Phylogenetic Analysis and Emerging Drug Resistance against Different Nucleoside Analogues in Hepatitis B Virus Positive Patients

Several nucleotide analogues have been approved for use in treating hepatitis B virus (HBV) infection. Long-term exposure to therapy leads to the emergence of mutations within the HBV DNA polymerase gene, resulting in drug resistance, a major factor contributing to therapy failure. Chronic HBV patients from the Khyber Pakhtunkhwa province, Pakistan, who had completed 6 months of therapy participated in this study. Samples were collected from 60 patients. In this study, the entire reverse transcriptase domain of the HBV polymerase gene was amplified using nested polymerase chain reaction and sequenced. Drug-resistant mutations were detected in nine (22.5%) patients. All of these patients had lamivudine-resistant mutations (rtM204V + L180M), while seven individuals (17.5%) had both lamivudine- plus entecavir-resistant mutations (L180M + M204V + S202G). N236T, a mutation that gives rise to tenofovir and adefovir resistance, was observed in two (5%) patients. T184A, a partial drug-resistant mutation to entecavir, was found in five (12.5%) patients. Furthermore, other genotypic variants (100%) and vaccine escape mutations (5%) were additionally observed. Moreover, pN459Y (35%), pN131D (20%), pL231S (20%), pP130Q (17.5%), pS189Q (12.5%), pP161S (5%), pH160P (2.5%), pT322S (2.5%), and pA223S (2.5%) mutations in the polymerase gene, as well as sA166V (17.5%), sQ181K (12.5%), sV184R (7.5%), sA17E (5%), sP153S/K (5%), sW156C (5%), sC76Y (2.5%), and S132F (2.5%) mutations in the small surface gene, were identified for the first time in this study. Phylogenetic analysis showed that genotype D was predominant amongst the HBV carriers. Subtype D1 was found in most patients, while two patients were subtype D9. These novel findings may contribute to the body of knowledge and have clinical significance for treating and curing HBV infections in Pakistan.

Hepatitis B virus activity in untreated hepatitis B e antigen-negative human immunodeficiency virus-hepatitis B virus co-infected patients from sub-Saharan Africa

BACKGROUND

In human immunodeficiency virus (HIV) and hepatitis B virus (HBV) co-infected patients from sub-Saharan Africa with hepatitis B e antigen (HBeAg)-negative status, data are limited on the evolution of HBV activity when antiretroviral treatment (ART) is absent.

METHODS

A total of 43 HBeAg-negative co-infected patients not indicated for ART (per concomitant World Health Organization recommendations) were followed during participation in a randomized controlled trial in Côte d'Ivoire. Chronic HBeAg-negative phases were classified at yearly visits and defined as 'infection' (HBV DNA ≤10 000 copies/mL and normal alanine aminotransferase [ALT]) or 'hepatitis' (HBV DNA >10 000 copies/mL and/or above normal ALT). Dispersion in HBV DNA and ALT levels during follow-up was assessed using interquartile range (IQR) regression.

RESULTS

During a median 25 months (IQR 19-31), 17 (40%) patients consistently had 'infection', 5 (12%) consistently had 'hepatitis' and 21 (48%) fluctuated between phases. Wider dispersion in HBV DNA over time was associated with higher baseline HIV RNA (p=0.02) and higher baseline HBV DNA levels (p=0.008), while wider dispersion in ALT was associated with higher baseline HIV RNA (p<0.001), higher baseline ALT levels (p=0.02) and baseline hepatitis surface antigen >4.0 log10 IU/mL (p=0.02).

CONCLUSIONS

HBV activity is common with HBeAg-negative status, whose variation is partly linked to HIV replication. Fluctuations in disease phase make it difficult to assess the risk of morbidity and mortality after ART initiation.

