Table 2.

Predictive factors of response to anti-TNF-α available in clinical practice.

Patient-related factors Age (earlier age at the start of IFX was associated with better outcomes in patients with CD) Weight (weight below 82 kilograms was associated with increased rates of clinical remission in UC patients treated with ADA)

Disease-related factors ●Disease duration (shorter disease duration was associated with increased efficacy in CD patients) ●Disease severity (disease severity was associated with worse therapeutic outcomes in UC patients) ●Disease phenotype (inflammatory phenotype is a predictive factor of response to anti-TNF-α than a complicating phenotype) ●Laboratory (biological) factors ✓High baseline CRP levels are predictive of response to anti-TNF-α in CD patients ✓High baseline Hb levels are associated with better response in UC patients ✓Low serum albumin levels are negatively correlated with response to anti-TNF-α in UC patients

Treatment-related factors Early clinical response ((i.d. within 3 months from starting therapy) is a predictive factor of long-term response in patients with UC) Mucosal healing (predictive factor for better therapeutic outcomes both in CD and UC patients) Trough levels of anti-TNF-α (anti-TNF-α serum concentration is directly correlated with better therapeutic outcomes in IBD patients) ATI (sustained high levels are associated to LOR)

IFX: infliximab; CD: Crohn’s disease; UC: ulcerative colitis; ADA: adalimumab; ATI: Antibodies to IFX; IBD: inflammatory bowel diseases; LOR: Loss of Response.