Systemic vasculitis with latent tuberculosis infection and associated factors: a cross-sectional multicenter study

Systemic vasculitis patients are at a higher risk of developing latent tuberculosis infection (LTBI). However, there is currently no literature elucidating the positivity rate and risk factors for LTBI in systemic vasculitis patients.

Our study is a multi-center, cross-sectional study that enrolled systemic vasculitis patients from 13 comprehensive hospitals in China. T-SPOT.TB as the screening method for LTBI, the study investigated the positivity rate of LTBI in systemic vasculitis patients and the factors associated with T-SPOT.TB results.

A total of 191 systemic vasculitis patients were included and the positive rate of T-SPOT.TB was 31.4%. The highest T-SPOT.TB positivity rate was observed in Behçet's syndrome (BD) (72/191, 37.7%). There were statistically significant differences between the LTBI group and non-LTBI group in terms of systemic vasculitis type (P = 0.010), albumin levels (P = 0.034), erythrocyte sedimentation rate (P = 0.016), and corticosteroid dosage (P = 0.047). Multivariate regression analysis revealed that smoking history (aOR = 3.809, 95%CI: 1.341-10.817) and BD (aOR = 2.106, 95%CI: 1.042-4.254) were independent risk factors of T-SPOT.TB postive results, besides decreased lymphocyte count (aOR = 0.114, 95%CI: 0.013-0.973), and high-dose glucocorticoids use (aOR = 0.386, 95%CI: 0.149-1.003) were independent risk factors of T-SPOT.TB negative results.

The prevalence of LTBI is high in systemic vasculitis patients, especially those with BD or smoking history. Patients with decreased lymphocyte counts and high-dose glucocorticoid use are more likely to have a negative T-SPOT.TB results. Therefore, LTBI screening should be performed based on the characteristics of the patient during the diagnosis and treatment of systemic vasculitis. Key Points • We explored the positivity rate and risk factors of LTBI in systemic vasculitis patients from 13 hospitals in China. • There were 191 systemic vasculitis patients in our study. The positive rate of T-SPOT.TB was 31.4%. The predominant type of systemic vasculitis was BD, with a T-SPOT.TB positive rate of 44.4%. The second type was TA, with a T-SPOT.TB positive rate of 25.0%. • The prevalence of LTBI is high in systemic vasculitis patients, especially those with Behçet's syndrome or smoking history. Decreased lymphocyte counts and high-dose glucocorticoid use are more likely to have a negative T-SPOT.TB results. • LTBI screening using T-SPOT.TB should be conducted during the diagnosis and treatment of systemic vasculitis.