Global seroprevalence of neutralizing antibodies against adeno-associated virus serotypes used for human gene therapies.

Adeno-associated virus (AAV) vectors are promising gene therapy candidates, but pre-existing anti-AAV neutralizing antibodies (NAbs) pose a significant challenge to successful gene delivery. Knowledge of NAb seroprevalence remains limited and inconsistent. We measured activity of NAbs against six clinically relevant AAV serotypes across 10 countries in adults (n = 502) and children (n = 50) using a highly sensitive transduction inhibition assay. NAb prevalence was generally highest for AAV1 and lowest for AAV5. There was considerable variability across countries and geographical regions. NAb prevalence increased with age and was higher in females, participants of Asian ethnicity, and participants in cancer trials. Co-prevalence was most frequently observed between AAV1 and AAV6 and less frequently between AAV5 and other AAVs. Machine learning analyses revealed a unique clustering of AAVs that differed from previous phylogenetic classifications. These results offer insights into the biological relationships between the immunogenicity of AAVs in humans beyond that observed previously using standard clades, which are based on linear capsid sequences. Our findings may inform improved vector design and facilitate the development of AAV vector-mediated clinical gene therapies.

Outcomes of Adult Intestinal Transplant Recipients Requiring Dialysis and Renal Transplantation.

BACKGROUND: Data on dialysis and renal transplantation (RT) after intestinal transplantation (IT) are sparse. Whether changes in immunosuppression and surgical techniques have modified these outcomes is unknown. METHODS: Two hundred eighty-eight adult intestinal transplants performed between 1990 and 2014 at the University of Pittsburgh were analyzed for incidence, risk factors and outcomes after dialysis and RT. Cohort was divided into 3 eras based on immunosuppression and surgical technique (1990-1994, 1995-2001, and 2001-2014). Receiving RT, or dialysis for 90 days or longer was considered as end-stage renal disease (ESRD). RESULTS: During a median follow-up of 5.7 years, 71 (24.7%) patients required dialysis, 38 (13.2%) required long-term dialysis and 17 (6%) received RT after IT. One-, 3-, and 5-year ESRD risk was 2%, 7%, and 14%, respectively. No significant era-based differences were noted. Higher baseline creatinine (hazard ratio [HR], 3.40 per unit increase, P < 0.01) and use of liver containing grafts (HR, 2.01; P = 0.04) had an increased ESRD risk. Median patient survival after dialysis initiation was 6 months, with a 3-year survival of 21%. Any dialysis (HR, 12.74; 95% CI 8.46-19.20; P < 0.01) and ESRD (HR, 9.53; 95% CI, 5.87-15.49; P < 0.01) had higher mortality after adjusting for covariates. For renal after IT, 1- and 3-year kidney and patient survivals were 70% and 49%, respectively. All graft losses were from death with a functioning graft, primarily related to infectious complications (55%). CONCLUSIONS: In intestinal transplant recipients, renal failure requiring dialysis or RT is high and is associated with increased mortality. Additionally, the outcomes for kidney after IT are suboptimal due to death with a functioning graft.

The natural history of ALS is changing: improved survival.

In the past two decades new practice parameters for clinical care in ALS were developed and several clinical trials were performed. We sought to review information in these prospective datasets and assess whether natural history of ALS has changed over time. Survival and the rate of functional decline were compared across the placebo arms of efficacy trials conducted from 1999 to 2005 by the Northeast ALS Consortium (NEALS). Similar data from the placebo arms of 12 other published efficacy ALS trials conducted between 1990 and 2008 were compared descriptively. In the three NEALS clinical trials, survival improved over time in the placebo cohort (p=0.05) while the rate of change in maximum voluntary isometric contraction (MVIC) (p=0.15), ALS Functional Rating Scale (ALSFRS) (p=0.6) and vital capacity (%VC) (p=0.5) was unchanged. No differences were observed in the mean rates of decline of these outcome measures in the published clinical trials. However, survival improved in the more recently conducted trials. Survival improved over time in placebo controlled participants enrolled in clinical trials in ALS since 1990. However, the decline in measures of function appears unchanged since then. These changes in natural history reflect improvements in symptomatic care of ALS.