BZLF1 and EBNA1 gene variants in pediatric Epstein-Barr virus infection

LORENZETTI, M.; PAOLA ANDREA CHABAY; MOSCATELLI G; MORONI S; ALTCHEH J; PRECIADO, M. V.

Buenos Aires, Argentina

Congreso; 6th World Congress of the World Society for Pediatric Infectious Diseases; 2009

Society for Pediatric Infectious Diseases

Epstein-Barr virus (EBV) is lymphotropic. In Argentina infection occurs at an early age and may occasionally develop infectious mononucleosis (IM). EBV is also related with lymphoma. Two EBV genotypes, EBV1 and EBV2, were described. Viral variants display polymorphisms in EBNA1 and BZLF1 promoter. Objective: To study viral type and variants distribution among children with IM at diagnosis (T0), a month (T1) and three months (T2) and compare them with EBV+ pediatric lymphomas. Methods: Oral secretions (OS) and peripheral blood mononuclear cells (PBMC) from 10 VCA IgM+ children with IM and biopsies from 13 EBV+ lymphomas were included. Three PCR strategies were performed: EBNA3C for genotyping, BZLF1 promoter and EBNA1 C-ter. PCR products were directly sequenced. Results: Among IM EBV1 was predominant. BZLF1 variants were Zp-P and Zp-V3. EBNA1 variants were P-ala, P-thr and V-leu. Co-infection with two EBV variants was observed in PBMC but not in OS of 1 patient as revealed by BZLF1 and EBNA1 analysis. All patients showed the same genotype and variants during follow up. Among tumors: Both EBV genotypes showed similar incidence, a new BZLF1 variant (Zp-V3+49) and the two previously described were observed, and EBNA1 variants were the same as described in IM. A significant correlation was observed between Zp-V3 and EBV2 (p=0.0002). Conclusions: Zp-P, Zp-V3 and V-leu variants were found in IM and lymphomas, but were not malignancy related as previously described. Zp-V3+49 could reflect a new variant circulating in our geographic region which in time may be associated with malignancy. Variants at T0 were sustained all through follow up both in OS and PBMC. This is the first study to address distribution and compartmentalization in pediatric patients with IM and its convalescence.