Evaluation of HBV resistance to tenofovir in patients with chronic hepatitis B using ZNA probe assay in Kerman, southeast of Iran

ObjectiveTo evaluate the mutation rate of polymerase gene and it's correlation with tenofovir resistance in patients with chronic hepatitis B.MethodsA total of 64 serum samples (36 men and 28 women) were collected from patients with chronic hepatitis B. All of these samples were tested for hepatitis B virus (HBV) DNA level, alanin amino transferase/aspartic amino transferase enzymes and serological markers such as hepatitis B surface antigen (HBsAg)/hepatitis Be antigen (HBeAg) (Electro-chemi-luminescence).ResultsIn this study, out of those 64 patients, 13 cases had mutations in the polymerase region (A194T). All mutant cases were HBsAg positive and 5 (38.5%) of them were males and 8 (61.5%) were females, while 6 (46.2%) of the mutants were HBeAg positive and 7 (53.8%) were HBeAg negative and most of the mutants have more than 109 HBV DNA level. Statistical analyses on the 64 samples showed that there was no significant relation between age and HBsAg level but there was a significant relationship between HBV DNA load (P = 0.001) and A194T mutation.ConclusionsHBeAg had a correlation with A194T mutation (P = 0.02) and tenofovir resistance was seen in 13 patients. Real-time PCR with zip nucleic acid probes is a rapid method to detect mutations in the polymerase region of HBV with high sensitivity and specifity. This method could be used for mutation detection in nt-194 position of polymerase gene for tenofovir resistance and other mutations in drug resistance researches.