Precision Prediction of Biliary Atresia Survival

Though young age at the time of Kasai and surgical experience have been identified as factors in the long-term outcome of patients with biliary atresia (BA), why is it that some with timely intervention still fail to respond?  Conceptually, I’ve considered those who had progressive disease as probably having an intrahepatic component of their biliary disease that a Kasai operation cannot help.

New research (Z Luo, P Shivakumar, R Mourya, S Gutta, JA Bezerra. Gastroenterol 2019; 157: 1138-52) identifies genetic factors that are likely a more powerful predictor of Kasai response then the traditional clinical factors.

The science in this study is fascinating –combining genetic heat maps, and survival curves.  The prediction with a 14-gene signature is amplified with serum total bilirubin at 3 months post-Kasai.  In addition, these studies are combined with a mouse model treated with N-acetylcysteine (NAC).  Histologic changes were then assessed.

Key findings:

  • The 14-gene mRNA expression pattern predicted shorter and longer survival times in both the discovery (n=121) and validation sets (n=50) of children with BA (see figure below: red curve vs blue curve)
  • When this 14-gene expression pattern was paired with total bilirubin level 3 months after Kasai, this identified children who survived with their native liver at 24 months with an area under the curve of 0.948 in the discovery set and 0.813 in the validation set (P<.001).
  • In those with transplant-free survival, many of the mRNAs expressed had increased scores for glutathione metabolism.  Subsequently, mice with BA were treated with NAC (which promotes glutathione metabolism) & had reduced bile duct obstruction, liver fibrosis, and increased survival times.
  • In children with lower survival rates, there was increased mRNA expression of proteins encoding fibrosis genes in the liver tissues.

My take: This 14-gene signature has the potential to change our approach to children with BA.  Also, when evaluating surgical success rate, these underlying genetic factors will need to be incorporated.

Image available online

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Bilary Atresia Prognosis After 2-Year Survival with Native Liver

A recent study (M Witt et al. JPGN 2018; 689-94) indicates that among patients with biliary atresia who reached 2 years of life with native liver survival (NLS), they continued to be at risk for progressive liver failure.

Key findings:

  • Upon a median follow-up of 16.4 years, NLS rates at 5, 10, 15, 18 years of age were 89%, 72%, 60%, 54%, respectively.
  • Corresponding overall survival rates were 98%, 90%, 87%, 87%, respectively
  • NLS ended in 37% by liver transplantation (LTx) and in 6% by (pre-transplant) mortality.
  • Abstract Link: Prognosis of Biliary Atresia After 2-year Survival With Native Liver

My take: This data provides more precise information for families about prognosis and reinforces the need for careful followup.

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Parker Ridge, near Banff

 

 

The Half Empty Glass: Rumination Outcomes

Briefly noted:

A Alioto, C DiLorenzo. JPGN 2018; 66: 21-25.  In this study based on patient follow-up questionnaires, among 47 adolescents with rumination syndome who received inpatient treatment, Key findings:

  • ~20% reported complete cessation of rumination for at least 6 months; though, even in this group, 73% had at least some recurrent symptoms.
  • 40% reported a reduction in rumination intensity following discharge and ~80% reported having at least one day with no rumination.
  • Triggers for recurrence of rumination symptoms included stress (51.4%), illness (27%), menstruation (10.8%), and certain foods (18.9%).
  • Treatment of rumination syndrome helped eliminate the need for supplemental tube feedings in the “vast majority of patients.”

One important limitation of this study is the patient selection; this group of inpatients with rumination syndrome at a specialized center likely had more severe rumination syndrome.

My take: Like many GI conditions, the expectation for rumination syndrome should probably be improvement/management rather than resolution/cure.

Signage on Bright Angel Trail, Grand Canyon

Helpful Review on Biliary Atresia

Biliary atresia (BA) remains the leading cause of pediatric liver transplantation and a frequent cause of cholestasis in newborns.  A recent review (AG Feldman, CL Mack. JPGN 2015; 61: 167-75) provides a helpful update. The article begins with a review on pathogenesis, though this remains unknown and continues to be an area of speculation.

The section on evaluation includes a suggested diagnostic algorithm for neonatal cholestasis.  In short, for a 2 week old with jaundice , the authors recommend (STEP 1) fractionating the bilirubin.  The infant is considered cholestasis if the direct bilirubin is ≥1 mg/dL (if total bilirubin is <5 mg/dL) or if direct bilirubin ≥20% of total bilirubin (if total bilirubin is >5 mg/dL).

