Liver Briefs -June 2019

YH Yeo et al. Hepatology 2019; 69: 1385-97.  The prevalence of high risk individuals in the U.S. who are susceptible (not immune) to hepatitis B has decreased from 83% to 69% from 2003 to 2014.  That still leaves 64 million who would benefit from HBV vaccination.

M Sharma et al. Hepatology 2019; 69: 1657-75. This meta-analysis compared therapies for primary prevention of esophageal varices and concluded that nonselective beta-blocker (NSBB) monotherapy may decrease all-cause mortality and carried a lower risk of serious complications than variceal band ligation (VBL). However, the commentary (1382-84 by L Laine) reaches a different conclusion. “Current recommendations for primary prevention with VBL or NSBB or carvediolo still appear to be acceptable…using a shared decision-making approach” to weigh issue such as daily medication or periodic endoscopy.

J Nguyen et al. J Pediatr 2019; 207: 90-6. This study modeled the cost-effectiveness of early treatment with direct-acting antiviral therapy in adolescents with hepatitis C infection.  With pangenotypic agenst, the cost would be $10000 to $21000 per QALY gained.

S Trinh et al. Clin Gastroenterol Hepatol 2019; 17: 948-56. This retrospective hepatitis B study examined the changes in renal function between 239 tenofovir disoproxil fumarte (TDF) treated patients and 171 entecavir treated patients.  Key finding: TDF was not associated with higher risk of worsening renal function in this cohort with a mean followup of 43-46 months in patients with baseline normal renal function.  In patients with renal impairment, deterioration of renal function was noted in TDF-treated patients.  Thus, TDF should be avoided in patients with impaired renal function.

 

Rhododendrom in Sandy Springs

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Comprehensive 2018 AASLD Guidance for Chronic Hepatitis B

NA Terrault et al. Hepatology 2018; 67: 1560-99. Here’s the full link: Update on Prevention, Diagnosis, and Treatment of Chronic Hepatitis B: AASLD 2018 Hepatitis B Guidance

Some of the key points:

Table 4 (pg 1565): provides a refresher on interpretation of serology

Table 5 (pg 1567): Children and Adults Who Are HBsAg Positive:

  • Can participate in all activities, including contact sports
  • Should not be excluded from daycare or school participation and should not be isolated from other children
  • Can share food and utensils and kiss others

Figure 1 (pg 1571) Treatment algorithms.

  • For both HBsAg-positive/HBeAg-positive and HBsAg-positive/HBeAg-negative patients, treatment is recommended if ALT ≥2 x ULN.
  • For both groups, treatment is NOT recommended for those with ALT ≤ULN and low HBV DNA levels (<20,000 IU/mL for HBeAg-positive and <2,000 IU/mL for HBeAg-negative).
  • In those who do not fall into these categories, ongoing monitoring is recommended

Figure 1 from AASLD Guidance Link

Guidance Statements for HCC Screening in HBsAg‐Positive Persons

  • All HBsAg‐positive patients and high risk adults (see page 1574) with cirrhosis should be screened with US examination with or without AFP every 6 months.
  • There are insufficient data to identify high‐risk groups for HCC in children. However, it is reasonable to screen HBsAg‐positive children and adolescents with advanced fibrosis (F3) or cirrhosis and those with a first‐degree family member with HCC using US examination with or without AFP every 6 months.

Treatment: 

  • In adults: The AASLD recommends peg‐IFN, entecavir, or tenofovir (TDF) as preferred initial therapy for adults with immune‐active CHB
  • In children: The AASLD suggests antiviral therapy in HBeAg‐positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV‐DNA levels, with the goal of achieving sustained HBeAg seroconversion.

Perinatal transmission:

  • The AASLD suggests antiviral therapy to reduce the risk of perinatal transmission of HBV in HBsAg‐positive pregnant women with an HBV‐DNA level >200,000 IU/mL..The only antivirals studied in pregnant women are lamivudine, telbivudine, and TDF. Of these 3 options, TDF is preferred to minimize the risk of emergence of viral resistance during treatment. Interim studies show high efficacy of TDF in preventing mother‐to‐child transmission.
  • The infants of all HBsAg‐positive women should receive immunoprophylaxis (HBV vaccination with or without hepatitis B immunoglobulin, per World Heath Organization and Centers for Disease Control and Prevention recommendations)

Treatment & prevention of HBV reactivation in patients receiving immunosuppressive or cytotoxic drugs (section 6 pages 1577-9)

