Development of anti-erythrocyte antibodies in mice infected with Babesia rodhaini.

Anti-erythrocyte and anti-parasite antibodies were detected in sera of mice infected with a lethal strain of Babesia rodhaini by an enzyme linked immunosorbent assay (ELISA). Both antibodies were produced soon after infection, and their levels increased rapidly in parallel with increasing parasitemias. The number of erythrocytes decreased as parasitemias increased. Serum levels of both antibodies increased in mice injected with sonicated parasite antigens derived from infected erythrocytes, but not in mice injected with a similar preparation derived from non-infected erythrocytes. Immunoglobulins were detected by on ELISA on the membrane of erythrocytes from mice infected with B. rodhaini or injected with the sonicated antigens. The erythrocytes-associated immunoglobulins seemed to be mainly IgG. These results indicate that B. rodhaini infections induce the production of anti-erythrocyte antibodies as well as anti-parasite antibodies, and the parasite antigens may contain some factors capable of inducing the anti-erythrocyte autoimmune responses.