The natural history of chronic hepatitis B virus (HBV) infection is usually divided into four phases: immune tolerant (IT), immune active (IA), immune carrier (IC), and immune reactive (IR). Many patients still cannot be classified into the four phases, called "Grey Zone (GZ)". This study aimed to analyze the liver histological features of the GZ patients to guide antiviral therapy.

We retrospectively analyzed the 1454 patients with chronic HBV infection who underwent liver biopsy. GZ patients with identical serum hepatitis Be antigen (HBeAg) and alanine aminotransferase (ALT) levels as those in the IT, IA, IC, and IR phases were categorized into the IT-GZ, IA-GZ-1, IA-GZ-2, IC-GZ, and IR-GZ groups, respectively. We analyzed and compared the histological distribution of liver in these patients. We evaluated independent influencing factors for significant liver histological changes (SLHC) in patients in the GZ subgroups.

Among the 1454 patients, 690(47.5%) patients in GZ. Among the 690 patients of the GZ, 322(46.7%) patients for whom histological examinations indicated SLHC. The proportion of SLHC within the GZ subgroups was as follows: IT-GZ (50.5%), IA-GZ-1 (75.0%), IA-GZ-2 (48.4%), IC-GZ (32.1%), and IR-GZ (59.6%). In the IT-GZ group, the proportion of patients aged ≤ 30 years with SLHC was 47.1%, and in the IC-GZ group, this proportion was 42.1%.

46.7% of GZ patients had significant liver histological changes. For HBeAg-negative patients with ALT ≤ 40U/L, HBV DNA ≥ 2000IU/mL, and an age of ≤ 30 years old, antiviral therapy was recommended; if they expressed concern, a liver biopsy was suggested.

Hepatitis B virus (HBV) infection is a dynamic disease where patients progress through several stages defined by HBV e-antigen (HBeAg) status, HBV-DNA levels and transaminase elevations, with antiviral therapy indicated only in specific stages. However, some patients cannot be classified into one of the stages and are said to fall into an 'indeterminate phase' or 'grey zone'. Exact definitions of the indeterminate phase vary from guideline to guideline as a result of different cut-off values for biomarker measurements. Data suggest that as many as 50% of HBV patients may be in an indeterminate phase and may not rapidly transition out of this phase. Clinical data that suggest these patients are at increased risk of hepatocellular carcinoma (HCC) are complemented by molecular evidence of integrations of HBV-DNA into the host genome, chromosomal translocations and immune activation despite liver enzymes that may suggest lack of inflammation. Antiviral therapy reduces these hepatocarcinogenic mechanisms and is reflected in a reduction of fibrosis and HCC risk. We review key data on patients in the indeterminate phase, with emphasis on HCC as an outcome. We take a holistic approach and link new biological data with clinical observations as well as examine the potential role of antiviral therapy in reducing HCC risk among patients in the indeterminate phase. With the availability of safe and effective oral antivirals, consideration must be given as to how much residual risk of HCC should be tolerated among patients in the indeterminate phase.

Measurement of O-glycosylated middle hepatitis B surface antigen (HBsAg glycan isomer, HBsAgGi) has been developed to quantify hepatitis B virus (HBV) infectious virions and distinguish them from subviral particles. This study aimed to evaluate the association between serum HBsAg seroclearance and serum HBV virions measured by HBsAgGi in patients with chronic hepatitis B (CHB).

Serum HBsAgGi levels were quantified in 232 treatment-naïve patients with CHB genotype C. Cox proportional hazards analysis was used to calculate hazard ratios (HRs) for factors associated with HBsAg seroclearance.

Baseline HBsAgGi levels showed significant differences among HBV phenotypes. During a median follow-up period of 7.4 years, 22 of the 232 patients achieved HBsAg seroclearance. Multivariate analysis demonstrated that quantitative HBsAg, nucleoside/nucleotide analog therapy during the follow-up period, and HBsAgGi levels were independent predictors of seroclearance. The adjusted HR indicated that the HBsAg seroclearance probability in patients with low HBsAgGi (≤3.5log ng/mL) was over five times higher than that in patients with high HBsAgGi. Kaplan-Meier analysis indicated that the 10-year probabilities of HBsAg seroclearance were 21.0% and 3.0% in patients with low and high HBsAgGi levels, respectively (p < 0.001), and that patients with high HBsAgGi levels showed low seroclearance probabilities irrespective of the other predictors.

Serum HBV infectious virion levels, measured using HBsAgGi, may be a novel predictor of HBsAg seroclearance.

Studies with large size samples on the liver histological changes of indeterminate phase chronic hepatitis B (CHB) patients were not previously conducted.

To assess the liver histological changes in the indeterminate phase CHB patients using liver biopsy.

The clinical and laboratory data of 1532 untreated CHB patients were collected, and all patients had least once liver biopsy from January 2015 to December 2021. The significant differences among different phases of CHB infection were compared with t-test, and the risk factors of significant liver histological changes were analyzed by the multivariate logistic regression analysis.

