Programmed death 1 expressing CD8+ CXCR5+ follicular T cells constitute effector rather than exhaustive phenotype in patients with chronic hepatitis B

BACKGROUND AND AIMS

Classical CD8 T cells are implicated for protective and pathogenic roles in chronic hepatitis B (CHB) infection. Recently, a subset of CD8 T cells expressing C-X-C chemokine receptor type 5 (CXCR5) and exhibiting features of TFH cells has been identified during chronic viral infections. However, in CHB, knowledge of their roles is limited.

APPROACH AND RESULTS

We characterized circulating CD8+ CXCR5+/- cells and investigated their association with clinical and viral factors. We found that CHB infection did not influence the overall frequencies of CD8+ CXCR5+ cells whereas CD8+ CXCR5- cells were increased. However, among CHB, CD8+ CXCR5+ cells were higher in patients with low HBsAg and HBV-DNA levels, patients who were HBeAg negative and had high fibrosis scores, and these cells exhibited a significant association with HBsAg and HBV-DNA reduction. Contrarily, CD8+ CXCR5- cells were expanded and positively correlated with patients having high HBsAg, HBV-DNA, and alanine aminotransferase levels. CD8+ CXCR5+ cells express costimulatory molecules ICOS, OX40, CD40 ligand, inhibitory molecule programmed death 1, transcription factors B-cell lymphoma (BCL)-2, BCL-6, and signal transducer and activator of transcription 3, and are enriched in effector and central memory phenotype. Moreover, these cells are heterogeneous in nature given that they constitute different subsets of cytotoxic follicular T cells (TCF), including TCF1, TCF2, TCF17, and TCF22. Despite expressing high PD-1, CD8+ CXCR5+ cells are activated, proliferating, secreting more IFN-γ, IL-21, and IL-22, and have better cytolytic potential than CD8+ CXCR5- cells, which were inhibited after PD-1/PD-L1 blockade. CD8+ CXCR5+ cells are efficient in helping B cells in terms of plasmablasts and plasma cell generation.

CONCLUSIONS

In conclusion, CD8+ CXCR5+ cells are enriched in effector phenotypes, produce HBV-specific cytokines despite increased PD-1, and are associated with HBsAg and HBV-DNA reduction. These cells competently support B-cell function, required for viral clearance, which may serve as potential therapeutic targets for CHB.

Chronic Hepatitis B Infection: A Review

IMPORTANCE

More than 240 million individuals worldwide are infected with chronic hepatitis B virus (HBV). Among individuals with chronic HBV infection who are untreated, 15% to 40% progress to cirrhosis, which may lead to liver failure and liver cancer.

OBSERVATIONS

Pegylated interferon and nucleos(t)ide analogues (lamivudine, adefovir, entecavir, tenofovir disoproxil, and tenofovir alafenamide) suppress HBV DNA replication and improve liver inflammation and fibrosis. Long-term viral suppression is associated with regression of liver fibrosis and reduced risk of hepatocellular carcinoma in cohort studies. The cure (defined as hepatitis B surface antigen loss with undetectable HBV DNA) rates after treatment remain low (3%-7% with pegylated interferon and 1%-12% with nucleos[t]ide analogue therapy). Pegylated interferon therapy can be completed in 48 weeks and is not associated with the development of resistance; however, its use is limited by poor tolerability and adverse effects such as bone marrow suppression and exacerbation of existing neuropsychiatric symptoms such as depression. Newer agents (entecavir, tenofovir disoproxil, and tenofovir alafenamide) may be associated with a significantly reduced risk of drug resistance compared with older agents (lamivudine and adefovir) and should be considered as the first-line treatment.

CONCLUSIONS AND RELEVANCE

Antiviral treatment with either pegylated interferon or a nucleos(t)ide analogue (lamivudine, adefovir, entecavir, tenofovir disoproxil, or tenofovir alafenamide) should be offered to patients with chronic HBV infection and liver inflammation in an effort to reduce progression of liver disease. Nucleos(t)ide analogues should be considered as first-line therapy. Because cure rates are low, most patients will require therapy indefinitely.

Hepatitis B virus reactivation during direct-acting antiviral therapy for hepatitis C: a systematic review and meta-analysis

BACKGROUND

Direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection might pose a risk for hepatitis B virus (HBV) reactivation in patients coinfected with chronic or resolved HBV infection. The need for HBV antiviral prophylaxis during DAA treatment remains controversial. We aimed to analyse the absolute risk of HBV reactivation in patients with active or resolved HBV infection treated with DAAs for HCV infection.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and Web of Science from Oct 1, 2010, to Sept 30, 2017, to identify studies of patients with chronic or resolved HBV infection at baseline treated with DAAs for chronic HCV infection. Conference proceedings, abstract books, and references from relevant reviews were also examined for potential studies. Two independent researchers extracted data and assessed quality and risk of bias. Data were pooled by use of random-effects models. The primary outcome was HBV reactivation defined by standardised nomenclature. This study is registered with PROSPERO, number CRD42017065882.

FINDINGS

We identified 17 observational studies involving 1621 patients with chronic (n=242) or resolved (n=1379) HBV infection treated with different DAAs. The pooled proportion of patients who had HBV reactivation was 24% (95% CI 19-30) in patients with chronic HBV infection and 1·4% (0·8-2·4) in those with resolved HBV infection. In patients with chronic HBV infection, the pooled proportion of patients with HBV-reactivation-related hepatitis was 9% (95% CI 5-16) and the relative risk (RR) of HBV-reactivation-related hepatitis was significantly lower in patients with HBV DNA below the lower limit of quantification at baseline than in those with quantifiable HBV DNA (RR 0·17, 95% CI 0·06-0·50; p=0·0011). Three major clinical events related to HBV reactivation in patients with chronic HBV infection were reported (one patient had liver decompensation and two had liver failure, one of whom required liver transplantation). In patients with resolved HBV infection, no HBV-reactivation-related hepatitis was reported.

INTERPRETATION

HBV reactivation occurs frequently in patients with chronic HBV and HCV coinfection receiving DAA therapy but is rare among patients with resolved HBV infection. Use of antiviral prophylaxis might be warranted in patients who test positive for hepatitis B surface antigen (HBsAg), particularly those with quantifiable HBV DNA.

FUNDING

None.