Loss of HBsAg and antiviral treatment: from basics to clinical significance

Describing immune factors associated with Hepatitis B surface antigen loss: A nested case-control study of a Chinese sample from Wuwei City

Background

Hepatitis B surface antigen (HBsAg) loss is considered a functional cure for chronic hepatitis B (CHB), however, several factors influence HBsAg loss.

Methods

29 CHB patients who had achieved HBsAg loss, were selected and 58 CHB patients with persistent HBsAg were matched, according to gender and age (+/- 3 years). Logistic regression and restricted cubic spline (RCS) modelling were performed.

Results

Multivariate-adjusted logistic regression, based on stepwise selection, showed that baseline HBsAg levels negatively correlated with HBsAg loss (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.98-0.99). Interferon treatment positively related with HBsAg loss (OR = 7.99, 95%CI = 1.62-44.88). After adjusting for age, HBsAg level, ALT level, HBeAg status and interferon treatment, MMP-1 (OR = 0.66, 95%CI = 0.44-0.97), CXCL9 (OR = 0.96, 95%CI = 0.93-0.99) and TNF-R1 (OR = 0.97, 95%CI = 0.94-0.99) baseline levels all negatively correlated with HBsAg loss. Our multivariate-adjusted RCS model showed that baseline CXCL10 was associated with HBsAg loss although the relationship was “U-shaped”.

Conclusions

Cytokines such as MMP-1, CXCL9, CXCL10 and TNF-R1 are important factors which influence HBsAg loss. It may be possible to develop a nomogram which intercalates these factors; however, further research should consider immune processes involved in HBsAg loss.

Antiviral treatment for chronic hepatitis B: Safety, effectiveness, and prognosis

The goal of chronic hepatitis B (CHB) therapy is to improve the patient prognosis through the sustained inhibition of viral replication. However, due to the uncertainty and potentially unlimited duration of the treatment course, nucleus(t)ide analogue (NA) resistance and safety, financial costs and patient compliance, different endpoints of antiviral treatment have been proposed in CHB prevention and treatment guidelines. Different treatment endpoints are closely associated with the safety of drug withdrawal and improvements in prognosis. Antiviral treatment suppresses HBV DNA replication, drug withdrawal leads to relapse, and long-term treatment causes drug safety and resistance issues. Although hepatitis B e antigen seroconversion based on HBV DNA inhibition is considered as “a satisfactory endpoint”, drug withdrawal still leads to high relapse rates. Hepatitis B surface antigen (HBsAg) clearance is the “ideal endpoint” in terms of the safety of drug withdrawal and improvements in prognosis. However, the HBsAg clearance rate is low using the conventional single drug treatment and fixed course regimens. Recently, the application of an “optimized antiviral treatment strategy” has improved the HBsAg clearance rate, and make an “ideal endpoint” possible. This article reviews the different antiviral treatment endpoints in terms of the safety of drug withdrawal, improvements in prognosis and relevant advances.

VDR rs7975232/ApaI genetic variation predicts sustained HBsAg loss in HBeAg-positive chronic hepatitis B patients treated with pegylated interferon

AIM

To evaluate the predictive value of vitamin D and its metabolic pathway gene polymorphisms in response to pegylated interferon (Peg-IFN) in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients.

METHODS

One hundred and nineteen HBeAg-positive CHB patients who received Peg-IFN monotherapy for 48 weeks and then were followed-up for another 48 weeks were prospectively enrolled; baseline 25-hydroxy vitamin D (25-(OH)D) and hepatitis B virus serologic marker levels were detected, nine critical single nucleotide polymorphisms within vitamin D metabolism were genotyped.

RESULTS

Forty-five (37.8%), 44 (37.0%), 35 (29.4%), and 11 (9.2%) of the patients achieved virological response (VR), HBeAg loss, combined response (CR), and hepatitis B surface antigen (HBsAg) level < 200 IU/mL at the end of treatment (EOT; week 48), respectively; 42 (35.3%) and six (5.0%) people achieved HBeAg and HBsAg loss at the end of follow-up (EOF; week 96). Baseline HBeAg level was independent predictor of VR (odds ratio [OR], 0.470; 95% confidence interval [CI], 0.294-0.751; P = 0.002), HBeAg loss (OR, 0.395; 95% CI, 0.243-0.643; P < 0.001), CR (OR, 0.392; 95% CI, 0.215-0.714; P = 0.002) at EOT and HBeAg loss at EOF (OR, 0.334; 95% CI, 0.203-0.559; P < 0.001); baseline HBsAg level itself was independent predictor of both HBsAg < 200 IU/mL at EOT (OR, 0.257; 95% CI, 0.103-0.642; P = 0.004) and HBsAg loss at EOF (OR, 0.232; 95% CI, 0.077-0.702; P = 0.010). Age was also independent predictors of HBsAg loss at EOF (OR, 0.775; 95% CI, 0.634-0.948; P = 0.013). Concerning genetic variation of VDR rs7975232/ ApaI, A allele was the genetic independent predictor of VR at EOT (OR, 1.824; 95% CI, 1.024-3.248; P = 0.041) and HBsAg loss at EOF (OR, 3.566; 95% CI, 1.057-12.029; P = 0.040).

CONCLUSIONS

Genetic variation of VDR rs7975232/ ApaI is a pretreatment predictor of sustained HBsAg loss in HBeAg-positive CHB patients with Peg-IFN monotherapy.