Among cholestatic infants, the authors recommend (STEP 2) next checking ultrasound and alpha-one antitrypsin (A1AT) (level & phenotype).  The text implies that the authors would check a GGTP.  While this is not in their algorithm, many would suggest checking urine reducing substances, coags, serum glucose, and consideration of sepsis evaluation; these tests can identify issues that are more urgent than identifying biliary atresia.

STEP 3: If U/S and A1AT, are not diagnostic, consider urine culture, urine reducing substances, urine succinylacetone, and additional infectious studies.

STEP 4: Proceed with liver biopsy. If findings of biliary atresia (eg. bile plugs, bile duct proliferation, portal fibrosis), proceed with intraoperative cholangiogram.

Other points:

  • “It is rare for an infant with BA to have a GGTP level <200 U/L.” If low GGTP, consider PFIC, inborn error of bile acid metabolism, and panhypopituitarism.
  • Extensive differential diagnosis table given ((Table 1)
  • “Late diagnosis of BA remains a problem in the United States. The average age of HPE [hepatoportoenterostomy] is 61 days and 44% of patients still undergo HPE after 60 days of life.”  The authors indicate a goal for HPE of taking place  at <45 days of life.
  • Successful HPE can occur even with late diagnosis. 10% to 20% of children who undergo HPE after 100 to 120 days of life still have success in restoring bile flow.”
  • Early/successful HPE is helpful in increasing 10-year transplant-free rate.  Early on, 3 months after HPE, those with a total bilirubin <2 mg/dL compared with those with a total bilirubin of >6 mg/dL have a much lower likelihood of liver transplantation by 2 years of age: 84% vs. 16%.
  • Recommends checking a pulse oximetry at routine followup visits following HPE to look for the possibility of hepatopulmonary syndrome.
  • The article reviews complications including ascites, portal hypertension/GI bleeding, cholangitis, malignancy, and hepatopulmonary syndrome/portopulmonary hypertension.
  • Outcomes: With HPE, “up to two-thirds of patients with BA have short-term clearance of jaundice.” Yet, “80% of patients with biliary atresia will require liver transplantation during childhood.”

Also noted:

“Biliary Atresia is Associated with Hypertension” JPGN 2015; 61: 182-86.

“Pathogenesis of biliary atresia: defining biology to understand clinical phenotypes” A Asai, A Miethke, JA Bezerra. Nat Rev Gastroenterol Hepatol 2015; 12: 343-52.  This review provides in-depth review examines more precise phenotyping, influencing factors (eg. cytomegalovirus), and potential mechanisms.

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From Mt Washburn, Yellowstone

From Mt Washburn, Yellowstone

Inequality in Pediatric Health Care

“Of all the forms of inequality, injustice in health care is the most shocking and inhuman.”

-Martin Luther King, Jr

This quote is part of an editorial (Flores G, “Dead Wrong: The Growing List of Racial/Ethnic Disparities in Childhood Mortality” J Pediatr 2015; 166: 790-3). The author discusses the disparities among African-American (AA) and Latino children in comparison to white children.

Key points:

  • AA children and young adults had ~6 times the death rate for drowning in swimming pools, 4 times more likely of dying after liver transplant, and about twice the likelihood of dying due to acute lymphoblastic leukemia.
  • Latino children have higher cancer death rates with about twice the likelihood of dying due to acute lymphoblastic leukemia and increased drowning death rate as well.
  • One new study (pages 812-8) shows that black children have increased in-hospital mortality (OR 1.66) after complications following congenital heart surgery and that hispanic children have an increased complication rate following surgery (OR 1.13). This was a retrospective study using the Kids’ Inpatient Database with approximately 3 million discharge abstracts for three separate years.
  • A second study (pages 819-26) with a data set of 98,833 children shows that birth defects resulted in higher 8-year adjusted hazards of death for black, latino, and Asian/Pacific Islander children.

Recognizing these disparities inevitable leads to the question of why. Dr. Flores postulates several factors.

  • Genetic differences.  For example, some ethnicities have more difficult to treat cancers, either due to genetic mutations or due to metabolism of medications.
  • Delays in diagnosis and treatment.  Patients who present at a later stage of diagnosis often have lower cure/response rates. The author notes that black children receive a diagnosis of autism a mean of 1.4 years later than white children.
  • Barriers to specialty care.  Specialty care can result in improved outcomes.
  • Bias in healthcare delivery, both conscious and unintentional.

Bottomline: The problems of racial inequality is not just a matter of relationships between the police and the community.  It is clear that more needs to be done to improve outcomes in healthcare as well.

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