Plasma levels and urinary excretion of prostaglandins in patients with rheumatoid arthritis.

No significant differences were found in plasma concentrations and urinary excretion of prostaglandin E2 (PGE2), 6-keto-prostaglandin-F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2), between rheumatoid arthritis patients and controls. However, urinary excretion of PGEe and 6-keto-PGF1 alpha tended to be greater and plasma levels of TxB2 lower in rheumatoid arthritis. Plasma concentrations and urinary excretion showed no marked circadian variation, although night or morning values were slightly lower. Plasma and urine prostaglandins do not correlate with clinical symptomatology in rheumatoid arthritis.