Effect of glycosylphosphatidylinositol (GPI)-deficient granulocyte clone size on incidence of venous thrombosis (primary prophylaxis patients excluded).

When primary prophylaxis patients are excluded, the 10 year cumulative incidence rate of thrombosis in patients with PNH granulocyte clone size of > 50% is 44%, compared with a thrombosis rate of 5.8% in those with clone size of < 50% (P < 0.01*).

* P value calculated with use of the log-rank test;