Profiles of serum soluble programmed death-1 and programmed death-ligand 1 levels in chronic hepatitis B virus-infected patients with different disease phases and after anti-viral treatment

Plasma levels of soluble PD-1, TIM-3, LAG-3 and galectin-3 and the degree of liver fibrosis in CHC and the impact of successful antiviral treatment on their levels

Chronic hepatitis C (CHC), caused by the hepatitis C virus, commonly leads to liver fibrosis. CHC is also related to T-cell exhaustion, phenotypically manifesting as overexpression of inhibitory receptors (iRs), e.g., programmed death receptor-1 (PD-1), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) and lymphocyte activation gene 3 (LAG-3), which have corresponding plasma-soluble analogs. Galectin-3 (Gal-3) is a pro-fibrotic and pro-inflammatory molecule, but its role in CHC is controversial. The study aimed to assess the relationship between plasma levels of soluble PD-1 (sPD-1), sTIM-3, sLAG-3 and Gal-3 and the degree of fibrosis in CHC and successful CHC treatment effect on these markers. The study comprised 98 CHC patients, qualified for treatment with direct-acting antivirals. Plasma samples were collected prior to and six months post-treatment. iRs were determined by ELISA. sPD-1 levels were significantly higher in more advanced fibrosis (F2 + F3 vs. F0/1). Regardless of the degree of fibrosis, sPD-1 and sLAG-3 levels significantly decreased after therapy. sTIM-3 levels also decreased, however, mostly in patients with no or mild (i.e., F0/1) fibrosis. Furthermore, Gal-3 increased in patients with more advanced fibrosis (F2 + F3). sPD-1 is associated with liver disease stage in CHC and effective treatment is related to the iRs levels reduction.

Predictive value of soluble PD-1 for HBsAg loss in HbeAg-negative patients with chronic hepatitis B: results from a prospective study

BACKGROUND

Soluble PD-1 (sPD-1) has emerged as a potential biomarker in chronic hepatitis B (CHB), but its predictive value for treatment response remains unclear.

OBJECTIVE

To examine the relationship between sPD-1 dynamics and HBsAg loss in HBeAg-negative CHB patients undergoing IFN-based therapy and assess the potential of sPD-1 as a biomarker for treatment response.

METHODS

We enrolled 222 HBeAg-negative CHB patients from a prospective study. Patients received at least 48 weeks of PEG-IFNα-2b therapy and were grouped based on HBsAg status at week 48 (loss vs. persistence). Peripheral blood sPD-1 levels were measured by ELISA, and PD-1 expression on CD4+ and CD8+ T cells was analyzed by flow cytometry. Propensity score matching (PSM) and Cox regression were applied to identify predictors of HBsAg loss.

RESULTS

Among the patients, 38.7% (86/222) achieved HBsAg loss. After PSM, both the HBsAg loss and HBsAg persistence groups included 74 patients, respectively. A reduction in HBsAg of more than 70% at week 12 (p = 0.012) and baseline sPD-1 level lower than 100 pg/mL (p = 0.016) were identified as independent predictors of HBsAg loss. sPD-1 levels showed a positive correlation with HBsAg levels, whereas PD-1 expression on peripheral CD4+ and CD8+ T cells demonstrated no significant association with HBsAg levels, suggesting that sPD-1 may better reflect systemic immune status.

CONCLUSIONS

sPD-1 may serve as a potential biomarker for predicting HBsAg loss in HBeAg-negative CHB patients undergoing IFN-based therapy.

Companion diagnostics and predictive biomarkers for PD-1/PD-L1 immune checkpoint inhibitors therapy in malignant melanoma

Programmed cell death receptor 1 (PD-1), when bound to the ligand programmed death-ligand 1 (PD-L1), can suppress cellular immunity and play a critical role in the initiation and development of cancer. Immune drugs targeting these two sites have been developed for different cancers, including malignant melanoma. The accompanying diagnostic method has been approved by the FDA to guide patient medication. However, the method of immunohistochemical staining, which varies widely due to the antibody and staining cut-off values, has certain limitations in application and does not benefit all patients. Increasing researches begin to focus on new biomarkers to improve objective response rates and survival in cancer patients. In this article, we enumerated three major groups, including tumour microenvironment, peripheral circulation, and gene mutation, which covered the current main research directions. In the future, we hope those biomarkers may be used to guide the treatment of patients with malignant melanoma.

