Concentrations of prostaglandins D2, E2, F2 alpha, 6-keto-F1 alpha and thromboxane B2 in synovial fluid from patients with inflammatory joint disorders and osteoarthritis.

The concentrations of PGD2, PGE2, PGF2 alpha, 6-keto-PGF1 alpha and TXB2 in synovial fluid from patients with rheumatoid arthritis (RA), Reiter's disease (RD), acute gouty arthritis (GA) and osteoarthritis (OA) were measured by radioimmunoassay. PGE2 was found to be the most predominant prostanoid (pg/ml; Mean +/- S.E.M.): RA 887 +/- 85, RD 870 +/- 71, GA 1064 +/- 155 and OA 665 +/- 71. In patients with OA lower mean levels of all the prostanoids were found than compared to the other groups of patients. Only in patients with RA a slight correlation between PGD2/PGF2 alpha, PGE2/PGF2 alpha and PGE2/6-keto-PGF1 alpha could be demonstrated. No significant correlations between the leucocyte cell counts in the synovial fluid and the prostanoid concentrations were found. In patients with RA developing recurrent knee joint effusions within four weeks after the first sampling significantly lower levels of PGE2 and TXB2 were found in the recurrent samples (PGE2 792 +/- 183; TXB2 179 +/- 33) than compared with the original samples (PGE2 984 +/- 146; TXB2 239 +/- 32).