TITLE:
Performance of Loop-Mediated Isothermal Amplification (LAMP)-Lateral Flow Detection and Xpert MTB/RIF Ultra for Diagnosis of Pulmonary Tuberculosis
AUTHORS:
Siripan Kounmee, Uraporn Phumisantiphong, Yutthana Apichatbutr
KEYWORDS:
LAMP-LFD Assay (TB d-Tect), Xpert MTB/RIF Ultra, Pulmonary TB
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.9 No.4,
November
10,
2021
ABSTRACT: Background: Due to the limitations of diagnosis by Xpert MTB/RIF assay, WHO suggests
Loop—Mediated Isothermal Amplification (TB-LAMP) instead of sputum-smear
microscopy for pulmonary TB diagnosis in patients. Dr. Thongchai Kaewphinit et al. invented a fast TB detection kit called TB d-tect (LAMP-LFD
assay). There was no clinical trial to estimate the performance of TB d-tect. Objective: This study was aimed to find the performance of LFD assay and Xpert MTB/RIF
ultra for pulmonary TB. Material and methods: A
cross-sectional study was conducted. Suggestive pulmonary TB patients were
enrolled from June 2020-28 February 2021. Respiratory
specimens were collected from each patient and sent for AFB smear, LAMP-LFD assay,
Xpert MTB/RIF ultra and culture TB. Result: 139 patients with suspected
pulmonary TB were enrolled. 51% of patients were diagnosed with pulmonary tuberculosis. Based on
culture TB as a gold standard, the sensitivity and specificity of LAMP-LFD
assay were 85.4% (95% CI: 70.8% - 94.4%) and 87.8% (95% CI: 79.6 -
93.5), respectively. The sensitivity and specificity of Xpert MTB/RIF ultra
were 95.1% (95% CI: 83.5% - 99.4%) and 74.5% (95% CI: 64.7 - 82.8),
respectively. According to ROC curve, it was found that the areas under the
curve of LAMP-LFD assay and Xpert MTB/RIF ultra were 0.866 and 0.848,
respectively (p = 0.546). Conclusion:
The diagnostic sensitivity and specificity of LAMP-LFD assay appeared to be
comparable to those of Xpert MTB/RIF ultra. LAMP-LFD assay could be used in
resource limiting laboratory.