More sensitive and precise: New PCR technology in the diagnostics of chronic “C“ virus hepatitis

Introduction: The detection of viraemia and the quantitation of virus level in chronic C and B virus hepatitis are performed using PCR based nucleic acid amplification. The efficacy (sustained response) of the currently applied pegilated interferon and ribavirin combined therpy (“stop rule“) is determined on the basis of HCV-RNS level changes. In the past few years we applied COBAS Amplicor HCV Monitor test based on end-point PCR technology for the quantitation of virus nucleic acid, whose linear detection limit is between 600–600.000 IU/ml. HCV nucleid acid quantitation has been performed with the newly developed Cobas TaqMan 48 Analyzer in our laboratory for six month. With High Pure System TaqMan test we are able to get more precise virus level results with real-time technology in a very wide measure range (10–2E+8 IU/ml) and linear detection limit (30–8.500.000 IU/ml).

Aim: 1. Presenting the different features of the two above-mentioned PCR-based technologies. 2. We performed parallel HCV RNS quantitations in the serum of 30 patients with the two tests. In specimens with virus levels of over 100.000 IU/ml measured with Cobas Amplicor Monitor test the results were significantly higher when measured with Cobas TaqMan. These deviations may be due to differences of sample preparation and of detection of the PCR products.

Conclusion: 1. Cobas TaqMan Test is more sensitive in detecting low virus levels. 2. Our results show that High Pure, real time technology gives us more precise results in detecting high virus levels. 3. Testing with Cobas TaqMan 48 Analyzer is recommended in the follow up of the virus titer changes of chronic C virus hepatitis during therapy.