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.

Soluble Programmed Cell Death 1 Protein Is a Promising Biomarker to Predict Severe Liver Inflammation in Chronic Hepatitis B Patients

Background and Aims: Liver inflammation is important in guiding the initiation of antiviral treatment and affects the progression of chronic hepatitis B(CHB). The soluble programmed cell death 1 protein (sPD-1) was upregulated in inflammatory and infectious diseases and correlated with disease severity. We aimed to investigate the correlation between serum sPD-1 levels and liver inflammation in CHB patients and their role in indicating liver inflammation. Methods: 241 CHB patients who underwent liver biopsy were enrolled. The correlation between sPD-1 levels and the degree of liver inflammation was analyzed. Univariate and multivariate logistic regression analyses were performed to analyze independent variables of severe liver inflammation. Binary logistic regression analysis was conducted to construct a predictive model for severe liver inflammation, and the receiver operating characteristic curve (ROC) was used to evaluate the diagnostic accuracy of the predictive model. Results: sPD-1 was highest in CHB patients with severe liver inflammation, which was higher than that in CHB patients with mild or moderate liver inflammation (P < 0.001). Besides, sPD-1 was weakly correlated with AST (r = 0.278, P < 0.001). Multivariable analysis showed that sPD-1 was an independent predictor of severe liver inflammation. The predictive model containing sPD-1 had areas under the ROC (AUROCs) of 0.917 and 0.921 in predicting severe liver inflammation in CHB patients and CHB patients with ALT ≤ 1× upper limit of normal (ULN), respectively. Conclusions: Serum sPD-1 level is associated with liver inflammation in CHB patients, and high levels of sPD-1 reflect severe liver inflammation. Serum sPD-1 is an independent predictor of severe liver inflammation and shows improved diagnostic accuracy when combined with other clinical indicators.

Immune checkpoints on T and NK cells in the context of HBV infection: Landscape, pathophysiology and therapeutic exploitation

In hepatitis B virus (HBV) infection, the interplay between the virus and the host immune system is crucial in determining the pathogenesis of the disease. Patients who fail to mount a sufficient and sustained anti-viral immune response develop chronic hepatitis B (CHB). T cells and natural killer (NK) cells play decisive role in viral clearance, but they are defective in chronic HBV infection. The activation of immune cells is tightly controlled by a combination of activating and inhibitory receptors, called immune checkpoints (ICs), allowing the maintenance of immune homeostasis. Chronic exposure to viral antigens and the subsequent dysregulation of ICs actively contribute to the exhaustion of effector cells and viral persistence. The present review aims to summarize the function of various ICs and their expression in T lymphocytes and NK cells in the course of HBV infection as well as the use of immunotherapeutic strategies targeting ICs in chronic HBV infection.

The Complex Role of HBeAg and Its Precursors in the Pathway to Hepatocellular Carcinoma

Hepatitis B virus (HBV) is one of the seven known human oncogenic viruses and has adapted to coexist with a single host for prolonged periods, requiring continuous manipulation of immunity and cell fate decisions. The persistence of HBV infection is associated with the pathogenesis of hepatocellular carcinoma, and various HBV proteins have been implicated in promoting this persistence. The precursor of hepatitis e antigen (HBeAg), is translated from the precore/core region and is post-translationally modified to yield HBeAg, which is secreted in the serum. HBeAg is a non-particulate protein of HBV and can act as both a tolerogen and an immunogen. HBeAg can protect hepatocytes from apoptosis by interfering with host signalling pathways and acting as a decoy to the immune response. By evading the immune response and interfering with apoptosis, HBeAg has the potential to contribute to the hepatocarcinogenic potential of HBV. In particular, this review summarises the various signalling pathways through which HBeAg and its precursors can promote hepatocarcinogenesis via the various hallmarks of cancer.

