Response to the anti-tumour necrosis factor (TNF) agents and the anti-integrin-α4β7 antibody, vedolizumab, in ulcerative colitis (UC) is variable. There are few clinical predictors of long term efficacy to biological therapy apart from prior exposure to anti-TNF therapy. Identification of readily available clinical and biochemical predictors will enable better utilization of these expensive drugs. We sought to evaluate the role of clinical factors and faecal calprotectin prior to initiation of therapy in predicting steroid free remission at 1 year.Methods
The case records of all patients who commenced biological therapy for UC were examined. Baseline clinical factors including disease extent, duration, smoking status, body mass index, concurrent immunomodulatory or steroid therapy and biochemical factors including C-reactive protein and faecal calprotectin were recorded. Patients with acute severe colitis were excluded. Remission was defined as simple clinical colitis activity index of <3. A multi-variate logistic regression was performed to assess the role of baseline variables in predicting steroid free remission at 1 year.Results
A total of 150 patients commenced biological therapy during the study period (2014–2017). Eighteen patients (12%) were excluded from the final analysis (Adverse reactions, N=5, 3.3%, Surgery, N=6, 8%, and data unavailable, N=7, 4.6%). After exclusion, a total of 98 patients commenced anti-TNF therapy (37 infliximab, 14 golimumab and 12 adalimumab) and 34 commenced vedolizumab. Twenty-three (23.5%) of the anti-TNF treated and 16 (47%) of vedolizumab treated patients were in steroid free remission at 12 months. Forty-seven patients had extensive colitis and 4 patients were active smokers. A baseline calprotectin of >500 µg/g was associated with a lower probability of remission to vedolizumab (OR 0.23, 95% CI 0.05 to 0.98, P<0.047) and anti-TNF therapy (OR 0.39, 95% CI 0.14 to 1.07, P=0.067) at 12 months. None of the other clinical variables examined (BMI, disease extent, duration, concurrent immunomodulatory therapy) predicted steroid free remission at 12 months.Conclusions
A raised basal calprotectin was associated with a lower probability of steroid free clinical remission with both anti-TNF and anti-integrin biological therapy in UC. None of the other clinical variables including BMI at baseline predicted steroid free clinical remission at 1 year.