Persistent epstein-barr virus infection mimicking juvenile chronic myelogenous leukemia: immunologic and hematologic studies.

Epstein-Barr virus (EBV) infections may induce a diverse clinical picture, ranging from the well characterized infectious mononucleosis (IM) syndrome to the rare X-linked lymphoproliferative syndrome. We describe two unrelated children, a 21-mo-old white boy and a 15-mo-old black girl, who presented with the clinical and laboratory findings characteristically seen in juvenile chronic myelogenous leukemia (JCML). Results of periodic serodiagnostic tests indicated that they likely have persistent infection with EBV. Both had elevated IgG antibody to viral capsid antigen (greater than or equal to 1:320) and antibody to early antigen (1:20-1:40) that have persisted for 3 yr of more. Both patients had EBV-specific suppressor cell activity, decreased natural killer cell activity, and diminished antibody-dependent cell-mediated cytotoxicity (ADCC) activity. These changes suggest an underlying defect in the immunoregulatory network controlling EBV infection. The patients have shown clinical improvement without treatment. It appears that EBV infections are capable of inducing symptoms similar to those seen in JCML. Careful evaluation for evidence of EBV infection in patients presenting with symptoms compatible with JCML seems warranted.