Investigation of diagnostic values of different antihcv reactives based on immunoassay method used in the laboratory diagnosis of hepatitis c infection in turkey

HCV infection is an important health problem for reasons such as 80% of infection become chronic, cause to hepatocellular carsinoma and liver cirrhosis and lead to liver transplantation. Nowadays different diagnostic methods used to obtain the correct results, in the diagnosis of HCV infection. In this study, it was aimed to investigate diagnostic values of the five different anti-HCV tests and HCV core antigen test used in the routine laboratories for the diagnosis of HCV infection in Turkey. One hundred seventy nine sera samples were included into the study sent to Afyon Kocatepe University Faculty of Medicine ANS Practice and Research Hospital Medical Microbiology Laboratory for routine anti-HCV and/or HCV RNA testing between 1 September 2014 and 30 June 2015. Sera samples were aliquoted as to be at least 3 cc and were kept in -800C deep freezer until the study days. Samples were tested by Vitros anti-HCV (Ortho-Clinical Diagnostics, High Wycombe, UK), Advia Centaur anti-HCV (Siemens Healthcare Diagnostics, Tarrytown NY, USA), Elecsys anti-HCV II (Roche Diagnostics, Mannheim, Germany), Architect anti-HCV (Wesbaden, Germany), Liaison anti-HCV (DiaSorin, Saluggia, İtaly), Architect HCV Ag (Wesbaden, Germany), recomLine HCV IgG (Mikrogen Diagnostik, Neuried, Germany), Cobas® AmpliPrep/ Cobas® TaqMan® HCV Quantitative Test, version 2.0 (Roche Diagnostics, Mannheim, Germany) and Innotest HCV Ab IV (Fujirebio, Gent, Belgium) only for discrepant results. In terms of results in the five different anti-HCV tests, the highest and the lowest agreement was detected respectively in Elecsys II- Liaison anti-HCV tests with 94.9% and Advia Centaur-Vitros anti-HCV tests with 86.5%. It was determined that the lowest agreement showed in the Advia Centaur with the other anti-HCV tests. The overall concordance rate of five different anti-HCV tests was found 83.8% (150/179). The best S/Co correlation value was obtained between Architect and Liaison (r=0.842) anti-HCV tests. The lowest correlation was observed between Advia Centaur and Elecsys II (r=0.251) anti-HCV tests. There was no correlation between Elecsys anti-HCV II and the other tests. In the calculations that HCV RNA was accepted as the gold standart, sensitivity and NPV of all anti-HCV tests was determined to be 100%. All the studied anti-HCV tests evaluated for the analytical performances and Advia Centaur was found to be the highest, the other anti-HCV tests: Liaison, Architect, Elecsys and Vitros graded respectively. The critical values for Vitros anti-HCV, Advia Centaur anti-HCV, Elecsys anti-HCV II, Architect anti-HCV and Liaison anti-HCV tests were determined as 6.6 S/Co, 5.28 S/Co, 14.88 COI, 3.6 S/Co and 4.3 S/Co respectively. It was not determined any correlation between anti-HCV tests (S/Co or COI) and HCV RNA (IU/mL) values. It was determined a good correlation between HCV core antigen and HCV RNA concentrations by Spearman correlation test (r=0.943, p<0.001, n=90). It was observed low viral load (2.7x101 IU/mL) in one sample which the antigen test is negative and HCV RNA result is positive. HCV core antigen values was found between 3.56-6.43 fmol/L in five samples which samples HCV RNA negative and antigen repeatedly positive. The third generation anti-HCV tests based on EIA and CIA methods used for screening of diagnosis of HCV infection nowadays, should be supported by additional tests due to give false positive results. HCV RNA test is considered as the gold standard test, but in the absence of viremia, should be noted that HCV RNA test result could be negative. In cases of suspected infection the test should be repeated. The fourth generation anti-HCV tests with high specifity and sensitivty came into use in recent years, gives very good results in the elucidation of discordant results. HCV core antigen tests can be used as an alternative test in order to show the presence of infection when HCV RNA test can not be studied. Problems in diagnostic algorithm approaches still continues. This problems may be solved properly only by the way that improving new generation anti-HCV reactives that embedded pure structural antigens obtained from HCV cell cultures into the new generation anti-HCV reactives.