[Detection of hepatitis B virus DNA in serum by gene amplification in patients with chronic hepatitis B and in patients chronic hepatitis C]

Background: The polymerase chain reaction (PCR) constitutes important methodological progress for detecting the presence of viral nucleic acids when these are found in small quantities in serum or tissues. The aim of this study was the use of PCR to detect DNA of the hepatitis B virus (HBV) in patients with chronic HBsAg positive hepatitis (HC-B) and in patients with chronic non A non B hepatitis with antibodies against the virus of hepatitis C (anti-HCV) positive (HC-C).
Methods: The DNA of the HBV was determined with PCR in the serum of 40 patients with HC-B and in 15 with HC-C. Moreover, the presence of anti-HCV was studied in the patients with HC-B.
Results: The presence of DNA of the HBV was detected by PCR in 69% of the HC-B patients presenting HBeAg positive and DNA of the HBV negative by simple hybridization as well as in 50% of the patients with HBeAg negative, anti-HBe positive and DNA of HBV negative by simple hybridization. In addition, DNA of HBV was detected by PCR in 27% (4/15) of the subjects with HC-C, three of whom had anti-HBc antibodies. On the other hand, 20% of the patients with HC-B had anti-HCV. Anti-HCV positivity was associated to a greater hypertransaminasemia in patients with HC-B in a non replicative phase.
Conclusions: PCR is a sensitive method for detecting viral replication. Its use permits the detection of low DNA concentrations of the HBV in a low but appreciable percentage of chronic negative HBsAg hepatitis. Coinfection by the B and C viruses of hepatitis is not exceptional and explains hypertransaminasemia in some HC-B in a non replicative phase.