Mitochondrial respiratory chain hepatopathies: role of liver transplantation. A case series of five patients.

INTRODUCTION: Orthotopic liver transplantation (OLT) in patients with mitochondrial respiratory chain disorders (MRCD) is controversial because of possible multi-organ involvement. AIM: To illustrate the clinical diversity of MRCD, the difficulty in making an accurate tissue diagnosis and whether to undertake OLT in five patients with proven MRCD. A review of the reported cases in the literature is presented.
METHODS: Retrospective chart review from 1995 to 2007 at a paediatric liver transplant centre where five children with hepatic MRCD were identified.
RESULTS: Patient 1 was transplanted for 'cryptogenic' cirrhosis. The diagnosis of MRCD was made on the explant. The patient remains well 5 years after transplant. Patient 2 presented with fulminant liver failure at 3 months of age. Although no extrahepatic manifestations were identified, OLT was not considered. Patient 3 presented with recurrent hypoglycaemia and was transplanted for fulminant hepatic failure at 12 months of age. He died of pulmonary hypertension 9 months post OLT. Patient 4 was diagnosed with MRCD at the age of 2 years. Death occurred at the age of 14 years, while listed for combined liver-kidney transplant, after a stroke-like episode following severe sepsis. Patient 5 developed liver failure after valproic acid was instituted for seizures. Mitochondrial DNA depletion syndrome was diagnosed and transplantation was not offered.
CONCLUSION: Hepatic MRCD has a variable presentation. Diagnosis requires the measurement of respiratory chain enzymes on tissue from liver biopsy. Whether to proceed to OLT is a difficult decision given a good outcome in a minority of cases, suggesting that MRCD should not be an absolute contraindication to liver transplantation.