Fibrinogen turnover in progressive systemic sclerosis.

Large amounts of fibrin are seen in the intima of the renal arterioles in progressive systemic sclerosis (scleroderma). The half-life or half disappearance time of plasma fibrinogen in 15 patients with scleroderma was studied using 125I fibrinogen to find whether there is an increased turnover of plasma fibrinogen paralleling this morphologic abnormality. Patients had a more rapid fibrinogen turnover than normal controls (60.7 versus 90.6 hours); the subgroup of patients with "progressive" scleroderma had a more rapid fibrinogen half-life than those with "stable" scleroderma (56.5 versus 73.2 hours). The mean fibrinogen half-life of 8 patients given intravenous heparin increased to within one standard deviation of normal, a finding that suggested that the fibrinogen molecule in these patients was capable of normal survival. There was a considerable variation of normal survival. There was a considerable variation of fibrinogen half-lives in individual scleroderma patients over time (not seen in the normal controls) which may be the result of intermittently increased fibrinogen consumption.