title: Dynamics of coexisting HCMV-UL97 and UL54 drug-resistance associated mutations in patients after haematopoietic cell transplantation.
abstract: BACKGROUND
  Resistance to antiviral drugs can be a severe problem in transplant recipients. Mutations in the HCMV phosphotransferase-gene (UL97) and the polymerase-gene (UL54) are responsible for resistance against ganciclovir (GCV), cidofovir (CDV) and foscarnet (PFA). Most frequently mutations in the UL97-gene are associated with resistance to GCV. Resistance against PFA and CDV is associated to mutations in the UL54-gene. There are only few reports about multidrug-resistance with mutations in both genes in patients after allogeneic haematopoietic cell transplantation (HCT).
  
  
  OBJECTIVE
  To asses retrospectively the role of UL97/UL54-mutations for clinical deterioration.
  
  
  METHODS
  We present here three patients after HCT developing multidrug-resistance with coexisting UL97 and UL54-mutations. Genotypical resistance screening was done with restriction-fragment-length-polymorphism (RFLP), sequencing of UL97/UL54, and LightCycler real-time PCR. Phenotyipcal testing was performed by a cell-associated plaque-reduction-assay. Plasma viral-load (VL) was determined longitudinally using Roche Cobas-Amplicor-System (Roche Diagnostics). In one case VL was also correlated to different ratios of coexisting UL97-wildtype and mutant variants.
  
  
  RESULTS
  All three patients developed multidrug resistant HCMV-infections with one or more UL97 and UL54-mutation detected by RFLP, sequencing and LightCycler-analysis. Two out of three patients showed biphasic VL kinetics with manifestation of UL97 drug-resistance prior/or at peak VL. UL54-mutations emerged also in all three patients either at increasing VL levels of ≥10(5)copies/ml or at peak VL.
  
  
  CONCLUSIONS
  The development of coexisting HCMV UL97 and UL54-mutations conferring drug-resistance after HCT is not strictly associated with fatal outcome in one of our three patients. Manifestation of drug resistant combined UL97/UL54-mutations occurred prior to a second VL peak under (V)GCV/PFA co-treatment.
authors: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital of Tübingen, 72076 Tübingen, Germany.
authors: Katharina
authors: K
authors: Göhring
authors: Dana
authors: D
authors: Wolf
authors: Wolfgang
authors: W
authors: Bethge
authors: Elfriede
authors: E
authors: Mikeler
authors: Christoph
authors: C
authors: Faul
authors: Wichard
authors: W
authors: Vogel
authors: Matthias C
authors: MC
authors: Vöhringer
authors: Gerhard
authors: G
authors: Jahn
authors: Klaus
authors: K
authors: Hamprecht
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology; D003587:Cytomegalovirus / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000188:drug therapy / Q000821:virology*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D024882:Drug Resistance, Viral; D017809:Fatal Outcome; D015774:Ganciclovir / Q000494:pharmacology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012189:Retrospective Studies; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D000998:Antiviral Agents; C109367:UL54 protein, Human herpesvirus 5; D014764:Viral Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C075365:ganciclovir kinase; D004259:DNA-Directed DNA Polymerase; D015774:Ganciclovir