Inhibition of anti-a by group a plasma in group 0 recipients

The effect of group A plasma products on the levels of anti-A in group O individuals was investigated. The study consisted of six group O patients undergoing liver transplant surgery. These patients all received a minimum of 12 units of whole blood or its equivalent within 24 hours from the start of surgery. Three patients acted as a control population and were infused with group 0 plasma products while the other three patients received group A plasma products. All patients received only group 0 red blood cells. The anti-A scores at 24 hours were compared and found to be greatly diminished but not totally eliminated in those receiving group A plasma products, while the scores in the control group showed little change. This observation is thought to be primarily due to hemodilution, but neutralization with soluble group A substance probably played a minor role. An unexplained rise in the anti-A scores in four of the patients at approximately two weeks postoperatively was noted.