title: Retrospective analysis of varicella zoster virus (VZV) copy DNA numbers in plasma of immunocompetent patients with herpes zoster, of immunocompromised patients with disseminated VZV disease, and of asymptomatic solid organ transplant recipients.
abstract: BACKGROUND
  Varicella zoster virus (VZV) causes significant morbidity and mortality in immunocompromised patients. Subclinical reactivation has been described in solid organ recipients and has been associated with graft versus host disease in bone marrow transplantation. Newer studies assessing the prevalence and impact of subclinical VZV reactivation in solid organ transplant (SOT) recipients are lacking.
  
  
  RESULTS
  In a first step we developed a highly sensitive quantitative polymerase chain reaction (qPCR) assay for VZV DNA with a detection limit of < or = 20 copies/mL. Using this assay, we retrospectively analyzed plasma samples of different patient groups for VZV DNA. VZV DNA was found in 10/10 plasma samples of immunocompetent patients with herpes zoster (VZV copy numbers/mL: mean+/-SEM 1710+/-1018), in 1/1 sample of a human immunodeficiency virus-infected patient with primary VZV disease (15,192 copies/mL) and in 4/4 plasma samples of immunocompromised patients with visceral VZV disease (mean of first value 214,214+/-178,572). All 108 plasma samples of asymptomatic SOT recipients off any antiviral therapy, randomly sampled over 1 year, were negative for VZV DNA.
  
  
  CONCLUSIONS
  Our qPCR assay proved to be highly sensitive (100%) in symptomatic VZV disease. We did not detect subclinical reactivation in asymptomatic SOT recipients during the first post-transplant year. Thus, subclinical VZV reactivation is either a rare event or does not exist. These data need to be confirmed in larger prospective trials.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, Department of Internal Medicine, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Kronenberg
authors.forename: W
authors.initials: W
authors.lastname: Bossart
authors.forename: R P
authors.initials: RP
authors.lastname: Wuthrich
authors.forename: C
authors.initials: C
authors.lastname: Cao
authors.forename: S
authors.initials: S
authors.lastname: Lautenschlager
authors.forename: N D
authors.initials: ND
authors.lastname: Wiegand
authors.forename: B
authors.initials: B
authors.lastname: Mullhaupt
authors.forename: G
authors.initials: G
authors.lastname: Noll
authors.forename: N J
authors.initials: NJ
authors.lastname: Mueller
authors.forename: R F
authors.initials: RF
authors.lastname: Speck
mesh_terms: D000328:Adult; D002644:Chickenpox / Q000276:immunology / Q000821:virology; D004279:DNA, Viral / Q000097:blood*; D018628:Gene Dosage / Q000235:genetics*; D006562:Herpes Zoster / Q000276:immunology / Q000821:virology; D014645:Herpesvirus 3, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007121:Immunocompetence; D016867:Immunocompromised Host; D016377:Organ Transplantation / Q000009:adverse effects*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014766:Viremia / Q000276:immunology / Q000821:virology
chemical_list: D004279:DNA, Viral