Plasma 6 keto PGE1 alpha concentration in Raynaud's phenomenon

To examine the possibility that prostaglandin metabolism is pathophysiologically important in Raynaud's phenomenon, peripheral venous 6-keto prostaglandin F1 alpha (6-keto PGF1 alpha) and thromboxane B2 (TXB2) concentrations were measured in 45 patients with severe Raynaud's phenomenon. Patients with Raynaud's phenomenon had a significantly higher plasma concentration of 6-keto PGF1 alpha compared to controls (p less than .001), although their plasma TXB2 concentration was not statistically different from control patients. Subgroup analysis revealed that only patients with progressive systemic sclerosis (PSS) had an elevated plasma 6-keto PGF1 alpha concentration. To gauge the functional significance of the 6-keto PGF1 alpha elevations, seven patients with Raynaud's phenomenon were chronically administered indomethacin (50 mg P.O. b.i.d.); six of the seven patients noted no improvement in their Raynaud's phenomenon. Three of the patients developed pedal edema shortly after starting indomethacin. This study suggests that the increased plasma 6-keto PGF1 alpha concentration in Raynaud's phenomenon may be due to a compensatory release of prostacyclin and that the pathophysiologic defect does not involve the thromboxane mechanism.