title: Lack of association of polyomavirus and herpesvirus types 6 and 7 in human lymphomas.
abstract: BACKGROUND
  The association of viruses with several human tumors has been studied for almost 100 years, and it remains a very controversial issue. Due to the fact that the presence of polyomaviruses and herpes viruses reportedly are associated with lymphomas, albeit with striking results and differences between the many studies, the authors undertook a study into the presence of viral sequences of polyomavirus (BK virus, JC virus, and especially simian virus 40 [SV40]) in human lymphomas in an attempt to explain this contradictory association. To complete the study, the presence of different virus types from the herpesviriridae family were analyzed, such as herpesvirus type 6 (HHV6), HHV7, HHV8, and Epstein-Barr virus, in human lymphomas.
  
  
  METHODS
  DNA was isolated from 83 frozen human lymphoma samples, and different polymerase chain reaction techniques were used to find polyomavirus and herpesvirus sequences in these samples. To assess the incidence of the presence of sequences in lymphomas, a parallel analysis was made of 53 samples from normal donor spleen lymphocytes. Positive samples were analyzed for polyomavirus sequences by immunohistochemistry.
  
  
  RESULTS
  Polyomavirus sequences were detected in 9 of 83 lymphomas (11%), and SV40 sequences could be confirmed in only 1 lymphoma. Immunohistochemistry for large-T antigen was negative in all samples. Herpesviruses were detected in 53 of 83 lymphomas (63.9%), were detected more frequently in Hodgkin lymphomas (80%) than in non-Hodgkin lymphomas (58.7%), and were detected in > 60% of normal spleen lymphocytes.
  
  
  CONCLUSIONS
  The current results did not support a clear association of polyomavirus and HHV6 or HHV7 with lymphomas; HHV6 and HHV7 sequences were detected in a similar percentage of normal samples and lymphomas. The lack of significant differences between normal and malignant lymphocytes and the absence of viral protein expression in the tumor cells did not allow the establishment of a clinical correlation between polyomaviruses or HHVs (HHV6, HHV7, HHV8) and lymphomas. Nevertheless, because viral products can be lost during tumor progression, and because host factors can modulate the oncogenic role of some viruses, the hypothetical role of these viruses cannot be discarded completely.
authors.affiliation: Department of Pathology, Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Hernández-Losa
authors.forename: Cesar Giovanni
authors.initials: CG
authors.lastname: Fedele
authors.forename: Francisco
authors.initials: F
authors.lastname: Pozo
authors.forename: Antonio
authors.initials: A
authors.lastname: Tenorio
authors.forename: Victor
authors.initials: V
authors.lastname: Fernández
authors.forename: Josep
authors.initials: J
authors.lastname: Castellví
authors.forename: Carlos
authors.initials: C
authors.lastname: Parada
authors.forename: Santiago
authors.initials: S
authors.lastname: Ramón y Cajal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D016022:Case-Control Studies; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015654:Herpesvirus 6, Human / Q000302:isolation & purification*; D016199:Herpesvirus 7, Human / Q000302:isolation & purification*; D006689:Hodgkin Disease / Q000473:pathology / Q000821:virology*; D006801:Humans; D007150:Immunohistochemistry; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D018570:Risk Assessment; D012494:Sampling Studies; D013539:Simian virus 40 / Q000302:isolation & purification*; D013030:Spain; D014412:Tumor Virus Infections / Q000175:diagnosis*
chemical_list: D004279:DNA, Viral