Refractory neutrophils and monocytes in patients with inflammatory bowel disease after repeated bouts of prolonged exercise

Abstract

Study highlights:1. Patients with stable IBD who perform exercise have significantly fewer flare-ups of disease 2. Relative refractory neutrophils and monocytes were demonstrated in peripheral blood of IBD patients after prolonged exercise.3. Increased knowledge on the pathophysiological mechanism on the effect of exercise on IBD facilitates future therapy to prevent flare-ups.AbstractRationale Neutrophils and monocytes are key immune effector cells in inflammatory bowel disease (IBD) that is associated with chronic inflammation in the gut. Patients with stable IBD who perform exercise have significantly fewer flare-ups of the disease, but no underlying mechanism has been identified. Therefore, the aim of this study was to compare the responsiveness of these innate immune cells after repeated bouts of prolonged exercise in IBD patients and controls.Methods Patients with IBD and age-and gender-matched healthy controls were recruited from a cohort of walkers participating in a 4-day walking event. Blood analysis was performed at baseline and after 3 days of walking. Responsiveness to the bacterial/mitochondrial N-Formylmethionine-leucyl-phenylalanine (fMLF) was tested in granulocytes and monocytes by measuring the expression of activation markers after adding this stimulus to whole blood Results In total 38 participants (54±12 years) were included in this study: 19 walkers with and 19 walkers without IBD. After 3 days of prolonged exercise, a significant increase in responsiveness to fMLF was observed in all participants irrespective of disease. However, IBD patients showed significantly smaller increase in neutrophils (p=0.010; p=0.030; p=0.010, respectively) and monocytes (p=0.001; p=0.008; p=0.005, respectively), compared to controls.