Serious Corneal & Limbus Insult treated by stem cells
It has been reported recently on www.singualarityhub.com that Italian researchers have demonstrated the long term effectiveness of using stem cells to cure corneal blindness. From 1998 to 2006 the team, headed by Graziella Pellegrini at the University of Modena, performed 125 stem cell procedures on 112 patients, all who had lost partial or complete vision due to chemical or thermal burns. Stem cells were taken from the limbus in the patient’s own eye, cultured, and then grafted back on the eye. These reports have emanated from a published article in the New England Journal of Medicine. The grafts had a success rate of 76.6% – leading to restored or improved vision. Better still, the positive results have lasted – one patient has been followed for more than 10 years and still has healthy vision.
The NEJM article also describes an important development in being able to predict the success of a stem cell treatment. Many of the patients in the study had mild to severe limbal damage, limiting the amount of healthy stem cells that could be harvested and cultured. Pellegrini’s team monitored levels of p63 transcription factor in the stem cells they harvested from patients. When the number of ‘p63-bright’ cells was greater than 3%, the success rate of the eventual transplant ended up around 78%. When it was less than 3%, the outcome was successful only 11% of the time. This work demonstrates that very little of the limbus need remain healthy for the stem cell transplant to still work. Using p63 levels as a metric could allow doctors to present patients with a better idea if a corneal stem cell transplant would be successful. It also hints that p63 transcription factor could be augmented or controlled in some way to improve stem cell therapies of this kind.
It’s important to note that while the study followed one patient for more than 10 years, the average follow-up was closer to three years (with large variation).