title: Enhanced neutrophil extravasation may be a contributing factor in the determination of neutropenia in patients with chronic idiopathic neutropenia of adults.
abstract: To test the hypothesis that low numbers of circulating neutrophils may be due to enhanced neutrophil extravasation in patients with chronic idiopathic neutropenia of adults (CINA), serum levels of endothelial cell-derived soluble cell adhesion molecules (sE-selectin, sICAM and sVCAM) usually used as indicators of endothelial cell activation, serum levels of two potent endothelial cell activators (IL-1beta and TNF-alpha), and serum levels of the chemokine interleukin-8 (IL-8) which is one of the main chemoattractant substances for neutrophils at sites of inflammation, were measured in 84 CINA patients and 30 healthy volunteers using the respective micro-ELISA methods. We found that serum sE-selectin, sICAM, sVCAM, IL-1beta and TNF-alpha concentrations were all significantly increased in the group of patients compared to controls, and were correlated inversely with the number of circulating neutrophils. Serum levels of IL-8 were also markedly increased in the patients compared to controls, and they were correlated positively with the levels of serum sE-selectin, sICAM, sVCAM, IL-1beta and TNF-alpha, and inversely with the number of circulating neutrophils. No significant differences were noted between patients and normal controls in the proportions of neutrophils carrying the cell adhesion molecules CD11a/ CD18, CD15 and CD62L. These findings suggest strongly that CINA patients have activated endothelium to which circulating neutrophils may adhere by interacting with counter-structures found on their surface. Subsequent diapedesis and subendothelial migration may be facilitated by IL-8 and possibly other chemoattractant substances. We conclude that an enhanced neutrophil extravasation may be involved, at least in part, in the determination of neutropenia in CINA patients.
authors.affiliation: Department of Haematology of the University of Crete School of Medicine, University Hospital of Heraklion, Greece.
authors.forename: H A
authors.initials: HA
authors.lastname: Papadaki
authors.forename: G D
authors.initials: GD
authors.lastname: Eliopoulos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002448:Cell Adhesion / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002908:Chronic Disease; D004730:Endothelium, Vascular / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000097:blood* / Q000276:immunology / Q000473:pathology; D018375:Neutrophil Activation / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology* / Q000473:pathology*
chemical_list: D015815:Cell Adhesion Molecules