HEPATITIS-C VIRUS POLYMERASE CHAIN-REACTI ON - ENHANCED SENSITIVITY BY AMPLIFICATION OF SHORT CDNA FRAGMENTS

The aim of our study was to compare the sensitivity of hepatitis C vir us polymerase chain reaction (HCV-PCR) by use of two different primer sets which amplify PCR products of different length. Serum samples of 70 patients with chronic hepatitis C were tested by ''nested primer'' PCR, using either ''NCR primers'' that amplify cDNA-fragments of 340 b asepairs (bp), or by ''PT primers'' which amplify fragments of 59 bp o nly. HCV-RNA was detected in 40 patients (57%) by ''NCR primers'' and in 69 patients (90%) by ''PT primers'' (p< 0,001). 23 of 70 patients ( 33%), which were HCV-RNA negative by ''NCR primers'', were positive by ''PT primers'', but no patient negative by ''PT primers'' was found t o be positive by ''NCR primers''. 20 healthy controls tested by both p rimer sets were all HCV-RNA negative. We conclude that the sensitivity of HCV-PCR is significantly improved by use of primers that amplify ' 'short'' PCR products and recommend the use of ''PT primers'' for HCV- PCR.