Assuntos
Antígenos Transformantes de Poliomavirus/análise , Transtornos Linfoproliferativos/virologia , Infecções por Polyomavirus/epidemiologia , Vírus 40 dos Símios/patogenicidade , Infecções Tumorais por Vírus/epidemiologia , Animais , Estudos de Casos e Controles , Costa Rica/epidemiologia , Contaminação de Medicamentos , Humanos , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/virologia , Linfoma/epidemiologia , Linfoma/virologia , Linfoma de Células B/epidemiologia , Linfoma de Células B/virologia , Transtornos Linfoproliferativos/epidemiologia , Neoplasias Experimentais/virologia , Vacina Antipólio de Vírus Inativado , Infecções por Polyomavirus/virologia , Pseudolinfoma/epidemiologia , Pseudolinfoma/virologia , Roedores , Vírus 40 dos Símios/isolamento & purificação , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/virologia , Infecções Tumorais por Vírus/virologiaRESUMO
BACKGROUND AND OBJECTIVES: Simian virus 40 (SV40) is an oncogenic DNA virus implicated in some human malignancies, including lymphomas. In the present masked case-control study, we investigated the prevalence of SV40 sequences and the expression of the viral oncoprotein, large tumor antigen (T-ag), in lymphomas and control specimens from patients negative for the human immunodeficiency virus in Costa Rica. DESIGN AND METHODS: Coded specimens were anlyzed by polymerase chain reaction for SV40 and Epstein-Barr virus (EBV). SV40 sequences were confirmed by Southern blot and DNA sequence analysis. Immunohistochemistry was used to detect the expression of SV40 T-ag in coded samples and to immunophenotype the lymphomas. RESULTS: When samples were decoded, SV40 DNA sequences were detected significantly more often in lymphomas than in control samples (30/125, 24% vs. 0/91, 0%; p=0.001). SV40 DNA was detected in 26% and 10% of non-Hodgkin's and Hodgkin's lymphomas, respectively. EBV DNA was detected in 10% of lymphomas and 33% of control specimens. None of the lymphomas was positive for both SV40 and EBV. Expression of SV40 T-ag was detected in 64% of B-cell lymphomas that contained T-ag DNA sequences and in none of the samples negative for viral DNA. Not all cells in a positive tumor expressed T-ag and the reactions were relatively low intensity. A germinal center B-cell-like profile was frequently associated with SV40-positive lymphomas. Of note, 20% of patients with SV40-related lymphomas were born in the 1970s and 1980s. INTERPRETATION AND CONCLUSIONS: These results indicate that SV40 is significantly associated with some B-cell neoplasms in Costa Rica today.