A Comparative Study on the Role of Xpert MTB/RIF in Testing Different Types of Spinal Tuberculosis Tissue Specimens.

AIMS: The aim of the present study was to compare the efficacy of the commercial Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) test for evaluating different types of spinal tuberculosis (TB) tissue specimens. METHODS: Pus, granulation tissue, and caseous necrotic tissue specimens from 223 patients who were diagnosed with spinal TB and who underwent curettage were collected for bacterial culture and the Xpert MTB/RIF assay to calculate the positive rate. Bacterial culture and phenotypic drug sensitivity testing (pDST) were adopted as the gold standards to calculate the sensitivity and specificity of the Xpert bacterial detection and drug resistance (DR) test. RESULTS: The positive rate (68.61% ± 7.35%) from the Xpert MTB/RIF assays of spinal TB patients' tissue specimens was higher compared with bacterial culture (44.39% ± 6.51%, Z = 5.1642, p < 0.01), and the positive rates from Xpert MTB/RIF assays on the three types of specimens were all higher than those of bacterial culture, with statistically significant results for pus and granulation tissue specimens. The positive rates for pus using the two bacteriological tests were higher than those for granulation tissue but were not statistically significant. However, the positive rates obtained from granulation tissue were statistically significantly higher than those obtained from caseous necrotic tissue. With bacterial culture and pDST as the gold standards, the sensitivity of Xpert MTB/RIF assays for MTB was 96.97%, while the sensitivity and specificity of the DR test also remained relatively high. CONCLUSION: For efficient and accurate diagnosis of spinal TB and DR and timely provision of effective treatment, multiple specimens, especially the pus of spinal TB patients, should be collected for Xpert MTB/RIF assays.

Study on the relationship between vitamin D deficiency and susceptibility to spinal tuberculosis.

OBJECTIVE: To investigate the effect of vitamin D deficiency on susceptibility to spinal tuberculosis and its pathological development. METHODS: A case-control design was used in this study. A total of 163 treatment-naïve patients with spinal tuberculosis admitted to this institute for an operation from June 2013 to May 2016 were included in the case group, and 170 subjects who received a health examination in the same hospital were included in the control group. Control group patients were frequency-matched with the case group by age, gender, and season. Serum 25-hydroxyvitamin D levels were detected using an enzyme linked immunosorbent assay (ELISA). Pathological classification of patients in the case group was conducted according to intraoperative findings, and definite diagnosis of spinal tuberculosis was confirmed after operation. RESULTS: The serum level of vitamin D [23.99 (20.55, 29.54) nmol/L] in the case group was lower than that in the control group [42.94 (35.68, 51.04) nmol/L], and the difference was statistically significant (Z = -9.048, P < 0.05). Out of the 163 patients with spinal tuberculosis who underwent pathological classification, 107 cases of caseous necrosis and 56 cases of hyperplasia were identified. Based on the vitamin D levels of the patients in the case group, these patients were further divided into a low-level group (<25 nmol/L) and a high-level group (≥25 nmol/L). The proportion of patients with caseous necrosis in the low-level group (79.17%) was higher than that in the high-level group (46.27%), with a statistically significant difference (χ2 = 18.937, P < 0.05). CONCLUSION: Vitamin D deficiency is associated with susceptibility to spinal tuberculosis and its pathological classification, and vitamin D deficiency affects the occurrence and development of spinal tuberculosis.