Pronounced decline of serum HBsAg in chronic hepatitis B patients with long-term effective nucleos(t)ide analogs therapy

AIMS

This study aims to investigate the kinetics of serum HBsAg levels in chronic hepatitis B patients with long-term nucleos(t)ide analogs (NAs) therapy.

METHODS

This was a retrospective clinical study. Serum HBsAg in serial samples of 94 patients, who received at least 8 years of NAs therapy, were measured using Elecsys^® HBsAg II Quant Assay.

RESULTS

In this cohort, serum HBsAg levels reduced from 3.80 log10 IU/mL at baseline to 2.72 log10 IU/mL at year 8 (p < .001), and the percentage of patients with HBsAg <1000 IU/mL increased from 14.9% at baseline to 55.3% at year 8 (p < .001). The reduction of serum HBsAg did not differ significantly between patients stratified by baseline virological parameters and type of antiviral agents. But as compared to patients without HBeAg seroconversion, HBsAg levels were significant lower in patients with HBeAg seroconversion (3.19 vs. 2.47 log10 IU/mL at year 8, p = .001). As compared to patients with slow (0-1 log10 IU/mL) or steady HBsAg(≤0 log10 IU/mL) decline at year 1, patients with a rapid HBsAg (≥1 log10 IU/mL) decline had a significantly lower HBsAg levels from year 2 to 8. However, Cox regression analysis showed that only absolute HBsAg levels at year 1 was an independent predictor of subsequent HBsAg <1000 IU/mL at year 8 of antiviral therapy(HR 0.242, p = .004).

CONCLUSION

Pronounced HBsAg declines could be achieved in patients after long-term effective therapy with NAs, and on-treatment low serum HBsAg level at year 1 might be a predictor of serum HBsAg <1000 IU/mL at year 8.

Clinical features of HBsAg seroclearance in hepatitis B virus carriers in South Korea: A retrospective longitudinal study

AIM

To investigate the characteristic features of hepatitis B surface antigen (HBsAg) seroclearance among Korean hepatitis B virus (HBV) carriers.

METHODS

Carriers with HBsAg seroclearance were selected by analyzing longitudinal data collected from 2003 to 2015. The period of time from enrollment to the negative conversion of HBsAg (HBsAg-NC) was compared by stratifying various factors, including age, sex, hepatitis B e antigen (HBeAg), HBV DNA, sequential changes in the signal-to-cutoff ratio of HBsAg (HBsAg-SCR), as measured by qualitative HBsAg assay, and chronic liver disease on ultrasonography (US-CLD). Quantification of HBV DNA and HBsAg (HBsAg-QNT) in the serum was performed by commercial assay.

RESULTS

Among the 1919 carriers, 90 (4.7%) exhibited HBsAg-NC at 6.2 ± 3.6 years after registration, with no differences observed among the different age groups. Among these carriers, the percentages of those with asymptomatic liver cirrhosis (LC) and hepatocellular carcinoma (HCC) at registration were 31% and 7.8%, respectively. The frequency of HBsAg-NC significantly differed according to the HBV DNA titer and US-CLD. HBeAg influenced HBsAg-NC in the 40-50 and 50-60 year age groups. HBsAg-SCR < 1000 was correlated with an HBsAg-QNT < 200 IU/mL. A gradual decrease in the HBsAg-SCR to < 1000 predicted HBsAg-NC. Six patients developed HCC after registration, including two before and four after HBsAg-NC. The rate at which the patients developed new HCC after HBsAg seroclearance was 4.8%. LC with excessive drinking and vertical infection were found to be risk factors for HCC in the HBsAg-NC group.

CONCLUSION

HCC surveillance should be continued after HBsAg seroclearance. An HBsAg-SCR < 1000 and its decrease in sequential testing are worth noting as predictive markers of HBsAg loss.

Ethnic differences in incidence of hepatitis B surface antigen seroclearance in a real-life multicenter clinical cohort of 4737 patients with chronic hepatitis B infection

BACKGROUND

Hepatitis B surface antigen (HBsAg) positivity is associated with increased risk for cirrhosis and hepatocellular carcinoma (HCC). HBsAg seroclearance is thought to be rare in general, but cohort data from US patients are limited.

AIM

To determine the incidence of HBsAg seroclearance in a real-life US cohort.

METHODS

In total, 4737 patients with chronic hepatitis B from five primary care, gastroenterology and multispecialty centres, and a university medical centre were retrospectively enrolled between 2001 and 2014 with data obtained by manual review of individual patient medical records. Seroclearance was determined by loss of HBsAg seropositivity. Persistent HBsAg was confirmed by direct serology or by proxy with positive hepatitis B e-antigen (HBeAg) or HBV DNA levels.

RESULTS

HBsAg seroclearance occurred in 52 patients over 16 844 person-years (0.31% annually, 1.2% overall). Median follow-up was 32 months, and mean age 45 ± 14 years. Incidence of HBsAg seroclearance was higher in non-Asians, age >45, males, and those with baseline HBV DNA ≤10 000 IU/mL. On multivariate Cox proportional modelling, non-Asian ethnicity (HR 2.8), male sex (HR 2.1), baseline HBVDNA ≤10 000 (HR 2.0) and age >45 (HR 1.8) were significant independent predictors of seroclearance.

CONCLUSION

HBsAg seroclearance rates were lower than previously described in this real-life cohort of patients with chronic hepatitis B, especially among Asian, female and younger patients.