title: Role of inflammatory cells, cytokines and matrix metalloproteinases in neutrophil-mediated skin diseases.
abstract: Pyoderma gangrenosum (PG) is a rare, immune-mediated inflammatory skin disease presenting with painful ulcers having undermined edges. Less commonly, bullous and vegetative variants exist. Histology consists of a neutrophil-rich dermal infiltrate. We characterized immunohistochemically the infiltrate in different variants of PG and in another neutrophilic dermatosis as Sweet's syndrome. We studied 21 patients with PG, eight with Sweet's syndrome and 20 controls, evaluating skin immunoreactivity for inflammatory cell markers (CD3, CD163 and myeloperoxidase), cytokines [tumour necrosis factor (TNF)-α, interleukin (IL)-8 and IL-17], metalloproteinases (MMP-2 and MMP-9) and vascular endothelial growth factor (VEGF). Immunoreactivities of CD3, CD163, myeloperoxidase, TNF-α, IL-8, IL-17, MMP-2, MMP-9 and VEGF were significantly higher in both PG and Sweet's syndrome than in controls (P=0·0001). Myeloperoxidase (neutrophil marker), IL-8 (cytokine chemotactic for neutrophils) and MMP-9 (proteinase-mediating tissue damage) were expressed more significantly in both ulcerative and bullous PG than in vegetative PG as well as in Sweet's syndrome (P=0·008-P=0·0001). In ulcerative PG, the expression of CD3 (panT cell marker) and CD163 (macrophage marker) were significantly higher in wound edge than wound bed (P=0·0001). In contrast, the neutrophil marker myeloperoxidase was expressed more significantly in wound bed than wound edge (P=0·0001). Our study identifies PG as a paradigm of neutrophil-mediated inflammation, with proinflammatory cytokines/chemokines and MMPs acting as important effectors for the tissue damage, particularly in ulcerative and bullous PG where damage is stronger. In ulcerative PG, the wound bed is the site of neutrophil-recruitment, whereas in the wound edge activated T lymphocytes and macrophages pave the way to ulcer formation.
authors.affiliation: Unità Operativa di Dermatologia, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Dipartimento di Anestesiologia, Terapia Intensiva e Scienze Dermatologiche, Università degli Studi di Milano, Milano, Italy.
authors.forename: A V
authors.initials: AV
authors.lastname: Marzano
authors.forename: M
authors.initials: M
authors.lastname: Cugno
authors.forename: V
authors.initials: V
authors.lastname: Trevisan
authors.forename: D
authors.initials: D
authors.lastname: Fanoni
authors.forename: L
authors.initials: L
authors.lastname: Venegoni
authors.forename: E
authors.initials: E
authors.lastname: Berti
authors.forename: C
authors.initials: C
authors.lastname: Crosti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism* / Q000473:pathology; D009195:Peroxidase / Q000378:metabolism; D017511:Pyoderma Gangrenosum / Q000378:metabolism* / Q000473:pathology; D011956:Receptors, Cell Surface / Q000378:metabolism; D016463:Sweet Syndrome / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D055815:Young Adult; D000098902:CD163 Antigen
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000098902:CD163 Antigen; D017252:CD3 Complex; D016207:Cytokines; D018836:Inflammation Mediators; D020381:Interleukin-17; D016209:Interleukin-8; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D009195:Peroxidase; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9