ABSTRACT
Previous studies with stored red cells collected into EDTA anticoagulant had shown that commercial polyclonal anti-C, -c, and -E reagents gave acceptable reactions for 60 days, hut polyclonal anti- e reagents reliably detected the e antigen only through 14 days. At that time it was noted that a monoclonal anti-e reacted 3+ to 4+ with red cells that no longer reacted, or reacted very weakly, with the polyclonal anti-e reagents. This observation led to a comparison study of the reactivity of monoclonal versus polyclonal R h reagents with stored red cells. Monoclonal and polyclonal anti-C, -c, and -E reagents showed comparable reaction strengths, and gave acceptable reactions over the entire testing period. Polyclonal anti-e reagents, which are known to he of lower titer, again did not give reliable reactions with stored cells after 14 days. However, three different monoclonal anti-e reagents were able to detect the presence of the e antigen on stored cells for many weeks, This study showed that the monoclonal anti-e reagents tested are superior to polyclonal anti-e reagents for typing specimens that have been stored for more than 14 days.
ABSTRACT
Commercial blood grouping reagents are not approved for testing EDTA anticoagulated blood specimens that are more than 48 hours old. Many studies on the stability of blood group antigens in other anticoagulants have been reported, but none are available for EDTA. This study was undertaken to assess whether current commercially available blood grouping reagents give acceptable reactions with red cell antigens when the cells are stored for mended periods in EDTA We defined acceptable reaction strength to be 2+ (score 8). As expected, the A, B, and D reactions were very stable with red cells stored for 60 days. All antigens except Lea exhibited 2+ (score 8) or greater reactions at day 14, and at day 2 1 only the Lea, Fyb, and e antigens were less than 2+. On day 60, twelve of twenty-one antigens tested still exhibited 2+ or greater reactions. This study shows that antigen reactivity for red cells collected and stored in EDTA is at least equal to that for clotted specimens These red cells can be used for reliable antigen typing for at least 14 days, and even longer for most antigens.
ABSTRACT
The high-frequency Chido (Ch) antigen, found predominantly in plasma, is a determinant of the C4d fragment of the C4 molecule and is acquired by red cells during in vivo complement activation. Antibodies are made by Ch- people who lack C4S. It has often been reported that anti-Ch (and anti-Rg) do not cause hemolytic transfusion reactions. Reported here is a case of a transfusion reaction caused by anti-Ch. The antibody did not cause red cell destruction, but did cause a life-threatening anaphylactic reaction during transfusion of plasma proteins in pooled platelets. The antibody was of the IgG4 subclass and might have caused a short-term, sensitizing anaphylactic response. This case, and one previously reported in which a patient with anti-Rg experienced a severe reaction to fresh-frozen plasma and a plasma derivative, illustrates that these antibodies can cause severe, life-threatening reactions in patients who receive plasma-containing components.
