Prevention of latent TB reactivation in rheumatology patients prior to anti-TNF therapy: Evaluation of a risk stratification strategy in a low prevalence area

Introduction: Anti-tumour necrosis factor (anti-TNF) therapy is associated with the risk of reactivation of Tuberculosis (TB). There is a wide variation in screening practices for latent TB infection (LTBI) prior to anti-TNF therapy, and low prevalence areas lack robust screening process. Objective: To evaluate a risk stratification strategy followed by Interferon gamma release assay (IGRA) testing for LTBI in patients prior to anti-TNF therapy in a low TB prevalence area in UK. Method: Standardised risk assessment questionnaire was used to screen 352 patients for LTBI prior to anti-TNF therapy over a 5 year period (61% had rheumatoid arthritis, 71% were on Adalimumab, F:M=1.4:1, mean age 52 (±14.4) yrs). 9Low risk9 group started anti-TNF with no further testing and were not offered chemoprophylaxis. 9At risk9 group was assessed and QuantiFERON- TB Gold In-Tube (QFT-GIT) was performed. All patients were followed up for development of active TB. Results: The study population was mainly White British (93.8%). Nine (2.6%) were diagnosed with LTBI; only one was from a high risk ethnicity. Five of them completed prophylaxis and started anti-TNF treatment. Four declined TB prophylaxis and did not wish to proceed to anti-TNF therapy. None of the 9at risk9 groups (either IGRA negative or following TB chemoprophylaxis) developed active TB. Similarly, 9low risk9 group remained disease free (average length of follow up, 30 months, SD 15.3). Conclusion: In a low TB prevalence area, initial risk assessment followed by IGRA testing seems to be effective in preventing development of active TB in patients starting anti-TNF therapy.