberculosis remains a global prevalent infectious disease and a serious public-health problem in Taiwan. This study was purposed to evaluate the performance of identifying Mycobacterium tuberculosis complex (MTBC) by following two methods: Roche COBAS TaqMan MTB Test (COBAS assay) which is a real-time PCR-based kit, and MP FASTSURE TB DNA Rapid Test (MP assay) which uses the cross-priming amplification technology for the qualitative detection of MTBC DNA. We collect 210 clinical samples to assess the performance of these two methods between January and December 2011. The results obtained were compared with those from conventional methods. The sensitivity, specificity, and positive/negative predictive values (PPV/NPV) of MP assay for 144 routine clinical specimens were 92.75%, 98.67%, 98.46%, and 93.67%, respectively; and those were 91.30%, 89.33%, 100%, 93.06% for COBAS assay. The sensitivity, specificity, PPV and NPV of MP assay for 50 positive BACTEC MGIT 960 cultures give satisfying outcomes (100%, 100%, 100% and 100%, respectively) ; and those were 100%, 52.94%, 100%, 100% for COBAS assay. Furthermore, the sensitivity, specificity, PPV and NPV of MP assay for 16 positive Löwenstein-Jensen cultures give satisfying outcomes (100%, 100%, 100% and 100%, respectively) ; and those were 50%, 16.67%, 100%, 100% for COBAS assay. Finally, the sensitivity and specificity of MP assay for total 210 samples were 95.28% and 99.04%, respectively; and those were 92.45%, 75% for COBAS assay. Nevertheless, results also indicate that both working time and cost required for MP assay were more effective than COBAS assay. MP assay could be considered as an alternative to currently available identification methods.