Abstract:

Objective To investigate the value of GeneXpert MTB/RIF (GeneXpert) and line probe assay for rapid diagnosis of osteoarticular tuberculosis and detection of rifampicin resistance. Methods A total of 172 suspected osteoarticular tuberculosis patients who received focal cleaning or paracentesis between March to December 2018 were selected. GeneXpert, line probe assay and BACTEC MGIT 960 mycobacterial culture were used to test the samples. Using clinical comprehensive diagnosis as the reference standard, the efficacy of GeneXpert, linear probe assay and combination of the two methods in diagnosis of osteoarticular tuberculosis were evaluated. Using mycobacterial culture drug sensitivity test as the reference standard, the efficacy of GeneXpert, linear probe assay and combination of the two methods in detecting rifampicin resistance were evaluated. Results According to the clinical comprehensive diagnosis of the 172 suspected osteoarticular tuberculosis patients, 112 were diagnosed with osteoarticular tuberculosis, whereas 60 were non-tuberculosis. Using clinical comprehensive diagnosis as the reference standard, the sensitivity and specificity of GeneXpert were 82.14% (92/112) and 96.67% (58/60). The results of GeneXpert was consistent with that of clinical comprehensive diagnosis (Kappa=0.74). The sensitivity and specificity of line probe assay were 69.64% (78/112) and 90.00% (54/60). The consistency with clinical comprehensive diagnosis was not good (Kappa=0.54). The sensitivity and specificity of combination of the two methods were 82.14% (92/112) and 90.00% (54/60). The combination method had good consistency with clinical comprehensive diagnosis (Kappa=0.68).The area under the receiver operating characteristic (ROC) curve of GeneXpert, line probe assay and combination of the two methods were 0.89, 0.80 and 0.86, respectively, indicating good diagnosis performance. Using mycobacterial culture drug sensitivity test as the reference standard, the sensitivity and specificity of GeneXpert in inspection to rifampicin resistance were 100.00% (18/18) and 92.31% (24/26), the results was highly consistent (Kappa=0.91), and the area under the ROC curve was 0.96. The sensitivity and specificity of line probe assay in inspection to rifampicin resistance were 100.00% (18/18) and 88.46% (23/26), the results was highly consistent (Kappa=0.86), and the area under the ROC curve was 0.94. The results of combination of the two methods was consistent with that of the linear probe assay. Conclusion GeneXpert and line probe assay can rapidly and accurately diagnose osteoarticular tuberculosis and detect rifampicin resistance, having good clinical application value.

Key words: Tuberculosis, osteoarticular, Microbial sensitivity tests, Molecular probe techniques, Nucleic acid amplification techniques, Evaluation studies