Among 1532 untreated CHB patients, 814 (53.13%) patients were in the indeterminate phase. Significant liver histological changes (defined as biopsy score ≥ G2 and/or ≥ S2) were found in 488/814 (59.95%) CHB patients in the indeterminate phase. Significant liver histological changes were significant differences among different age, platelets (PLTs), and alanine aminotransferase (ALT) subgroup in indeterminate patient. Multivariate logistic regression analysis indicated that age ≥ 40 years old [adjust odd risk (aOR), 1.44; 95% confidence interval (CI): 1.06-1.97; P = 0.02], PLTs ≤ 150 × 109/L (aOR, 2.99; 95%CI: 1.85-4.83; P < 0.0001), and ALT ≥ upper limits of normal (aOR, 1.48; 95%CI: 1.08, 2.05, P = 0.0163) were independent risk factors for significant liver histological changes in CHB patients in the indeterminate phase.

Our results suggested that significant liver histological changes were not rare among the untreated CHB patients in indeterminate phase, and additional strategies are urgently required for the management of these patients.

Pregnant women with chronic hepatitis B (CHB) exhibit unique clinical features in terms of postpartum immune system reconstitution and recovery from pregnancy-related changes. However, current studies focus primarily on the outcomes of maternal-infant transmission and postpartum hepatitis flares. We aimed to evaluate the profiles of hepatitis B core-related antigen (HBcrAg) and pregenomic RNA (pgRNA) in pregnant women with CHB.

This retrospective analysis included treatment-naïve pregnant women with CHB who were followed up regularly in an outpatient clinic from 2014 to 2021. Baseline HBcrAg and pgRNA levels were compared in patients with different disease phases. Changes in these parameters were examined in a subset of patients receiving antiviral prophylaxis. HBcrAg and pgRNA levels were measured before treatment, at 32 weeks of gestation, and postpartum.

The final analysis included a total of 121 patients, 100 of whom were hepatitis B e antigen (HBeAg)-positive (96 and 4 in the immune-tolerant and -indeterminate phases, respectively) and 21 of whom were HBeAg-negative (6 and 15 in the immune-active and -inactive carrier phases, respectively). The HBeAg-negative group vs the HBeAg-positive group had lower levels of baseline HBcrAg (median [interquartile range {IQR}], 3.7 [3.0-5.9] vs 8.6 [8.4-8.7] log10 U/mL; P < .01) and pgRNA (median [IQR], 0.0 [0.0-2.5] vs 7.8 [7.6-8.1] log10 copies/mL; P < .01). The serum levels of HBcrAg and pgRNA were highest in immune-tolerant carriers and lowest in immune-inactive carriers. In HBeAg-positive patients, the correlation coefficients of HBcrAg and pgRNA with hepatitis B virus (HBV) DNA were 0.40 and 0.43, respectively; in HBeAg-negative patients, they were 0.53 and 0.51, respectively (all P < .05). The correlation coefficients with hepatitis B surface antigen (HBsAg) were 0.55 and 0.52 (P < .05) in HBeAg-positive patients, respectively, while in HBeAg-negative patients they were 0.42 and 0.37, respectively (P > .05). Among 96 patients receiving antiviral prophylaxis, we detected a rapid decrease in HBV DNA to an undetectable level during treatment but relatively stable levels of pgRNA and HBcrAg.

HBcrAg and pgRNA levels are lower in HBeAg-negative patients than in HBeAg-positive patients. These 2 markers are significantly associated with HBV DNA irrespective of HBeAg status, while they are significantly associated with HBsAg only in HBeAg-positive patients.

The timing of antiviral therapy for chronic hepatitis B (CHB) patients with normal alanine transaminase (ALT) or aged < 30 years is still undetermined. We aimed to elucidate the correlation between liver histology, age, and ALT level in CHB patients and analyze the histological characteristics of the liver among patients with persistently normal ALT or aged < 30 years.

A retrospective analysis was conducted on 697 treatment-naive CHB patients. Liver biopsies were performed, and significant histological damage was defined as the grade of liver inflammation ≥ G2 and/or fibrosis ≥ S2 based on the Scheuer scoring system.

The liver inflammation grades and fibrosis stages correlated positively with age, ALT, AST, GGT levels and negatively with the counts of PLT (all p < 0.050) in HBeAg-positive patients. Higher ALT levels and lower PLT counts were independently associated with significant liver inflammation and fibrosis in both HBeAg-positive and HBeAg-negative patients. Furthermore, among those with persistently normal ALT levels, the incidence of significant liver inflammation and fibrosis were 66.1% and 53.7% in HBeAg-positive groups, and 63.0% and 55.5% in HBeAg-negative groups. Moreover, there was no significant difference in the prevalence of significant liver damage between patients aged < 30 years and those aged ≥ 30 years, in both HBeAg-positive (≥ G2 or ≥ S2: 63.8% vs. 75.8%, p = 0.276) and HBeAg-negative (≥ G2 or ≥ S2: 65.9% vs. 72.5%, p = 0.504) groups, among patients with persistently normal ALT levels.

A considerable proportion of CHB patients with persistently normal ALT, including those below the age of 30 years, exhibited significant histological damage. This highlights the importance of initiating early antiviral therapy for HBV-infected individuals, even in the absence of elevated ALT levels.

We aimed to define gender-specific, optimal alanine aminotransferase (ALT) cut-off values for the prediction of significant liver histological changes (SLHC) in Chinese patients with grey zone (GZ) chronic hepatitis B (CHB) and normal ALT.

