Category Archives: Pediatric Gastroenterology Liver Disease

First-Hand Account: Living-Donor Liver Transplantation

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From NY Times: Donating an Organ to My Son

An excerpt:

It has been a year and half since the surgery. Sammy looks great and is on minimal medication. He goes to school full time, and most people have no idea what he went through. The scar on his abdomen has mostly faded, and we aren’t sure if he even has any memories of this experience.

My liver has grown to full size and my scars are nearly invisible. But that doesn’t mean I am entirely recovered. There are moments, and they are less frequent and further between, that I get spontaneously choked up. This experience was both frightening and inspiring. I had to briefly give up being both doctor and a mother to become a patient. It was as a living donor that I was able to help my son the most.

Another comic account of living liver donation:

Chattahoochee River

Chattahoochee River

Newborn Bilirubin Measurements To Identify Biliary Atresia

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It is remarkable how tricky making a diagnosis of biliary atresia can be, even when one has seen the presentation many times.  For parents and many providers, one of the pitfalls includes the inability of recognizing acholic stools. To identify biliary atresia, promotion of stool color cards, over the last two decades, has not been very effective. To address this problem, a recent study (S Harpavat et al. JPGN 2016; 62: 799-803) describes the use of direct or conjugated bilirubin measurements in the newborn period. This study was conducted between 2009-2011.

As with previous studies, 35 infants with biliary atresia all had elevated direct bilirubin. In the non-biliary atresia group, 8936 of 9102 infants had direct bilirubin measurements within the laboratory’s reference range.  Thus, this study suggests that newborn direct bilirubin has a sensitivity 100% and specificity of 98.2%.

In a related publication, the same group published a letter to the editor (NEJM 2016; 2016; 375: 605-6) that describes a prospective two-stage screening of newborns for biliary atresia.  Of 11,636 infants included over a 15-month period, 121 were identified who had direct-bilirubin >95% reference interval in their laboratory.  At a median of 14 days, 11 remained abnormal: 2 had biliary atresia.  Overall, they state the net sensitivity was 100%, then net specificity of 99.9%, and the positive predictive value was 18.2%.

Related blog posts:

Sullivan's Island, SC

Sullivan’s Island, SC

Early Preview of Basic Science Review: Biliatresone

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Generally, one of the best lectures at our national meeting is the “Basic Science Year in Review.”  I would be surprised if a recent study (O Waisbourd-Zinman et al. Hepatology 2016; 64: 880-93) does not get some attention during this review.

Even though biliary atresia (BA) remains the leading cause of pediatric liver transplantation, the exact reasons for its development have not been elucidated.  There are data “implicating both immune dysregulation and genetic factors in human BA.  Toxin-induced BA is not inconsistent with these findings and may represent a primary injury, with immune dysregulation representing a secondary insult.”

One of the reasons for suspecting a toxin dates back to outbreaks of a BA-like disease in newborn lambs that occurred in New South Wales in 1964 and 1988. During both these periods, severe droughts led to pregnant livestock grazing on atypical flora.  Ultimately, a plant toxin termed “biliatresone” was isolated from Australian plants (Dysphania species).

Here’s how this study advanced the science on biliatresone:

  • The authors treated mouse cholangiocytes in 3D spheroid culture and neonatal extrahepatic duct exlplants with biliatresone and compounds that regluate glutathione (GSH)
  • The authors determined the effects of biliatresone on SOX17 levels and the effects of Sox17 knockdown on cholangiocytes in 3D culture

Key findings:

  • “Biliatresoe caused disrupton of cholangiocyte apical polarity and loss of monolayer integrity.”
  • “Neonatal bile duct explants treated with the toxin showed lumen obstruction with increased subepithelial staining for α-smooth muscle actin and collagen, consistent with fibrosis”
  • “Biliatresone caused a rapid and transient decrease in GSH…and caused a significant decrease in cholangiocyte SOX17, and Sox17 knockdown in cholangiocyte spheroids mimicked the effects of biliatresone.”
  • These findings are easiest to appreciate in their figures, particularly Figure 4 and 5.

While pregnant women are not likely exposed to biliatresone, the authors showed that the effects of the toxin on lowering GSH was sufficient for cholangiocyte injury.; in addition, they showed that “SOX17 is required to maintain the epithelial architecture of the gallbladder and the cystic duct.”  Thus, there are likely other exposures that could lead to similar outcomes

My take: I will let Dr. Barnard explain the elegant experiments.  This study strongly supports maternal dietary factors as a contributing role in the pathophysiology of BA.  Now identifying these teratogens is crucial.

Also noted: X Zhao et al. Hepatology 2016; 64: 894-907. This study “strongly support redox stress as a critical contributing factor in biliatresone-induced cholangioctye injury” in Zebrafish.  Specifically, the authors identified that gene transcripts involved in redox stress, particularly regarding glutathione were upregulated after exposure to biliatresone.

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Glacier Natl Park

Glacier Natl Park

HBV Vaccination Prevents Cancer

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In a Gastroenterology study from Taiwan, HBV vaccination has been shown to reduce the risk of Hepatocellular Carcinoma.

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Results

Of the 1509 patients with HCC, 1343 were born before, and 166 were born after, the HBV vaccination program began. HCC incidence per 105 person-years was 0.92 in the unvaccinated cohort and 0.23 in the vaccinated birth cohorts. The RRs for HCC in patients 6–9 years old, 10–14 years old, 15–19 years old, and 20–26 years old who were vaccinated vs unvaccinated were 0.26 (95% confidence interval [CI], 0.17–0.40), 0.34 (95% CI, 0.25–0.48), 0.37 (95% CI, 0.25–0.51), and 0.42 (95% CI, 0.32–0.56), respectively. The RR for HCC in 6- to 26-year-olds was lower in the later vs the earlier cohorts (born in 1992–2005 vs 1986–1992; P < .001 and 1986–1992 vs 1984–1986; P < .002). Transmission of HBV from highly infectious mothers and incomplete immunization were associated with development of HCC.

