Deficiency of plasma prostacyclin or PGI2 regenerating ability in sickle cell anaemia.

We have demonstrated that patients with sickle cell disease greater than 2 years of age have a marked decrease in their plasma PGI2 or prostacyclin regenerating ability (0.05 +/- 0.08 ng/mg of vascular tissue) when compared to normal controls (0.44 +/- 0.12). This abnormality was not present in other chronic haemolytic states, and was not related to concomitant hyposplenism. Normal activity was observed in patients with sickle cell disease following a period of prophylactic red cell transfusions (0.32 +/- 0.13). Since vascular prostacyclin is antiaggregatory and antithrombotic, the deficiency in the prostacyclin regenerating ability of patients with sickle cell disease may play a pathogenic role in the development of the microvascular and thrombotic complications seen in this disorder.