Plasma protein C levels in children with sickle cell disease.

Since thrombotic phenomena have important roles in the vasoocclusive manifestations in sickle cell disease (SCD), protein C (PC) was determined in 32 children with SCD during steady state and vasoocclusive crisis (VOC) and in controls. Children with SCD during steady state had significantly lower PC levels as compared to controls. During VOC there was marked decrease in PC as compared to levels during steady state, and these levels increased to initial levels or higher with clinical improvement. It is postulated that the decreased levels of PC in SCD are probably secondary to increased consumption as well as decreased production because of altered liver function. This data suggests that decreased levels of PC may increase the risk of thrombosis in these patients.