AMD,NIH,干细胞治疗 z-bo 2020-09-30 379

　　Researchers at the National Eye Institute (NEI) are conducting clinical trials to evaluate the clinical safety of the new treatment based on patients' autologous stem cells to treat geographic atrophy. GA is an advanced form of dry AMD. He is 65 years old this year, the main cause of people’s vision loss. Currently, there is no cure for AMD’s geographic atrophy.

　　This is a safety trial led by NEI for age-related luteal degeneration that is currently incurable. The researchers obtained the patient's blood cells and guided them to iPS cells in the laboratory, which may become various cells in the body. Then instruct ips cells to differentiate into retinal pigment epithelial cells. Retinal pigment epithelial cells die prematurely in the atrophic area of the eye of AMD patients.

　　Age-related yellowing (AMD) is the main cause of irreversible blindness among middle-aged and elderly people in developed areas. About 8.7% of the global population suffers from AMD. In addition, this number will increase to approximately 196 million in 2020 and 288 million by 2040. The global direct cost associated with AMD is estimated at $255 billion. The pathological features of AMD are changes in drusen of the choroid/retinal pigment epithelium (RPE) and pigmentation of the corpus luteum. The central area of the retina controls the main vision. The stages of AMD progression include dry and neovascular (wet) morphology. There is no clear way to distinguish the two. Age-related luteal degeneration (ARMD) is generally divided into two categories: dry and wet. With age, the vision of both eyes or one eye gradually declines, causing irreversible damage to the luteal area of the fundus. The cause of age-related yellowing is currently unclear, and may be related to genetics, birth defects, chronic light damage, nutritional deficiencies, poisoning, drugs, immune diseases, hypertension, arteriosclerosis, trauma, etc.

　　Slow onset, usually eye disease, with gradual decline in vision and vision loss. In the early stage of fundus examination, the posterior pole of yellow-white, hard, hard drusen is more common, while in the later stage, posterior pole pigmentation disorders, geographic atrophy and even large residual choroidal vessels are observed. Wet ARMD is also called exudative or angiogenic ARMD. It often occurs in one eye. The course of the disease is long, but the vision suddenly deteriorates, leading to visual distortion and black spots in the center. On the fundus, dark red or dark bleeding is seen below the sensory layer of the posterior pole, and the lesion area is elevated. In the later stage, the hemoglobin of the tissue is too large to form a disc-shaped scar and completely lose central vision.

　　Currently, there is no fully effective treatment plan for dry AMD. The only alternative preventive measure is the concept of Age-Related Eye Disease Research (AREDS). This is expected to reduce the incidence of AMD by 25% in the next five years. – 30%. EI Eye and Stem Cell Transformation Research said: “This treatment can prevent blindness in animal models and is the first clinical trial in the United States that uses patient-derived induced pluripotent stem cells (iPSC) as a replacement tissue.” Kapil Ba, the team’s lead researcher Said Dr. Kapil Bharti. Say. EI is part of the National Institutes of Health. Treatment involves collecting blood cells from patients and converting them into iPS cells in the laboratory. These iPS cells can be transformed into any type of cells in the human body. ips cells differentiate into retinal pigment epithelial (RPE) cells and die prematurely during the geographic atrophy of leukoplakia. PE cells nourish photoreceptor cells, which are the photoreceptor cells of the retina. In geographic atrophy, when RPE cells die, photoreceptor cells eventually die, leading to blindness. The therapy attempts to maintain the normal function of the remaining photoreceptor cells by replacing dead RPE with ipsC-derived RPE. Before transplantation, iPSC-derived RPE is stacked on a thick cell sheet to reproduce the natural structure of the eye. RPE monolayer cells derived from ipsC are grown on a biodegradable scaffold designed to promote cell fusion in the retina. The surgeon uses surgical tools specifically designed for this purpose to place the patch between the RPE and the photoreceptor. According to the phase I/IIa clinical trial protocol, the ipsC-derived RPE will be transplanted into one eye of 12 patients with advanced geographic atrophy and closely monitored for at least 1 year to confirm safety. In stem cell-based therapy, attention should be paid to the potential carcinogenic risk, that is, the risk of uncontrolled cell growth and the formation of tumors. In animal models, the researchers performed genetic analysis on ipsC-derived RPE cells and found no potential tumor growth-related mutations. In addition, the use of single (self) blood cells can minimize the risk of implant rejection in the body. If early safety can be confirmed, more patients will be included in the later research phase to evaluate the effectiveness of implants in preventing blindness and restoring vision in patients with geographic atrophy.

　　The prerequisite for the US Food and Drug Administration (FDA) to conduct clinical trials is to establish a Good Manufacturing Practice (GMP) contract to ensure that the RPE derived from ipsC is a clinical grade product. That is. GMP procedures are essential for reproducible treatment and mass production after FDA approval. The preclinical research of the trial was supported by the NEI internal research program and the NIH Mutual Fund Treatment Challenge Award. The exam is taken at the NIH Clinical Center in Bethesda, Maryland.