Hepatitis E Update

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Briefly noted:

B Fischler et al. JPGN 2016; 63: 288-94.  This position paper by ESPGHAN suggests testing children with increased transaminases for hepatitis E virus (HEV) and notes that immunocompromised children with HEV may require treatment (with ribavirin or lowering immunosuppression). Best tests: serology for IgM and IgG and HEV RNA PCR.

F Huang et al Hepatology 2016; 64: 350-59. This study from China showed frequent Hepatitis E excreted in milk from infected cows and that this milk is capable of transmit infection when given to rhesus macaques, even if pasteurized.  Also, the article notes that seroprevalence of HEV in recent years has been higher than prior estimates (21% from 1988-94 and 6% from 2009-2010).

Glacier Natl Park

Glacier Natl Park

Prevalence of Diabetes with Pediatric NAFLD

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Prevalence of Prediabetes and Type 2 Diabetes in Children With Nonalcoholic Fatty Liver Disease  (JAMA Pediatr. Published online August 01, 2016. doi:10.1001/jamapediatrics.2016.1971)

According to a a multicenter, cross-sectional study at 12 pediatric clinical centers across the United States participating in the National Institute of Diabetes and Digestive and Kidney Diseases NASH Clinical Research Network and with 675 participants (mean age 12.6 yrs):

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NPR: Children Missing Out on Hepatitis C Treatment

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From NPR: Children Missing Out on Hepatitis C Treatment

An excerpt:

A study by the Philadelphia Department of Health points to what Wen and others in the medical profession see as a worrisome trend: Children with hepatitis C may be unaware of their diagnosis and the potential need for treatments down the road in order to prevent long-term liver damage.

Using city surveillance data, the study found that as many as 8 in 10 children at high risk for hepatitis C exposure in Philadelphia were never screened for the condition. More specifically, of the approximately 500 moms-to-be who were registered as having hepatitis C between 2011 and 2013, only 84 of their newborns, or about 16 percent, were tested for the virus by 20 months of age.

My take: As the article discusses, with the advent of better treatments, which will be available for children (?next 1-2 years), identifying Hepatitis C acquired prenatally is becoming important.

Related blog posts:

Rising HCV mortality

Preventing Neonatal Hepatitis B Transmission with Tenofovir

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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.

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Intellectual Disability in Pediatric Liver Transplantation

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A recent study (A Wightman et al. JPGN 2016; 62: 808-12) describes the prevalence of intellectual disability in a retrospective cohort from 2008-2013. The importance and the discomfort of the topic is referenced in the introduction:

  • “A 2005 survey of pediatric liver transplant programs (n=12) found that 33% of centers reported that cognitive disability was “always or usually” considered in their decision. No pediatric centers, however, considered mild or moderate cognitive disability alone (IQ 35-70) to be a relative or absolute contraindication to transplantation.”
  • The 2005 AASLD guideline states that “children with mental retardation pose significant logistical and ethical challenges” but does not comment on whether this is a contraindication.

This retrospective study of children who underwent an isolated liver transplant from 2008-2013 (n=254).

Key findings:

  • 15% of all first pediatric liver transplantation recipients have intellectual disability
  • Graft function and patient survival were similar among those with and without intellectual disabilities.  Metabolic disease, as the indication for liver transplantation, was the etiology more commonly among children with intellectual disability.

This study had numerous limitations.  Due to these limitations (eg. selection bias, lack of a standardized mechanism of measuring intellectual disability), it is likely that intellectual disability occurs more commonly than in 15% of pediatric liver transplant recipients. In fact, a previous study showed 42% of recipients required special education and 29% had IQ <85 (Cognitive Outcomes after Liver Transplantation | gutsandgrowth).

Related neurocognitive recommendations from the 2014 AASLD Pediatric Liver Transplantation Guidelines:

  • 28. “Neurocognitive testing should be performed in children awaiting LT to identify areas warranting early intervention to minimize later cognitive diffi- culties (2-B).”
  • 75, 76, and 92. LT is contraindicated with Alper’s disease, multiorgan mitochondrial disease, and Niemann-Pick type C.
  • In nearly 40 pages of recommendations, this guideline offers very little guidance on this topic.
AASLD 2014 Pediatric Transplantation Guidelines

AASLD 2014 Pediatric Transplantation Guidelines

Solitary Hepatic Nodule and Alagille Syndrome

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A retrospective study (A Alhammad et al. JPGN 2016; 62: 226-32) of 55 children from 1999-2014 examined the frequency of a solitary hepatic nodule adjacent to the right portal vein as a potential diagnostic finding for Alagille syndrome.  Only 39 had appropriate imaging to examine.

Key findings:

  • In 12 (of 39) focal hepatic lesions were evident (11 were solitary).
  • The median diameter was 8.1 cm.
  • In those with pathology review, the cases were suggestive of a regenerative nodule.
  • In all but one case, the alpha-fetoprotein levels were normal.
  • 10 of these lesions were adjacent to the right portal vein.

One other point from the discussion:

  • ~21% of patients with Alagille require liver transplantation, primarily for unremitting cholestasis and pruritus

My take: Recognition of this entity will help avoid mistaking this lesion for hepatocellular carcinoma.

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