Latent tuberculosis prevalence, diagnosis and treatment in Multiple Sclerosis as a strategy for reducing infection reactivation during immunosuppressant therapy

Background: Tuberculosis is an infectious disease with a risk of reactivation in Multiple Sclerosis patients on immunosuppressant therapy. Diagnosis and treatment of Latent Tuberculosis Infection (LTBI) prevents the infection.

Objective: To diagnose and treat LTBI in Multiple Sclerosis (MS).

Methods: Cross-sectional study of the prevalence and treatment of LTBI in MS, between February 2021 and June 2023. LTBI was defined as an absence of symptoms, positive PPD or IGRA and normal chest X-ray.

Results: Of the 58 patients with MS, 17 (29.3 %) were diagnosed with LTBI, 15 with PPD > 5 mm and 2 with positive IGRA, 10 (58.8 %) female and 7 (41.1 %) male, mean age of 41.3 (SD ±13.4) years. All patients with LTBI were treated with immunomodulators or immunosuppressants: Fingolimod 5 (29.4 %), Natalizumab 5 (29.4 %), Cladribine 2 (11.8 %), Glatiramer 2 (11.8 %), Ocrelizumab 2 (11.8 %), and Interferon beta 1 (5.9 %). Steroids therapy for relapses, were used in 5/17 (93.8 %) with LTBI and 30/37 (81.1 %) without LTBI. To treat LTBI, 11 (64.7 %) received Isoniazid and 6 (35.3 %) Isoniazid plus Rifapentine. Hepatotoxicity occurred in 3 (17.6 %) with INH. There were no interruptions of ILTB treatment during the study.

Conclusion: The prevalence of LTBI was found to be high and treatment proved safe.