Prevention and treatment of Epstein-Barr virus (EBV)-associated lymphoproliferative diseases in immune deficient patients.

Prevention of EBV-associated lymphoproliferative diseases in immune deficient individuals is preferred; however, standard therapy for the B cell lymphomas has been successful. Chemotherapy must be given cautiously lest further immune compromise result in opportunistic infections. Recently, Acyclovir has decreased morbidity of patients with acute infectious mononucleosis in immune competent persons. In contrast, immunodeficient patients with X-linked lymphoproliferative (XLP) syndrome do not seem to respond favorably. Hence, a prospective study is underway using prophylactic immunoglobulin containing (EBV)-specific antibodies. The mortality rate is 85% following EBV infection in XLP due to fatal infectious mononucleosis associated with fulminant hepatitis and virus-associated hemophagocytic syndrome, acquired hypogammaglobulinemia or malignant B cell lymphoma. We can detect XLP by noting failure of switching from IgM to IgG antibody production on secondary challenge with bacteriophage phi X174. Also, linkage studies with the XLP locus using restriction fragment length polymorphisms are being done to detect affected males pre-EBV infection. Our rationale for prevention of phenotypes of XLP is based on observations that infants in tropical Africa and males with XLP do not develop EBV-induced diseases while neutralizing maternal antibodies are present. An EBV vaccine will be used, when available, in seronegative males with XLP. Prevention of acquired immune deficiency by screening blood for human immune deficiency virus, encouraging prudent life styles, development of specific immunosuppressive agents, development of new antiviral agents (i.e., DHPG), and identification of high risk seronegative patients offer possibilities for preventing life-threatening EBV-induced diseases.