title: Dominance of variant A in human herpesvirus 6 viraemia after renal transplantation.
abstract: BACKGROUND
  Human herpesvirus 6 (HHV-6), mostly variant B reactivation in renal transplant patients has been published by other authors, but the pathogenetic role of HHV-6 variant A has not been clarified. Our aims were to examine the prevalence of HHV-6, to determine the variants, and to investigate the interaction between HHV-6 viraemia, human cytomegalovirus (HCMV) infection and clinical symptoms.
  
  
  METHODS
  Variant-specific HHV-6 nested PCR and quantitative real-time PCR were used to examine blood samples from renal transplant patients and healthy blood donors for the presence and load of HHV-6 DNA and to determine the variants. Active HHV-6 infection was proved by RT-PCR, and active HCMV infection was diagnosed by pp65 antigenaemia test.
  
  
  RESULTS
  HHV-6 viraemia was significantly more frequent in renal transplant patients compared to healthy blood donors (9/200 vs. 0/200; p = 0.004), while prevalence of HHV-6 latency was not significantly different (13/200 vs. 19/200; p > 0.05). Dominance of variant A was revealed in viraemias (8/9), and the frequency of HHV-6A was significantly higher in active infections compared with latency in renal transplant patients (8/9 vs. 2/13; p = 0.0015). Latency was established predominantly by HHV-6B both in renal transplant patients and in healthy blood donors (11/13 and 18/19). There was no statistical significant difference in occurrence of HCMV and HHV-6 viraemia in renal transplant patients (7/200 vs. 9/200). Statistical analysis did not reveal interaction between HHV-6 viraemia and clinical symptoms in our study.
  
  
  CONCLUSIONS
  Contrary to previous publications HHV-6A viraemia was found to be predominant in renal transplant patients. Frequency of variant A was significantly higher in cases of active infection then in latency.
authors.affiliation: Institute of Medical Microbiology, University of Debrecen, Nagyerdei krt, 98, Debrecen, Hungary. csomae@freemail.hu
authors.forename: Eszter
authors.initials: E
authors.lastname: Csoma
authors.forename: Beáta
authors.initials: B
authors.lastname: Mészáros
authors.forename: Tamás
authors.initials: T
authors.lastname: Gáll
authors.forename: László
authors.initials: L
authors.lastname: Asztalos
authors.forename: József
authors.initials: J
authors.lastname: Kónya
authors.forename: Lajos
authors.initials: L
authors.lastname: Gergely
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000956:Antigens, Viral / Q000097:blood; D001769:Blood / Q000821:virology; D002648:Child; D015897:Comorbidity; D003586:Cytomegalovirus Infections / Q000150:complications / Q000453:epidemiology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D019349:Roseolovirus Infections / Q000150:complications / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D014180:Transplantation; D014766:Viremia / Q000150:complications / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D055815:Young Adult
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral