Analysis of Epstein-Barr virus in short-term pediatric carriers as a risk for early lymphoma development

VISTAROP A; COHEN, M; DE MATTEO E; PRECIADO MV; PAOLA ANDREA CHABAY

Rio de Janeiro

Congreso; World Society of Pediatric Infectious Diseases Congress 2015; 2015

World Society of Pediatric Infectious Diseases

The Epstein-Barr virus was the first human virus associated to malignancy, even though in most carriers behaves as a harmless passenger. The reason why some of them develop EBV-Associated neoplasias still remains unknown. In order to characterize EBV biologu and its possible involvement with lymphoma development, viral infection was previously studied in adults, with primary infection and healthy carriers. In Argentina primary infection is mostly subclinical at young age, and EBV-associated B-cell lymphoma prevail in patients younger than 10 years. Therefore, it represents an interesting population to analyze EBV infection. Tonsil biopsies in short-term pediatric carriers were studied, to characterize EBV infection, to localize histological regions of latent and lytic protein expression, and to assess B-cell infected subpopulation. Latency II (LII) was statistically associated with non GC region, while Latency III (LIII) was predominant and related to GC region (p=0,0159; Chi2 test). Viral antigen presence in the subepitelial and Interfollicular lymphocytes at young age was established, where probably the virus has recentry got access and it displays the LIII. In contrast, EBV presence in the G region and in epithelial cells, where the virus can spread, are observed in older patients, perhaps because they have been infected time ago. This finding is also sustained by viral load, which is higher at the subepiteliial and IF region and decreases when EBV is not expressed at the subepitelial region (o.o236 M-W test). The majority of cases displayed EBERS+/IgD+ cells (p=0.0021; Chi2 test), with high viral load without specific association with age. Patients with EBERS+/CD27+ cells exhibited a trend to lower median age. Given that LIII pattern prevailed in our series, the oncogenic potential of those viral proteins, particularly EBNA3A and LMP1, expressed together could be involved in pediatric B cell lymphomagenesis at young age observed in Argentina. This analysis will shed light on some aspects of EBV pathogenesis, in order to assess if viral expression and occasional transformation process could eventually arise as a complication of early primary infection. In addition, infection of naïve B cell along with viral protein expression prevalent in the If region, confirms that both EBV infection models are not mutually exclusive in our population.