Young Seok Lee1, Hye-Rim Kang2, Si-Hyeong Lee2, Yunmi Kim2, Mi-Yeong Kim2, Jeong Hwan Shin3, Jae Young Moon4, Hyun-Kyung Lee2, So Young Park5, Eun-Kyung Mo5, Yong Bum Park5, Soo-Yoon Moon5, Minkyung Oh6, Yousang Ko2,5. 1. a Division of Pulmonology, Department of Internal Medicine , Institute of Chest Disease, Severance Hospital, Yonsei University College of Medicine , Seoul ; 2. b Division of Pulmonary Allergy and Critical Care Medicine, Department of Internal Medicine , Busan Paik Hospital, Inje University College of Medicine , Busan ; 3. c Department Laboratory Medicine , Busan Paik Hospital, Inje University College of Medicine , Busan ; 4. d Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine , Chungnam National University Hospital , Daejeon ; 5. e Department of Pulmonary and Critical Care Medicine , Hallym University Kangdong Sacred Heart Hospital , Seoul ; 6. f Department of Pharmacology and Clinical Trial Center , Inje University Busan Paik Hospital , Busan , Republic of Korea.
Abstract
BACKGROUND: The aim of this study was to evaluate the diagnostic accuracy of the GenoType MTBDRplus assay in detecting drug-resistant tuberculosis (DR-TB) by using acid-fast bacilli (AFB) smear-negative specimens with positive TB-PCR results. METHODS: The MTBDRplus assay was performed with 2 different categories of 117 samples, including AFB smear-positive specimens (n = 53) and AFB smear-negative specimens (n =64), which exhibited positive TB-PCR results, at a single institution. The results were retrospectively compared with the results of the phenotypic drug susceptibility test (DST), for reference. RESULTS: A total of 105 tests were finally analyzed. Of these, 54 tests were conducted using AFB smear-negative specimens with positive TB-PCR results. The MTBDRplus assay for these 54 samples demonstrated a sensitivity of 100%, specificity of 98%, positive predictive value (PPV) of 75%, and negative predictive value (NPV) of 100% in detecting rifampicin resistance. With these same species, the sensitivity, specificity, PPV, and NPV values for the MTBDRplus assay were 83.3%, 97.9%, 83.3%, and 97.9%, respectively, for the detection of isoniazid resistance. The overall correlation between the MTBDRplus assay and phenotypic DST demonstrated excellent agreement for detection of rifampicin resistance (κ = 0.847) and for detection of INH resistance (κ = 0.812), respectively. CONCLUSIONS: The MTBDRplus assay can be used effectively even on AFB smear-negative specimens from TB patients, when the TB-PCR is positive. This result might help clinicians to manage patients with suspected DR-TB in difficult situations.
BACKGROUND: The aim of this study was to evaluate the diagnostic accuracy of the GenoType MTBDRplus assay in detecting drug-resistant tuberculosis (DR-TB) by using acid-fast bacilli (AFB) smear-negative specimens with positive TB-PCR results. METHODS: The MTBDRplus assay was performed with 2 different categories of 117 samples, including AFB smear-positive specimens (n = 53) and AFB smear-negative specimens (n =64), which exhibited positive TB-PCR results, at a single institution. The results were retrospectively compared with the results of the phenotypic drug susceptibility test (DST), for reference. RESULTS: A total of 105 tests were finally analyzed. Of these, 54 tests were conducted using AFB smear-negative specimens with positive TB-PCR results. The MTBDRplus assay for these 54 samples demonstrated a sensitivity of 100%, specificity of 98%, positive predictive value (PPV) of 75%, and negative predictive value (NPV) of 100% in detecting rifampicin resistance. With these same species, the sensitivity, specificity, PPV, and NPV values for the MTBDRplus assay were 83.3%, 97.9%, 83.3%, and 97.9%, respectively, for the detection of isoniazid resistance. The overall correlation between the MTBDRplus assay and phenotypic DST demonstrated excellent agreement for detection of rifampicin resistance (κ = 0.847) and for detection of INH resistance (κ = 0.812), respectively. CONCLUSIONS: The MTBDRplus assay can be used effectively even on AFB smear-negative specimens from TB patients, when the TB-PCR is positive. This result might help clinicians to manage patients with suspected DR-TB in difficult situations.
Authors: Thales Alves Campelo; Paulo Rafael Cardoso de Sousa; Lucas de Lima Nogueira; Cristiane Cunha Frota; Paulo Renato Zuquim Antas Journal: Access Microbiol Date: 2021-08-02