Distribution of 16 hemostatic laboratory variables assayed in 100 blood donors

The aim of the present study was to establish the normal range of 16 hemostatic variables routinely assayed in our laboratory. We therefore measured the activated partial thromboplastin time, the prothrombin time, and the plasma levels of fibrinogen (Fg), factors II, V, VII + X, VIII, IX, XI, XII, von Willebrand factor-antigen (vWf), protein C (PC), total (tPS) and free (fPS) protein S-antigen, C4b binding protein (C4bBP) and fibrin degradation products (FDP), in 100 unselected adult blood donors (58 males, 42 females). We further examined the influence of age and sex on these variables. Age was shown to affect the plasma level of free PS: in comparison with a normal reference plasma, the levels of measured fPS in subjects less than or equal to 40 years (n = 67) and greater than 40 years (n = 33) were 86% (normal range: 52-143%) and 99% (60-162%), respectively (P = 0.01). The plasma levels of factors VIII, vWf, C4bBP and PS were significantly influenced by sex. This finding was particularly marked for fPS: in males (n = 31) and females (n = 36) less than or equal to 40 years, plasma levels of fPS were 94% (59-150%) and 80% (49-132%), respectively (P = 0.008). Finally, we studied the relationships existing between these factors. We found that plasma levels of most coagulation factors were interrelated. In addition, FDP values were positively correlated with plasma level of Fg (r = 0.26); P = 0.008).