In a retrospective study, we included 1101 consecutive patients with GZ CHB and normal ALT assigned to training or internal validation cohorts. We included an independent cohort of 842 patients for external validation. We performed receiver operating characteristic (ROC) curve, smoothed curve fitting, and threshold effect analyses to determine optimal ALT cut-off values. Area under the curve (AUC) values were calculated to assess their predictive performance.

A proportion of 79.3% of patients with GZ CHB and normal ALT (≤40 U/L) had SLHC. ROC curve analysis initially identified optimal ALT cut-off values of 29 U/L (male) and 22 U/L (female). After smoothed curve fitting and threshold effect analyses, new optimal cut-off values were 27 U/L for males and 24 U/L for females. AUCs for these values were 0.836 (male) and 0.833 (female) in the internal validation cohort, and 0.849 (male) and 0.844 (female) in the external validation cohort. The accuracy and discriminative ability of the newly defined ALT cut-off values were greater than those of the current recommendations.

This study established novel optimal ALT cut-off values for more precise prediction of SLHC among Chinese patients with GZ CHB and normal ALT levels. This may help identify individuals who will benefit from timely antiviral therapy.

Risk scores have been designed to predict the development of hepatocellular carcinoma (HCC) in treatment-naive patients with chronic hepatitis B (CHB). However, little is known about their predictive accuracy in HBeAg-negative patients in the grey zone (GZ). We aimed to develop a HBcrAg-based HCC risk score and explore whether it outperforms other risk scores in GZ patients.

Two retrospective cohorts of HBeAg-negative patients with American Association for the Study of Liver Diseases-defined GZ were established for derivation and validation (Taiwanese, N = 911; Japanese, N = 806). All of them were non-cirrhotic at baseline and remained treatment-naive during the follow-up. The primary endpoint was HCC development.

In a median follow-up period of 15.5 years, 85 patients developed HCC in the derivation cohort. We found that age, sex, alanine aminotransferase, platelet count, and HBcrAg, but not HBV DNA levels, were independent predictors and a 20-point GZ-HCC score was developed accordingly. The 10-year and 15-year area under the ROC curve (AUROC) ranged from 0.83 to 0.86, which outperformed the HBV DNA-based HCC risk scores, including REACH-B and GAG-HCC scores (AUROC ranging from 0.66 to 0.74). The better performance was also validated in EASL- and Asian Pacific Association for the Study of the Liver-defined GZ patients. These findings remained consistent in the validation cohort. Finally, the low-risk and high-risk GZ patients (stratified by a score of 8) had an HCC risk close to inactive CHB and immune-active CHB patients, respectively, in both cohorts.

The HBcrAg-based GZ-HCC score predicts HCC better than other HBV DNA-based risk scores in GZ patients who are HBeAg-negative patients, which may help optimise their clinical management.

We have developed a risk score based on HBcrAg, which has shown better predictive ability for HCC compared with other risk scores based on HBV DNA. Using a score of 8, GZ patients can be classified into low- and high-risk groups, which can guide follow up and early treatment, respectively. This validated risk score is a valuable tool for optimising the management of GZ patients who are HBeAg-negative.

The presence of significant liver inflammation is an important indication for antiviral treatment in patients with chronic hepatitis B (CHB) in the indeterminate phase. We aimed to establish a non-invasive nomogram to predict significant liver inflammation in these patients. A total of 195 CHB patients in the indeterminate phase were randomly split into training and validation sets. The least absolute shrinkage and selection operator and logistic regression were applied to identify risk factors and establish a predictive model. A calibration curve, decision curve analysis (DCA), and receiver operating characteristic (ROC) curve were applied to assess the performance of the nomogram. The median age was 42.0 y and 59.5% of the patients were male. Alkaline phosphatase, γ-glutamyl transpeptidase, and prothrombin time were independent predictors for significant liver inflammation and selected to establish the AGP-nomogram. The calibration plot demonstrated that the predicted results matched the actual values. The DCA showed a high net benefit when the threshold probability was 25-83% in the training set and 31-100% in the validation set. The areas under ROC curves of AGP-nomogram in predicting significant inflammation were significantly higher than ALT in the training set (0.744 vs. 0.642, P = 0.049) and validation set (0.766 vs. 0.660, P = 0.047). The ability of AGP-nomogram in predicting advanced inflammation was also superior to ALT. The AGP-nomogram can accurately identify significant inflammation in CHB patients in the indeterminate phase, and its application may reduce the need for liver biopsy and help identify candidates for antiviral treatment.Abbreviations: AASLD: American Association for the Study of Liver Diseases; ALB: albumin; ALP: alkaline phosphatase; ALT: alanine aminotransferase; APRI: aspartate aminotransferase-to-platelet ratio index; AST: aspartate aminotransferase; AUROC: area under the receiver operating characteristic curve; CHB: chronic hepatitis B; CI: confidence interval; DCA: decision curve analysis; FIB-4: fibrosis index based on the four factors; GLB: globulin; GGT: γ-glutamyl transpeptidase; HBcAb: hepatitis B core antibody; HBeAg: hepatitis B e antigen; HBsAg: hepatitis B surface antigen; HBV: hepatitis B virus; HCC: hepatocellular carcinoma; HIV: human immunodeficiency virus; INR: international-normalized ratio; IQR: interquartile range; LASSO: least absolute shrinkage and selection operator; LB: liver biopsy; LR: Likelihood ratio; NAFLD: non-alcoholic fatty liver disease; NPV: negative predictive value; PLT: platelets; PPV: positive predictive value; PT: prothrombin time; ROC: receiver operating characteristic; TB: total bilirubin; TE: transient elastography; ULN: upper limit of normal.

