Incidence of latent tuberculosis in rheumatic diseases after taking immunesuppressive drugs

Tuberculosis remains a serious public health concern. Comorbidity in immunocompromised patients makes its diagnosis more difficult. The present study was conducted to assess the prevalence of positive tuberculin skin test and Chest X-ray changes in patients with rheumatologic diseases treated with immunosuppressive medications in the city of Birjand, Iran. The present prospective study was conducted in 2020 in the city of Birjand, Iran on 40 patients with rheumatologic diseases and 40 healthy people. Inclusion criteria were patients with the diagnosed rheumatic disease under treatment with immunosuppressive drugs. Exclusion criteria were active tuberculosis and changes in chest X-ray in favor of tuberculosis. Purified protein derivative solution was used to carry out a tuberculin skin test and screen both groups for latent tuberculosis and Chest X-ray to ascertain the presence or absence of the radiographic signs of old tuberculosis in the patients' group at the initiation of treatment and six months after. The collected data were recorded in a checklist and then analyzed in SPSS-22 using descriptive and statistical tests. Mean age was 47.32 ± 13.61 years in the case group and 46.40 ± 14.19 years in the control. Also, 7.5% of the case group patients taking immunosuppressive medications were tuberculin skin test positive, but no significant difference was observed between the case and control groups (P value = 0.24). In the positive tuberculin skin test group, 66.6% had spondyloarthritis of whom, 100% were taking Cinnora (Adalimumab). The emergence of latent tuberculosis in rheumatic patients after taking immunosuppressive medications is likely, and clinicians should be aware of its risk.