Performance of conventional histopathology and GeneXpert MTB/RIF in the diagnosis of spinal tuberculosis from bone specimens: A prospective clinical study.

OBJECTIVE

Xpert MTB/RIF is recommended to detect pulmonary tuberculosis; however, there is insufficient data on its utility for bone samples. This study aimed to assess the accuracy of Xpert MTB/RIF compared with conventional histopathology in diagnosing spinal tuberculosis (STB) based on bone specimens in high burden settings.

MATERIALS AND METHODS

Totally, 128 suspected STB participants were enrolled into this study. The bone specimens were obtained through puncture or operation for histological and Xpert MTB/RIF analyses, so as to compare their accuracy in diagnosing STB by the composite reference standard (CRS).

RESULTS

Finally, 106 subjects with suspected STB were recruited into the analysis, including 27 confirmed and 33 clinically diagnosed STB patients. Relative to histopathology, Xpert MTB/RIF achieved a 86.7% sensitivity, and 12 out of 30 STB patients were positive, while the negative results in them were obtained upon histopathology. Based on CRS, Xpert MTB/RIF yielded a 63.3% sensitivity, which significantly elevated relative to that obtained upon histopathological test (50.0%, p < 0.001). In addition, the pooled sensitivity obtained using the above 2 approaches was as high as 95.0%, which was higher than that of any of the 2 approaches alone. The pooled specificity was 97.8%. Moreover, the area under the curve (AUC) value was 0.75 for Xpert MTB/RIF and 0.81 for histopathology, with no statistical significance. The two methods showed moderate concordance in the diagnosis of STB.

CONCLUSIONS

The Xpert MTB/RIF test achieves superior specificity and fair sensitivity, which can not be recommended to replace the conventional examinations for the diagnosis of STB. The combined application of these 2 approaches can improve the pooled diagnostic sensitivity and accuracy for STB.