CONVERSION OF ENDOGENOUS ARACHIDONIC-ACID TO 5,15-DIHETE AND LIPOXINSBY POLYMORPHONUCLEAR CELLS FROM PATIENTS WITH RHEUMATOID-ARTHRITIS

The conversion of endogenous arachidonic acid (AA) by polymorphonuclea r cells (PMN) from patients with rheumatoid arthritis (RA) was studied before (DO) and one day (D1) after antiinflammatory drug therapy. The biosynthesis of 5,15-diHETE and lipoxins (LXS), were investigated ex vivo, after PMN stimulation by ionophore A23187 without exogenous addi tion of 15-HETE. The eicosanoids were resolved by RP-HPLC and simultan eously detected at 246 and 302 nm respectively. Large amounts of 5,15- diHETE (50 to 400 ng/10(7) PMN) and significant levels of LXS (from 2 to 20 ng/10(7) PMN) were produced with individual differences between donors. Metabolite levels varied between patients but this work showed for the first time a linear relationship between the amounts of 5,15- diHETE and LXS. Moreover LXS production after treatment may be related to long-term clinical improvement of patients.