Asian Research Thesis Index

Abstract

Hepatitis virus infections are among major health problems worldwide and the clinical outcomes of such infections are often underestimated and the therapeutic options for such infections are not fully explored and are time required. Hepatitis B is the foremost cause of the liver cancer globally and cause of the liver failure which contribute to the major mortality rate. However, Hepatitis Delta virus (HDV) being satellite virus of Hepatitis B virus (HBV) is more frightening, as the life threatening rate increases more than 10 times in dual infection of HDV among HBV positive patients as compared to HBV mono-infection. HDV is a highly pathogenic virus. Clinical presentation of hepatitis D in majority of the patients ranges from the fulminant hepatitis, increasing severity of underlying hepatitis B infection, accelerated progression to cirrhosis, early decomposition of the liver functions and development of hepatocellular carcinoma. Almost among 240 million chronic carriers of HBV worldwide, currently about 15 to 20 million people have been thought to be infected with HDV. Pakistan account for a significant proportion of the global hepatitis burden and is considered as endemic to HDV. Most of the data reported from the country based on seroprevalence of HDV however only three reports are available for genotype of HDV from the country with small sample size and not covering all major provinces (Punjab, Khyber Pakhtunkhawa and Sindh) while no full genome of this virus have been reported from Pakistan so far. Therefore, to estimate the current prevalence rate and circulating genotypes of HDV in HBV positive patients, a molecular based study was conducted and HDV genotyping was done along with the sequencing of the complete genome of the virus. Total 1913 hepatitis suspected samples recruited for the study. 1176 (61.5%) were from Punjab and 714 (37.3%) were from KPK and 23 (1.2%) were from Sindh. Out of total 1043 (54.5%) were males and 870 (45.5%) were females. HBV genotyping from HDV positive samples was also done along with genotyping of HDV. Whole genome from HDV samples were amplified using two primer pairs and were sequenced using Next Generation Sequencing. Out of Total, 276 (14.4%) samples were positive for HBV. From HBV positive cases, 46 (16.7%) samples were positive for HDV coinfection. From 181 HBV positive samples (121 males (66.85%), 60 females (33.15%)) from Punjab, 26 samples (14.36%) were positive for HDV among which 17 were males and 9 were females. From 85 HBV positive samples samples (49 males (57.65%), 36 females  viii   (42.35%)) from Khyber Pakhtunkhwa, 13 samples (15.29%) were positive for HDV among which 9 were males and 4 were females. From 10 HBV positive samples (6 Males (60%), 4 females (40%)) from Sindh, 7 samples (70%) were positive for HDV among which 5 were males and 2 were females. HBV genotyping from HDV positive samples showed the prevalence of Genotype D in 36 (74.5%) samples while Genotype A was prevalent in 13(25.5%) samples. HDV genotyping of the samples showed the prevalence of only Genotype I in all the positive genotyped samples. Whole genome of HDV samples were amplified and sequenced using NGS. Partial and complete sequences were submitted to NCBI GenBank data base. The phylogenetic analysis of the nucleotide sequence of the Pakistani HDV isolates cluster with HDV genotype I clade and showed 83% to 91% similarity with the reference sequence. This study gives a detailed picture of the true molecular prevalence of the HBV/HDV dual infection in the major regions of the country. This is the first study from the country to cover most of the regions with great sample size. Also this study reports the complete sequence of the HDV Pakistani isolate for the first time from the country. More studies can be done in future on viral quasispecies to understand more about the pathogenesis of the virus in the population. This will be helpful in designing drugs, study virus cell Interactions and will also helpful in vaccine development.

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