Read the full paper here: http://gut.bmj.com/content/...
To cite: Yarur AJ, Jain A, Sussman DA et al. Gut 2016;65:249-255 doi:10.1136/gutjnl-2014-308099
The aim of this study was to assess the correlation between serum and intestinal anti-tumour necrosis factor levels, and their relationship to endoscopic disease activity and levels of TNF.
Cross-sectional study of 30 patients receiving treatment with infliximab or adalimumab for Crohn's disease or UC. For each patient, a sample of serum was matched to tissue biopsies. Endoscopic and histological disease activity was recorded for each tissue sample.
There was a significant positive correlation between anti-TNF in serum and tissue, especially in uninflamed tissue, but not with those samples that had inflammation. Anti-TNF concentration in tissue correlated with degree of endoscopic inflammation, except for tissue with severe inflammation in which anti-TNF levels were again lower. The ratio of anti-TNF-to-TNF in tissue was highest in uninflamed areas and lowest in severely inflamed areas. Patients with active mucosal disease had a higher rate of serum to tissue drug level mismatch when compared to those in remission.
Our data suggest that local tissue inflammation characterised by high levels of TNF serves as a sink for anti-TNF. We further postulate that some patients with high serum anti-TNF levels have active disease because tissue levels of anti-TNF are insufficient to neutralise local TNF production.