Background: Programmed death-1 (PD-1) is an immuneregulatory molecule functioning by down-regulating immune responses. PD-1 is present on follicular helper T cells (TFH) and is important in the formation of plasma cells.PD-1 exists in a bioactive soluble form (sPD-1) and is thought to be implicated in disease activity in rheumatoid arthritis (RA).
Objectives: to measure the levels of soluble programmed death-1(sPD-1) in RA patients and to correlate it with clinical and laboratory parameters of disease activity and severity.
Method: We measured sPD-1 at in plasma (n = 60) and synovial fluid (SF) (n = 24) from patients with RA. We tested for correlations with the Disease Activity Score using 28 joint counts (DAS28), the Health Assessment Questionnaire(HAQ)score, immunoglobulin M rheumatoid factor (IgM-RF), anti-cyclic citrullinated peptide(anti-CCP) antibodies, C-reactive protein (CRP) and total Sharp score (TSS). We also measured sPD-1 in plasma from healthy volunteers (HV) (n = 30).
Results: In RA, sPD-1 concentrations in plasma (mean 1416.9 pg/ml) and SF (mean 1503.9 pg/ml) were increased compared with HV (median 165 pg/mL)(all p |
