title: Macrophages expressing the scavenger receptor CD163: a link between immune alterations of the gut and synovial inflammation in spondyloarthropathy.
abstract: The objective of this study was to investigate CD163+ macrophages in the synovial membrane of patients with spondyloarthropathy (SpA). Immunohistochemistry was performed on synovium of 17 SpA and 18 rheumatoid arthritis (RA) patients, on colonic biopsies of 16 SpA patients and ten healthy controls, and on paired synovial biopsies of eight SpA patients, before and after anti-TNFalpha therapy. Phenotype and cytokine production were analysed by flow cytometry. CD163+ macrophages were increased in the synovial lining and sublining in SpA versus RA, as well as in colonic lamina propria in SpA versus controls. The number of CD163+ macrophages in the synovial sublining correlated with C-reactive protein levels and erythrocyte sedimentation rate. Paralleling the increase of CD163, HLA-DR was increased in the synovial lining and sublining of SpA. In contrast, the co-stimulatory molecules CD80 and CD86 and the dendritic cell markers CD1a and CD83 were scarce in SpA synovium. Flow cytometry indicated that CD163+ macrophages expressed high levels of HLA-DR and could produce in vitro tumour necrosis factor alpha (TNFalpha) but not interleukin-10 (IL-10). Finally, anti-TNFalpha therapy in vivo induced a decrease of CD163+ macrophages in the synovial lining and sublining. In conclusion, macrophages expressing the scavenger receptor CD163 are increased in synovium and in colonic mucosa in SpA, highlighting the relationship between joint and gut in this disease. The correlation with inflammatory parameters, the expression of HLA-DR, the production of TNFalpha but not IL-10, and the reduction by anti-TNFalpha therapy support a role for CD163+ macrophages in the synovial inflammation in SpA.
authors.affiliation: Department of Rheumatology, OK121B, Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. dominique.baeten@rug.ac.be
authors.forename: Dominique
authors.initials: D
authors.lastname: Baeten
authors.forename: Pieter
authors.initials: P
authors.lastname: Demetter
authors.forename: Claude A
authors.initials: CA
authors.lastname: Cuvelier
authors.forename: Elli
authors.initials: E
authors.lastname: Kruithof
authors.forename: Nancy
authors.initials: N
authors.lastname: Van Damme
authors.forename: Martine
authors.initials: M
authors.lastname: De Vos
authors.forename: Eric M
authors.initials: EM
authors.lastname: Veys
authors.forename: Filip
authors.initials: F
authors.lastname: De Keyser
mesh_terms: D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D002452:Cell Count; D003106:Colon; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007167:Immunotherapy; D007413:Intestinal Mucosa / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000276:immunology*; D025242:Spondylarthropathies / Q000276:immunology* / Q000628:therapy; D018709:Statistics, Nonparametric; D013583:Synovial Membrane / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D000098902:CD163 Antigen
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000098902:CD163 Antigen; D006684:HLA-DR Antigens; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein