A case of severe chronic active infection with Epstein-Barr virus: immunologic deficiencies associated with a lytic virus strain.

Infectious mononucleosis (IM) is a self-limiting, lymphoproliferative disease induced by primary infection with the Epstein-Barr virus (EBV). Infection with EBV leads in general to lifelong asymptomatic persistence of the virus. We report the case of a woman who acquired IM at the age of 15 years and then suffered from recurrent high fever, fatigue, and signs of immunologic disorder for more than 12 years until she died of liver failure. In an attempt to describe and to define the course of chronic active infection with EBV, we performed immunologic and molecular assays that demonstrated lytic replication of EBV in the B and T cells of the peripheral blood. In addition to signs of humoral and cellular immune deficiency, we detected an EBV strain with an impaired capability to immortalize B cells and a tendency to lytic replication, thus contributing to the pathogenesis of this chronic active infection.