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Quality control of leucocyte depleted blood products has become a problem since the introduction of bedside leucocyte filtration. At our Blood Centre, this problem has been circumvented by testing a sample taken as the filtration is completed by sealing off a 10 cm piece of tubing just under the filter. We have tested four brands of erythrocyte filters, Pall RC100, Erypur Optima b, Sepacell R-200A and Sepacell R-500A(II) using two erythrocyte concentrates for each filter. We have tested two brands of thrombocyte filters, Pall PL100 with 6-8 thrombocyte concentrates, and Sepacell PL-5A with 2-6 concentrates. No transfusion should give more than 5 x 10(6) leucocytes. Pall PL100, Pall RC100 and Sepacell R-500A(II) met the criteria.

Serum ferritin levels were measured in 613 women and 376 men included in our Blood Donor Registry in 1990, prior to their first donation. The mean serum ferritin was 34 micrograms/l in females and 98 micrograms/l in males. For men less than 20 years of age mean serum ferritin was 52 micrograms/l which is significantly lower than for the other age groups. For women greater than or equal to 50 years of age mean serum ferritin was 61 micrograms/l, which is significantly higher than for the younger age groups. In 22% of the women and 1.3% of the men serum ferritin was less than 15 micrograms/l upon registration. Female blood donors with an initial serum ferritin of less than 10 micrograms/l had donated on average 1.2 times 11 to 23 months later, and 56% were temporarily or permanently deferred from donation. Females with an initial serum ferritin of between 30 and 39 micrograms/l had donated 2.5 times, and 26% were deferred.

In analyses of cost-effectiveness it is customary to count knowledge of having a high serum cholesterol level as a negative factor. There is little support for this practice in the literature. We have studied the attitude of 305 Norwegian blood donors towards cholesterol testing. 63% stated that they were interested in their serum cholesterol level, and 40% said they knew their own serum cholesterol level. The attitude towards cholesterol testing was clearly positive, both among men and among women, regardless of age. Only one donor stated that she did not want to have her serum cholesterol tested in conjunction with blood donation.

Serum cholesterol levels were measured in 280 blood donors between November 1988 and May 1989 and again between February and April 1991. In 84 of these persons the cholesterol level was also measured between November 1989 and January 1990. The 122 females showed a 9.6% reduction in mean serum cholesterol from 5.8 mmol/l in the first sample to 5.2 mmol/l in the final sample. The 158 males showed a 7.4% reduction from 5.7 to 5.3 mmol/l. Females with initial values greater than 6 mmol/l showed an average reduction in serum cholesterol of 15.2%. For males with initial values greater than 6 the reduction was 14.0%. There was no difference in reduction between those whose cholesterol was measured at the beginning and the end of the study and those whose cholesterol was also controlled during the course of the study. Our study shows that, in the case of blood donors, a programme involving measuring serum cholesterol and distributing written information can lead to a substantial reduction in serum cholesterol.

In the present study the effect of a change from whole blood to plasma donation on iron stores is investigated by measuring serum ferritin levels. Paired serum samples from 125 plasma donors showed a significant increase in mean serum ferritin level with plasmapheresis. 76% of the plasma donors showed an increase in serum ferritin. For plasma donors the haemoglobin concentration is not related to serum ferritin level and hence to iron stores, and a change in haemoglobin concentration is not related to a change in serum ferritin. Plasma donation is a good alternative to whole blood donation for fertile women and for blood donors opposed to iron supplements.

We present the results from a study of 97 female blood donors who reappeared for donation after giving birth from nine to 60 months before. The donors answered a questionnaire about number of pregnancies, the time since last pregnancy, iron medication before and during pregnancy, and methods of contraception. Serum ferritin was determined in a blood sample drawn before donation. In this group, mean serum ferritin was 21.5 +/- 14 micrograms/l. In a control group consisting of young women who registered as donors the mean serum ferritin was 39.4 +/- 29.4 micrograms/l. There was a decrease in serum ferritin with increasing age and parity. The mean serum ferritin value was higher among women who had taken iron supplements regularly before and during pregnancy than among women who had not taken iron supplements. The differences were statistically significant for iron supplementation during pregnancy. Iron supplements during pregnancy seem justified, but further information should be obtained about necessary does and appropriate time for starting supplementation.

We present the results of serum-cholesterol measurements in 956 blood donors and an evaluation of their motivation for dietary changes based on answers to a questionnaire. The mean serum-cholesterol level was 5.5 mmol/l for women and 5.7 mmol/l for men, with an increase in serum-cholesterol with age. Motivation for dietary changes was food, since 85% answered that they would change their diet if their serum-cholesterol was high. 65% of those who knew their serum-cholesterol to be high before this study had changed their diet. 38% of the smokers answered that they would stop smoking if their serum-cholesterol was high. Eight to 14 months later, serum-cholesterol measurements in 201 of the blood donors showed that 72.4% of those with serum-cholesterol greater than 6 mmol/l had changed their diet and that these had reduced their serum-cholesterol by an average 10.6%.

Since 1986, we have performed 26,500 plasma donations at the Red Cross and National Hospital Blood Centre. In conjunction with these donations, 4,000 serum samples from 3,400 donors have been tested for IgG and albumin level. 125 donors who donated plasma regularly were studied further. In this group we found a mean reduction in IgG of 0.3 g/l, but no significant reduction in albumin. Even for donors who donate regularly the mean time interval between donations was more than 40 days. Today's recommendation of regular IgG and albumin control is a result of experiences from twice weekly plasma donations in the USA. We conclude that such testing is unnecessary in Norway.

In the present study we have examined serum ferritin in experienced male and female blood donors and in women who had never donated blood before, but had registered at the Blood Centre as future donors. There was no coincidence between low haemoglobin and low s-ferritin when haemoglobin was within normal range. Iron stores (s-ferritin less than 20 micrograms/l) were reduced in 40% of the female blood donors and in 21% the iron stores (s-ferritin less than 10 micrograms/l were completely empty. 10% of the male donors had iron stores, while in 3% the iron stores were empty. Among the females who had not donated blood, 30% had s-ferritin values below 20 micrograms/l and 6% had values below 10 micrograms/l. We conclude that measuring s-ferritin is a better method of identifying individuals at risk for iron depletion than measuring hemoglobins. A combination of longer intervals between donations and iron therapy may prevent depletion of iron stores in blood donors.

Sera from 142 Norwegian couples were assayed for the presence of antibody to Cytomegalovirus. Sixty-four percent were seropositive and the yearly conversion rate was approximately 1.65%. The couples included significantly more seropositive women than men. This may indicate that seropositive men infect seronegative women, while seropositive women seldom infect seronegative men.