Active Pulmonary Tuberculosis During Interferon Beta-1a Therapy in a Child with Multiple Sclerosis: A Case Report

Interferon (IFN) beta (β) is a potent anti-inflammatory and immunomodulatory agent that is used for treating patients with multiple sclerosis (MS). In this study, we present the case of a 15-year-old female patient diagnosed with MS and treated with IFN β-1a for six months who was referred to the emergency department with complaints of fatigue, fever, and coughing. She was diagnosed with pulmonary tuberculosis (TB). IFN β-1a therapy was stopped and anti-TB treatment was initiated. After nine months of therapy, she recovered from TB. This case presented with a rare side effect during the treatment of pediatric-onset MS with immunomodulatory drugs, demonstrating the importance of screening and close follow-up of patients with TB.