1136 THE AMOUNT OF ALCOHOL CONSUMPTION NEGATIVELY IMPACTS SHORT-TERM MORTALITY IN PATIENTS WITH ALCOHOLIC HEPATITIS: CLINICAL IMPLICATIONS

acute neurologic attacks.Severe and recurrent attacks are a life-threatening condition that can be cured only by liver transplantation.Aim: To develop a clinical grade recombinant adenoassociated vectors (rAAV) expressing human PBGD protein driven by a liver specific promoter in order to provide long-lasting protection against porphyria attacks.Methods: rAAV2/8-cDNA hPBGD (produced in HEK293 cells) and rAAV2/5 carrying an optimized codon usage engineered cDNA PBGD (produced in scale-up system in Sf9 cells) were tested in a predictive mouse model of AIP.Results: AIP mice receiving saline/luciferase reporter vector exhibit decreased hepatic PBGD activity and massive urinary porphyrin precursor excretion after treatment with phenobarbital.Peripheral neuropathy was assessed by a motor coordination test.AIP mice showed lower numbers of motor axons and a functional block of motor conduction in the sciatic nerve.At a dose of 5×10 12 rAAV2/5 genome copies/kg, AAV8 and AAV5-mediated hepatic hPBGD expression prevents phenobarbital-induced acute attacks in AIP mice.This is shown by the lack of accumulation of heme precursors and normal motor coordination.Lower doses of therapeutic vector show low hPBGD expression but still provided a significant metabolic and phenotypic correction.Three months after the viral injection, transduction efficiency was similar in males and females injected with rAAV2/8.Hepatic PBGD activity in animals injected with 5×10 12 rAAV2/5 gc/kg was 20% lower in females as compared to males.However, females still showed more than 10% of hepatocytes expressing high amount of PBGD which provided full phenotypic protection against porphyric attacks as induced in AIP mice.Furthermore, long-term hPBGD over-expression in the liver protected against both the loss of motor axons and the sciatic nerve dysfunction that were induced by recurrent phenobarbital administrations.Conclusions: Long-lasting expression of hPBGD was observed in the liver of AIP mice transduced with rAAV-hPBGD vectors.Recombinant AAV vectors offer an attractive option to develop new therapeutic strategies for patients with recurrent porphyria attacks and/or neuropathy.