The evaluation of Recombinant Immunoblot assay (RIBA) and HCV-RNA test results in patients with low titer Anti-HCV positivity

Abstract

Objectives: Laboratory diagnosis of hepatitis C virus (HCV) infection is based on the detection of anti-HCV antibodies by enzyme immunoassay (EIA) or chemiluminescence immunoassay (CIA) techniques. However, a consensus related to the problem of low titer (Serum/Cut-off; S/C= 1.0) anti-HCV antibodies is still lacking. The study attempts to evaluate the clinical status of the patients with low titer anti-HCV antibodies detected by third generation anti-HCV tests during February 2013- May 2014 retrospectively. Methods: Serum samples were studied by Advia Centaur XP autoanalyser (Bayer-Siemens, Germany) for anti-HCV, and line immunoassay (Inno-LIATM HCV Score, Innogenetics, Belgium) for anti-HCV confirmatory test, Cobas AmpliPre/Cobas AMPLICOR HCV Test (Roche diagnostics, Switzerland) for HCV RNA. Results: A total of 55.631 serum samples were studied, and 55 of them were anti-HCV positive of which with low antibody levels (sample/cutoff [S/CO]). S/CO values ranged from 1.15 to 6.15. Seventeen (31%) of patients who have low antibody levels were defined as positive and 2 (4%) patients were intermittent and 36 (65%) patients were negative with line immunoassay. HCV-RNA was not detected in any of the samples. Conclusions: It is thought that antibody positivity must be verified in cases of recurrent reactivity when considering the cost-effectiveness of molecular tests. In the study was concluded that the use of molecular tests would be appropriate diagnosis, and the effectiveness of treatment if necessary after evaluation of patients with biochemical analysis. J Clin Exp Invest 2014; 5 (4): 553-556