Comparison of Epstein-Barr virus presence in Hodgkin lymphoma in pediatric versus adult Argentine patients.

CONTEXT

In developed countries and high socioeconomic groups, Hodgkin lymphoma has an initial peak in young adulthood, whereas in undeveloped countries and low socioeconomic groups, it shows an early childhood peak. In developing countries, 90% of children are infected with the Epstein-Barr virus (EBV) by the age of 6 years, but in developed countries, only 30% to 40% are seropositive by that age. Early childhood EBV infection in 75% of Argentine patients was demonstrated.

OBJECTIVE

To explore the epidemiology of Hodgkin lymphoma and its relationship with EBV in Argentine patients.

METHODS

The presence of EBV was assessed by Epstein-Barr encoded RNA in situ hybridization and latent membrane protein 1 immunohistochemistry. We studied 92 pediatric and 42 adult Hodgkin lymphoma cases from a public center as well as 39 adult cases from a private center.

RESULTS

The mixed cellularity Hodgkin lymphoma had a prevalence of 52% in the pediatric group, while similar frequencies of both nodular sclerosis Hodgkin lymphoma (47%) and mixed cellularity Hodgkin lymphoma (44%) were observed in adults. As for Epstein-Barr encoded RNAs, 55% of the pediatric cases and 31% of the adult cases were positive. Among adult EBV+ cases, 38% were from the public hospital, and 23% were from the private center. EBV was present in 77% of the pediatric mixed cellularity Hodgkin lymphoma cases when compared with the other histologic subtypes of Hodgkin lymphoma. EBV was mainly detected in mixed cellularity cases (39% in the adult group).

CONCLUSION

Our findings strengthen the argument that EBV is involved in the pathogenesis of Hodgkin lymphoma in most children younger than 10 years. Our findings of EBV prevalence, along with both childhood and second-decade peaks as well as comparable frequencies for Hodgkin lymphomas of mixed cellularity and nodular sclerosis, distinguish our population from others in developing countries.