P478 Vitamin D status and response to anti-tumor necrosis factor-alpha therapy in inflammatory bowel disease
N.F. Bak*1, S. Hald1, M.B. Rasch1, A. Dige2, J.S. Agnholt1, J.F. Dahlerup1
1Aarhus University Hospital, Department of Hepatology and Gastroenterology, Aarhus, Denmark, 2Regional Hospital Horsens, Department of Medicine, Horsens, Denmark
Vitamin D has immune modulating potential in inflammatory bowel disease (IBD) and might have a synergistic effect on anti-tumor necrosis factor- α (anti-TNF α ) therapy. We wanted to investigate whether pre-treatment P-25-hydroxyvitamin D (25-vitD) levels affect IBD-patients' response to anti-TNF α therapy.
We performed a retrospective, single-centre study on all IBD-patients receiving anti-TNF α therapy from 2011 to 2014. Seventy-eight patients were included (57 with Crohn's disease (CD), 21 with ulcerative colitis). We collected patients' 25-vitD status, clinical scores (Harvey Bradshaw Index (HBI), Simple Clinical Colitis Activity Index and Short Health Scale (SH)) and inflammatory markers prior to and 6, 14, 22 and 52 weeks after treatment initiation. Patients were categorised according to their 25-vitD status as either insufficient (25-vitD < 50 nmol/L) ("D-low") or sufficient (25-vitD > 50 nmol/L) ("D-normal"). Data were analysed using a mixed model.
At baseline, D-low patients (n = 15) had more active disease than D-normal patients (n = 63) estimated by CRP (4.1 times higher, 95% CI: 2.0 - 8.1 (p < 0.001)), albumin (0.91 times lower, 95% CI: 0.86 - 0.98 (p < 0.05)) and HBI for CD patients (3 points higher, 95% CI: 0.6 - 5.4 (p < 0.05)) (figure 1). At this point, SCCAI, SH, haemoglobin and f-calprotectin did not differ significantly between the two groups. Initially, both groups responded equally to anti-TNF α treatment, but after 14 weeks the D-low group had higher CRP and f-calprotectin levels than did the D-normal group (3.1 times higher, 95% CI: 1.4 - 7.1 (p < 0.01)) and (5.6 times higher, 95% CI: 2.1 - 15.5, (p = 0.001)) respectively. CRP continued to be higher in the D-low group at week 22 (3.1 times higher, 95% CI = 1.2 - 7.7 (p < 0.05)) and these patients also reported a worse quality of life than D-normal patients (SH 7.5 points higher, 95%CI: 0.3 - 14.8 (p < 0.05)). After one year the two groups had responded equally to anti-TNF α therapy.
“Mixed model of response to anti-TNF-alpha therapy”
Vitamin D insufficiency is associated with increased disease activity in IBD and a poorer response to anti-TNF α therapy from week 14-22. Clinical studies are needed to clarify whether vitamin D supplementation will improve the response to anti-TNF α therapy.