Virological and serological tools to optimize the management of patients with chronic hepatitis B

Potential role of Vitamin D in immune response in patients with viral hepatitis

BACKGROUND

To study the relationship of Vitamin D with innate and adaptive immune response parameters in chronic hepatitis B and C patients.

METHODS

The laboratory data between January 1, 2013 and February 1, 2023, for patients with chronic hepatitis B (CHB), and chronic hepatitis C (CHC) were extracted. Serum 25-hydroxyl vitamin D, hepatitis B virus serological markers, complements, and subsets of T lymphocytes were determined. Study cohorts were divided into groups based on serum 25-hydroxyl vitamin D levels with further evaluation of laboratory data.

RESULTS

In CHB and CHC patients the percentage of CD4+ T lymphocytes and the CD4+/CD8+ ratio significantly decreased (P < 0.05), but the percentage of CD8+ increased (P < 0.05) compared to the control group. In CHB patients Vitamin D decrease was significant (P < 0.001) but not in CHC patients. Vitamin D showed a moderate negative influence on the CD8 cell count in CHB patients. The positive ratio of HBV DNA and HBsAg decreased with increasing serum vitamin D levels. The vitamin D deficient group showed significantly lower antibody production compared to the normal group, and exhibited significantly decreased CD4 numbers and increased CD8 numbers (P < 0.05 and P < 0.001, respectively), while the CD4/CD8 ratio was also significantly decreased in the insufficiency group (P < 0.001). Complement C3 levels were not associated with CD4 and CD8, but had an inverse relation with Vitamin D. Vitamin D levels were significantly associated with complement C3, CD8+, CD4+, CD19+ cells, and HBV DNA levels.

CONCLUSIONS

Vitamin D may be a modulator of immune function not only via CD8+ and CD4+ cells but also via CD19+ cells in the course of chronic HBV infection. The negative relationship between vitamin D and complement C3 needs elucidation. Moreover, the increased proportion of B cells and decreased CD4+ cells in Vitamin D deficiency disrupt the immune response against HBV since the expected antibody response was not obtained despite the increase in B cell ratio. This indicates an influence of CD4+ cells for B cell functionality. In summary, sufficient levels of Vitamin D may lead to a sustained virological response that is debatable by artificially correcting the deficiency.

Controversies in Treating Chronic HBV: The Role of PEG-interferon-alfa

Pegylated interferon-alpha therapy is one of the first-line chronic hepatitis B treatment. Finite treatment duration, absence of drug resistance, delayed response, and higher hepatitis B surface antigen loss than nucleos(t)ides analog therapy are the advantages of pegylated interferon-alpha treatment. Common side effects and subcutaneous injections requirement limit its use. Identifying patients likely to respond to pegylated interferon-alpha and optimizing treatment is reasonable. Motivating patients to complete the 48-week treatment is necessary. Treatment is stopped or switched to other treatment strategies in patients with stopping rule criteria. Combination therapy with nucleos(t)ides analog may improve response, but remains controversial.

Hepatitis B virus downregulates vitamin D receptor levels in hepatoma cell lines, thereby preventing vitamin D-dependent inhibition of viral transcription and production

Background

Vitamin D is a key immune-modulator that plays a role in the innate and adaptive immune systems. Certain pathogens impair the immune defense by downregulating the vitamin D receptor (VDR) pathway. Low serum levels of vitamin D are associated with increased hepatitis B virus (HBV) replication. Our study aimed to assess the in-vitro relationship between HBV production and Vitamin D signaling pathway and to explore the associated mechanism(s).

Methods

HBV transcription and replication was evaluated by qRT-PCR of the HBV-RNA and covalently closed circular DNA (cccDNA). Furthermore, we have transfected the 1.3 X HBV-Luc plasmid to the cells and measured the Luciferase activity using Luminometer. Vitamin D signaling pathway activation was evaluated by measuring the expression levels of VDR, CYP24A1, Tumor necrosis factor α (TNFα) and cathelicidin (CAMP) by qRT-PCR. All assays were performed on HepG2.2.15, HepG2, and HepAD38 cells treated with or without Vitamin D active metabolite: calcitriol.

Results

Calcitriol did not suppress HBV transcription, cccDNA expression or HBV RNA levels in HepG2.2.15 cells. However, VDR transcript levels in HepG2.215 cells were significantly lower compared to HepG2 cells. Similar results were obtained in HepAD38 cell where VDR expression was down-regulated when HBV transcript level was up-regulated. In addition, calcitriol induced VDR-associated signaling, resulting in upregulation of CYP24A1, TNFα and CAMP expression level in HepG2 cells but not in the HepG2.2.15 cells.