Predicting changes in disease activity and serological endpoints is necessary for the management of patients with chronic hepatitis B (CHB). We examined whether HBV RNA and hepatitis B core-related antigen (HBcrAg), two specialized virological markers proposed to reflect the activity of covalently closed circular DNA, may improve the ability to predict not sustained inactive carrier phase, spontaneous alanine aminotransferase (ALT) flare, HBeAg loss, and HBsAg loss.

Among eligible participants enrolled in the North American Hepatitis B Research Network Adult Cohort Study, we evaluated demographic, clinical, and virologic characteristics, including HBV RNA and HBcrAg, to predict not sustained inactive carrier phase, ALT flare, HBeAg loss, and HBsAg loss through a series of Cox proportional hazard or logistic regression models, controlling for antiviral therapy use. Among the study population, 54/103 participants experienced not sustained inactive carrier phase, 41/1006 had a spontaneous ALT flare, 83/250 lost HBeAg, and 54/1127 lost HBsAg. HBV RNA or HBcrAg were predictive of all 4 events. However, their addition to models of the readily available host (age, sex, race/ethnicity), clinical (ALT, use of antiviral therapy), and viral factors (HBV DNA), which had acceptable-excellent accuracy (e.g., AUC = 0.72 for ALT flare, 0.92 for HBeAg loss, and 0.91 for HBsAg loss), provided only small improvements in predictive ability.

Given the high predictive ability of readily available markers, HBcrAg and HBV RNA have a limited role in improving the prediction of key serologic and clinical events in patients with CHB.

The main aim of antiviral therapy in patients with chronic hepatitis B (CHB) is to prevent disease progression and reduce the risk of hepatocellular carcinoma (HCC). In general, treatment is recommended for select patient groups viewed as being at higher risk of developing adverse outcomes from CHB. However, patients who do not meet treatment criteria under current international guidelines may still benefit from antiviral therapy to reduce CHB-related complications. Moreover, well-tolerated antiviral drugs that are highly effective at suppressing viral replication are now widely available, and withholding therapy from patients with viremia is increasingly controversial. In this article, we review traditional treatment paradigms and argue the merits of expanding treatment eligibility to patients with CHB who do not meet current treatment criteria.

Chronic HBV infection patients who do not conform to any of the usual immune states are regarded as 'grey zone' patients. We aimed to investigate the proportion of chronic HBV infection patients in the grey zone, and evaluate the clinical characteristics and liver pathological changes in grey zone patients. Clinical data of 1391 treatment-naive chronic HBV infection patients with liver biopsy were collected. Natural history of HBV infection was determined based on European Association for the Study of the Liver (EASL) 2017, American Association for the Study of Liver Diseases (AASLD) 2018 and Chinese 2019 guidelines for the prevention and treatment of chronic HBV infection. Significant liver histological changes and associated risk factors of normal ALT grey zone patients were analysed. According to EASL, AASLD and Chinese criteria, there were 50.0%, 28% and 37.4% chronic HBV infection patients in the grey zone. Among the 353 grey zone patients with normal ALT, 72.4% had significant liver histological changes. ALT (optimal cut-off value 25 IU/L) and HBV DNA (optimal cut-off value 18,000 IU/mL) were independent risk factors of significant liver histological abnormalities. In conclusion, a substantial proportion of grey zone patients with normal ALT have significant liver histological changes that can be predicted by levels of serum ALT and HBV DNA. These results provide guidance of antiviral treatment in grey zone patients.

To investigate the immune status of Chinese chronic hepatitis B (CHB) pregnant women and their clinical characteristics.

About 1544 CHB pregnant women without antiviral therapy from 2013 to 2018 were selected from the hospital records. The definition of immune status is based on American Association for the Study of Liver Diseases (AASLD) 2018 Hepatitis B Guidance, and those who did not meet any criteria of the immune status were referred to in the gray zones (GZ).

There were 284 patients in the immune-tolerance phase, 72 patients in the HBeAg-positive immune active phase, 553 patients in the inactive phase, 61 patients in the HBeAg-negative immune active phase. Of note, 574 (37.18%) patients did not fit into any of the above phases were defined as the GZ. Patients with elevated ALT had a higher rate of intrahepatic cholestasis of pregnancy (ICP). Mother to child HBV transmission was rare (only two cases) and occurred in mothers in the immune-tolerant phase.

Our data showed that more than one-third of CHB pregnant women were classified into the GZ. In standard stages, advanced age is associated with HBeAg-negative and a higher cesarean rate in the inactive phase. The incidence of ICP was higher in immune active phases, including GB and GD. The probability of mother-to-child transmission in gray zones is low.

Withdrawal of nucleos(t)ide analog therapy is increasingly being evaluated in chronic hepatitis B infection as a strategy to induce hepatitis B surface antigen (HBsAg) loss. The Hepatitis B Research Network Immune-Active Trial evaluated treatment with tenofovir (TDF) for 4 years ± an initial 6 months of peginterferon-α (PegIFN) (NCT01369212) after which treatment was withdrawn.

