An increased Bax/Bcl

Predicting the response of inflammatory bowel disease (IBD) patients to infliximab (IFX) is an unmet clinical need. The expression and density of transmembrane tumor necrosis factor-α in circulating leukocytes maybe directly related to response by promoting apoptosis. We tested the hypothesis that direct apoptosis assessment by real-time polymerase chain reaction evaluation of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) proteins in peripheral blood mononuclear cells (PBMCs) might be associated with response to IFX. IFX na？ve patients (Crohn’s disease, 32 and ulcerative colitis, 20; 35 responders and 17 non-responders) were evaluated for Bax and Bcl-2 mRNA expression levels before and 2 weeks after the first infusion. In a subset of patients, apoptosis was also evaluated using flow cytometry. After the first infusion, Bax increased more in responders than in non-responders (0.7±？0.38 vs 0.81？±？0.32 and 0.86？±？0.37 vs 0.87？±？0.45, respectively, p？=？0.071). Bcl-2 decreased more in responders than in non-responders (0.71？±？0.12 vs 0.63？±？0.13 and 0.81？±？0.28 vs 0.77？±？0.27, respectively, p？=？0.038). The Bax/Bcl-2 ratio increased more in responders than in non-responders (0.99？±？0.5 vs 1.3？±？0.51 and 1.03？±？0.17 vs 1.1？±？0.28, respectively, p？=？0.005). The Bax/Bcl-2 ratio was able to predict response in 33/52 patients and was correlated to flow cytometry-assessed apoptosis (r？=？0.911; p？<？0.001). An increased Bax/Bcl-2 ratio in PBMCs was associated with therapeutic response to IFX in IBD patients