Effects on Blood Group Antigens from Storage at Low Ionic Strength in the Presence of Neomycin¹

Abstract

Red blood cells (RBC) stored without plasma in a neomycin, low ionic strength medium at 4 degrees C in excess of 24 h show alterations in antigen reactivity. There is a loss of protease-sensitive RBC antigens and a protease-type increased IgG saline agglutinability of Rh antigens that is associated with increased binding of 125I anti-D. Both the serological findings and the alteration in RBC membrane polypeptides are consistent with protease modification of the membrane due to contamination of the RBC by leukocytes. Neomycin, low ionic strength or leukocytes alone or in dual combination do not produce the observed changes in antigen reactivity. The role of neomycin and low ionic strength in this phenomenon and implication for quality control of reagent RBC used for antibody detection and identification are discussed.

Erythrocyte Endogenous Proteinase Activity during Blood Bank Storage

“…These events can be ascribed to endogenous red cell proteinases since the hypothetical effect of leukocyte lyso somal enzymes for ghost proteolysis [1,2,18,19,21] could be excluded by experiments in which leukocytes were re moved or where the addition of preservative solution did not result in WBC degranulation. Therefore, we hypothe size that damage to membrane structure during storage [22] may induce a subsequent susceptibility of ghost proteins to the action of endogenous proteinases.…”

“…red cells in plasma plus CPDA-1) most ghost proteolysis is delayed to the middle period of red cell storage. Although plasma antiproteinases are likely to play a role in inhibiting proteolytic activity on red cell mem branes [2], the simultaneous presence of additive solution…”

“…Studies on red blood cell abnormalities during storage revealed changes in membrane antigen expression resem bling those accompanying proteolytic modification of the red cell [1][2][3] ; these alterations appear to be more relevant when red cells are stored in protein-free media [3]. How ever, the previously published data primarily explored sur face-exposed red blood cell antigens with the aid of serolog ical techniques and not the structural changes of membrane proteins.…”

“…How ever, the previously published data primarily explored sur face-exposed red blood cell antigens with the aid of serolog ical techniques and not the structural changes of membrane proteins. It has been suggested that proteinases released by granulocytes during storage may promote red blood cell membrane alterations leading to a loss of antigen sites as well as increased hemolysis [1][2][3], Several authors have reported on the presence and the activity of cytosolic and membrane-bound erythrocyte proteinases [4][5][6][7][8][9][10], which may also account for postsynthetic abnormalities of red cell membrane proteins [11][12][13].…”

In vitro reactions with red blood cells that are not due to blood group antibodies: a review

“…Malyska et al 67 showed that if RBCs were stored without plasma in a low ionic-strength medium containing neomycin, there was a loss of protease-sensitive antigens. Interestingly, there was an increased binding of anti-D and enhanced reactions with agglutinating anti-D.…”