Coexistence of Epstein-Barr virus and Parvovirus B19 in tonsillar tissue samples: quantitative measurement by real-time PCR.

OBJECTIVE: In this study, we aimed to investigate the presence and copy number of six different viruses in tonsillar tissue samples removed surgically because of chronic recurrent tonsillitis or chronic obstructive tonsillar hypertrophy. METHODS: In total, 56 tissue samples (tonsillar core) collected from 44 children and 12 adults were included in this study. The presence of viruses was investigated using a new TaqMan-based quantitative real-time PCR assay. RESULTS: Of the 56 tissue samples, 67.9% (38/56) were positive for at least one of the six viruses. Epstein-Barr virus was the most frequently detected virus, being found in 53.6% (30/56), followed by human Parvovirus B19 21.4% (12/56), human adenovirus 12.5% (7/56), human Cytomegalovirus 5.4% (3/56), BK polyomavirus 1.8% (1/56), and Herpes simplex virus 1.8% (1/56). Precancerous or cancerous changes were not detected in the tonsillar tissue samples by pathologic examination, whereas lymphoid hyperplasia was observed in 24 patients. In contrast to other viruses, B19 virus was present in high copy number in tonsillar tissues. The rates of EBV and B19 virus with high copy number (>500.000 copies/ml) were higher in children than in adults, and a positive relationship was also found between the presence of EBV and the presence of B19 virus with high copy number (P=0.037). CONCLUSIONS: It is previously reported that some viral agents are associated with different chronic tonsillar pathologies. In the present study, the presence of B19 virus in tonsillar core samples was investigated quantitatively for the first time, and our data suggests that EBV infections could be associated with B19 virus infections or could facilitate B19 virus replication. However, further detailed studies are needed to clarify this observation.