A potential antiviral role for CCR5+CD8+ T cells in children with hepatitis B.

While dysfunctional exhausted CD8+ T cells hamper viral control when children acquire hepatitis B virus (HBV) infection, it's crucial to recognize that CD8+ T cells have diverse phenotypes and functions. This study explored a subset of CD8+ T cells expressing C-C chemokine receptor type 5 (CCR5) in children with HBV infection. Thirty-six patients in the immune tolerant group, 33 patients in the immune active group, 55 patients in the combined response group, and 22 healthy control children were enrolled. The frequency, functional molecules, and effector functions of the CCR5+CD8+ T cell population in different groups were evaluated. The frequency of CCR5+CD8+ T cells correlated positively with the frequency of CCR5+CD4+ T cells and patient age, and it correlated negatively with alanine aminotransferase, aspartate transaminase, HBV DNA, hepatitis B surface antigen, and lactic dehydrogenase levels. CCR5+CD8+ T cells had higher levels of inhibitory and activated receptors and produced higher levels of IFN-γ, IL-2, and TNF-α than CCR5-CD8+ T cells. CCR5+CD8+ T cells were partially exhausted but possessed a stronger antiviral activity than CCR5-CD8+ T cells. The identification of this subset increases our understanding of CD8+ T cell functions and serves as a potential immunotherapeutic target for children with HBV infection.

Humoral immune responses to inactivated COVID-19 vaccine up to 1 year in children with chronic hepatitis B infection.

Background: Inactivated SARS-CoV-2 vaccination has recently been approved for children aged 3-17 years in China. However, data on long-term humoral responses to inactivated vaccines in children with chronic hepatitis B (CHB) are still limited. Methods: In this prospective observational study, CHB children after primary inactivated SARS-CoV-2 vaccines were recruited consecutively and followed up for 1 year. CHB adults from another cohort study (NCT05007665) were used as a control. The receptor-binding domain IgG antibody (anti-RBD-IgG), neutralizing antibody (NAb), neutralization against Omicron (BA2.12.1, BA.4 and BA.5), and memory B -cell (MBC) responses were evaluated. Results: Overall, 115 CHB children and 351 CHB adults were included in this analysis. The antibody titers decreased over the first ~180 days and then plateaued up to 1 year in CHB children. However, lower and faster declines in antibody responses were observed in CHB adults. Interestingly, the seroprevalence of antibodies was still high after over 8 months in CHB children (anti-RBD-IgG [90%] and NAbs [83%]). However, neutralization against Omicron subvariants was significantly reduced in CHB children (-3.68-fold to -8.60-fold). Notably, neutralization against the BA.5 subvariant was obviously diminished in CHB children compared with adults. Moreover, CHB children had similar RBD-specific MBCs but higher RBD-specific atypical MBCs compared with adults. Conclusion: Inactivated vaccination could elicit more robust and durable antibody responses to the wild-type SARS-CoV-2 strain in CHB children than in CHB adults but showed inferior responses to Omicron subvariants (especially to the BA.5 strain). Hence, new Omicron-related or all-in-one vaccines are needed immediately for CHB children.

PgRNA kinetics predict HBsAg reduction in pregnant chronic hepatitis B carriers after treatment cessation.