Effect of hepatitis B virus (HBV) surface-gene variability on markers of replication during treated human immunodeficiency virus-HBV infection in Western Africa

BACKGROUND & AIMS

Replication markers exhibit substantial variation during chronic hepatitis B virus (HBV) infection, part of which can be explained by mutations on the surface (S) gene. We aimed to identify S-gene mutations possibly influencing the quantification of HBV replication markers (MUPIQH) in HBV genotype E infection, common to Western Africa.

METHODS

Seventy-three antiretroviral treatment (ART)-naïve human immunodeficiency virus (HIV)-HBV co-infected patients from Côte d'Ivoire, initiating anti-HBV-containing ART, had available HBV S-gene sequences. S-gene MUPIQHs were screened at ART initiation based on lower HBV-DNA or HBsAg quantification (qHBsAg) compared to wildtype. Their association with HBV virological response and qHBsAg slope during treatment was evaluated.

RESULTS

Genotype E was predominant (95.9%). At ART initiation, median HBV-DNA was 7.27 log₁₀ copies/mL (IQR = 5.26-8.33) and qHBsAg 4.08 log₁₀ IU/mL (IQR = 3.49-4.61). Twelve S-gene MUPIQHs were identified among 21 patients (28.8%): sS140L (n = 4), sD144A (n = 1), sS167L (n = 2), sS174N (n = 6), sP178Q (n = 2), sG185L (n = 2), sW191L (n = 2), sP203Q/R (n = 2), sS204N/I/R/K/T/G (n = 7), sN207T (n = 2), sF212C (n = 1) and sV224A/Y (n = 7). MUPIQHs at positions s185+s191+s224 and s178+s204 were within highly covarying networks of S-gene mutations. Older age (P = 0.02), elevated transaminases (P = 0.03) and anti-hepatitis B "e" antibody-positive serology (P = 0.009) were significantly associated with prevalent MUPIQHs at ART initiation. During treatment, baseline MUPIQHs were not associated with time-to-undetectable HBV-DNA (P = 0.7) and qHBsAg levels decreased at similar rates between those with vs without MUPIQHs (P = 0.5).

CONCLUSION

Several novel S-gene mutations were associated with reductions in replication markers among West African co-infected patients. These mutations, however, do not affect response during antiviral treatment. Their diagnostic and clinical consequences need clarification.

Surface gene variants of hepatitis B Virus in Saudi Patients

BACKGROUND/AIMS

Hepatitis B virus (HBV) continues to be one of the most important viral pathogens in humans. Surface (S) protein is the major HBV antigen that mediates virus attachment and entry and determines the virus subtype. Mutations in S gene, particularly in the "a" determinant, can influence virus detection by ELISA and may generate escape mutants. Since no records have documented the S gene mutations in HBV strains circulating in Saudi Arabia, the current study was designed to study sequence variation of S gene in strains circulating in Saudi Arabia and its correlation with clinical and risk factors.

PATIENTS AND METHODS

A total of 123 HBV-infected patients were recruited for this study. Clinical and biochemical parameters, serological markers, and viral load were determined in all patients. The entire S gene sequence of samples with viral load exceeding 2000 IU/mL was retrieved and exploited in sequence and phylogenetic analysis.

RESULTS

A total of 48 mutations (21 unique) were recorded in viral strains in Saudi Arabia, among which 24 (11 unique) changed their respective amino acids. Two amino acid changes were recorded in "a" determinant, including F130L and S135F with no evidence of the vaccine escape mutant G145R in any of the samples. No specific relationship was recognized between the mutation/amino acid change record of HBsAg in strains in Saudi Arabia and clinical or laboratory data. Phylogenetic analysis categorized HBV viral strains in Saudi Arabia as members of subgenotypes D1 and D3.

CONCLUSION

The present report is the first that describes mutation analysis of HBsAg in strains in Saudi Arabia on both nucleotide and amino acid levels. Different substitutions, particularly in major hydrophilic region, may have a potential influence on disease diagnosis, vaccination strategy, and antiviral chemotherapy.