Proteolytic enzyme techniques may be useful in identifying which of the following antigen groups?

Proteolytic enzyme techniques are important in blood group serology because they can enhance the reactivity of certain antigens found on red blood cells. Among the antigen groups listed, the Kidd blood group system is particularly associated with this enhancement when treated with enzymes such as papain or ficin.

The Kidd antigens (Jka and Jkb) are known to be sensitive to proteolytic enzymes; the treatment can increase the expression of these antigens on the red cell surface, making them more easily detectable in serological testing. This can be particularly useful when trying to resolve weak antigen expressions or when antibodies against these antigens might not be easily detectable in routine testing.

In contrast, the other antigen groups do not share the same sensitivity to proteolytic enzyme treatment. The Rh group antigens, for example, are not significantly affected by proteolytic enzymes, as are the Lewis and Duffy antigens, which may show varying degrees of reactivity but do not benefit from enzyme treatment to the same extent as the Kidd antigens. Hence, using proteolytic enzymes is a valuable technique specifically for identifying and enhancing the reactivity of the Kidd antigens in blood group serology.