Latent tuberculosis infection in patients with psoriasis using biologic therapies

Some studies have demonstrated a high prevalence of latent tuberculosis infection (LTBI) in patients with psoriasis and a higher risk of active tuberculosis (TB) in patients with severe psoriasis. The objective of this study is to identify the prevalence of LTBI before starting treatment with different biologicals and to identify the prevalence of LTBI and active TB while using these medications. We conducted a cross-sectional study with retrospective data collection in the outpatient department of dermatology at a general, tertiary care, university-affiliated hospital. The electronic medical records of all adult patients (≥18 years old) with psoriasis undergoing treatment with biologics were reviewed, and information about psoriasis, the type of biological therapy used, and the tuberculin skin test (TST) results were collected. The patients included had an indication for the TST test according to the Ministry of Health. In total, 126 patients were included in the study. The median duration of disease was 20 years. A total of 31 patients (24.6%) had LTBI diagnosed at screening before the use of biologicals, and an additional 17 (17.9%) patients had a diagnosis of LTBI during biological therapy. There were no cases of active TB during treatment with biologicals. There was no difference in the prevalence of LTBI during treatment with tumor necrosis factor inhibitors, interleukin (IL)-17 inhibitors, IL-23 inhibitors, and IL-12/23 inhibitors (p=0.228). In conclusion, we found that 24.6% of patients with psoriasis in an endemic TB region had LTBI. Additionally, 16.8% had a diagnosis of LTBI during biological therapy. Our data corroborate the recommendation that patients who live in high TB incidence settings should be tested annually for LTBI.