Diagnosis of EBV-positive Hodgkin's disease (HD), non-Hodgkin's lymphoma (NHL; all histological subtypes except Burkitt's lymphoma), or EBV (associated)-T/NK-LPD, or chronic active EBV infection (CAEBV) after second or subsequent relapse including after autologous or syngeneic stem cell transplant (or first relapse or with active disease if immunosuppressive chemotherapy contraindicated). CAEBV is defined as i) illness for greater than 3 months duration (EBV-related illness or symptoms including fever, persistent hepatitis, extensive lymphadenopathy, or hepatosplenomegaly); ii) increased amounts of EBV-DNA in peripheral blood (equal or greater than 400 genome copies per ug of DNA) or abnormal high levels of EBV antibodies (VCA IgG equal or greater than 1:5120 or EA IgG equal or greater than 1:640; and iii) no evidence of previous immunological abnormalities or other recent infection that might explain the observed condition.