Adeno-associated virus type 2 (AAV2) mediated gene therapy providing a potential treatment in the eye. However,
immune responses can limit virally mediated gene transfer and therapy. To assess preexisting AAV2 neutralizing
factors (NF) titers in peripheral blood and the vitreous in patients with age-related macular degeneration (AMD) and
polypoidal choroidal vasculopathy (PCV). 130 subjects were enrolled: 50 with neovascular AMD, 30 with PCV, and 50
controls. The serum and the vitreous were obtained for AAV2 NF assay. We found AAV2 NF are present in all of AMD,
PCV patients and controls we tested. There were no significant differences in prevalence of NAb in serum between AMD,
PCV and controls (P =0.999). There was no correlation between NF in serum and in vitreous (P>0.05), and NF in vitreous
was significantly less than in serum. Our results for the first time showed in Chinese population, NF against AAV2 was
present in serum of all the patients with AMD or PCV and controls, and there were no significant differences among these
groups. Therefore, it demonstrated there were no correlations between AAV2 NF titer and these diseases. We found NF in
vitreous was considerably less than in serum in all groups. We also found no direct correlation between NF in vitreous and
in serum suggesting serum antibody levels may not be used to predict their counterparts in the vitreous. Our results will
provide crucial information for future clinical studies in the development of new therapies based on AAV2 mediated gene
delivery in the eye.
Keywords: Neutralizing factors, adeno-associated virus types 2, age related macular degeneration, polypoidal choroidal vasculopathy.
Rights & PermissionsPrintExport