Detection of polyomavirus SV40 in tonsils from immunocompetent children.
BACKGROUND
BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40) are nonenveloped DNA viruses, members of the family Polyomaviridae. BK and JC viruses establish persistent infections in humans, and evidence suggests that SV40 can infect humans, as well. Whether persistence occurs in the lymphoid system is unknown.


METHODS
Paraffin-embedded tonsils from 220 immunocompetent children (mean age 9.3 years) were examined by polymerase chain reaction (PCR) to detect viral DNA of BKV, JCV, SV40, and Epstein-Barr virus (EBV).


RESULTS
Polyomavirus-specific DNA sequences were detected in 8.3% (29/351) of specimens collected from 220 children. Twenty-one (9.5%) children had polyomavirus DNA present in at least one tonsil, with sequences identified as SV40 (n=20) and BKV (n=1). Polyomavirus JCV was not detected. Among patients positive for SV40, 8 of 14 (57%) contained viral DNA in both available tonsils. EBV DNA was detected in 99 (28.2%) samples from 67 (30.5%) patients. Eleven samples (3.1%) from 8 (3.6%) children were positive for both polyomavirus and EBV. SV40-positive children were significantly older than the SV40-negative subjects (P<0.001). T-antigen expression was detected in an SV40 DNA-positive tonsil by immunohistochemistry.


CONCLUSIONS
These results suggest that SV40 can infect tonsils, that lymphoid tissue may represent a site for polyomavirus persistence, and that immunohistochemistry is not a useful detection assay when there are very few virus-infected cells in a tissue.
Patel
Niraj C
NC
Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX 77030, United States.
Vilchez
Regis A
RA
Killen
Deanna E
DE
Zanwar
Preeti
P
Sroller
Vojtech
V
Eldin
Karen W
KW
López-Terrada
Dolores
D
Butel
Janet S
JS
D000293:Adolescent; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D005260:Female; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D007121:Immunocompetence; D008297:Male; D014066:Palatine Tonsil / Q000473:pathology / Q000821:virology*; D010608:Pharyngeal Diseases / Q000175:diagnosis* / Q000821:virology; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000175:diagnosis* / Q000821:virology; D013539:Simian virus 40 / Q000235:genetics / Q000302:isolation & purification*; D014412:Tumor Virus Infections / Q000175:diagnosis*
D000952:Antigens, Polyomavirus Transforming