title: Analysis of hepatitis C virus (HCV) RNA load in platelets of HCV-monoinfected patients receiving antiviral therapy.
abstract: BACKGROUND
  Detection of hepatitis C virus (HCV) has been reported in extrahepatic sites such as peripheral blood mononuclear cells and platelets. Quantitation of HCV-RNA in platelets from patients under antiviral therapy has not been reported.
  
  
  METHODS
  HCV-RNA levels in paired serum and platelet samples of 17 chronically HCV-infected patients were determined at baseline, week 12, end-of-treatment, and 24 weeks after completion of treatment with pegylated interferon plus ribavirin. Quantitation of HCVRNA load was performed using COBAS® TaqMan® HCV Test v 2.0 (lower limit of detection, 25 IU/mL). The cohort predominantly consisted of female (59%) with a mean age of 50.7 ± 10.0 years.
  
  
  RESULTS
  Measurements of HCV-RNA in relation to different timepoints of therapy revealed baseline viral load was most frequently detected in higher levels in serum than in platelets (5.6 x 104 IU/mL vs. 379.0 IU/mL; p = 0.0002), a trend also demonstrated in most samples throughout the study. HCV-RNA was also found at low levels (< 25.0-314.0 UI/mL) persistently in platelets of three patients who have lost detectable HCV-RNA in serum during antiviral therapy, resulting in virological relapse.
  
  
  CONCLUSIONS
  HCV-RNA levels are most frequently detected in higher levels in serum than in platelets, independent of timepoint of antiviral therapy. Further studies with an increase in size of the samples are needed to better evaluate whether or not patients who presented HCV-RNA at low levels in platelets after having lost detectable HCV-RNA in serum during antiviral therapy are at increased risk of relapse of HCV infection during follow-up evaluation.
authors.affiliation: Viral Hepatitis Laboratory, Institute Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil. paschoal@ioc.fiocruz.br
authors.forename: Márcia Paschoal do
authors.initials: MP
authors.lastname: Espírito-Santo
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Brandão-Mello
authors.forename: Vanessa Alves
authors.initials: VA
authors.lastname: Marques
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lampe
authors.forename: Adilson José De
authors.initials: AJ
authors.lastname: Almeida
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000821:virology*; D001938:Brazil; D004359:Drug Therapy, Combination; D005260:Female; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood*; D011994:Recombinant Proteins / Q000627:therapeutic use; D012008:Recurrence; D012254:Ribavirin / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b