Gene therapy has brought new hope to people living with serious eye diseases that were once thought to be impossible to treat.
Scientists have been developing ways to use healthy genes to slow or even stop vision loss caused by conditions such as age-related macular degeneration, glaucoma, and diabetic eye disease.
These illnesses affect millions of people around the world and are among the leading causes of blindness. In the United Kingdom alone, about 2 million people live with sight loss, and more than 1 million have permanent blindness or partial loss of vision.
Although gene therapy has produced encouraging results, researchers are still working to understand why some patients experience unwanted side effects.
A new study from the University of Bristol has found that a person’s age and sex may play an important role in how the body responds to gene therapy for eye diseases. The researchers discovered that older females had a much stronger inflammatory response after treatment than other groups.
Their findings suggest that older women could face a higher risk of harmful inflammation that may damage the retina, the light-sensitive tissue at the back of the eye. The study was published in the journal Molecular Therapy.
Gene therapy works by delivering healthy copies of genes into cells that are no longer working properly. To carry these genes safely into the body, scientists often use a harmless virus called an Adeno-Associated Virus, or AAV.
This virus has been widely used in research because it does not normally cause disease in humans. Once inside the eye, it delivers the healthy genes to retinal cells, helping them function better and slowing further damage.
Even though this approach has shown great promise, doctors have noticed that some patients develop inflammation after treatment. In some cases, the inflammation becomes serious enough to reduce vision instead of protecting it.
Scientists believe this happens because the immune system recognizes the virus used to deliver the genes as something foreign and launches a defense against it. This immune reaction can damage healthy eye tissue and may also make it harder for doctors to choose the safest and most effective treatment dose.
To better understand why these reactions occur, the Bristol research team studied eye cells collected from male and female animals of different ages. The scientists examined young, middle-aged, and older cells and focused on how the immune system reacted to the gene therapy rather than the eye disease itself.
The results showed that young male and female cells both reacted to the treatment, but they did so in different biological ways. As the cells became older, inflammation lasted longer and became more intense in both sexes.
However, the biggest difference appeared in older female cells. These cells produced a much stronger inflammatory response and showed signs of stress that were linked with damage to the retina. Older male cells also responded to the treatment, but their immune reactions were more stable and less severe.
Lead researcher Dr. Alison Clare said the findings are the first to show that both age and sex can influence the risk of serious inflammation after gene therapy in the eye. She explained that these differences should be considered when planning treatment.
Instead of using the same approach for every patient, doctors may eventually adjust treatment plans according to age and sex to reduce the chance of harmful side effects.
The study does not suggest that gene therapy is unsafe. On the contrary, gene therapy remains one of the most exciting advances in modern medicine and continues to offer hope to people with inherited and age-related eye diseases that previously had few treatment options.
However, the findings show that treatments may need to become more personalized so that each patient receives the safest possible care.
The researchers believe future studies should investigate why older female cells react so strongly and explore ways to reduce inflammation without reducing the benefits of gene therapy. Better control of the immune response could make these treatments safer and allow more patients to benefit from them.
As scientists continue to improve gene therapy, understanding how different groups of people respond will be an important part of developing more effective treatments. This research provides valuable new information that could help doctors better protect patients while continuing to advance treatments that may preserve sight for millions of people in the future.
The research was led by scientists at the University of Bristol and was published in the journal Molecular Therapy.
If you care about health, please read studies that vitamin D can help reduce inflammation, and vitamin K could lower your heart disease risk by a third.
For more health information, please see recent studies about new way to halt excessive inflammation, and results showing foods that could cause inflammation.
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