Conclusions

These findings indicate that VDR expression is downregulated in HBV-transfected cells, thereby preventing vitamin D from inhibiting transcription and translation of HBV in vitro. HBV might use this mechanism to avoid the immunological defense system by affecting both TNFα and CAMP signaling pathways.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0055-0) contains supplementary material, which is available to authorized users.

Sequence analysis of the Pre-S gene in chronic asymptomatic HBV carriers with low-level HBsAg

In a hepatitis B virus (HBV)-infected population, persistently low expression levels of serum HBV serum antigen (HBsAg) are present, particularly in chronic asymptomatic HBV carriers (ASCs). The present study sequenced the HBV Pre-S gene, and aimed to elucidate its features in ASCs with low HBsAg expression compared with in the established HBV Pre-S reference gene sequences from ASCs with high HBsAg expression. A total of 1,308 ASCs were grouped according to HBsAg serum levels (cut-off value, 10 IU/ml), and clinical characteristics were analyzed in detail. The HBV Pre-S gene was sequenced in 276 ASCs with low-level HBsAg; in addition, 100 of the remaining 1,032 ASCs with high-level HBsAg were randomly selected for HBV Pre-S gene sequencing on the basis of age matching with the low-level HBsAg group. Comparative analysis of the gene sequences from these groups was subsequently conducted. The major clinical features of the population with low-level HBsAg were as follows: Most were ASCs with chronic HBV infection; 97.1% were HBsAg/anti-HBe/anti-HBc-positive; 82.54% carried the B genotype; and 84.13% displayed the adw serotype. The results indicated that there were novel and meaningful mutations, including co-mutations, at numerous loci and sites in the Pre-S gene, as well as deletion mutations in the Pre-S2 gene. These mutations in the Pre-S1 and Pre-S2 gene frag ments accounted for 65.38% (68/104) of the 104 B genotype cases in the low-level HBsAg group and 90.91% (20/22) of the 22 C genotype cases in the low-level HBsAg group, respectively. In conclusion, Pre-S gene mutations may be associated with HBV replication defects, which may be the cause of the observed low expression levels of HBsAg.

Serum M2BPGi level is a novel predictive biomarker for the responses to pegylated interferon-α treatment in HBeAg-positive chronic hepatitis B patients

Serum Mac‐2‐binding protein glycosylation isomer (M2BPGi) level was found to be a useful prognostic marker for hepatitis B e antigen (HBeAg)‐positive chronic hepatitis B (CHB) patients treated with nucleoside/nucleotide analogs (NUCs) therapy, and the aim of our study is to evaluate the clinical implementation of M2BPGi level in the prediction of antiviral responses to pegylated‐interferon‐α (PEG‐IFN‐α) treatment in HBeAg‐positive CHB patients. Ninety‐six CHB patients who received PEG‐IFN‐α treatment for at least 48 weeks were recruited. The serum M2BPGi, alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), HBeAg, and HBV DNA levels at baseline, weeks 4, 12, and 24 after PEG‐IFN‐α treatment were determined and their associations with antiviral responses were evaluated and the virological response (VR) rate and serological response (SR) rate after 48 weeks of treatment were 65.6% and 35.4%, respectively. Baseline serum M2BPGi level was significantly different between VR and non‐VR (P = 0.002) or SR and non‐SR groups (P = 0.012). Multivariate analyses suggested that baseline serum M2BPGi level was independently associated with VR and SR of PEG‐IFN‐α treatment at week 48. The area under the ROC curve (AUC) of baseline M2BPGi was 0.682 in predicting VR, which was superior to HBsAg (AUC = 0.566) or HBV DNA (AUC = 0.567). The AUC of baseline M2BPGi in predicting SR was 0.655, which was also higher than that of HBsAg (AUC = 0.548) or HBV DNA (AUC = 0.583). These results suggested that baseline serum M2BPGi level was a novel predictor of VR and SR for PEG‐IFN‐α treatment in HBeAg‐positive CHB patients.

Predictive role of serum HBsAg and HBcrAg kinetics in patients with HBeAg-negative chronic hepatitis B receiving pegylated interferon-based therapy

OBJECTIVES

To investigate the role of serum hepatitis B core-related antigen (HBcrAg) kinetics in predicting long-term outcome of pegylated interferon (PEG-IFN)-based therapy in patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB).

