RESUMEN
T-cell non-Hodgkin's lymphomas (NHLs) represent 10% to 15% of all diagnosed lymphomas in Western countries. Various geographic frequencies of T-cell NHL have been documented, in part reflecting increased exposure to pathogenic factors such as Epstein-Barr virus (EBV). Our aims were to assess EBV and p53 expression in Argentine pediatric T-cell lymphoma and to correlate them with patients' survival. Epstein-Barr encoded RNAs (EBERs) in situ hybridization and LMP1 and p53 immunohistochemical staining were performed on formalin-fixed paraffin-embedded lymph node biopsies from 25 pediatric T-lymphoma patients. In 17 of 25 samples good-quality DNA was obtained, and EBER polymerase chain reaction was assessed to confirm in situ hybridization and immunohistochemical results. Epstein-Barr virus expression was found in 8.0% of cases. p53-positive staining was distributed in 92% of pediatric cases. Kaplan-Meier survival analysis showed that neither EBV nor p53 expression was statistically significantly associated with event-free survival. Our data showed a low frequency of EBV association with pediatric T-cell lymphoma. It seems that p53 plays an important role in proliferation in our studied population, since it is overexpressed in 92% of T-cell lymphoma cases.
Asunto(s)
Biomarcadores de Tumor/análisis , Infecciones por Virus de Epstein-Barr/epidemiología , Leucemia de Células T/metabolismo , Leucemia de Células T/virología , Proteína p53 Supresora de Tumor/biosíntesis , Antígenos CD/biosíntesis , Argentina , Niño , Infecciones por Virus de Epstein-Barr/complicaciones , Femenino , Citometría de Flujo , Herpesvirus Humano 4 , Humanos , Inmunohistoquímica , Hibridación in Situ , Estimación de Kaplan-Meier , Leucemia de Células T/mortalidad , Masculino , Reacción en Cadena de la Polimerasa , ARN Viral/análisisRESUMEN
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.