DETECTION OF CYTOKINE MESSENGER-RNA IN HUMAN, ARTICULAR-CARTILAGE FROM PATIENTS WITH RHEUMATOID-ARTHRITIS AND OSTEOARTHRITIS BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION

Cytokines are signalling glycoproteins mediating acute inflammation, c hronic inflammation, and connective tissue destruction. The present st udy was designed to characterize the profile of cytokine message in no rmal human articular cartilage and from patients with rheumatoid arthr itis (RA) and osteoarthritis (OA), by means of the reverse transcripta se-polymerase chain reaction (RT-PCR). Message RNA (mRNA) was extracte d from fresh or frozen cartilage. The results showed expression of mRN A for IL-6, IL-6R, IL-7, IL-8, IL-10, and IL-12 (p35 and p40) exclusiv ely in the RA cartilage. Except for mRNA for IL-8 and IL-10, no other cytokine or cytokine receptor was expressed in OA and control cartilag e. mRNA for IL-1 beta, IL-4, TNF-alpha, and TNFR-p75, was not detected in any cartilage sample except for one RA specimen expressing IL-1 be ta mRNA. However, the expression of message for pro-inflammatory cytok ines was far more prominent than antiinflammatory cytokines. This may suggest a disturbed balance of pro-and anti-inflammatory activity in R A cartilage.