La PCR dans la détection de l'ADN du virus de l'hépatite B : choix des amorces

Hepatitis B remains an important public health problem in the world; the agent causing this disease was characterized by its genetic variability. Hepatitis B surface antigen (HBs Ag) has been used for a long time for the indirect detection of the virus. Recently, the detection of the viral DNA by polymerase chain reaction (PCR) has been shown as a significant methodological progress for detecting the presence of viral nucleic acids even when these are found in small quantities in serum. This molecular diagnosis of the hepatitis B virus (HBV) infection based on PCR is confronted with problems of reproducibility and sensitivity and with difficulties of results interpretation. In this study, 13 primers specific and the primers consensus covering various regions of the hepatitis B virus genome were selected in order to perform an efficient and reproducible diagnostic test of HBV infection. The specificity and sensibility of PCR amplification were studied on sera of patients reached of chronic hepatitis B. Satisfactory results were obtained in the pre-S and X regions with respectively two successive PCR using the primers consensus or nested PCR using the couple Xa/Xb for the first amplification and the couple HBx1/HBx2 for the second. These results confirm that HBV DNA detection by PCR is a sensitive technique to detect the presence of HBV-DNA in the serum. It can be standardized to be apply in the currently diagnosis of HBV infection.