title: Increased macrophage subset in inflammatory bowel disease: apparent recruitment from peripheral blood monocytes.
abstract: Mucosal specimens from active Crohn's disease (ileum, n = 6; colon, n = 6), active ulcerative colitis (n = 9), normal ileum (n = 6), and normal colon (n = 6) were subjected to paired immunofluorescence staining for characterisation of macrophage subsets in situ. In the normal state, only few CD68+ macrophages (< 10%) expressing the myelomonocytic L1 antigen (calprotectin) were seen. In inflamed mucosa, especially near small vessels, the CD68+L1+ fraction increased with the degree of inflammation, near ulcers to median 65% (range 35-91%). Cells reactive with the monoclonal antibody RFD7 were also increased in inflammation but less than 5% of them costained for L1 antigen. It is concluded that L1 producing macrophages are distinct from the RFD7+ subset and probably recently recruited from peripheral blood monocytes. Like granulocytes, L1+ macrophages may be important in non-specific defence, providing calprotectin with putative anti-microbial and anti-proliferative properties.
authors.affiliation: Department A, University of Oslo, National Hospital, Rikshospitalet, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Rugtveit
authors.forename: P
authors.initials: P
authors.lastname: Brandtzaeg
authors.forename: T S
authors.initials: TS
authors.lastname: Halstensen
authors.forename: O
authors.initials: O
authors.lastname: Fausa
authors.forename: H
authors.initials: H
authors.lastname: Scott
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D015816:Cell Adhesion Molecules, Neuronal / Q000276:immunology*; D003093:Colitis, Ulcerative / Q000276:immunology; D003106:Colon / Q000276:immunology; D003424:Crohn Disease / Q000276:immunology; D005260:Female; D006801:Humans; D007082:Ileum / Q000276:immunology; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000276:immunology*; D007413:Intestinal Mucosa / Q000276:immunology*; D039841:Leukocyte L1 Antigen Complex; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015816:Cell Adhesion Molecules, Neuronal; D039841:Leukocyte L1 Antigen Complex; C067980:CD68 antigen, human; D000097382:CD68 Molecule