Change of prostaglandin E level in joint fluids after treatment with flurbiprofen in patients with rheumatoid arthritis and osteoarthritis.

The prostaglandin E (PGE) level in the knee joint fluid was determined by radioimmunoassay before and after anti-inflammatory therapy with flurbiprofen in 8 patients with rheumatoid arthritis (RA) and 4 patients with osteoarthritis (OA). The level of PGE in RA joint fluids before the anti-inflammatory treatment was 9.5-1.2 ng/ml and in proportion with the leucocyte count in the joint fluid. A marked decrease of the PGE level was attained with flurbiprofen treatment in 4 patients whose initial PGE levels had been higher than 3.2 ng/ml, while 4 patients with lower PGE levels, namely, 1.4-1.2 ng/ml, did not respond to the drug treatment. In all the OA patients the PGE levels was no higher than 1.5 ng/ml and refractory to the anti-inflammatory therapy.