Objective: Anti-TNF-α therapy is an effective therapy for Crohn’s disease (CD). Thus anti-TNF-α therapy may alter CD64 expression, one of the Fc receptors for IgG, in CD. We investigated CD64 expression on neutrophils before and after treatment with anti-TNF-α therapy in CD.

Methods: A total of 11 patients with active CD treated with anti-TNFα antibodies were enrolled. The severity of CD was assessed with the CD activity index (CDAI). Peripheral venous blood was obtained before and 2 weeks after the initial administration of anti-TNF-α antibody. CD64 expression on neutrophils was measured by FACS analysis of whole blood samples.

Results: CDAI, C-reactive protein value and CD64 expression decreased significantly after anti-TNF-α therapy. Both prior to and after anti-TNF treatment, there was a significant and positive correlation between CD64 expression and CDAI or CRP. Similarly, there was a significant and negative correlation between CD64 and albumin value.

Conclusion: Anti-TNF-α therapy suppresses CD64 expression of neutrophils, which may account for the mechanism underlying the efficacy of the medication in CD