Eligible participants (hepatitis B e antigen [HBeAg]-/anti-HBe+, hepatitis B virus [HBV] DNA <10 3 IU/mL, no cirrhosis) who discontinued TDF were followed for at least 1 year with optional follow-up thereafter. Retreatment was based on predefined criteria.

Among 201 participants who received 4 years of treatment, 97 participants (45 TDF and 52 TDF + PegIFN arm, 79 Asian) discontinued TDF. HBsAg loss occurred in 5 participants, 2 within 25 weeks and 3 within 89-119 weeks postwithdrawal (cumulative rate 4.3% by 2 years). Alanine aminotransferase (ALT) flares (>5× upper limit of normal) after TDF withdrawal occurred in 36 (37.1%) participants and occurred more frequently and earlier in those HBeAg- compared with HBeAg+ at treatment initiation. ALT flares were associated with older age and higher HBV DNA pretreatment and at the visit before the flare. ALT flares were not significantly associated with HBsAg decline or loss but were associated with immune active disease at 1 year (70.6% vs 11.9%, P < 0.0001) and 2 years (66.7% vs 25.9%, P = 0.03) postwithdrawal. Treatment reinitiation was required in 13 (13.4%) participants, and 13 others remained in a sustained inactive carrier state by the end of the study follow-up. No criteria reliably predicted safe treatment withdrawal.

Results from this trial do not support TDF withdrawal as a therapeutic strategy. HBsAg loss was infrequent within 2 years of stopping long-term TDF. If withdrawal is considered, HBV DNA should be carefully monitored with reinitiation of therapy if levels rise above 4 log 10 IU/mL to reduce the risk of ALT flares, as they were not associated with subsequent HBsAg decline or loss.

Most patients in the immunotolerant (IT) phase of chronic hepatitis B (CHB) transition to the immune active (IA-hepatitis B surface antigen [HBeAg]+) phase by early adulthood. We examined characteristics of adults in the IT vs IA-HBeAg+ phase and rate of transition from IT to other phases of CHB, with a focus on those ≥40 years.

Demographic, clinical, and virologic characteristics of participants in the Hepatitis B Research Network adult cohort study with IT CHB (alanine aminotransferase ≤1.5 × upper limit of normal, hepatitis B virus DNA >107 IU/mL) were compared by age category, and to those with IA-HBeAg+ CHB in cross-sectional analysis. This study received institutional review board approval at all participating centers.

Of 107 adult IT participants, 52 (48%) were <30, 33 (31%) were 30 to 39, and 22 (21%) were ≥40 years old (maximum, 71 years). Among IT groups, the proportion born in Asia and duration of CHB were greater in older IT groups, but virologic and liver disease characteristics were similar. Compared with IA-HBeAg+ participants (n = 192), IT participants were younger, fewer were men, more were Asian, and platelets, qHBsAg, and qHBeAg levels were higher. Similar differences were observed when comparisons were made with the ≥40 years IT group. Among IT participants, 60 (56%) transitioned during 206 person-years of follow-up. The phase transition rate per 100 person-years was highest in the <30 years group (33.0 [95% confidence interval [CI], 23.4-46.7]) vs the 30 to 39 years group (24.8 [95% CI, 15.6-39.4]) and ≥40 group (27.4 [95% CI, 14.8-50.9]), but 95% CIs overlapped.

In a large North American population, over 50% of adults in the IT phase of CHB were ≥30 years and 20% were ≥40 years old, but older IT patients had similar characteristics and rates of transition as younger IT patients.

Staining for hepatitis B viral antigens is often done in liver biopsies from patients with chronic hepatitis B, but its correlates with clinical phenotypes are not well described.

Biopsies were collected from a large cohort of adults and children with chronic hepatitis B viral infection through the Hepatitis B Research Network. Immunohistochemical staining of sections was done for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) and then centrally read by the pathology committee. The degree of liver injury and pattern of staining were then correlated with clinical characteristics, including the clinical phenotype of hepatitis B.

Biopsies from 467 subjects were studied, including 46 from children. Immunostaining for HBsAg was positive in 417 (90%) with scattered hepatocyte staining being the most common pattern. HBsAg staining correlated best with serum levels of HBsAg and hepatitis B viral DNA; the absence of HBsAg staining was often a prelude to loss of HBsAg from serum. HBcAg staining was positive in 225 (49%), and, while cytoplasmic staining was more frequent than nuclear staining, both nuclear and cytoplasmic positivity were often seen in the same specimen. Staining for HBcAg correlated with both level of viremia and liver injury. No biopsies from inactive carriers had stainable HBcAg, while 91% of the biopsies from those with hepatitis B e antigen-positive chronic hepatitis B stained positively for HBcAg.

Immunostaining for hepatitis B viral antigens may yield helpful insights into liver disease pathogenesis but appears to add little to commonly used serological and biochemical blood tests.

