Abstract:

Objective Patients with rheumatoid arthritis（RA）are immunocompromised and prone to latent tuberculosis infection（LTBI）. The diagnosis and treatment of LTBI are the key to eliminate TB. This study aims to investigate the risk factors of LTBI in patients with RA and provide the basis for clinical anti⁃tuberculosis prevention and treatment. Methods A total of 165 cases of RA with active tuberculosis were investigated retro⁃ spectively，including 59 cases in LTBI group and 106 cases in control group. Clinical data were collected，includ⁃ ing age，sex，disease duration，immunosuppressive therapy，smoking history，and laboratory routine parameters， and univariate and binary logistic regression were used to analyze the factors affecting LTBI in RA patients. Results Among 165 RA patients，the incidence of LTBI was higher in patients aged > 40 years（41.9%）than in patients aged ≤ 40 years（25.0%）. Complement C3，C4 levels，and monocyte count in the LTBI group were higher than those in the control group，and the differences were statistically significant（P < 0.05）；Among 165 RA patients，only 80 patients were tested for lymphocyte immune function，and CD4+ /CD8+ and NK cell counts in the LTBI group were significantly higher than those in the control group（P < 0.05）. Binary logistic regression analysis showed that complement C4，age（> 40 years），and monocyte count had a statistically significant effect on the probability of LTBI in patients with RA（P < 0.05）. Conclusion Complement C4 level，monocyte count and age （> 40 years）are independent risk factors of LTBI in RA patients. The older the age（> 40 years），the higher the complement C4 and monocyte count，the greater the risk of lLTBI.

Key words:

rheumatoid arthritis, latent tuberculosis infection, tuberculosis interferon?gamma release assay, multivariate analysis