Aplastic anemia following infectious mononucleosis: possible immune etiology.

A 17-year-old female developed severe aplastic anemia following serologically proven infectious mononucleosis. In vitro studies, using the granulocyte colony forming technique, suggested that the aplasia may have resulted from an immune mechanism. The patient's marrow grew no granulocyte colonies and caused inhibition of colony formation when mixed with normal marrows. The patient recovered fully after therapy with antithymocyte globulin and marrow cultures showed disappearance of the inhibitory effect. These observations suggest that the severe aplasia may have resulted from an aberrant immune response which followed infection by EB virus.