[Quantitative antibody analysis: use for the diagnosis of hepatitis C virus chronic infection].
Hepatitis C virus (HCV) infection has been estimated in 600,000 subjects in France, with about 80 % of chronic infection. In the latter, anti-HCV antibodies and viral RNA are found together in patients blood. Today, only the use of polymerase chain reaction (PCR) technology allows the diagnosis of HCV chronic infection, confirmed by a positive PCR. However, PCR is a laborious and cost effective method. The aim of this study was to distinguish HCV chronic infection to past-infection or false reactivity only using the serology testing. Therefore, we looked for a correlation between the results of PCR, using the HCV Cobas Amplicor 2.0 assay, and the level of anti-HCV antibodies, assessed by the AxSYM HCV v.3.0 and expressed in signal/cutoff (s/co) ratio. We found using a panel of 200 sera issued from 181 patients, a significant variation of s/co ratios between PCR positive and negative patients (respectively, 87.76 +/- 27.18 vs 10.13 +/- 13.68 s/co, p < 0.0001), only in non treated or previously treated patients, non HIV coinfected, non renal transplanted or haemodialysis patients. An anti-HCV cutoff value at 34 s/co allows a predictive PCR results with 100 % sensitivity and 93.3 % specificity. Thus, for patients having a s/co equal or over 34, a positive PCR was found in 98.1 % of cases, allowing the diagnosis of HCV chronic infection (positive predictive value). Conversely, in patients with less than 34, HCV chronic infection can be excluded in 100 % of cases (negative predictive value). In conclusion, in most cases, the use of anti-HCV quantitative analysis in the AxSYM HCV v.3.0 assay could avoid PCR testing and facilitate the diagnosis of HCV chronic infection.
Payan
C
C
Laboratoire de bactériologie-virologie, (réseau hépatite 49), CHU Angers, 4, rue Larrey, 49033 Angers cedex. ChPayan@chu-angers.fr
Raimbert
A
A
Fouchard-Hubert
I
I
Kouyoumdjian
S
S
Lunel-Fabiani
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003663:Decision Trees; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D005602:France / Q000453:epidemiology; D016174:Hepacivirus / Q000235:genetics*; D018937:Hepatitis C Antibodies / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D006801:Humans; D015151:Immunoblotting / Q000191:economics / Q000379:methods* / Q000592:standards; D007124:Immunoenzyme Techniques / Q000191:economics / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000191:economics / Q000592:standards*; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D018937:Hepatitis C Antibodies; D012367:RNA, Viral