Altered factor VIII complexes in patients with acute respiratory insufficiency.

ABSTRACT

Acute respiratory failure is an often-fatal syndrome of multiple etiologies in which altered factor VIII may be a marker of endothelial disease. 12 women with overwhelming viral pneumonia were studied with serial factor VIII antigen, procoagulant activity, and von Willebrand's factor assays. Antigen levels were elevated (range 86--1644%) out of proportion to procoagulant activity (range 35--521% by a one-stage assay), and factor VIII antigen to activity ratios were as high as 161. Von Willebrand's factor was normal but correlated best with procoagulant activity. All patients had abnormal antigen patterns on crossed immunoelectrophoresis, with increases in protein of both fast and slow mobility. These changes in factor VIII correlated with the patient's clinical courses.