Biologic-Induced Infections in Inflammatory Bowel Disease: The TNF-α Antagonists

Objective: To review the mechanism and association of infectious risk among the tumor-necrosis factor α (TNF-α) antagonists used in inflammatory bowel disease. Data Sources: A PubMed literature search was performed using the following search terms: infliximab, adalimumab, certolizumab, golimumab, inflammatory bowel disease, crohn’s, ulcerative colitis, adverse effects, adverse events, safety, and infection. Study Selection and Data Extraction: Meta-analyses and cohort studies with outcomes pertaining to quantitative infectious risk were reviewed. Case reports and case series describing association between TNF-α inhibitors and infection were also reviewed. Data Synthesis: A total of 7 recent meta-analyses of randomized trials demonstrate inconclusive association of infection with TNF-α antagonists. Registry data suggest that medications carry an independent risk of opportunistic infections. Risk factors for infection include older age, malnutrition, diabetes, and possibly combination therapy. Reported infections vary widely but include intracellular and granulomatous bacteria, viruses, and fungi. Conclusion: TNF-α antagonists are associated with an increased risk of opportunistic infection, although this risk has not been demonstrated conclusively in randomized controlled trials. Knowledge of concomitant risk factors, mechanism of infectious risk, and available treatment options can improve patient care in the clinical setting.