Use of nucleic acid testing for blood donor screening of human immunodeficiency virus and hepatitis C virus in the Saudi population.

OBJECTIVE: To determine the risk of transfusion associated infection for human immunodeficiency virus and Hepatitis C virus using nucleic acid testing. METHODS: During March 1998, 400 donor blood samples from the Saudi population that were negative by serology were further tested for human immunodeficiency virus 1 and 2 and Hepatitis C virus using nucleic acid testing. RESULTS: A total of 400 were tested by nucleic acid testing, 381 of these were negative, 4 were indeterminate but were found to be negative on repeat testing and one seronegative sample was found to be positive for Hepatitis C virus. CONCLUSION: Due to the low prevalence of human immuno-deficiency virus in the Kingdom of Saudi Arabia, nucleic acid testing of blood donors by serology is adequate for screening. But the higher prevalence of Hepatitis C virus and increased risk of transmission would indicate that nucleic acid testing may be warranted for Hepatitis C virus in the near future.

Quantitative study of starving platelets in a minimal medium: maintenance by acetate or plasma but not by glucose.

The requirement of donor platelets for fuels, plasma and calcium were studied using platelets washed, filtered to remove leucocytes and resuspended in a new glucose-free minimal platelet storage medium with low citrate (3 mmol/l), low buffer capacity and no calcium. This is the first study of platelets stored without plasma, glucose or calcium and it was shown that platelets continued to aggregate with collagen plus adrenaline for 48 h and showed only a 50% fall in 'swirl index', an objective morphology score, after 3 days, showing that by these criteria human platelets do not require glucose. Sodium acetate extended the storage time by between 2 and 4 days, depending on the index parameter. This is the first evidence showing that failure of platelets in these conditions is at least partly due to exhaustion of fuel, and the first evidence that acetate prolongs in vitro survival. As little as 10% low-glucose plasma extended the storage time, but it was no better than acetate. New observations using this system included a very rapid fall in pH during resuspension of the washed platelet pellet, a rising pH in the absence of added fuel and an increased pH with added acetate.