S1498 Prevalence and Outcomes of Active and Latent Tuberculosis Among Patients With Inflammatory Bowel Disease (IBD) in an Endemic Region

Introduction: Screening for tuberculosis infection (TBI) is recommended for patients with inflammatory bowel disease (IBD) prior to commencement of advanced therapies. The rate of TBI is variable by geographic location and data regarding TBI management in IBD is sparse. We aimed to evaluate the prevalence, risk factors and outcomes of TBI among IBD patients in an endemic region. Methods: This is a retrospective study from 1/1/2011-1/1/2024 of patients aged ≥14 years with a confirmed diagnosis of IBD at King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. We included patients with at least on resulted interferon-γ release assay (IGRA) (QuantiFERON-TB Gold). Latent TBI (LTBI) was defined as a positive IGRA test with absence clinical or radiographic signs of active TBI. The primary outcome was the rate of negative, indeterminate, and positive IGRA. Secondary outcomes included predictors and outcomes of active and LTBI. Results: A total of 424 patients with IBD (58.7% male; 81.1% Crohn’s disease; 17.2% ulcerative colitis) with a median age of 28 years [interquartile range (IQR) 22-38] were included. IGRA test was negative in 91.5% (n=388), positive in 3.5% (n=15) and indeterminate in 4.9% (n=21). LTBI was diagnosed in 3.8% (n=16; 4 with indeterminate IGRA) and active TBI in 0.9% (n=4; 1 with negative IGRA). Active and LTBI patients were more likely to have extraintestinal manifestations (35%, n=7) compared to those with negative TBI (12.1%; n=49) (P =0.003) (Table 1). Baseline IBD therapy in the active TBI included infliximab (IFX) plus azathioprine (AZA) (n=1), adalimumab (ADA) monotherapy (n=2) and ADA plus AZA (n=1). Anti-tumour necrosis factor (TNF) therapy was resumed in 3 patients while 1 patient was switched from ADA to IFX without recurrence of TBI after a median follow up of 58.5 months (IQR 28.3-74.8). In the LTBI group, 43.8% were on anti-TNF (IFX = 5, ADA = 2), 12.5% on vedolizumab, 6.3% on ustekinumab, 6.3% on guselkumab, and 12.5% on upadacitinib. Two patients were treated with mesalamine monotherapy and 1 with AZA. LTBI therapy was completed in 75% (n=12). IBD advanced therapies were held and continued after starting LTBI therapy without reactivation of TBI after a median follow up of 38 months (IQR: 11-67). Conclusion: In a TB endemic region and among patients with IBD, LTBI was noted in almost 4% and active TBI in 1%. Temporarily holding IBD advanced therapies including anti-TNF agents did not result in TBI reactivation. Table 1. - Characteristics of inflammatory bowel disease patients with active/latent tuberculosis infection vs no tuberculosis infection Characteristics Active/Latent TBI(n=20) Negative TBI(n=404) P-value Male, n (%) 14 (70.0) 235 (58.2) 0.29 Age, median (IQR) 33 (23-48.8) 28 (22-37) 0.12 Disease duration in years, median (IQR) 5.5 (1-10.8) 7 (2-12) 0.57 Smoking, n (%) 4 (20.0) 47 (11.6) 0.26 Previous surgery, n (%) 7 (35.0) 193 (47.8) 0.26 Disease subtype, n (%) 0.75 Crohn’s disease 15 (75.0) 329 (81.4) Ulcerative colitis 5 (25.0) 68 (16.9) IBD-U 0 3 (0.7) Pouchitis 0 4 (1) Perianal Crohn’s disease, n (%) 6 (40.0) 135 (40.9) 0.94 Extraintestinal Manifestations, n (%) 7 (35.0) 49 (12.1) 0.003 Labs Median CRP mg/L (IQR) 18.4 (3.2-46.7) 6.4 (2.3-29.8) 0.10 Median Albumin g/L (IQR) 40.8 (27-42.7) 42 (36.6-45) 0.09 Medications Immunomodulators, n (%) 8 (40.0) 155 (38.4) 0.88 Advanced Therapies, n (%) 17 (85.0) 351 (86.9) 0.81 Corticosteroids, n (%) 3 (15.0) 39 (9.7) 0.43 TBI: Tuberculosis infection; IQR: interquartile range; IBD-U: inflammatory bowel disease-unclassified; CRP: C-reactive protein.