title: Quantitation of human herpesvirus-6A, -6B and -7 DNAs in whole blood, mononuclear and polymorphonuclear cell fractions from healthy blood donors.
abstract: BACKGROUND
  Diagnosis of human herpesvirus-6A (HHV-6A), -6B (HHV-6B) or -7 (HHV-7) infections is often based on the measure of viral load in blood.
  
  
  OBJECTIVE
  The aim of this study was to define usual values of HHV-6A, HHV-6B and HHV-7 loads in blood fractions (whole blood [WB], mononuclear cells [PBMCs], polymorphonuclear leukocytes [PMNLs]) of blood donors.
  
  
  METHODS
  HHV-6A, HHV-6B and -7 DNAs were quantitated using real-time PCR assays in WB, PBMCs and PMNLs separated on Ficoll or dextran gradients, respectively, for 200 blood donors. Viral loads were expressed as the number of viral genomic copies per million cells (Cop/M) for all fractions, and also per milliliter for WB.
  
  
  RESULTS
  HHV-6B DNA was rarely detected in WB (8%), PBMCs (16.5%), and PMNLs (10.5%), HHV-6A was never detected, whereas HHV-7 DNA was often present in WB (51.5%), PBMCs (62%) and PMNLs (51.5%). Median loads were low with 81 Cop/M in WB, 62 Cop/M in PBMCs and 34.5 Cop/M in PMNLs for HHV-6B, and 129 Cop/M in WB, 225 Cop/M in PBMCs and 62 Cop/M in PMNLs for HHV-7. Viral load expression per million cells and per mL were equivalent. One subject had chromosomally integrated HHV-6 with high viral loads ranging from 2.23×10(6) to 3.21×10(6) Cop/M in all compartments and plasma.
  
  
  CONCLUSIONS
  These results allow to propose viral load in WB as a sensitive and suitable marker, with values for healthy subjects at approximately 100 Cop/M for both viruses. The prevalence of chromosomally integrated HHV-6 was 0.5%.
authors: UPMC Univ Paris 06, ER1 DETIV, 83 Boulevard de l'Hôpital, Paris F-75013, France.
authors: Bastien
authors: B
authors: Géraudie
authors: Mélinda
authors: M
authors: Charrier
authors: Pascale
authors: P
authors: Bonnafous
authors: Delphine
authors: D
authors: Heurté
authors: Marion
authors: M
authors: Desmonet
authors: Marc-Antoine
authors: MA
authors: Bartoletti
authors: Cécile
authors: C
authors: Penasse
authors: Henri
authors: H
authors: Agut
authors: Agnès
authors: A
authors: Gautheret-Dejean
mesh_terms: D000328:Adult; D001782:Blood Donors; D004279:DNA, Viral / Q000032:analysis / Q000097:blood*; D005602:France / Q000453:epidemiology; D015654:Herpesvirus 6, Human / Q000235:genetics*; D016199:Herpesvirus 7, Human / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology*; D009504:Neutrophils / Q000821:virology*; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D019349:Roseolovirus Infections / Q000097:blood / Q000821:virology; D019562:Viral Load
chemical_list: D004279:DNA, Viral