  • HBsAg and anti‐HBc (total or immunoglobulin G) testing should be performed in all persons before initiation of any immunosuppressive, cytotoxic, or immunomodulatory therapy.
  • HBsAg‐positive, anti‐HBc–positive patients should initiate anti‐HBV prophylaxis before immunosuppressive or cytotoxic therapy.
  • HBsAg‐negative, anti‐HBc–positive patients could be carefully monitored with ALT, HBV DNA, and HBsAg with the intent for on‐demand therapy, except for patients receiving anti‐CD20 antibody therapy (e.g., rituximab) or undergoing stem cell transplantation, for whom anti‐HBV prophylaxis is recommended.

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Tenofovir to Prevent Perinatal Transmission of Hepatitis B

Mother-to-child transmission of hepatitis B virus (HBV) accounts for the majority of cases of chronic HBV infection.  HBV infection affects more than 250 million people worldwide and in many cases results in cirrhosis or hepatocellular carcinoma.  As such, there has been interest in preventing perinatal transmission.

The most recent study (C Jourdain et al. NEJM 2018; 378: 911-23) again showed that tenofovir administration to pregnant women with HBV can prevent transmission.  This study enrolled 331 women.  Key findings:

  • 0% (0/147) infants in the tenofovir group developed HBV infection compared to 2% (3/147) in the control group. This did not reach statistical significance
  • The placebo group received HBV vaccination and hepatitis B immune globulin 1.2 hours and 1.3 hours after birth (median time).  This rapid provision of treatment along with completion of four doses of HBV vaccine likely helped keep the placebo group HBV infection rate low

In the related editorial (G Dusheiko. pg 952-3), it is noted that “current levels of evidence supporting antiviral therapy with TDF [tenofovir] (or possbily lamivudine or telbivudine) to reduce levels of maternal HBV DNA during pregnancy have been accepted by the” AASLD.

Related blog posts:

Preventing Neonatal Hepatitis B Transmission with Tenofovir

A recent study (CQ Pan et al. NEJM 2016; 374: 2324-34) showed that tenofovir administered to mothers starting at 30-32 weeks of gestation lowered the rate of perinatal hepatitis B virus (HBV) acquisition.This was a multi center, open-label, randomized parallel-group design trial.  The maternal tenofovir dose was 300 mg.

Key points:

  • 200 mothers with HBeAg and HBV DNA >200,000 IU/mL in this study
  • 68% achieved an HBV DNA level <200,000 IU/mL (compared with 2% of controls).  Above this threshold has been shown to be associated with increased HBV transmission.
  • 5 of 97 (5%) in the treatment group acquired HBV compared to 18 of 100 in the control group.  However, in the per-protocol analysis which excluded infants born to women who withdrew consent, were lost to follow-up, or discontinued therapy there were 0 cases of transmission (0 of 88).
  • There were no specific safety signals identified in this study.  In the discussion, the authors note that the Antiretroviral Pregnancy Registry which includes data from 4013 women who received tenofovir, the rate of birth defects with TDF was 2.4% compared to the general population rate of 2.7%.

My take: This study provides more evidence that antivirals can prevent perinatal HBV infection.

Related blog posts:

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More on Hepatitis B Treatment in Children

A recent post (New Hepatitis B Treatment Guidelines -AASLD) described the updated treatment recommendations.  When these guidelines were published, a separate review devoted specifically to pediatrics was published (Hepatology 2016; 63: 307-18).

Some of the key points:

  • This pediatric review included 14 studies with 1425 children.  The authors note that 7 of these trials had a high risk of bias.  Also, the studies are limited by relying on surrogate markers of long-term outcomes as clinical outcomes like cirrhosis, HCC, and death are rare in childhood.
  • Among oral agents, entecavir and lamivudine are approved for use in children ≥ 2 years, whereas adefovir and tenofovir are approved for use in children ≥ 12 years.  Both lamivudine and adefovir are associated with frequent development of viral resistance
  • For children with elevated ALT (>1.5 times upper limit of normal [ULN]), treatment is recommended:

9A. The AASLD suggests antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV DNA levels, with the goal of achieving sustained HBeAg seroconversion.

Why not treat everyone?

