title: Difference in the expression of IL-9 and IL-17 correlates with different histological pattern of vascular wall injury in giant cell arteritis.
abstract: OBJECTIVE
  GCA is a large- and medium-vessel arteritis characterized by a range of histological patterns of vascular wall injury. The aim of this study was to immunologically characterize the various histological patterns of GCA.
  
  
  METHODS
  Thirty-five consecutive patients with biopsy-proven GCA and 15 normal controls were studied. IL-8, IL-9, IL-9R, IL-17, IL-4, TGF-β and thymic stromal lymphopoietin expression was evaluated by RT-PCR and immunohistochemistry on artery biopsy specimens. Confocal microscopy was used to characterize the phenotypes of IL-9-producing and IL-9R-expressing cells. Five additional patients who had received prednisone when the temporal artery biopsy was performed were also enrolled to evaluate the effect of glucocorticoids on IL-9 and IL-17 expression.
  
  
  RESULTS
  IL-17 overexpression was observed mainly in arteries with transmural inflammation and vasa vasorum vasculitis. IL-9 overexpression and Th9 polarization predominated in arteries with transmural inflammation and small-vessel vasculitis. The tissue expression of both IL-9 and IL-17 was correlated with the intensity of the systemic inflammatory response. IL-4, TGF-β and thymic stromal lymphopoietin, which are involved in the differentiation of Th9 cells, were overexpressed in arteries with transmural inflammation and small-vessel vasculitis. IL-9R was also overexpressed in GCA arteries with transmural inflammation and was accompanied by increased expression of IL-8.
  
  
  CONCLUSIONS
  Herein we provide the first evidence that distinct populations of potentially autoreactive T cells, expressing different cytokines (Th17 vs Th9), characterize patients with particular histological subsets of GCA and may thus contribute to the heterogeneity of tissue lesions observed in these patients.
authors: Dipartimento Biomedico di Medicina Interna e Specialistica, Sezione di Reumatologia, Università di Palermo.
authors: Francesco
authors: F
authors: Ciccia
authors: Unità Operativa di Anatomia Patologica, Azienda Ospedaliera Ospedali Riuniti 'Villa Sofia-Cervello', Palermo.
authors: Aroldo
authors: A
authors: Rizzo
authors: Dipartimento Biomedico di Medicina Interna e Specialistica, Sezione di Reumatologia, Università di Palermo.
authors: Giuliana
authors: G
authors: Guggino
authors: Unità Operativa di Reumatologia, Azienda Ospedaliera Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia.
authors: Alberto
authors: A
authors: Cavazza
authors: Dipartimento di Biopatologia e Biotecnologie Mediche e Forensi and.
authors: Riccardo
authors: R
authors: Alessandro
authors: Dipartimento di Emergenze, Urgenze e Neuroscienze Cliniche, Università di Palermo, Palermo, Italy.
authors: Rosario
authors: R
authors: Maugeri
authors: Unità Operativa di Anatomia Patologica, Azienda Ospedaliera Ospedali Riuniti 'Villa Sofia-Cervello', Palermo.
authors: Alessandra
authors: A
authors: Cannizzaro
authors: Unità Operativa di Reumatologia, Azienda Ospedaliera Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia.
authors: Luigi
authors: L
authors: Boiardi
authors: Dipartimento di Emergenze, Urgenze e Neuroscienze Cliniche, Università di Palermo, Palermo, Italy.
authors: Domenico Gerardo
authors: DG
authors: Iacopino
authors: Unità Operativa di Reumatologia, Azienda Ospedaliera Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia.
authors: Carlo
authors: C
authors: Salvarani
authors: Dipartimento Biomedico di Medicina Interna e Specialistica, Sezione di Reumatologia, Università di Palermo, g.triolo@unipa.it.
authors: Giovanni
authors: G
authors: Triolo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism; D005260:Female; D013700:Giant Cell Arteritis / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D005938:Glucocorticoids / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D020381:Interleukin-17 / Q000378:metabolism*; D016906:Interleukin-9 / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D010641:Phenotype; D011241:Prednisone / Q000494:pharmacology / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000473:pathology; D013699:Temporal Arteries / Q000378:metabolism / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000378:metabolism; D057772:Vascular System Injuries / Q000378:metabolism* / Q000473:pathology*; D000094632:Thymic Stromal Lymphopoietin
chemical_list: D015415:Biomarkers; D016207:Cytokines; D005938:Glucocorticoids; D020381:Interleukin-17; D016906:Interleukin-9; D016212:Transforming Growth Factor beta; D011241:Prednisone; D000094632:Thymic Stromal Lymphopoietin
keywords: Th17; Th9; giant cell arteritis; small vessel vasculitis; vasa vasorum vasculitis