METHODS

A total of 121 Thai patients with HBeAg-negative CHB recruited from a previous randomized trial of 48-week PEG-IFN alone or combined with entecavir were enrolled. Hepatitis B surface antigen (HBsAg) and HBcrAg levels were serially examined. Paired biopsy samples taken at baseline and after treatment were assessed for intrahepatic covalently closed circular DNA (cccDNA).

RESULTS

Persistent virologic remission (PVR, defined by persistent hepatitis B virus (HBV) DNA <2000 IU/mL) and HBsAg clearance at 3 years after treatment were 29% (35/121) and 9% (11/121) respectively. Baseline HBcrAg correlated with HBV DNA and cccDNA but not with HBsAg. Baseline HBsAg, as well as HBsAg and HBcrAg, declines were associated with PVR, while HBsAg decline was predictive of HBsAg clearance. High baseline antigen levels (HBsAg ≥3.4 log₁₀ IU/mL plus HBcrAg ≥3.7 log₁₀ U/mL) yielded high negative predictive values of PVR (45/50, 90%) and HBsAg clearance (50/50, 100%). At week 12, declines of HBsAg, HBcrAg and both antigens combined of <0.5 log₁₀ yielded negative predictive values for PVR of 90% (71/79), 82% (61/74) and 96% (48/50) respectively.

CONCLUSIONS

Quantitative HBcrAg was significantly associated with cccDNA in HBeAg-negative CHB. This novel antigen, together with HBsAg, could identify patients with low probability of PVR and HBsAg clearance in long-term follow-up.

Mutations in basal core promoter is associated with significant fibrosis in both HBeAg positive and negative treatment-naïve chronic hepatitis B

AIM

Assessment of liver fibrosis is important for the decision of whether to administrate antiviral treatment in chronic Hepatitis B (CHB) patients. The objective was to investigate the relationship between clinical factors and fibrosis, identify predictors of significant fibrosis in Chinese CHB patients.

METHODS

Two hundred and seventy-four treatment-naïve CHB patients (208 HBeAg-positive and 66 HBeAg-negative) who performed transient elastography were consecutively included. We assessed ALT, HBsAg, HBeAg, HBV-DNA, HBV genotype and precore (PC)/basal core promoter (BCP) variants and liver stiffness measurement (LSM) values.

RESULTS

One hundred and nine patients (39.78%) had significant fibrosis (F≥2, include those with liver cirrhosis). On univariate analysis, significant fibrosis was associated with older age (P<0.001), high ALT levels (P=0.003), lower HBsAg levels (P<0.001), lower HBV DNA levels (P<0.001), HBeAg negative (P<0.001), presence of BCP (P<0.001) and combined BCP/PC mutations (P=0.001). Multivariate logistic regression analysis showed that the strongest independently associated predictors of significant fibrosis (F≥2) were the presence of HBV BCP mutations (P<0.001) and older age (P<0.001), followed by presence of lower HBsAg (P<0.001), higher ALT levels (P=0.006), PC mutations (P=0.011). The diagnostic accuracy of the combination (age, ALT, HBsAg, BCP/PC variants) model with an area under the receiver-operating characteristic curve of 0.819 (cut-off value was 0.349, P<0.001, 95% CI 0.731-0.914) in predicting significant fibrosis.

CONCLUSIONS

We identified four independent risk factors (age, ALT, HBsAg, HBV BCP/PC variants) in predicting significant fibrosis. HBV BCP variants was the strongest predictor of significant fibrosis. The combination of these four variables may facilitate the assessment and management of fibrosis in HBV infected patients.

Review of Laboratory Tests used in Monitoring Hepatitis B Response to Pegylated Interferon and Nucleos(t)ide Analog Therapy

There are only two currently approved classes of hepatitis B virus (HBV) antiviral agents, pegylated interferon (Peg-IFN), and nucleos(t)ide analogs (NAs) for chronic HBV infection. Although Peg-IFN is used for a finite 48-week duration and offers a greater chance of sustained off-treatment virological response, it is poorly tolerated and can only be offered to selected patients. The NAs are well tolerated but require prolonged therapy due to risk of relapse with treatment cessation. There is evolving data that novel virological assays (e.g., quantitative hepatitis B surface antigen, quantitative hepatitis B core antigen, quantitative antibody to core protein) in combination with hepatitis B genotype and more sensitive HBV DNA polymerase chain reaction (PCR) assays may be useful to predict response to IFN as well as off-treatment NA durability. Utilization of these clinical laboratory tests may be important given the development of novel anti-HBV therapies, hoping to achieve a cure for chronic hepatitis B infection.