THE PROTEINS C-S SYSTEM IN CHILDREN WITH SECONDARY PULMONARY HYPERTENSION

Plasma levels of protein C (PC), total protein S (PSt) and free protein S (PSf) were assessed by electro-immunodiffusion in 6 healthy children (1 to 14 yr) and in 6 children with pulmonary hypertension and polycythemia secondary to congenital heart disease (3 to 15 yr) before and after intentional hemodilution (HD) which was planned to achieve a 10% decrease in hematocrit. Results are expressed as a percentage of antigen (mean ± SD). Severe pulmonary vascular damage and hyperviscosity are likely to be the main causes of consuption coagulopathy in this syndrome, with decreased plasma levels of PC and PSf which are not significantly improved by moderate hemodilution.