Human neutrophil elastase degrades the therapeutic monoclonal antibodies effective in IBD

KOK K.; CURCIARELLO R; SOBANDE T; JHONES S; DOCENA G; MACDONALD TT

Congreso; ECCO Congress 2018; 2018

BackgroundA significant proportion of inflammatory bowel disease (IBD) patients are primary non-responders to biological therapies. Human Neutrophil Elastase (HNE) is highly expressed in IBD mucosa, especially in ulcerative colitis (UC). The aim of this study was to determine whether HNE degrades biologics, rendering them ineffective, and whether its action can be reversed by its natural inhibitor, Elafin.MethodsBiologics (Infliximab, Adalumimab, Vedolizumab) were digested using different concentrations of recombinant HNE, in the absence or presence of Elafin, overnight. Neutrophils where isolated from human blood (4 UC patients and two healthy donors) by gradient centrifugation with Na-Dextran solution. Neutrophils where lysed and elastase activity was quantified. Antibody integrity after recombinant or natural HNE digestion was then analysed by western blot, and the functional capacity of the anti-TNF antibodies to neutralise TNF-alpha was tested using recombinant human TNF-alpha and a TNFR reporter cell line.ResultsRecombinant and HNE from blood cells fully degrades all anti-TNF-alpha agents and Vedolizumab in a dose-dependent manner (HNE 0.125?5 µg/ml degrades biologics from 6% to 99.9%, respectively). This activity is significantly inhibited by recombinant Elafin (p < 0.001). Treatment with HNE also partially prevented the ability of the biologicals to inhibit TNF-alpha bioactivity (HNE at 10 µg/ml causes 90% reduction of the anti-TNF´s neutralising ability, while HNE at 5 µg/ml diminishes 25% of their neutralising activity).ConclusionsThese results may explain some of the reasons for primary non-responsiveness to biological therapies in IBD patients.