RESEARCH OF SERUM ANTIBODIES ANTI-SV40 IN NORMAL INDIVIDUALS AND ONCOLOGIC PATIENTS.

Background:Simian virus 40 (SV40) is a small DNA tumor virus found associated with specific human cancers, such as brain and bone tumors, malignant pleural mesothelioma, and non-Hodgkin lymphoma. SV40 sequences were also detected, although at lower prevalence, in blood specimens from healthy donors. However, some studies failed to reveal the presence of SV40 in human samples, and its association with specific neoplasms. These conflicting results indicate the need of a specific standardized test, to be share within the scientific community, to study the SV40 infection in humans and its association with cancers. Methods: In this investigation we report on the presence in human sera of antibodies reacting against specific SV40 peptides revealed by an indirect ELISA. test. The immunologic assay was set up employing synthetic peptides corresponding to SV40 epitopes of the viral capsid proteins and the large T antigen (Tag), the SV40 oncoprotein. Sera from healthy donors and oncologic patients were tested with indirect ELISA assays. Overlapping results were obtained with this immunologic assay employing four specific peptides from early and late SV40 regions. Results: Data from immunologic assays indicate that in healthy individuals serum antibodies against SV40 are detectable since the early childhood. In healthy donors the seroprevalence increases with the age reaching the peak of 25% in subjects aged 1-10 years, it declines in subjects aged 11-17 with a prevalence of 15%, then it slightly increases to 20%, remaining stable till the age of 50 years old. In the cohort of individuals aged 51-65 year old the seroprevalence tends to decline with a prevalence 17%, while in elderly subjects aged 66-90 years the prevalence is the 23%. This result indicates that the SV40 circulation in humans is of low level compared to the prevalence of the closely related human polyomaviruses BK (80-90%) and JC (60-70%). In our investigation, serum samples from oncologic patients affected by bone and brain tumors, non-Hodgkin lymphoma, and malignant pleural mesothelioma, had a high prevalence of anti-SV40 antibodies. Conclusions: In our study, the prevalence of serum samples reacting with SV40 peptides was higher in sera from oncologic patients, compared to controls. Indeed, SV40-positive sera were detected at higher prevalence in patients affected by osteosarcoma (57%), non-Hodgkin lymphoma (51%), glioblastoma (34%) and mesotheliomas (32%) than in normal subjects (18%). No statistically significant difference in prevalence was revealed in sera from patients affected by breast cancer (21%) and undifferentiated nasopharyngeal carcinoma (25%), a neoplasm associated with the EBV infection, compared to samples from healthy donors. Our data further indicate the association of SV40 with specific human malignancies.