Hepatitis B virus (HBV) infection is a major public health problem, with an estimated 296 million people chronically infected and 820 000 deaths worldwide in 2019. Diagnosis of HBV infection requires serological testing for HBsAg and for acute infection additional testing for IgM hepatitis B core antibody (IgM anti-HBc, for the window period when neither HBsAg nor anti-HBs is detected). Assessment of HBV replication status to guide treatment decisions involves testing for HBV DNA, whereas assessment of liver disease activity and staging is mainly based on aminotransferases, platelet count, and elastography. Universal infant immunisation, including birth dose vaccination is the most effective means to prevent chronic HBV infection. Two vaccines with improved immunogenicity have recently been approved for adults in the USA and EU, with availability expected to expand. Current therapies, pegylated interferon, and nucleos(t)ide analogues can prevent development of cirrhosis and hepatocellular carcinoma, but do not eradicate the virus and rarely clear HBsAg. Treatment is recommended for patients with cirrhosis or with high HBV DNA levels and active or advanced liver disease. New antiviral and immunomodulatory therapies aiming to achieve functional cure (ie, clearance of HBsAg) are in clinical development. Improved vaccination coverage, increased screening, diagnosis and linkage to care, development of curative therapies, and removal of stigma are important in achieving WHO's goal of eliminating HBV infection by 2030.

Many patients with chronic hepatitis B (CHB) do not meet the definitions of the traditional natural phases and are classified as being in the grey zone (GZ).

To investigate liver histology, and to establish a management strategy for patients with CHB in the GZ.

This study included 1043 patients with CHB who underwent liver biopsy. Phases of natural history were determined according to the AASLD 2018 hepatitis B guidance. CHB patients in the GZ were divided into HBeAg-positive, normal ALT and HBV DNA ≤10⁶  IU/ml (GZ-A); HBeAg-positive, elevated ALT and HBV DNA ≤2 × 10⁴  IU/ml (GZ-B); HBeAg-negative, normal ALT and HBV DNA ≥2 × 10³  IU/ml (GZ-C) and HBeAg-negative, elevated ALT and HBV DNA ≤2 × 10³  IU/ml (GZ-D). Significant histological disease was defined as liver inflammation ≥G2 and/or liver fibrosis ≥S2.

Two hundred and forty two (23.2%) patients were in the GZ. Approximately 72.7% had significant histological disease. HBeAg-positive GZ CHB patients had a higher proportion of significant histological disease than HBeAg-negative GZ patients (91.1% vs. 68.5%, p = 0.002). GZ-D (42.6%) was the dominant category, followed by GZ-C (38.8%), GZ-A (10.3%) and GZ-B (8.3%). The highest proportion of significant histological disease was observed patients in GZ-B (100.0%), followed by GZ-A (84.0%), GZ-D (69.9%) and GZ-C (67.0%). Prothrombin time (PT) was an independent risk factor of significant histological disease in the HBeAg-negative GZ.

Over 70% of GZ CHB patients had significant histological disease. We recommend antiviral treatment for HBeAg-positive and HBeAg-negative GZ CHB patients with high PT.

Chronic hepatitis B (CHB) can be divided into immune tolerance (IT), immune clearance (IC), hepatitis B e antigen (HBeAg)-negative inactive/quiescent carrier (ENQ), and HBeAg-negative hepatitis (ENH) phases. The conventional biomarkers used to distinguish these phases have limitations. We examined the clinical significance of hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) as novel biomarkers.

One hundred eighty-nine patients without treatment currently were categorized by CHB phase (IT = 46, IC = 45, ENQ = 49, ENH = 49). The associations of HBV RNA and HBcrAg with HBV DNA and alanine transaminase (ALT) were analyzed. The decision tree model was used to distinguish the four phases in the natural course of CHB.

The concentrations of HBV RNA and HBcrAg were highest in the IT and IC phases (P < 0.01). Serum HBV RNA was similar to HBcrAg in treatment-naïve patients. HBV RNA and HBcrAg correlated with HBV DNA in the HBeAg⁺ and HBeAg^- status (HBV RNA: e⁺ r = 0.51, e^- r = 0.62; HBcrAg: e⁺ r = 0.51, e^- r = 0.71), but their association with HBV DNA differed among phases. The accuracy, sensitivity, and specificity of HBcrAg with ALT in distinguishing the CHB phases were 95.65%, 95.83%, and 95.55%, respectively.

Serum HBV RNA and HBcrAg may be useful to monitor CHB progression.

Many patients with chronic hepatitis B (CHB) are classified as indeterminate patients because they fall outside the defined CHB phases. We aimed to explore hepatocellular carcinoma (HCC) risk in hepatitis B e antigen (HBeAg)-negative patients with indeterminate phase and investigated whether the risk could be stratified by serum levels of hepatitis B core-related antigen (HBcrAg).

Two retrospective cohorts enrolling HBeAg-negative, treatment-naïve CHB patients without cirrhosis were constructed (N = 2,150 in Taiwanese discovery cohort and N = 1,312 in Japanese validation cohort with a mean follow-up period of 15.88 and 12.07 years, respectively). The primary end point was HCC development.

