Clinical Evaluation of Concentrated Red Cells

Concentrated red cells, depleted of all or almost all visible plasma, and then stored at 4°C for as long as 28 days, were administered as therapeutic transfusions. The 24-hour survival was over 70 per cent and was not affected by the degree of concentration. In four of six Group A1, B or A1B recipients, a positive direct antiglobulin test was observed immediately after transfusion of Group O cells with residual plasma, and the red cells in these samples agglutinated in the Auto-Analyzer without added antibody. However, the survival of the recipient's red cells was normal. Our data suggest that the removal of damaged red cells during transfusion was influenced by the state of the recipient's health; seriously ill patients exhibited an ineffective removal mechanism, where-as otherwise healthy recipients with accidental injuries removed the irreversibly damaged red cells promptly.