Immunophenotipic and molecular characterization of EBV-driven age-related lymphoproliferative disorders

Based on epidemiological studies, EBV-positive lymphoproliferative disorders (LPD) are associated with patient’s age, immune system status of the host, geography, and socioeconomic conditions. In particular, in immunocompetent patients EBV+ cHL occur more frequently in children from poorly developed countries and in older adults from developed countries, whereas EBV-negative cases are more frequent among young adults of developed countries (Armstrong et al 1998, Jarrett et al 2003). These differences have questioned the effective role of EBV in the pathogenesis of the disease, and have raised the possibility that EBV-positive and EBV-negative cHL may represent two distinct diseases (Harris et al 1998). It has been suggested that different factors may contribute to the development of EBV+ cHL in children and older patients. In the former, early age of EBV infection has been reported to greatly affect the association of EBV with cHL (Glaser et al 1997) while, in the latter immunosenescence related to patient’s age has been proposed as a key factor for the development of EBV+ cHL (Jarrett et al 2005, Dojcinov et al 2011). In both cases, it has been suggested that an impaired immune status of the host may contribute to the development of EBV+ cHL. However, whether or not EBV+ cHL occurring in children and in old patients represent the same disease remains to be clarified. To address this issue, we characterized and compared the immunophenotipic and molecular features of 57 cases of HL occurring in pediatric patients from Baghdad with those of 30 cases of HL diagnosed in old Italian patients.