Article Text


THU0086 Serum il-15 levels and peripheral blood lymphocyte (pbl) cd69 expression in rheumatoid arthritis (ra) patients
  1. AM Ortiz,
  2. R Garcia-Vicuña,
  3. E Tomero,
  4. A Laffon,
  5. I González-Alvaro
  1. Rheumatology, Hospital Universitario de La Princesa, Madrid, Spain


Background We have recently described that IL-15 induces higher CD69 expression on lymphocytes compared to several cytokines described in rheumatoid synovium. A growing body of evidence supports that these two molecules can play an important role in the perpetuation of synovitis in RA.

Objectives To determine IL-15 serum levels and the expression of CD69 on PBL from RA patients and to assess their possible correlation with several clinical and biological parameters.

Methods IL-15 and TNF-a serum levels were measured by ELISA (R&D Systems) and CD69 expression on PBL was assessed by flow cytometry, both in RA patients (n = 25) and healthy donors (n = 15). Each RA patient was evaluated at the time of sample collection for the following variables: morning stiffness (MS), pain visual analogic scale (0–100 mm), number of tender (TJC) and swollen (SJC) joints (Fuchs 28 joints count), patient and physician global disease activity assessment (GDA) in a Likert scale (0–4), ESR and CRP. Those patients that fulfilled 5 or more of the next criteria were considered to have an active disease: pain score > 25 mm; TJC > 5; SJC > 3; patient GDA > 1; physician GDA > 1; ESR > 25 mm and RCP > 0.8 mg/dl. DAS28 score was also calculated. Student t test and Pearson correlation test were applied for statistical analysis.

Results IL-15 and TNF-a serum levels from RA patients were significantly higher than that from healthy donors (314.6 ± 72.3 vs. 12.9 ± 3.1 pg/ml, p = 0.0001; and 233.1 ± 97.9 vs 74.2 ± 30 pg/ml, p = 0.06, respectively). The percentage of CD69 positive PBL in RA patients was also higher that in controls (12.6 ± 1.2 vs. 9.7 ± 0.8; p = 0.03). The percentage of CD69+ PBL correlated with DAS score (r = 0.382; p < 0.05). In addition, MS and TNF-a levels also correlated (r = 0.49; p = 0.015). Mean serum concentrations of IL15 and TNF-a in patients with active disease were higher than these cytokine levels in patients considered inactive (274 vs. 112.4 pg/ml and 337.6 vs. 211 pg/ml, respectively), although this difference did not reached statistical significance likely due to the low number of patients with inactive disease (n = 6).

Conclusion Our data showed a correlation between CD69 expression on PBL and clinical parameters, suggesting a pathogenic role for this molecule in RA. Further studies are needed to evaluate the clinical significance of elevated levels of IL15 in RA patients.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.