Treatment of Latent TB in IBD Patients Before Biologic Therapy

Anti-Tuberculosis Treatment Regimen

The European Crohn's and Colitis Organisation recommends isoniazid monotherapy as the cornerstone treatment for latent TB infection in IBD patients, with a dosing of 5 mg/kg up to 300 mg daily for 9 months 3, 2
Alternative duration of 6 months of isoniazid is acceptable but provides less protection, with a 60-80% effectiveness compared to 90% with 9 months 3
Baseline liver function tests are essential before starting isoniazid, and monitoring of transaminases at intervals is necessary to stop therapy if ALT/AST exceeds 3-fold normal with symptoms or 5-fold without symptoms 3

The European Crohn's and Colitis Organisation recommends delaying biologic therapy for at least 3-4 weeks after starting LTBI treatment, with a minimum of 4 weeks suggested in the 2021 guidelines 1, 2
In severe IBD cases requiring urgent treatment, biologics may be started earlier with specialist infectious disease consultation 1, 2

Anti-TNF agents carry the highest TB reactivation risk, with a 2.52-fold increased risk and incidence rate of 0.28 per 100 patient-years, according to the European Crohn's and Colitis Organisation 4, 1
Vedolizumab and ustekinumab have substantially lower risk, with an incidence rate of 0.02 per 100 patient-years for ustekinumab 1, 5
Combination therapy with thiopurines increases TB risk 13-fold compared to anti-TNF monotherapy, as reported by the European Crohn's and Colitis Organisation 6

The European Society of Gastrointestinal Endoscopy advises against relying solely on tuberculin skin test in immunosuppressed patients, as 83% of patients on steroids or immunomodulators show anergy to TST 4, 7

Annual re-screening should be considered for patients with ongoing TB risk factors, according to the European Crohn's and Colitis Organisation 6, 1
Infectious disease or pulmonology consultation is recommended for supervising TB therapy and determining optimal timing of biologic initiation, as suggested by the European Crohn's and Colitis Organisation 3