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.

A roadmap for serum biomarkers for hepatitis B virus: current status and future outlook

Globally, 296 million people are infected with hepatitis B virus (HBV), and approximately one million people die annually from HBV-related causes, including liver cancer. Although there is a preventative vaccine and antiviral therapies suppressing HBV replication, there is no cure. Intensive efforts are under way to develop curative HBV therapies. Currently, only a few biomarkers are available for monitoring or predicting HBV disease progression and treatment response. As new therapies become available, new biomarkers to monitor viral and host responses are urgently needed. In October 2020, the International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) held a virtual and interactive workshop on HBV biomarkers endorsed by the International HBV Meeting. Various stakeholders from academia, clinical practice and the pharmaceutical industry, with complementary expertise, presented and participated in panel discussions. The clinical utility of both classic and emerging viral and immunological serum biomarkers with respect to the course of infection, disease progression, and response to current and emerging treatments was appraised. The latest advances were discussed, and knowledge gaps in understanding and interpretation of HBV biomarkers were identified. This Roadmap summarizes the strengths, weaknesses, opportunities and challenges of HBV biomarkers.

Serum soluble programmed death-1 levels predict the spontaneous HBeAg seroclearance in chronic hepatitis B

BACKGROUND AND AIMS

In chronic hepatitis B virus (HBV) infection, earlier seroclearance of hepatitis B e antigen (HBeAg) is associated with more favorable outcomes. Soluble programmed cell death 1 (sPD-1) has been implicated in higher viral load and hepatocellular carcinoma. We investigated the association between sPD-1 levels and spontaneous HBeAg seroclearance.

METHODS

Baseline serum samples from 488 HBeAg-seropositive patients in the REVEAL-HBV cohort were tested for sPD-1 levels. Among them, 329 with available follow-up serum samples were further assayed. Multivariate Cox regression analysis was used to estimate the adjusted rate ratio (aRR) and 95% confidence interval (CI) with adjustment of host and viral factors. The 66th percentile and an annual reduction of ≥ 10% were used as the cut-off point for baseline sPD-1 levels (high/low) and sPD-1 trajectory (decline/no decline), respectively.

RESULTS

Lower baseline sPD-1 levels [aRR (95% CI): 2.19 (1.47-3.27)] and long-term decline in sPD-1 levels [aRR (95% CI): 4.08 (2.79-5.97)] were both independent predictors for HBeAg seroclearance. However, further stratification analysis by HBV genotype showed that lower baseline sPD-1 levels were significantly associated with HBeAg seroclearance only in genotype C infection [aRR (95% CI): 4.47 (2.38-8.37)] but not in genotype B infection. On the other hand, long-term decline in sPD-1 levels was predictive for HBeAg seroclearance regardless of HBV genotype with aRR (95% CI) of 4.62 (2.71-7.88) and 2.95 (1.68-5.17), respectively, for genotypes B and C.

CONCLUSION

Serum sPD-1 levels may serve as a novel immunological predictor for spontaneous HBeAg seroclearance in patients with chronic hepatitis B.

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.

Soluble programmed cell death-1 predicts hepatocellular carcinoma development during nucleoside analogue treatment

