J. Biol. Chem., Vol. 256, Issue 11, 5324-5326, 06, 1981
Prevention of the immune agglutination of methyl acetimidate-reacted sickle erythrocytes by prior reaction with pyridoxal 5'-phosphate
TL Chao and MR Berenfeld
The appearance of an immune response in some sickle cell anemia patients to
reinfused autologous erythrocytes which had been treated with methyl
acetimidate (Gabuzda, T. G., Chao, T. L., Berenfeld, M. R., and Gelbart, T.
(1980) Blood 56, 1041--1047) was a serious impediment to the clinical
application of this reagent as an extracorporeal antisickling agent. The
immune reaction was doubtlessly due to acetamidination of membrane protein
amino groups. Protection of these amino groups with a reversible reagent
prior to treatment of the cells with methyl acetimidate should prevent the
antigenic reaction. This result was realized by preequilibration of
erythrocytes with pyridoxal 5'-phosphate prior to addition of methyl
acetimidate. Subsequent washing of the cells to remove excess reagents and
to hydrolyze the pyridoxal 5'-phosphate/membrane protein Schiff base adduct
regenerates native protein amino groups of the erythrocyte membrane.