Fresh frozen plasma quality: relation to age and gender of blood donors

In view of demographic changes, it is becoming increasingly necessary to make allowance for the fact that older individuals in good health are generally more willing to donate blood and hence they should be allowed to do so irrespective of an upper age limit. In this respect, evidence has to be produced that there is neither an age-related increase in risks to the donor nor any influence on the safety and efficacy of the blood components. It was therefore of interest to examine the quality of therapeutic plasma in relation to a donor's age and also a donor's gender in view of the preferred use of male donor plasma for reducing the risk of transfusion related acute lung injury.

Citrate-phosphate-dextrose (CPD) units of whole blood taken in each case from 50 blood donors (30 men and 20 women) of three age groups (cohort 1 = 69-71 years, cohort 2 = 66-68 years and cohort 3 = 50-52 years) were filtered, centrifuged and then separated into the relevant blood components. The plasma samples were assessed for international normalized ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen, factor V (FV), factor VIII (FVIII), antithrombin (AT), protein S and plasminogen.

While aPTT showed only slight age-related differences of no significance, the INR levels of cohort 1 were significantly higher than those of cohorts 2 and 3. However, in terms of gender, this applied to male donors only. The differences in INR are demonstrated by lower FV levels of male cohort 1 donors, although this is not statistically significant in comparison with the other two age groups and with female donors. Female donors of all cohorts, however, exhibited noticeably lower aPTT levels than male donors. Lower INR and aPTT values in women could be a sign of a lower dilution affected by CPD anticoagulant as compared to male plasma. An increase in FVIII levels was also apparent with increasing age (P < 0·05), particularly in male donor plasma. The fibrinogen levels suggest a slight, though insignificant, age-related increase and no significant gender-dependent effect. The plasma levels of AT and plasminogen were unremarkable. The plasma of female cohort 3 donors exhibited a protein S concentration that was slightly lower by comparison. Compared with the other two cohorts, cohort 1 plasma levels were similarly above or below the normal range derived from cohort 3 (central 95% range) for all parameters tested.

International Normalized Ratio, aPTT, FVIII, FV, fibrinogen and protein S, as quality indicators for the efficacy of therapeutic plasma, revealed a moderate correlation with age and gender. Compared with the usual reference ranges, the differences were not significant enough to identify any relevant imbalance between procoagulating, anticoagulating and fibrinolytic factors that might influence product quality where the increasing age of the donors or the preference of male donor plasma was concerned.