Soluble immune checkpoint molecules are emerging novel mediators of immune regulation. However, it is unclear whether soluble immune checkpoint proteins affect the development of hepatocellular carcinoma (HCC) during nucleos(t)ide analogue (NA) treatment in patients with chronic hepatitis B virus infection. This study included 122 NA-naïve patients who received NA therapy. We assessed the associations of clinical factors, including soluble immune checkpoint proteins, with HCC development during NA treatment. The baseline serum concentrations of 16 soluble immune checkpoint proteins were measured using multiplexed fluorescent bead-based immunoassay. In total, 13 patients developed HCC during the follow-up period (median duration, 4.3 years). Of the 16 proteins, soluble inducible T-cell co-stimulator (≥ 164.71 pg/mL; p = 0.014), soluble programmed cell death-1 (sPD-1) (≤ 447.27 pg/mL; p = 0.031), soluble CD40 (≤ 493.68 pg/mL; p = 0.032), and soluble herpes virus entry mediator (≤ 2470.83 pg/mL; p = 0.038) were significantly associated with HCC development (log-rank test). In multivariate analysis, an sPD-1 level ≤ 447.27 pg/mL (p = 0.014; hazard ratio [HR], 4.537) and α-fetoprotein level ≥ 6.4 ng/mL (p = 0.040; HR, 5.524) were independently and significantly associated with HCC development. Pre-treatment sPD-1 is a novel predictive biomarker for HCC development during NA treatment.

Association of PD-L1 gene polymorphisms and circulating sPD-L1 levels with HBV infection susceptibility and related liver disease progression

Soluble molecules of programmed death ligand 1 (sPD-L1) are known to modulate T-cell depletion, an important mechanism of hepatitis B virus (HBV) persistence and liver disease progression. In addition, PD-L1 polymorphisms in the 3'-UTR can influence PD-L1 expression and have been associated with cancer risk, although not definitively. The purpose of this study was to investigate the association of PD-L1 polymorphisms and circulating levels of sPD-L1 in HBV infection and live disease progression. In this study, five hundred fifty-one HBV infected patients of the three clinically well-defined subgroups chronic hepatitis B (CHB, n = 186), liver cirrhosis (LC, n = 142) and hepatocellular carcinoma (HCC, n = 223) and 240 healthy individuals (HC) were enrolled. PD-L1 polymorphisms (rs2297136 and rs4143815) were genotyped by in-house validated ARMS assays. Logistic regression models were applied in order to determine the association of PD-L1 polymorphisms with HBV infection as well as with progression of related liver diseases. Plasma sPD-L1 levels were quantified by ELISA assays. The PD-L1 rs2297136 AA genotype was associated with HBV infection susceptibility (HBV vs. HC: OR = 1.6; 95%CI = 1.1-2.3; p = 0.0087) and disease progression (LC vs. CHB: OR = 1.8; 95%CI = 1.1-2.9; p = 0.018). Whereas, the rs2297136 GG genotype was a protective factor for HCC development. Plasma sPD-L1 levels were significantly high in HBV patients (p < 0.0001) and higher in the LC followed by CHB and HCC groups. High sPD-L1 levels correlated with increased liver enzymes and with advanced liver disease progression (Child-pugh C > B > A, p < 0.0001) and BCLC classification (BCLC D > C > B > A, p = 0.031). We could, for the first time, conclude that PD-L1 rs2297136 polymorphism and plasma sPD-L1 protein levels associate with HBV infection and HBV-related liver disease progression.

High levels of soluble programmed death-1 are associated with virological response in chronic hepatitis B patients after antiviral treatment

BACKGROUND

Soluble programmed cell death protein-1 (sPD-1) plays an important role in chronic hepatitis B virus (HBV) infection by counteracting the inhibitory effect of programmed death ligand-1 (PD-L1) on immune cells. Here, we investigated the ability of sPD-1 to predict the virological response (VR) in chronic hepatitis B (CHB) patients undergoing Nucleos(t)ide analogue (NA) therapy.

METHODS

CHB patients [hepatitis B surface antigen (HBsAg) positive ≥6 months] who initiated NA therapy in March 2007 at Peking University First Hospital (China) were enrolled in this study. Eighty-nine CHB patients were followed-up every 12 weeks for 96 weeks.