  • Children with immune-tolerant HBV infection (normal or near-normal ALT [< 1.5-2 times ULN] along with high HBV DNA [>10 million IU/mL]), “are not typically candidates for treatment because treatment with any of the currently available drugs has not been demonstrated to improve HBeAg seroconversion compared with no treatment.”
  • Children with ALT >10 time ULN may be in the process of spontaneous seroconversion “and should be observed for several months before treatment” is initiated.
  • “Prolonged treatment with nucleoside or nucleotide analogs in children who are in immune-tolerant phase has not been associated with substantial benefit and carries a risk of developing antiviral drug resistance…An exception may be those…undergoing immunosuppressive therapy.”
Mina Falls, El Yunque Rainforest

Mina Falls, El Yunque Rainforest

New Hepatitis B Treatment Guidelines

Link to full article: Updated Hepatitis B Treatment Guidelines from AASLD

With regard to pediatrics:

9A. The AASLD suggests antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV DNA levels, with the goal of achieving sustained HBeAg seroconversion.

“Most studies required ALT elevation (>1.3 times ULN) for at least 6 months with HBV DNA elevations for inclusion. Given that HBV DNA levels are typically very high during childhood (>106 IU/mL), there is no basis for a recommendation for a lower-limit value with respect to treatment. However, if a level <104 IU/mL is observed, therapy might be deferred until other causes of liver disease and spontaneous HBeAg seroconversion are excluded.”

“Duration of treatment with oral antivirals that has been studied is 1-4 years. It may be prudent to use HBeAg seroconversion as a therapeutic endpoint when oral antivirals are used, continuing treatment for an additional 12 months of consolidation, as recommended in adults. It is currently unknown whether a longer duration of consolidation would reduce rates of virological relapse.”

“Children who stop antiviral therapy should be monitored every 3 months for at least 1 year for recurrent viremia, ALT flares, and clinical decompensation.”

9B. The AASLD recommends against use of antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with persistently normal ALT, regardless of HBV DNA level.

Another nice summary of current treatment recommendations: P Martin et al. Clin Gastroenterol Hepatol 2015; 13: 2071-87.  Table 5 lists recommendations for treatment of HBeAg-positive.

  • The main group needing treatment (entecavir, tenofovir, or PEGinterferon alfa-2a) are those with HBV DNA >2000 IU/mL and elevated ALT.  Table 6 lists recommendations for those with HBeAg-negative.  Main group needing treatment are the same (HBV DNA >2000 IU/mL and elevated ALT).
  • With both groups (HBe-Ag negative and positive), “consider liver biopsy or transient elastography” if elevated HBV DNA >2000 and normal ALT.  If histologic disease present, consider treatment.
  • One point the authors make about therapy regards duration: “Historically, HBeAg seroconversion was considered a durable response, and discontinuation of antiviral therapy was recommended after a period of consolidation therapy of 6-12 months from the time of HBeAg seroconversion. However, patients who discontinue therapy …can experience recurrent viremia and ALT flares.  Thus, long-term therapy is justified.”
  • For HBeAg negative patients who have compensated liver disease, loss of HBsAg for 6-12 months may be discontinued from therapy.

Antivirals Reduce Vertical Transmission of Hepatitis B

Chelsea Market, NYC

Chelsea Market, NYC

The latest study that shows antivirals interrupt hepatitis B viral (HBV) transmission from mother-to-infant: H-L Chen et al. Hepatology 2015; 62: 375-86.

In this open-label, non-randomized controlled study from Taiwan, the researchers recruited women to receive tenofovir (TDF) at a dose of 300 mg once a day (n=62), initiated from gestational age 30-32 weeks until 1 month following delivery, and compared them to a control group (n=56).  There were high levels of viremia with HBV DNA ≥7.5 log10 IU/mL. All infants received HBV vaccination and HBIG within 24 hours of birth.

Key findings:

  • Infant transmission of HBV was reduced: at 6 months of age, infant HBsAg positivity was 1.54% versus 10.71%, P=0.0481).  At delivery, HBV DNA positivity was noted in 6.15% compared with 31.48% of the control group.
  • Maternal ALT was improved in the TDF group. ALT elevation more than two times the upper limit of normal for ≥3 months occurred in 3.23% compared with 14.29% of controls.
  • Adverse effects: only mild to moderate (self-limited) gastrointestinal and skin symptoms were noted. No fetal abnormalities were identified.

Bottomline: Antivirals, including both tenofovir and telbivudine, reduce vertical HBV transmission with a favorable safety profile.  The use of antivirals is complementary to standard prevention which consists of providing Hepatitis B immune globulin and Hepatitis B vaccine to infants of HBV-infected pregnant women within 12 hours of birth.

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