Exceptions for Valproate-Associated Liver Failure

Recent guidelines (AASLD/NASPGHAN 2014 Guidelines for Evaluation of Pediatric …) have included valproate-associated acute liver failure (VPA-ALF) as an absolute contraindication to liver transplantation.  The reason is that most of these VPA-ALF patients have Alpers-Huttenlocher syndrome (AS) and have done poorly after transplantation due to progressive neurological decline.

AS in turn has been recognized as secondary to mutations in DNA polymerase subunit gamma (POLG1).  This gene product’s role is to maintain the integrity of mitochondrial DNA (mtDNA).

New data (Liver Transplantation 2014; 20: 1402-14, editorial 1287-89) suggests that there are exceptions for some cases of VPA-ALF.  In this report, 4 VPA-ALF patients with POLG1 mutations underwent successful liver transplantation.  Three are alive at followup 4-19 years later and one died suddenly 2 years after transplantation.

Key findings:

  • These cases had mutations in POLG1 associated with later onset and milder disease.
  • In the three long-term survivors, VPA was introduced at 14, 20 , and 21 years of life.

Take-home points:

  • For children less than 10 years of age, “VPA-ALF should remain an absolute contraindication to LT because neurological progression is almost inevitable.”  Supportive treatment, including N-acetylcysteine and carnitine should continue.
  • There is a “strong case for screening for POLG1 mutations before VPA use…even a single mutation should be seen as a contraindication to VPA.”

Related blog posts:

Also, I added a link on yesterday’s post regarding measles to a story on NPR which explores the most recent increase in cases and provides background information.  For example: “Before a vaccine was developed in the 1960s, measles caused more than 2 million deaths per year.”  And worldwide, even now, “nearly 400 kids die from measles each day. In 2013, more than 70 percent of measles deaths were confined to six countries: the Democratic Republic of Congo (DRC), Ethiopia, India, Indonesia, Nigeria and Pakistan.”

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