Patterns of reactivity of IgG purified from RBC eluates with self-antigens in RBC membranes.

IgG purified from RBC eluates of patients' and blood donors' RBCs was incubated (30 μg/mL) with antigens in RBC membranes, as described in Materials and Methods. The mean densitometric profiles of reactivity of purified IgG (i.e., the arithmetic mean of the recorded intensities constituting the reactivity profile of each individual) of 4 patients with WAIHA (black area) and 4 healthy blood donors (gray curve) with antigens in RBC membranes are depicted. White areas show the densitometric pattern observed in the presence of the secondary antiFcγ antibody alone. Optical densities and migration distances are expressed as arbitrary units.