Background: Pregenomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) play significant roles in predicting discontinuing treatment outcomes. However, their role in pregnancy has rarely been reported. We aimed to evaluate the performance of pgRNA and HBcrAg kinetics in predicting HBeAg seroconversion and HBsAg reduction postpartum in HBeAg-positive pregnant women. Methods: Pregnant HBeAg-positive patients receiving antiviral prophylaxis and ceasing treatment postpartum were included. PgRNA and HBcrAg levels were measured before treatment, at 32 weeks of gestation, and at treatment withdrawal postpartum. Other virological and biochemical parameters were regularly examined until 96 weeks postpartum. Results: Of 76 pregnant chronic hepatitis B (CHB) carriers with a median treatment duration of 18.1 weeks, HBeAg seroconversion and HBsAg reduction >0.3 log10 IU/mL at 96 weeks postpartum occurred in 8 (10.5%) and 13 (17.1%) patients, respectively. HBsAg correlated most strongly with pgRNA, while HBeAg correlated most strongly with HBcrAg. Multivariable regression analysis revealed that postpartum pgRNA decline and peak ALT levels were independent predictors of HBsAg reduction. The area under the curve of the regression model was 0.79 and reached as high as 0.76 through bootstrapping validation. The calibration plot showed that the nomogram had a performance similar to that of the ideal model. A decision tree was established to facilitate application of the nomogram. In addition, HBcrAg kinetics, as an independent predictor, performed poorly in predicting HBeAg seroconversion. Conclusions: Postpartum pgRNA decline together with peak ALT levels may identify patients with a higher probability of HBsAg reduction after treatment cessation postpartum among pregnant CHB carriers receiving antiviral prophylaxis.

The efficacy of pegylated interferon alpha-2a and entecavir in HBeAg-positive children and adolescents with chronic hepatitis B.

BACKGROUND AND OBJECTIVES: Pegylated interferon alpha-2a (peg-IFN α-2a) and entecavir (ETV) are both recommended as the first-line antiviral drugs for chronic hepatitis B (CHB) at present. We aimed to compare the efficacy and safety between peg-IFN α-2a and ETV initial therapy in children and adolescents with CHB and investigate the potential factors affecting the treatment response during the first 48 weeks. METHODS: We retrospectively selected 70 treatment-naïve children and adolescents with CHB who received peg-IFN α-2a(n = 26) or ETV(n = 44) as initial therapy and completed 48-week follow-up for data analysis. Blood samples before treatment were collected from 26 patients of the cohort to assess the cytokine profiles. RESULTS: We found that initial peg-IFN therapy results in higher rates of hepatitis B surface antigen (HBsAg) serological response (SR) but lower rates of virological and biochemical response rates compared to ETV at week 48. As for achieving hepatitis B e antigen (HBeAg) SR, peg-IFN was comparable to ETV in the univariate analysis and turned out to be better than ETV after adjustment for important baseline factors. We also found that elevated pre-treatment IL-18 level was significantly associated with HBeAg SR, and remained as the only independent factor of predicting HBeAg SR after adjustment for other important factors. No serious adverse effects of the 2 drugs were reported during the 48-week follow-up. CONCLUSIONS: comparing to ETV, peg-IFN was superior in achieving HBsAg and HBeAg SR; higher baseline IL-18 levels were independently associated with HBeAg SR in this study of children and adolescents with CHB.

The Characteristics of Natural Killer Cells and T Cells Vary With the Natural History of Chronic Hepatitis B in Children.

Background and Aims: The immune status of children with chronic hepatitis B (CHB) in different phases is still unclear. The aim of this study was to investigate the phenotype and cytokine-producing ability of natural killer (NK) and T cells and to better understand the immune characteristics of children with different phases of CHB. Methods: Treatment-naive children with CHB were divided into groups with different clinical phases of CHB. Fresh peripheral blood drawn from hepatitis B virus (HBV)-infected and healthy children was processed to perform flow cytometric analysis. Results: A total of 112 treatment-naive children with CHB and 16 comparable healthy controls were included in this study. The expression of HLA-DR on NK cells and CD38 on T cells were upregulated, especially in the IA phase, in children with CHB compared with healthy controls. The ability of circulating NK cells instead of CD8+ T cells to produce IFN-γ in children with CHB was slightly increased, but TNF-α production seemed to be decreased compared with that in healthy controls. The expression of some activation markers varied among children with different phases of CHB, especially the higher CD38 expression found on T cells in the IA phase. Regression analysis revealed that IFN-γ and TNF-α production by NK cells and CD8+ T cells seemed to have positive correlations with ALT elevation and an activated status of NK cells or T cells. Conclusion: NK cells and T cells tended to be phenotypically activated (especially in the IA phase) in children with CHB compared with healthy controls. However, their cytokine-producing function was not obviously elevated, especially IFN-γ production by CD8+ T cells. More studies investigating the mechanism and observing the longitudinal changes in the immune status in children with CHB are needed.

