The special blood circulation, anatomy, and tissue structure of the spine may lead to significant differences in pathological features and drug resistance between spinal tuberculosis and pulmonary tuberculosis. Here, we collected 168 spinal tuberculosis cases and 207 pulmonary tuberculosis cases, and compared their clinical and pathological features as well as drug resistance. From the anatomical location, the highest incidence was of lumbar tuberculosis, followed by thoracic tuberculosis. PET-CT scans showed increased FDG uptake in the diseased vertebrae, discernible peripheral soft tissue shadow, visible internal capsular shadow, and an abnormal increase in FDG uptake. MRI showed infectious lesions in the diseased vertebral body, formation of paravertebral and bilateral psoas muscle abscess, and edema of surrounding soft tissues. As with control tuberculosis, the typical pathological features of spinal tuberculosis were chronic granulomatous inflammation with caseous necrosis. The incidence of granulomas was not statistically different between the groups. However, the proportions of caseous necrosis, acute inflammation, abscess, exudation, and granulation tissue formation in the spinal tuberculosis group were all significantly increased relative to the control tuberculosis group. Compared to the control tuberculosis group, the incidences of resistance to rifampicin (RFP) + isoniazid (INH) + streptomycin (STR) and INH + ethambutol (EMB) were lower in the spinal tuberculosis group, while the incidences of resistance to RFP + INH + EMB and RFP + EMB were higher. Moreover, we also found some differences in drug-resistance gene mutations. In conclusion, there are noticeable differences between spinal Mycobacterium tuberculosis and pulmonary tuberculosis in pathological characteristics, drug resistance, and drug resistance gene mutations.

Spinal tuberculosis is a common extrapulmonary type that is often secondary to pulmonary or systemic infections. Mycobacterium tuberculosis infection often leads to the balance of immune control and bacterial persistence. In this study, 64 patients were enrolled and the clinicopathological and immunological characteristics of different age groups were analyzed. Anatomically, spinal tuberculosis in each group mostly occurred in the thoracic and lumbar vertebrae. Imaging before preoperative anti-tuberculosis therapy showed that the proportion of abscesses in the older group was significantly lower than that in the younger and middle-aged groups. However, pathological examination of surgical specimens showed that the proportion of abscesses in the older group was significantly higher than that in the other groups, and there was no difference in the granulomatous inflammation, caseous necrosis, inflammatory necrosis, acute inflammation, exudation, granulation tissue formation, and fibrous tissue hyperplasia. B cell number was significantly lower in the middle-aged and older groups compared to the younger group, while the number of T cells, CD4⁺ T cells, CD8⁺ T cells, macrophages, lymphocytes, plasma cells, and NK cells did not differ. Meaningfully, we found that the proportion of IL-10 high expression and TGF-β1 positive in the older group was significantly higher than that in the younger group. TNF-α, CD66b, IFN-γ, and IL-6 expressions were not different among the three groups. In conclusion, there are some differences in imaging, pathological, and immune features of spinal tuberculosis in different age groups. The high expression of IL-10 and TGF-β1 in older patients may weaken their anti-tuberculosis immunity and treatment effectiveness.

In recent years, the incidence of tuberculosis (TB) and mortality caused by the disease have been decreasing. However, the number of drug-resistant tuberculosis patients is increasing rapidly year by year. Here, a total of 380 Mycobacterium tuberculosis (MTB)-positive formalin-fixed and paraffin-embedded tissue (FFPE) specimens diagnosed in the Department of Pathology of the Eighth Medical Center, Chinese PLA General Hospital were collected. Among 380 cases of MTB, 85 (22.37%) were susceptible to four anti-TB drugs and the remaining 295 (77.63%) were resistant to one or more drugs. The rate of MDR-TB was higher in previously treated cases (52.53%) than in new cases [(36.65%), p < 0.05]. Of previously treated cases, the rate of drug resistance was higher in females than in males (p < 0.05). Among specimens obtained from males, the rate of drug resistance was higher in new cases than in previously treated cases (p < 0.05). Of mutation in drug resistance-related genes, the majority (53/380, 13.95%) of rpoB gene carried the D516V mutation, and 13.42% (51/380) featured mutations in both the katG and inhA genes. Among the total specimens, 18.68% (71/380) carried the 88 M mutation in the rpsL gene, and the embB gene focused on the 306 M2 mutation with a mutation rate of 19.74%. Among the resistant INH, the mutation rate of −15 M was higher in resistance to more than one drug than in monodrug-resistant (p < 0.05). In conclusion, the drug resistance of MTB is still very severe and the timely detection of drug resistance is conducive to the precise treatment of TB.