Isolated hepatocyte transplantation in an infant with a severe urea cycle disorder.
OBJECTIVE
Transplantation of isolated hepatocytes in animal models has been shown to correct inborn errors of metabolism. Based on these studies and our experience with hepatocyte transplantation in a child with Crigler-Najjar syndrome, isolated hepatocyte transplantation was performed to attempt metabolic reconstitution in a male infant with severe ornithine transcarbamylase (OTC) deficiency.


METHODS
An infant with an antenatal diagnosis of OTC deficiency was managed intensively to prevent hyperammonemia. Isolated hepatocytes were obtained by collagenase perfusion of donated livers not used for transplantation. Hepatocytes were infused in batches over the first 4 weeks of life via an umbilical venous catheter positioned in the portal vein. Immunosuppression consisted of tacrolimus and corticosteroids.


RESULTS
Over 4 billion viable hepatocytes were transplanted during the first 3.5 weeks of life. A period of metabolic stability was achieved between days 20 and 31 during which normal protein intake was tolerated while phenylbutyrate was weaned. During this time, plasma ammonia and glutamine remained within normal limits. Hyperammonemia reappeared abruptly on day 31 of life. Protein tolerance diminished to baseline; metabolic stability was subsequently reattained only following successful liver transplantation at 6 months of age.


CONCLUSIONS
Isolated hepatocyte transplantation appeared to result in temporary relief of hyperammonemia and protein intolerance attributable to OTC deficiency. The metabolic stability achieved was lost after 11 days presumably because of rejection of the transplanted cells because of insufficient immunosuppression. Future attempts at isolated hepatocyte transplantation for inborn errors of metabolism in humans should include adequate immunosuppression and a liver biopsy as a means of proving hepatocyte engraftment and function.
Horslen
Simon P
SP
Section of Pediatric Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska 68198-3285, USA. shorslen@surgery.unmc.edu
McCowan
Timothy C
TC
Goertzen
Timothy C
TC
Warkentin
Phyllis I
PI
Cai
Hung Bo
HB
Strom
Stephen C
SC
Fox
Ira J
IJ
D000328:Adult; D003414:Crigler-Najjar Syndrome / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics / Q000628:therapy*; D005260:Female; D006580:Genetic Carrier Screening; D022781:Hepatocytes / Q000637:transplantation*; D006801:Humans; D022124:Hyperammonemia / Q000201:enzymology / Q000628:therapy; D007223:Infant; D016031:Liver Transplantation; D008297:Male; D020163:Ornithine Carbamoyltransferase Deficiency Disease / Q000175:diagnosis / Q000235:genetics / Q000628:therapy*; D011296:Prenatal Diagnosis; D014508:Urea / Q000378:metabolism*
D014508:Urea