Interleukin-17A Inhibitors in Patients with Psoriasis and Tuberculosis Infection: A 2-Year Prospective Study on Safety Without Preventive Treatment

Introduction: The necessity for tuberculosis preventive treatment (TPT) and routine T-SPOT.TB monitoring in patients with psoriasis and tuberculosis infection (TBI) undergoing interleukin (IL)-17A inhibitor therapy remains uncertain. This study aims to evaluate the long-term safety of IL-17A inhibitors administered without TPT and analyze changes in T-SPOT.TB among these patients. It also identifies risk factors for TBI in patients with psoriasis.

Methods: This single-center prospective study enrolled adult patients with plaque psoriasis and TBI receiving IL-17A inhibitors. TBI was defined as positive T-SPOT.TB results (≥ 6 spots) without symptoms or evidence of active tuberculosis (ATB). TPT administration was based on contraindications, tuberculosis risk factors, and patient preferences. The primary endpoint was the incidence of ATB over 2 years. Secondary outcomes included T-SPOT.TB changes and TBI risk factors.

Results: Of the 129 patients with psoriasis and TBI enrolled in the study, 97 (75.2%) did not receive TPT, while 32 (24.8%) did. Among them, 109 patients (84.5%) completed the 2-year follow-up. During the 235 person-years of observation, no ATB cases were identified. Median T-SPOT.TB values showed no significant changes from baseline to year 2 in both the non-TPT (20 vs. 17 spots, p = 0.975) and TPT groups (55 vs. 58 spots, p = 0.830). T-SPOT.TB reversed in 14 patients (12.8%), mostly in the non-TPT group. Moreover, for TBI risk factor analysis, a cohort of 212 patients with psoriasis with negative baseline T-SPOT.TB was evaluated, revealing a TBI prevalence of 37.8%. Logistic regression analysis highlighted age ≥ 45 years (odds ratio [OR] 2.44, 95% confidence interval [CI] 1.50-3.99, p < 0.001) and body mass index (BMI) < 24.0 kg/m² (OR 2.12, 95% CI 1.27-3.54, p = 0.004) as independent risk factors for TBI.

Conclusion: IL-17A inhibitors do not appear to reactivate tuberculosis in patients with psoriasis and TBI, potentially reducing the need for routine TBI screening and preventive treatment.

Trial registration: Chinese Clinical Trial Registry, ChiCTR2100045823.