Outcomes of 38 patients with PFIC3: Impact of genotype and of response to ursodeoxycholic acid therapy.

Background & Aims: Progressive familial intrahepatic cholestasis type 3 (PFIC3) is a rare liver disease caused by biallelic variations in ABCB4. Data reporting on the impact of genotype and of response to ursodeoxycholic acid (UDCA) therapy on long-term outcomes are scarce. Methods: We retrospectively describe a cohort of 38 patients with PFIC3 with a median age at last follow-up of 19.5 years (range 3.8-53.8). Results: Twenty patients presented with symptoms before 1 year of age. Thirty-one patients received ursodeoxycholic acid (UDCA) therapy resulting in serum liver test improvement in 20. Twenty-seven patients had cirrhosis at a median age of 8.1 years of whom 18 received a liver transplant at a median age of 8.5 years. Patients carrying at least one missense variation were more likely to present with positive (normal or decreased) canalicular MDR3 expression in the native liver and had prolonged native liver survival (NLS; median 12.4 years [range 3.8-53.8]). In contrast, in patients with severe genotypes (no missense variation), there was no detectable canalicular MDR3 expression, symptom onset and cirrhosis occurred earlier, and all underwent liver transplantation (at a median age of 6.7 years [range 2.3-10.3]). The latter group was refractory to UDCA treatment, whereas 87% of patients with at least one missense variation displayed an improvement in liver biochemistry in response to UDCA. Biliary phospholipid levels over 6.9% of total biliary lipid levels predicted response to UDCA. Response to UDCA predicted NLS. Conclusions: Patients carrying at least one missense variation, with positive canalicular expression of MDR3 and a biliary phospholipid level over 6.9% of total biliary lipid levels were more likely to respond to UDCA and to exhibit prolonged NLS. Impact and implications: In this study, data show that genotype and response to ursodeoxycholic acid therapy predicted native liver survival in patients with PFIC3 (progressive familial intrahepatic cholestasis type 3). Patients carrying at least one missense variation, with positive (decreased or normal) immuno-staining for canalicular MDR3, and a biliary phospholipid level over 6.9% of total biliary lipids were more likely to respond to ursodeoxycholic acid therapy and to exhibit prolonged native liver survival.

Immune Response and Intraocular Inflammation in Patients With Leber Hereditary Optic Neuropathy Treated With Intravitreal Injection of Recombinant Adeno-Associated Virus 2 Carrying the ND4 Gene: A Secondary Analysis of a Phase 1/2 Clinical Trial.

Importance: Intravitreal gene therapy is regarded as generally safe with limited mild adverse events, but its systemic effects remain to be investigated. Objective: To examine the association between immune response and intraocular inflammation after ocular gene therapy with recombinant adeno-associated virus 2 carrying the ND4 gene (rAAV2/2-ND4). Design, Setting, and Participants: This secondary analysis of an open-label, dose-escalation phase 1/2 randomized clinical trial of rAAV2/2-ND4 included data from February 13, 2014 (first patient visit), to March 30, 2017 (last patient visit at week 96), the first 2 years after injection. Patients older than 15 years with diagnosed ND4 Leber hereditary optic neuropathy (LHON) and visual acuity of at least counting fingers were enrolled in 1 of 5 cohorts. Four dose cohorts of 3 patients each were treated sequentially. An extension cohort of 3 patients received the dose of 9 × 1010 viral genomes per eye. Interventions: Patients received increasing doses of rAAV2/2-ND4 (9 × 109, 3 × 1010, 9 × 1010, and 1.8 × 1011 viral genomes per eye) as a single unilateral intravitreal injection. Patients were monitored for 96 weeks after injection; ocular examinations were performed regularly, and blood samples were collected for immunologic testing. Main Outcomes and Measures: A composite ocular inflammation score (OIS) was calculated based on grades of anterior chamber cells and flare, vitreous cells, and haze according to the Standardization of Uveitis Nomenclature. The systemic immune response was quantified by enzyme-linked immunospot (cellular immune response), enzyme-linked immunosorbent assay (IgG titers), and luciferase assay (neutralizing antibody [NAb] titers). Results: The present analysis included 15 patients (mean [SD] age, 47.9 [17.2] years; 13 men and 2 women) enrolled in the 5 cohorts of the clinical trial. Thirteen patients experienced intraocular inflammation after rAAV2/2-ND4 administration. Mild anterior chamber inflammation and vitritis were reported at all doses, and all cases were responsive to treatment. A maximum OIS of 9.5 was observed in a patient with history of idiopathic uveitis. Overall, OIS was not associated with the viral dose administered. No NAbs against AAV2 were detected in aqueous humor before treatment. Two patients tested positive for cellular immune response against AAV2 at baseline and after treatment. Humoral immune response was not apparently associated with the dose administered or with the immune status of patients at baseline. No association was found between OISs and serum NAb titers. Conclusions and Relevance: In this study, intravitreal administration of rAAV2/2-ND4 in patients with LHON was safe and well tolerated. Further investigations may shed light into the local immune response to rAAV2/2-ND4 as a potential explanation for the observed intraocular inflammation.