title: Synovial biomarkers in psoriatic arthritis.
abstract: OBJECTIVE
  To find candidate biomarkers of psoriatic arthritis (PsA). A panel of synovial fluid (SF) and synovial tissue (ST) biomarkers was analyzed in patients with resistant peripheral PsA, in relation to clinical and imaging outcomes of synovitis response following serial intraarticular (IA) etanercept injections (12.5 mg).
  
  
  METHODS
  Fourteen PsA patients with resistant knee joint synovitis were treated with 4 IA etanercept injections in a single knee joint, once every 2 weeks. Primary outcome (Thompson's knee index: THOMP) and secondary outcomes were assessed at baseline and end of study: C-reactive protein, Knee Joint Articular Index (KJAI), Health Assessment Questionnaire disability index, maximal synovial thickness (MST) by gray-scale ultrasonography, contrast-enhanced magnetic resonance imaging (C+MRI), ST-cluster differentiation (CD)45+ mononuclear cell, ST-CD31+ vessels, and ST-CD105+ angiogenic endothelial cells, along with levels of SF interleukin 1ß (IL-1ß), IL-1 receptor antagonist (Ra), and IL-6.
  
  
  RESULTS
  At the end of the study, clinical and imaging outcomes, ST and SF biological markers were significantly reduced compared to baseline. There was a significant association between IL-6 and either THOMP or KJAI; between either ST-CD31+ or ST-CD105+ or ST-CD45+; between ST and SF biomarkers expression (CD45+ and IL-1ß) and between ST-CD45+ and both KJAI and MRI-MST. Comparing pre- versus post-IA etanercept injection changes (Δ), Δ IL-1ß was significantly correlated with both Δ IL-6 and with Δ IL-1Ra and Δ IL-6 with Δ IL-1Ra.
  
  
  CONCLUSIONS
  The association to disease activity and the changes following IA treatment indicate that ST-CD45+ and ST-CD31+, along with SF-IL-6 and SF-IL-1ß, may represent candidate biomarkers of the knee synovitis response to IA tumor necrosis factor-α blockade.
authors: Department of Medicine, University of Padua, Padua, Italy. ugo.fiocco@unipd.it
authors: Ugo
authors: U
authors: Fiocco
authors: Francesca
authors: F
authors: Oliviero
authors: Paolo
authors: P
authors: Sfriso
authors: Fiorella
authors: F
authors: Calabrese
authors: Francesca
authors: F
authors: Lunardi
authors: Elena
authors: E
authors: Scagliori
authors: Leopoldo
authors: L
authors: Rubaltelli
authors: Roberto
authors: R
authors: Stramare
authors: Antonio
authors: A
authors: Di Maggio
authors: Roberto
authors: R
authors: Nardacchione
authors: Luisella
authors: L
authors: Cozzi
authors: Beatrice
authors: B
authors: Molena
authors: Mara
authors: M
authors: Felicetti
authors: Katia
authors: K
authors: Gazzola
authors: Alessandro
authors: A
authors: Lo Nigro
authors: Benedetta
authors: B
authors: Accordi
authors: Pascale
authors: P
authors: Roux-Lombard
authors: Jean-Michel
authors: JM
authors: Dayer
authors: Leonardo
authors: L
authors: Punzi
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D015535:Arthritis, Psoriatic / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D001706:Biopsy; D002097:C-Reactive Protein / Q000378:metabolism; D004185:Disability Evaluation; D004334:Drug Administration Schedule; D000071063:Endoglin; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000008:administration & dosage; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D007270:Injections, Intra-Articular; D053590:Interleukin 1 Receptor Antagonist Protein / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000008:administration & dosage; D011795:Surveys and Questionnaires; D013582:Synovial Fluid / Q000378:metabolism*; D013583:Synovial Membrane / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; C064206:ENG protein, human; D000071063:Endoglin; C507763:IL1RN protein, human; C508600:IL6 protein, human; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D053590:Interleukin 1 Receptor Antagonist Protein; D053583:Interleukin-1beta; D015850:Interleukin-6; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011956:Receptors, Cell Surface; D018124:Receptors, Tumor Necrosis Factor; D002097:C-Reactive Protein; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human; D000068800:Etanercept