Specificity and Immunoglobulin Characteristics of Autoantibodies in Acquired Hemolytic Anemia

Abstract

In a study of 55 red cell eluates obtained from patients with acquired hemolytic anemia of the warm type (AHA), it was established that antibodies of varying Rh specificities can be involved in the disease. Some were specifically reactive against well defined red cell antigens of the Rh system (anti-e, anti-C, and the like), some against all normal Rh red cells (anti-nl), some against partially deleted Rh red cells (anti-pdl), and some against fully deleted Rh red cells (anti-dl).Antibodies against well defined Rh antigens (CDEce) were not often found in the red cell eluates. In contrast, anti-nl, anti-pdl and anti-dl autoantibodies were frequently present in the red cell eluates.The demonstration of serum complement components on the red cells of patients seemed to be associated exclusively with autoantibodies of multiple immunoglobulin classes or multiple red cell specificities. The structural heterogeneity of immunoglobulin types (IgG, IgM and IgA) for the various varieties of autoantibodies (anti-nl, anti-pdl and anti-dl) can be pictured as arising from multiple antibody-forming cell lines.The findings suggest that the initial site of action of autoantibody development in AHA results from a defect of the structural composition of the Rhesus genome, which is thereafter rejected by a normal immune mechanism. The subsequent development of a more generalized auto-immune abnormality involving the formation of multiple autoantibody-forming cell lines does not necessarily indicate the establishment of an aberrant immune apparatus.