title: Significance of anti-HCV signal-to-cutoff ratio in predicting hepatitis C viremia.
abstract: OBJECTIVE
  Hepatitis C virus (HCV) RNA testing can be performed using qualitative or quantitative assays, and it is still unclear which is more useful as a primary test in patients positive for anti-HCV. The present study evaluated the usefulness of anti-HCV signal-to-cutoff ratio (S/CO ratio) for predicting HCV RNA results.
  
  
  METHODS
  Patients on whom a qualitative HCV RNA test was performed due to a positive anti-HCV enzyme immunoassay were enrolled. Patients were divided into viremia and no-viremia groups according to HCV RNA results. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO for a diagnosis of viremia.
  
  
  RESULTS
  In total, 487 patients were enrolled. HCV RNA was positive in 301 subjects (61.8%). Age, serum ALT level, and anti-HCV S/CO ratio were significantly different between the viremia and no-viremia groups. By ROC curve analysis, anti-HCV S/CO ratio (area, 0.989; 95% confidence interval, 0.981 to 0.998) accurately predicted the presence of viremia, with a cutoff value of 10.9 (sensitivity, 94.4%; specificity, 97.3%).
  
  
  CONCLUSIONS
  Anti-HCV S/CO ratio was found to be highly accurate at predicting HCV viremia. The anti-HCV S/CO ratio can be used to determine whether a quantitative or qualitative HCV RNA test should be used to confirm HCV viremia in patients with a positive anti-HCV by the following criteria: if the anti-HCV S/CO ratio is <10.9, a qualitative HCV RNA test can be used, and if the anti-HCV S/CO ratio is >or=10.9 a quantitative HCV RNA test can be performed.
authors: Department of Internal Medicine, Korea University College of Medicine, Seongbuk-gu, Seoul, Korea.
authors: Yeon Seok
authors: YS
authors: Seo
authors: Eun Suk
authors: ES
authors: Jung
authors: Jeong Han
authors: JH
authors: Kim
authors: Young Kul
authors: YK
authors: Jung
authors: Ji Hoon
authors: JH
authors: Kim
authors: Hyonggin
authors: H
authors: An
authors: Hyung Joon
authors: HJ
authors: Yim
authors: Jong Eun
authors: JE
authors: Yeon
authors: Kwan Soo
authors: KS
authors: Byun
authors: Chang Duck
authors: CD
authors: Kim
authors: Ho Sang
authors: HS
authors: Ryu
authors: Soon Ho
authors: SH
authors: Um
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006526:Hepatitis C / Q000175:diagnosis*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood*; D014766:Viremia / Q000175:diagnosis*
chemical_list: D018937:Hepatitis C Antibodies; D012367:RNA, Viral