title: Quantitative polymerase chain reaction for detection of human herpesvirus-7 infection in umbilical cord blood donors.
abstract: OBJECTIVE
  Umbilical cord blood (UCB) has been a reasonable alternative to granulocyte colony-stimulating factor-mobilized peripheral blood or bone marrow, as a source of hematopoietic stem cells with a lower risk of graft-versus-host disease. In immunocompromised hosts after transplantation, the risk of viral infection in adults, especially with beta-herpesviruses such as human herpesvirus-7 (HHV-7), may be increased. This virus in immunocompromised patients can be reactivated from latency and converted to an active phase. Therefore, light-upon-extension real-time polymerase chain reaction (PCR) was developed to assess the prevalence and load of HHV-7 in the plasma and buffy coat of donors.
  
  
  METHODS
  About 825 UCB samples under standard protocol from donors were collected. Then, DNA from plasma and buffy coat was extracted and quantitative real-time PCR was performed with light-upon-extension primers.
  
  
  RESULTS
  Overall, HHV-7 was detected in 3.64% (30/825) of UCB donors. HHV-7 DNA was detected in 26 (3.2%) buffy coat samples (latent infection), and only 4 (0.48%) of them were positive for HHV-7 DNA in plasma samples (active infection); the mean HHV-7 viral load was 1.31 × 10(1) copies/mL in latent infection, and 1.94 × 10(5) copies/mL in active infection.
  
  
  CONCLUSIONS
  We suggest that real-time PCR in plasma and buffy coat could be a useful method to detect active and latent HHV-7 infection in UCB donors and determine its role in subsequent transmission events.
authors.affiliation: Department of Immunology, Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran.
authors.forename: E
authors.initials: E
authors.lastname: Abedi
authors.forename: M
authors.initials: M
authors.lastname: Kheirandish
authors.forename: Z
authors.initials: Z
authors.lastname: Sharifi
authors.forename: S
authors.initials: S
authors.lastname: Samiee
authors.forename: P
authors.initials: P
authors.lastname: Kokhaei
authors.forename: Z
authors.initials: Z
authors.lastname: Pourpak
authors.forename: M J
authors.initials: MJ
authors.lastname: Ashraf
mesh_terms: D000293:Adolescent; D000328:Adult; D001782:Blood Donors; D036101:Cord Blood Stem Cell Transplantation / Q000009:adverse effects*; D005260:Female; D005312:Fetal Blood / Q000821:virology*; D016179:Granulocyte Colony-Stimulating Factor; D016199:Herpesvirus 7, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008969:Molecular Sequence Data; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D019349:Roseolovirus Infections / Q000175:diagnosis / Q000517:prevention & control / Q000635:transmission / Q000821:virology*; D019562:Viral Load; D055815:Young Adult
chemical_list: D016179:Granulocyte Colony-Stimulating Factor
keywords: human herpesvirus-7; real-time polymerase chain reaction; umbilical cord blood transplantation