title: Analysis of Programmed Death-1 in Patients with Psoriatic Arthritis.
abstract: Programmed death-1 (PD-1) is an inhibitory co-receptor that is highly expressed in T lymphocytes that has been shown to downregulate inflammatory responses in several inflammatory diseases including systemic lupus erythematosus and rheumatoid arthritis. Yet, the role of PD-1 in psoriatic arthritis (PsA) has not been studied. In order to fill this gap, we measured the expression levels of PD-1 in peripheral T cells from patients with active disease. Twenty patients and fifteen age-matched healthy control subjects were recruited. The percentage of CD3(+)PD-1(+) T cells was measured by flow cytometry. Despite normal concentration of peripheral T cells, the expression levels of PD-1 were significantly higher in patients compared to healthy controls. Interestingly, among the patients, the expression levels inversely correlated with disease activity measured by disease activity scores (DAS28). PD-1 expression levels strongly correlated with the number of tender and swollen joints, but not with C-reactive protein (CRP) levels or psoriasis area and severity index (PASI). Functionally, in vitro ligation of PD-1 receptor in PsA T cells inhibited interleukin-2 (IL-2) secretion, Akt phosphorylation, and Rap1 activation. These findings suggest that PD-1 might serve as a biomarker for disease activity in PsA and highlight the need for additional studies in order to establish the role of PD-1 in PsA pathogenesis.
authors: The Department of Medicine, New York University School of Medicine, 450 E 29th Street, New York, NY, 10016, USA.
authors: Michael
authors: M
authors: Peled
authors: Marianne
authors: M
authors: Strazza
authors: Inbar
authors: I
authors: Azoulay-Alfaguter
authors: Gregg J
authors: GJ
authors: Silverman
authors: Jose U
authors: JU
authors: Scher
authors: Adam
authors: A
authors: Mor
mesh_terms: D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000175:diagnosis* / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000096:biosynthesis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor