Reaction of I-131 anti-Rh-o(D) with enzyme treated red cells.

Abstract

The effect of proteolytic enzymes (papain, trypsin, ficin and bromelin) on Rho(D) positive and negative red cells was studied with I131 anti‐Rho(D). Enzymatic pretreatment of red cells results in almost a two‐fold increase in the amount of I131 antiRho(D) bound to these cells. The “enzyme exposed Rho(D)” antigen by some criteria (stability to hemolysis, absence of an increase in negative cells and studies on the supernatant solutions) appears to have the same specificity as the Rho(D) antigen on the untreated cell. The ability of proteolytic enzymes to produce this effect on Rho(D) positive red cells does not correlate directly with the ability of these enzymes to digest casein, although the effect appears to be associated with the proteolytic activity of these enzymes. The amount of increase in uptake of I131 anti‐Rho(D) induced by enzymes is directly proportional to the quantity of antibody bound by the untreated cell, irrespective of the Rh phenotype or zygosity of the red cell.