ONCOGENE EXPRESSION IN SYNOVIAL-FLUID CELLS IN REACTIVE AND EARLY RHEUMATOID-ARTHRITIS - A BRIEF REPORT

Since it has been implied that cellular oncogenes might have a role in the pathogenesis of rheumatoid arthritis (RA), we have examined the e xpression of c-myc, c-myb, c-fos, c-jun and c-Ha-ras oncogenes in the cells from synovial fluid (SF) and peripheral blood (PB) of patients w ith reactive arthritis (ReA) and early RA. Oncogene expression was stu died using RNA hybridizations with P-32-labelled probes. From the SF, mononuclear and granulocyte cell fractions were used separately. Signi ficant differences between ReA and RA were observed only for c-myb in PB mononuclear cells and c-jun in SF granulocytes. Regarding the expre ssion of c-myc, c-Sos and c-Ha-ras oncogenes, no difference between Re A and RA was observed. Comparison to normal controls was made using PB mononuclear cells; only the expression of c-fos tended to be slightly increased in RA, without statistical significance, however. We conclu de that oncogene activation in the synovial inflammation is not a phen omenon specific for RA.