Interleukin-8, interleukin-10, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression levels are higher in synovial tissue from patients with rheumatoid arthritis than in osteoarthritis

The aim of this work was to determine differences in pro- and anti-inflamma tory cytokine and adhesion molecule expression in synovial tissue from pati ents with rheumatoid arthritis (RA) or osteoarthritis (OA). Synovial tissue samples were obtained from patients with RA and OA, and from healthy indiv iduals. The expression of mRNA of interleukin (IL)-1 beta, IL-4, IL-6, IL-8 , IL-10, IL-13, tumour necrosis factor-alpha (TNF-alpha) and transforming g rowth-factor-beta 1 (TGF-beta 1) was evaluated by the polymerase chain reac tion (PCR). In addition, IL-8 and IL-10 transcripts were measured by quanti tative PCR. The expression of IL-8 and IL-10 proteins was determined by imm unoperoxidase staining. To evaluate the inflammatory stage of synovial tiss ue, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion m olecule-1 (ICAM-1) protein expression was also determined. RA patients were found to display higher levels of adhesion molecules than patients with OA , PCR analysis showed a similar profile of cytokine transcripts between the OA and RA groups. Gene expression of IL-4 and IL-13 in synovium was undete ctable. In contrast, IL-1 beta, IL-6, IL-8, IL-10, TNF-alpha and TGF-beta 1 transcripts were expressed by both groups, Increased levels of IL-8 and IL -10 transcripts and their proteins were observed in synovium from RA patien ts when compared to patients with OA and healthy controls. Thus, our data s how that IL-8, IL-10, ICAM-1 and VCAM-1 expression levels are higher in syn ovial tissue from patients with RA than in similar tissue from patients wit h OA.