Lifelong elimination of hyperbilirubinemia in the Gunn rat with a single injection of helper-dependent adenoviral vector

Proc Natl Acad Sci U S A. 2005 Mar 15;102(11):3930-5. doi: 10.1073/pnas.0500930102. Epub 2005 Mar 7.


Crigler-Najjar syndrome is a recessively inherited disorder characterized by severe unconjugated hyperbilirubinemia caused by a deficiency of uridine diphospho-glucuronosyl transferase 1A1. Current therapy relies on phototherapy to prevent kernicterus, but liver transplantation presently is the only permanent cure. Gene therapy is a potential alternative, and recent work has shown that helper-dependent adenoviral (HD-Ad) vectors, devoid of all viral coding sequences, induce prolonged transgene expression and exhibit significantly less chronic toxicity than early-generation Ad vectors. We used a HD-Ad vector to achieve liver-restricted expression of human uridine diphospho-glucuronosyl transferase 1A1 in the Gunn rat, a model of the human disorder. Total plasma bilirubin levels were reduced from >5.0 mg/dl to <<1.4 mg/dl for >2 yr after a single i.v. administration of vector expressing the therapeutic transgene at a dose of 3 x 10(12) viral particles per kg. HPLC analysis of bile from treated rats showed the presence of bilirubin glucuronides at normal WT levels >2 yr after one injection of vector, and i.v. injection of bilirubins IIIalpha and XIIIalpha in the same animals revealed excess bilirubin-conjugating capacity. There was no significant elevation of liver enzymes (alanine aminotransferase) and only transient, moderate thrombocytopenia after injection of the vector. A clinically significant reduction in serum bilirubin was observed with a dose as low as 6 x 10(11) viral particles per kg. We conclude that complete, long-term correction of hyperbilirubinemia in the Gunn rat model of Crigler-Najjar syndrome can be achieved with one injection of HD-Ad vector and negligible chronic toxicity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviridae*
  • Alanine Transaminase / blood
  • Animals
  • Bilirubin / blood
  • DNA / pharmacology
  • Genetic Therapy*
  • Genetic Vectors* / toxicity
  • Glucuronosyltransferase / genetics*
  • Glucuronosyltransferase / metabolism
  • Humans
  • Hyperbilirubinemia / drug therapy*
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Gunn


  • RNA, Messenger
  • Ugt1a1 protein, rat
  • DNA
  • UGT1A1 enzyme
  • Glucuronosyltransferase
  • Alanine Transaminase
  • Bilirubin