The proportion of tuberculosis disease among adult patients receiving biologic agents at a tertiary centre in Kenya

Objectives Tuberculosis (TB) remains a major global health challenge. Kenya is a high-TB burden country, with a prevalence of 558 cases per 100,000 adults according to the 2016 Kenya Tuberculosis Prevalence Survey. Biologic agents have been linked to an increased risk of TB infection due to their immunosuppressive effects. However, data on TB occurrence among patients receiving biologic agents in Kenya are lacking. This study aimed to determine the proportion of TB disease among adult patients receiving biologic agents at a tertiary centre in Kenya. Methods A retrospective cohort study of adult patients receiving biologic agents at Aga Khan University Hospital, Nairobi, between January 2018 and December 2023 was conducted. Data were extracted from the medical records of eligible patients using an abstraction tool, and statistical analysis was performed. Results A total of 204 patients were included. The median age was 45.8 years (IQR, 36.3-60.1), and 59.3% were female. Rheumatologic disorders were the most common indication for biologic therapy, followed by malignancies and neuroinflammatory disorders. Anti-CD20 agents, predominantly rituximab, accounted for 71.6% of biologic use. Only 69.1% of patients had pretreatment TB infection screening. Three patients (1.5%) developed TB disease, all while receiving rituximab. Conclusions All TB disease cases occurred during rituximab therapy, contrary to evidence emphasising a higher risk with anti-tumour necrosis factor alpha agents, highlighting the importance of systematic TB screening and monitoring across all biologic therapies in TB-endemic settings.