RESULTS

Serum sPD-1 levels at baseline were negatively correlated with hepatitis B surface antigen (HBsAg) and HBV DNA. Immune-active CHB patients exhibited higher serum sPD-1 levels at baseline. Patients with VR during the antiviral treatment exhibited higher sPD-1 levels and lower HBsAg levels at baseline. Receiver operating characteristic (ROC) curves were generated to determine the predictive value of sPD-1 and HBsAg for VR in patients who received first-line therapy (entecavir, ETV). The area under ROC (AUROC) values of sPD-1 and HBsAg at baseline were 0.850 (95%CI:0.729-0.971, P = 0.0005) and 0.785 (95%CI: 0.642-0.929, P = 0.005), respectively, and the optimal cut-off values were 459.46 pg/mL and 14,710 IU/mL, respectively. The combination of sPD-1 and HBsAg exhibited a higher AUROC value (0.870,95% CI: 0.748-0.983, P = 0.001) than did sPD-1 or HBsAg alone. In patients administered second-line therapy (lamivudine, LAM/adefovir divipoxil, ADV), baseline sPD-1 levels above 677.2 pg/mL were significantly associated with higher incidence of VR after 96 weeks of antiviral therapy. It is 7.956 times the level of ≤677.2 pg/mL.

CONCLUSIONS

By combining sPD-1 and HBsAg, we obtained a biomarker significantly associated with VR in CHB patients. The sPD-1 levels could be used to screen out patients with poor prognosis of antiviral therapy.

Soluble programmed death-1 is predictive of hepatitis B surface antigen loss in chronic hepatitis B patients after antiviral treatment

BACKGROUND

Hepatitis B surface antigen (HBsAg) loss, a functional cure in patients with chronic hepatitis B (CHB) undergoing antiviral therapy, might be an ideal endpoint of antiviral treatment in clinical practice. The factors that contribute to the functional cure remain unclear, and the predictors of functional cure are worth exploring. The concentration and kinetics of soluble programmed death-1 (sPD-1) in patients with CHB may play an important role in elucidating the immune response associated with functional cure after nucleos(t)ide analogs therapy.

AIM

To investigate the factors associated with HBsAg loss and explore the influence of sPD-1 Levels.

METHODS

This study analyzed the data and samples from patients with CHB who underwent antiviral treatment in a non-interventional observational study conducted at Peking University First Hospital in Beijing (between 2007 and 2019). All patients were followed up: Serum samples were collected every 3 mo during the first year of antiviral treatment and every 6 mo thereafter. Patients with positive hepatitis B e antigen levels at baseline and with available sequential samples who achieved HBsAg loss during antiviral treatment served as the case group. This case group (n = 11) was further matched to 44 positive hepatitis B e anti patients without HBsAg loss as controls. The Spearman’s rank correlation test and receiver operating characteristic curves analysis were performed.

RESULTS

The sPD-1 Levels were higher in patients with HBsAg loss than in those without HBsAg loss from baseline to month 96, and the differences were significant between the groups at baseline (P = 0.0136), months 6 (P = 0.0003), 12 (P < 0.0001), 24 (P = 0.0007), 48 (P < 0.0001), and 96 (P = 0.0142). After 6 mo of antiviral treatment, the sPD-1 levels were positively correlated with alanine transaminase (ALT) levels (r = 0.5103, P = 0.0017), and the sPD-1 levels showed apparent correlation with ALT (r = 0.6883, P = 0.0192) and HBV DNA (r = 0.5601, P = 0.0703) levels in patients with HBsAg loss. After 12 mo of antiviral treatment, the sPD-1 levels also showed apparent correlation with ALT (r = 0.8134, P = 0.0042) and HBV DNA (r = 0.6832, P = 0.0205) levels in patients with HBsAg loss. The sPD-1 levels were negatively correlated with HBsAg levels in all patients after 12 mo of antiviral treatment, especially at 24 (r = -0.356, P = 0.0497) and 48 (r = -0.4783, P = 0.0037) mo. After 6 mo of antiviral treatment, the AUC of sPD-1 for HBsAg loss was 0.898 (P = 0.000), whereas that of HBsAg was 0.617 (P = 0.419). The cut-off value of sPD-1 was set at 2.34 log pg/mL; the sensitivity and specificity were 100% and 66.7%, respectively.

CONCLUSION

The sPD-1 levels at 6 mo can predict HBsAg loss after 144 mo of antiviral treatment.