SV40 multiple tissue infection and asbestos exposure in a hyperendemic area for malignant mesothelioma

To assess the presence of SV40 in malignant mesothelioma tissue, 19 formalin-fixed paraffin-embedded pleural cancer samples of patients from a hyperendemic area of northeastern Italy were analyzed retrospectively. A total of 48 other tissues from the malignant mesothelioma subjects were investigated. The SV40 load was determined by real-time quantitative PCR. Exposure to asbestos was evaluated through a careful review of the occupational history of patients, supplemented by histology and isolation of asbestos bodies. Three of 19 (15.8%) malignant mesothelioma tissues harbored SV40 genomic signals. Two patients with SV40-positive malignant mesothelioma had viral sequences in another tissue. Overall, 3 of 18 (16.7%) normal liver tissues tested positive for SV40, as did 1 of 8 (12.5%) kidney tissues. SV40 viral loads were higher in malignant mesothelioma than in normal cells (P = 0.045). This survey shows that SV40 sustains infections in multiple tissues in malignant mesothelioma patients from a geographic area affected with asbestos-related mesothelioma.