Serum soluble programmed cell death 1 levels predict spontaneous functional cure in inactive carriers with chronic hepatitis B

Serum sPD-1 and sPD-L1 as predictive biomarkers for HBsAg clearance in HBeAg-negative CHB patients undergoing IFN-based therapy

BACKGROUND AND AIMS

For chronic hepatitis B (CHB) patients, there is still a need to improve hepatitis B surface antigen (HBsAg) clearance rates. This study aimed to assess the predictive effectiveness of soluble programmed cell death-1 (sPD-1) and soluble programmed cell death ligand-1 (sPD-L1) for HBsAg clearance in HBeAg-negative CHB patients undergoing peginterferon (Peg-IFN)-based antiviral treatment.

METHODS

This study encompassed 280 patients undergoing treatment with Peg-IFNα. Serum levels of sPD-1 and sPD-L1 were measured using ELISA kits at baseline, as well as at 12, 24 and 48 weeks. The primary endpoint of the study was the determination of HBsAg clearance at 48 weeks. Logistic regression analysis was employed to identify predictors of HBsAg clearance.

RESULTS

The clearance group demonstrated significantly lower serum sPD-L1 levels compared to the non-clearance group. While both groups exhibited an increase in sPD-1 levels, only the clearance group showed a rise in sPD-L1 levels. Multivariate analysis identified sPD-L1 increase at 24 weeks, and HBsAg decline at 24 weeks as predictors for HBsAg clearance at 48 weeks. The combined use of these indicators showed a predictive performance for HBsAg clearance with an AUROC of 0.907 (95% CI: 0.861-0.953, p < 0.001).

CONCLUSIONS

The study revealed an inverse relationship between the trends of sPD-1/sPD-L1 and HBsAg clearance during combined IFN and NAs treatment. Moreover, the magnitude of HBsAg reduction and sPD-L1 increase emerged as significant predictors for HBsAg clearance.

Role of CXCR5+ CD8+ T cells in human hepatitis B virus infection

The replication of HBV in hepatocytes can be effectively inhibited by lifelong antiviral therapy. Because of the long-term presence of HBV reservoirs, the virus rebound frequently occurs once the treatment is stopped, which poses a considerable obstacle to the complete removal of the virus. In terms of gene composition, regulation of B cell action and function, CXCR5+ CD8+ T cells are similar to CXCR5+ CD4+ T follicular helper cells, while these cells are characterized by elevated programmed cell death 1 and cytotoxic-related proteins. CXCR5+ CD8+ T cells are strongly associated with progression in inflammatory and autoimmune diseases. In addition, CXCR5 expression on the surface of CD8+ T cells is mostly an indicator of memory stem cell-like failure in progenitor cells in cancer that are more responsive to immune checkpoint blocking therapy. Furthermore, the phenomena have also been demonstrated in some viral infections, highlighting the duality of the cellular immune response of CXCR5+ CD8+ T cells. This mini-review will focus on the function of CXCR5+ CD8+ T cells in HBV infection and discuss the function of these CD8+ T cells and the potential of associated co-stimulators or cytokines in HBV therapeutic strategies.

CD4+ T cell counts and soluble programmed death-1 at baseline correlated with hepatitis B surface antigen decline in HIV/HBV coinfection during combined antiretroviral therapy

Background

Several studies have described the rapid decline and clearance of hepatitis B surface antigen (HBsAg) in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfection after initiating combined antiretroviral therapy (cART). Early decline of HBsAg levels is associated with HBsAg seroclearance in the treatment of chronic HBV infection. This study aims to evaluate the HBsAg kinetics and the determinants of early HBsAg decline in patients with HIV/HBV coinfection during cART.

Methods

A total of 51 patients with HIV/HBV coinfection were enrolled from a previously established HIV/AIDS cohort and followed for a median of 59.5 months after cART initiation. Biochemical tests, virology and immunology assessments were measured longitudinally. The kinetics of HBsAg during cART were analyzed. Soluble programmed death-1 (sPD-1) levels and immune activation markers (CD38 and HLA-DR) were measured at baseline, 1-year and 3-year during treatment. HBsAg response was defined as a decline of more than 0.5 log₁₀ IU/ml at 6 months from the baseline after initiation of cART.

Results

HBsAg declined faster (0.47 log₁₀ IU/mL) in the first six months and attained a decrease of 1.39 log₁₀ IU/mL after 5-year therapy. Seventeen (33.3%) participants achieved a decline of more than 0.5 log₁₀ IU/ml at the first 6 months of cART(HBsAg response) of which five patients achieved HBsAg clearance at a median of 11 months (range: 6-51 months). Multivariate logistic analysis showed the lower baseline CD4⁺ T cell levels (OR=6.633, P=0.012) and sPD-1 level (OR=5.389, P=0.038) were independently associated with HBsAg response after cART initiation. The alanine aminotransferase abnormality rate and HLA-DR expression were significantly higher in patients who achieved HBsAg response than in those who did not achieve HBsAg response after cART initiation.

Conclusion

Lower CD4 ⁺ T cells, sPD-1, and immune activation were related to a rapid HBsAg decline in patients with HIV/HBV-coinfection after the initiation of cART. These findings imply that immune disorders induced by HIV infection may disrupt immune tolerance to HBV, leading to a faster decline in HBsAg levels during coinfection.

An automated, rapid fluorescent immunoassay to quantify serum soluble programmed death-1 (PD-1) protein using testing-on-a-probe biosensors

OBJECTIVES

Soluble programmed death-1 (sPD-1) plays an essential role in the pathogenesis and progression of various diseases, including chronic hepatitis B (CHB) and hepatocellular carcinoma (HCC). Currently, there is no Food and Drug Administration-approved sPD-1 immunoassay available for routine clinical testing. Most sPD-1 detections employed enzyme-linked immunosorbent assay (ELISA) method for research purpose, which is complicated by intensive manual operation and cannot achieve automatic detection. Therefore, we aimed to develop an automated, rapid immunoassay for sPD-1 measurement based on testing-on-a-probe (TOP) biosensors and evaluate its performance in patients with hepatic diseases.

METHODS

We developed an automatic fluorescent immunoassay using TOP biosensors using a pair of mouse anti-PD-1 monoclonal antibodies (mAbs), which were evaluated by biolayer interferometry. The sensitivity, linearity, and repeatability of the novel immunoassay were analyzed, and its compatibility with an established ELISA kit was evaluated. Further, we quantified sPD-1 level in healthy individuals as well as patients with CHB, hepatic cirrhosis, and HCC.

RESULTS

The TOP assay to quantify sPD-1 was developed and performed on an automatic fluorescent analyzer within 20 min, which showed good precision with coefficients of variation less than 10% and good linearity ranging from 2 to 3,000 pg/mL. The results tested by our TOP assay correlated well with the established ELISA assay (r=0.92, p<0.0001). Using our TOP assay, sPD-1 was significantly elevated in patients with chronic hepatitis, hepatic cirrhosis and hepatocarcinoma if compared to healthy control, respectively (p<0.0001).

CONCLUSIONS

An automated, rapid fluorescent immunoassay to quantify serological sPD-1 protein using TOP biosensors was developed and showed acceptable analytical performance including precision, linearity, and good correlation with the established ELISA assay, with the great potential in clinical practice.