Peripheral blood neutrophils in inflammatory bowel disease: morphological evidence of in vivo activation in active disease


D. A. McCarthy, Queen Mary & Westfield College, Mile End Road, London El 4NS, UK.


Morphological evidence of activation in vivo of circulating neutrophils in patients with inflammatory bowel disease (IBD) was sought by quantitative light microscope examination of toluidine bluestained leucocyte preparations made from peripheral venous bloods that had been fixed immediately ex vivo. The proportion of spherical (unactivated) circulating neutrophils was reduced in active Crohn's disease (73%; 46–96 (median; range), n= 11) compared with inactive Crohn's (90%; 45–99; n= 18, P<0.01) and normal subjects (94%; 44–98; n=13, P<0.05). There tended to be fewer spherical neutrophils in active ulcerative colitis (77%; 13–96; n= 17) than in quiescent colitis (88%; 57–99, n= 13, P<0.1) or normal subjects (P<0.05). Activated neutrophils occur in the circulating pool of patients with active IBD and can be detected by light microscopy of peripheral venous blood leucocyte preparations.