학술논문

Survival of an HLA-mismatched, bioengineered RPE implant in dry age-related macular degeneration.
Document Type
article
Source
Stem Cell Reports. 17(3)
Subject
allogeneic
clinical trial
geographic atrophy
histology
implant
macular degeneration
parylene
polarized
retinal pigmented epithelium
stem cells
Geographic Atrophy
Human Embryonic Stem Cells
Humans
Macular Degeneration
Prostheses and Implants
Retinal Pigment Epithelium
Language
Abstract
Cell-based therapies face challenges, including poor cell survival, immune rejection, and integration into pathologic tissue. We conducted an open-label phase 1/2a clinical trial to assess the safety and preliminary efficacy of a subretinal implant consisting of a polarized monolayer of allogeneic human embryonic stem cell-derived retinal pigmented epithelium (RPE) cells in subjects with geographic atrophy (GA) secondary to dry age-related macular degeneration. Postmortem histology from one subject with very advanced disease shows the presence of donor RPE cells 2 years after implantation by immunoreactivity for RPE65 and donor-specific human leukocyte antigen (HLA) class I molecules. Markers of RPE cell polarity and phagocytosis suggest donor RPE function. Further histologic examination demonstrated CD34+ structures beneath the implant and CD4+, CD68+, and FoxP3+ cells in the tissue. Despite significant donor-host HLA mismatch, no clinical signs of retinitis, vitreitis, vasculitis, choroiditis, or serologic immune response were detected in the deceased subject or any other subject in the study. Subretinally implanted, HLA-mismatched donor RPE cells survive, express functional markers, and do not elicit clinically detectable intraocular inflammation or serologic immune responses even without long-term immunosuppression.