According to the American Association for the Study of Liver Disease guidelines, 990 (46%) HBeAg-negative patients had indeterminate CHB phase at baseline in the Taiwanese cohort. Compared with the patients with inactive CHB and those with immune-active CHB, the indeterminate patients exhibited intermediate but diverse risk of HCC. When HCC risk was stratified by a HBcrAg level of 10,000 U/mL, 10-year HCC cumulative incidence was 0.51% and 5.33% for low HBcrAg and high HBcrAg groups, respectively, with a hazard ratio of 4.47 (95% confidence interval: 2.62-7.63). This cutoff was validated to stratify HCC risk not only in different subgroup analyses but also in an independent Japanese cohort. Finally, the overall HBeAg-negative CHB patients could be simply reclassified into high-risk and low-risk groups by combining ALT, hepatitis B virus DNA, and HBcrAg levels in both cohorts.

Serum HBcrAg level of 10,000 U/mL stratifies HCC risk in HBeAg-negative patients with indeterminate phase, which is useful for optimizing their clinical management.

Achieving HBsAg loss is an important landmark in the natural history of chronic hepatitis B (CHB). A more personalized approach to prediction of HBsAg loss is relevant in counseling patients. This study sought to develop and validate a prediction model for HBsAg loss based on quantitative HBsAg levels (qHBsAg) and other baseline characteristics.

The Hepatitis B Research Network (HBRN) is a prospective cohort including 1240 untreated HBeAg-negative patients (1150 adults, 90 children) with median follow-up of 5.5 years. Incidence rates of HBsAg loss and hepatitis B surface antibody (anti-HBs) acquisition were determined, and a predictor score of HBsAg loss using readily available variables was developed and externally validated.

Crude incidence rates of HBsAg loss and anti-HBs acquisition were 1.6 and 1.1 per 100 person-years (PY); 67 achieved sustained HBsAg loss for an incidence rate of 1.2 per 100 PY. Increased HBsAg loss was significantly associated with older age, non-Asian race, HBV phenotype (inactive CHB vs. others), HBV genotype A, lower HBV-DNA levels, and lower and greater change in qHBsAg. The HBRN-SQuARe (sex,∆quantHBsAg, age, race) score predicted HBsAg loss over time with area under the receiver operating characteristic curve (AUROC) (95% CIs) at 1 and 3 years of 0.99 (95% CI: 0.987-1.00) and 0.95 (95% CI 0.91-1.00), respectively. In validation in another cohort of 1253 HBeAg-negative patients with median follow-up of 3.1 years, HBRN SQuARe predicted HBsAg loss at 1 and 3 years with AUROC values of 0.99 (0.98-1.00) and 0.88 (0.77-0.99), respectively.

HBsAg loss in predominantly untreated patients with HBeAg-negative CHB can be accurately predicted over a 3-year horizon using a simple validated score (HBRN SQuARe). This prognostication tool can be used to support patient care and counseling.

There are limited data on noninvasive methods to identify hepatic steatosis in coexisting hepatitis B virus (HBV) infection.

To evaluate the diagnostic performance of noninvasive serum-based scores to detect steatosis using two distinct chronic HBV cohorts with liver histology evaluation.

Chronic HBV cohorts with untreated HBV mono-infection (N = 302) and with treated HBV-HIV (N = 92) were included. Liver histology was scored centrally. Four serum-based scores were calculated: hepatic steatosis index (HSI), nonalcoholic fatty liver disease Liver Fat Score (NAFLD-LFS), visceral adiposity index (VAI), and triglyceride glucose (TyG) index. Optimal cutoffs (highest sensitivity + specificity) to detect ≥ 5% HS, stratified by cohort, were evaluated.

HBV-HIV (vs. HBV mono-infected) patients were older (median 50 vs. 43 years), and a higher proportion were male (92% vs. 60%), were black (51% vs. 8%), had the metabolic syndrome (41% vs. 25%), and suppressed HBV DNA (< 1000 IU/mL; 82% vs. 9%). Applying optimal cutoffs, the area under the receiver operator curve for detecting ≥ 5% steatosis in HBV-only and HBV-HIV, respectively, was 0.69 and 0.61 for HSI, 0.70 and 0.76 for NAFLD-LFS, 0.68 and 0.64 for TyG, and 0.68 and 0.69 for VAI. The accuracy of optimal cutoffs ranged from 61% (NAFLD-LFS) to 67% (TyG) among HBV-only and 56% (HSI) to 76% (NAFLD-LFS) among HBV-HIV. Negative predictive values were higher than positive predictive values for all scores in both groups.

The relative utility of scores to identify steatosis in chronic HBV differs by co-infection/anti-HBV medication status. However, even with population-specific cutoffs, several common serum-based scores have only moderate utility. ClinicalTrials.gov NCT01924455.

Although chronic HCV infection increases mortality, thousands of patients remain diagnosed-but-untreated (DBU). We aimed to (1) develop a DBU phenotyping algorithm, (2) use it to facilitate case finding and linkage to care, and (3) identify barriers to successful treatment.

We developed a phenotyping algorithm using Java and SQL and applied it to ~2.5 million EPIC electronic medical records (EMRs; data entered January 2003 to December 2017). Approximately 72,000 EMRs contained an HCV International Classification of Diseases code and/or diagnostic test. The algorithm classified 10,614 cases as DBU (HCV-RNA positive and alive). Its positive and negative predictive values were 88% and 97%, respectively, as determined by manual review of 500 EMRs randomly selected from the ~72,000. Navigators reviewed the charts of 6,187 algorithm-defined DBUs and they attempted to contact potential treatment candidates by phone. By June 2020, 30% (n = 1,862) had completed an HCV-related appointment. Outcomes analysis revealed that DBU patients enrolled in our care coordination program were more likely to complete treatment (72% [n = 219] vs. 54% [n = 256]; P < 0.001) and to have a verified sustained virological response (67% vs. 46%; P < 0.001) than other patients. Forty-eight percent (n = 2,992) of DBU patients could not be reached by phone, which was a major barrier to engagement. Nearly half of these patients had Fibrosis-4 scores ≥ 2.67, indicating significant fibrosis. Multivariable logistic regression showed that DBUs who could not be contacted were less likely to have private insurance than those who could (18% vs. 50%; P < 0.001).

