title: Possible interference of human beta-herpesviruses-6 and -7 in gastrointestinal cancer development.
abstract: OBJECTIVE
  The high incidence of gastrointestinal cancer combined with high mortality from the disease if diagnosed at a late stage, signifies the need for better diagnostic, prognostic and predictive tools. Human beta-herpesviruses have been suggested as possible cofactors in the development of gastrointestinal cancer.
  
  
  METHODS
  Sixty five patients with gastrointestinal cancer before surgery and without any treatment were enrolled in this study and divided into two groups depending on lymphocytes' count: I group (n = 35) -- lymphocytes > 1400x10(6)/L and II group (n = 30) -- lymphocytes < 1400x10(6)/L. Nested polymerase chain reaction was used to detect latent and active stage of persistent human herpesvirus-6 and -7 infection, laser flow cytometry with monoclonal antibodies -- to determine immunological parameters.
  
  
  RESULTS
  Activation of herpesvirus-6 and -7 was more frequently observed in the patients' group with lymphopenia (HHV-6 1/1 (100%), HHV-7 4/8 (50%) and HHV-6 + HHV-7 6/9 (66%); p < 0.05). Cellular immune parameters were analysed in immunocompromised II group's patients dependently on beta-herpevirus infection. Although number of leukocytes was higher in patients with active HHV-6/-7 infection (p = 0.01), number of lymphocytes CD3(+), CD4(+), CD8(+) and CD38(+) in patients with active HHV-6/-7 infection tended to decrease (p < 0.0001, P = 0.0002, p = 0.0001 and p < 0.0001, respectively). However, number of CD19(+) had tendency to increase (p = 0.03).
  
  
  CONCLUSIONS
  Activation of herpesvirus-6 and -7 may lead to decrease of lymphocytes total count and develop immunosuppression in patients with gastrointestinal cancer.
authors.affiliation: Riga Stradins University, August Kirchenstein Institute of Microbiology and Virology, Riga LV-1067, Latvia. a.sultanova@inbox.lv
authors.forename: A
authors.initials: A
authors.lastname: Sultanova
authors.forename: M
authors.initials: M
authors.lastname: Chistjakovs
authors.forename: S
authors.initials: S
authors.lastname: Chapenko
authors.forename: S
authors.initials: S
authors.lastname: Donina
authors.forename: M
authors.initials: M
authors.lastname: Murovska
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005770:Gastrointestinal Neoplasms / Q000276:immunology* / Q000601:surgery / Q000821:virology*; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000472:pathogenicity*; D016199:Herpesvirus 7, Human / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007108:Immune Tolerance; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets; D008231:Lymphopenia / Q000821:virology; D008875:Middle Aged; D019349:Roseolovirus Infections / Q000175:diagnosis / Q000276:immunology / Q000821:virology*