Fibrinolysis in familial pulmonary hypertension.

Although an autosomal dominant mode of inheritance has been documented for many cases of primary pulmonary hypertension, the pathogenesis of the disease remains unclear. A report of abnormal fibrinolysis in familial pulmonary hypertension has raised the possibility that the pathogenesis may be related to an impaired ability to lyse recurrent pulmonary microemboli. Primary pulmonary hypertension was diagnosed in three of ten members of a kindred. The pattern of inheritance was compatible with an autosomal dominant gene. Eight members of the kindred were available for study, one of whom has primary pulmonary hypertension. The results of coagulation studies, caseinolytic determinations of plasminogen and antiplasmin, and fibrinolytic titers of antiurokinase did not differ significantly from those of the control group. These findings suggest that a deficient fibrinolytic system is not the cause of primary pulmonary hypertension, although differences in methodology may explain our inability to demonstrate abnormal circulating fibrinolysis in this kindred.