The digital DBU case-finding algorithm efficiently identified potential HCV treatment candidates, freeing resources for navigation and coordination. The algorithm is portable and accelerated HCV elimination when incorporated in our comprehensive program.

The clinical utility of two biomarkers, hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg), as compared to conventional markers of HBV replication and disease activity, is unclear.

Untreated participants in the North American Hepatitis B Research Network Adult Cohort Study were categorized by chronic hepatitis B (CHB) phases based on HBsAg and HBeAg status and HBV DNA and alanine aminotransferase (ALT) levels. HBV RNA and HBcrAg were measured (Abbott HBV pgRNA Research Assay and Fujirebio Lumipulse Immunoassay, respectively), and cross-sectional associations with conventional CHB markers were tested. Among 1,409 participants across all CHB phases, median HBV DNA was 3.8 log₁₀ IU/mL and ALT was 34 U/L. HBV RNA was quantifiable in 99% of HBeAg⁺ and 58% of HBeAg^- participants; HBcrAg was quantifiable in 20% of HBeAg⁺ (above linear range in the other 80%) and 51% of HBeAg^- participants. Both markers differed across CHB phases (P < 0.001), with higher levels in the HBeAg⁺ and HBeAg^- immune active phases. HBV RNA and HBcrAg correlated moderately strongly with HBV DNA in both HBeAg⁺ and HBeAg^- phases (HBV RNA: e⁺ ρ = 0.84; e^- ρ = 0.78; HBcrAg: e⁺ ρ = 0.66; e^- ρ = 0.56; P for all, <0.001), but with HBsAg levels among HBeAg⁺ phases only (HBV RNA: e⁺ ρ = 0.71; P < 0.001; e^- ρ = 0.18; P = 0.56; HBcrAg: e⁺ ρ = 0.51; P < 0.001; e^- ρ = 0.27; P < 0.001). Associations of higher HBV RNA and HBcrAg levels with higher ALT, APRI, and Fibrosis-4 levels were consistent in HBeAg^- , but not HBeAg⁺ , phases.

Despite clear relationships between HBV RNA and HBcrAg levels and CHB phases, these markers have limited additional value in differentiating CHB phases because of their strong association with HBV DNA and, to a lesser extent, with clinical disease indicators.

Hepatitis B e antigen (HBeAg) is a soluble viral protein in plasma of patients with hepatitis B virus infection. HBeAg loss is an important first stage of viral antigen clearance. We determined the rate and predictors of HBeAg loss in a North American cohort with chronic hepatitis B viral infection (CHB). Among children and adults with CHB and without HIV, HCV or HDV co-infection enrolled in the Hepatitis B Research Network prospective cohort studies, 819 were HBeAg positive at their first assessment (treatment naïve or >24 weeks since treatment). Of these, 577 (200 children, 377 adults) were followed every 24-48 weeks. HBeAg loss was defined as first HBeAg-negative value; sustained HBeAg loss was defined as ≥2 consecutive HBeAg-negative values ≥24 weeks apart. During a median follow-up of 1.8 years, 164 participants experienced HBeAg loss, a rate of 11.4 (95% CI, 9.8-13.3) per 100 person-years. After adjustment for confounders, HBeAg loss rate was significantly higher in males than females, in older than younger individuals, in Whites or Blacks than Asians, in those with genotype A2 or B versus C, and in those with basal core promoter/pre-core mutations versus wild type. Additionally, during follow-up, an ALT flare and a lower quantitative HBsAg, quantitative HBeAg or HBV DNA level predicted higher rates of HBeAg loss. The majority (88%) with HBeAg loss had sustained HBeAg loss. In conclusion, a number of specific demographic, clinical and viral characteristics impacted rate of HBeAg loss and may prove useful in design and interpretation of future therapeutic studies.

Antiviral therapy has greatly improved the outcomes of patients with chronic hepatitis B virus (HBV) infection and active liver disease or advanced fibrosis/cirrhosis. However, current treatment does not eradicate HBV and long-term treatment is needed in most patients to maintain clinical benefit. Thus, professional society guidelines do not recommend treatment of all patients with chronic HBV infection. This review article will examine evidence for and against expansion of treatment to patients in whom treatment is not recommended based on current guidelines.

Available data support expanding treatment to immune tolerant patients and patients in the grey zones who have evidence of active/advanced liver disease based on liver biopsy or non-invasive tests and those who remain in the immune tolerant phase after age 40. Evidence supporting treatment expansion to confirmed inactive carriers and other immune tolerant patients is lacking.

HBV treatment indications can be more liberal when new therapies that can achieve HBsAg loss safely in a high percentage of patients after a finite course of treatment are available.