Identifying potential biomarkers in hepatitis B virus infection and its response to the antiviral therapy by integrated bioinformatic analysis.

The antiviral treatment efficacy varies among chronic hepatitis B (CHB) patients and the underlying mechanism is unclear. An integrated bioinformatics analysis was performed to investigate the host factors that affect the therapeutic responsiveness in CHB patients. Four GEO data sets (GSE54747, GSE27555, GSE66698 and GSE66699) were downloaded from the Gene Expression Omnibus (GEO) database and analysed to identify differentially expressed genes(DEGs). Enrichment analyses of the DEGs were conducted using the DAVID database. Immune cell infiltration characteristics were analysed by CIBERSORT. Upstream miRNAs and lncRNAs of hub DEGs were identified by miRWalk 3.0 and miRNet in combination with the MNDR platform. As a result, seventy-seven overlapping DEGs and 15 hub genes were identified including CCL5, CXCL9, MYH2, CXCR4, CD74, CCL4, HLA-DRB1, ACTA1, CD69, CXCL10, HLA-DRB5, HLA-DQB1, CXCL13, STAT1 and CKM. The enrichment analyses revealed that the DEGs were mainly enriched in immune response and chemokine signalling pathways. Investigation of immune cell infiltration in liver samples suggested significantly different infiltration between responders and non-responders, mainly characterized by higher proportions of CD8+ T cells and activated NK cells in non-responders. The prediction of upstream miRNAs and lncRNAs led to the identification of a potential mRNA-miRNA-lncRNA regulatory network composed of 2 lncRNAs (H19 and GAS5) and 5 miRNAs (hsa-mir-106b-5p, hsa-mir-17-5p, hsa-mir-20a-5p, hsa-mir-6720-5p and hsa-mir-93-5p) targeting CCL5 mRNA. In conclusion, our study suggested that host genetic factors could affect therapeutic responsiveness in CHB patients. The antiviral process might be associated with the chemokine-mediated immune response and immune cell infiltration in the liver microenvironment.

Misclassification of chronic hepatitis B natural history phase: Insight from new ALT, AST, AKP, and GGT reference intervals in Chinese children.

BACKGROUND: The age- and sex-specific reference intervals (RIs) for liver chemistry in children are not available in China. Our study aimed to establish age and gender related RIs for ALT, AST, AKP, and GGT in China, and apply the new RI for ALT in children with chronic hepatitis B to use as a biochemical marker for disease progression. METHODS: Data were collected from the Children's Healthcare Center. The measurements of ALT, AST, AKP and GGT were performed on a Hitachi 7600 Chemistry Analyzer. Age- and sex-specific RIs were determined using a percentile (3rd-97th) method. The sensitivity and specificity were determined to test the ability of the newly proposed ALT thresholds to classify children with chronic HBV infection. RESULTS: The age- and sex-specific RIs of ALT, AST, AKP and GGT were established based on 4232 Chinese healthy children. Using the new median ALT threshold, the sensitivity was higher. The detection of chronic HBV infection was 31.2% in boys and 35.5% in girls, while a very slight decrease in specificity was found. Based on the newly proposed RIs of ALT, approximately 16.1% boys and 19.0% girls would be classified in the HBeAg-positive chronic hepatitis phase, but using the current ALT threshold of children's hospitals they were in HBeAg-positive chronic infection phase. CONCLUSIONS: Based on a large healthy population, we established the sex- and age-specific RIs of ALT, AST, AKP and GGT serum activities for Chinese children. Meanwhile, newly proposed liver chemistry RIs will benefit the understanding of liver function and the natural history of chronic HBV infection in children.