Molecular analysis of HBV pre-core gene mutations in patients co-infected with HIV at a tertiary care hospital in North India

Objective: Hepatitis B virus (HBV) spontaneous mutations may impact the severity of liver disease. This study aimed to assess the mutations in the PC region in HBV-HIV co-infected patients. Additionally, we explored its association with genotypes and examined the clinical implications. Methods: A total of 100 patients of HBV-HIV co-infected, and 50 HBV mono-infected were included in the study. Serum samples from individuals with detectable HBV DNA were submitted to polymerase chain reaction (PCR) amplification using pre-core primers. The pre-core region of the HBV genome was sequenced and analysed for PC mutant variants. PCR products underwent purification by the QIAquick Gel Extraction Kit (Qiagen, Germany), quantification was done on the Nanodrop 2000 spectrophotometer and sequencing by Sanger method at Eurofins Genomics. The generated sequences were assembled, annotated, were aligned in one frame, analyzed for the mutations and phylogenetic analysis was performed using the UGENE software. Phylogenetic analysis was used to carry out the genotyping. Results: The pre-core region was successfully amplified and sequenced in a total of 27 samples (16 HBV-HIV co-infected; 11 HBV mono-infected). Phylogenetic analysis revealed HBV genotypes D and A across all study samples, with genotype D comprising 24 (88.9%), and genotype A accounting for 3 (11.1%). A T to C mutation in the pre-core region at nucleotide position 1912 was found in 48.1% of the patients. A1850T, C1858T, G1899A, G1862T, G1951T, T1812C, T1809G, and additional novel pre-core region mutations, including C1936T, A2011G, T2020A, and C2044T were among the other HBV pre-core mutations found in this study. The genotyping results indicated that the patients had HBV genotypes A (11.1%) and D (88.9%). The incidence of detected pre-core mutations did not differ significantly between those with HBV mono-infection and those with HBV-HIV dual infection. Conclusion: This study emphasized the occurrence of PC mutations in HBV-HIV co-infected patients. Mutation T1912C was predominantly found in genotype D, whereas some mutations such as T1809C, A1850T, and C1858T were exclusively found in genotype A. Some of the mutations found in this study were already reported in previous studies, but some novel mutations were also reported. Further studies are required to study the clinical correlation of these novel mutations.