First two patients given retinal cells derived from human embryonic stem cells
Two women with severe macular disease have been given transplants of retinal pigment epithelium derived from human embryonic stem cells. Four months on, neither patient has signs of rejection, teratoma formation, or ectopic tissue, according to a preliminary safety report. All are potential dangers with transplants derived from embryonic stem cells, which can migrate, proliferate, and differentiate into unwanted cell types. The retinal pigment epithelial cells must be completely free from contaminating stem cells before transplantation, say the authors. These adults were given submacular injections of a pure suspension, with the primary intention of assessing safety.
The human retina is immunologically privileged, protected to some extent by the blood-ocular barrier. So it is a good anatomical site for early tests of a treatment derived from cells foreign to the recipient and grown using mouse fibroblasts. These are essentially xenotransplants, say the authors. The patients took immunosuppressants for at least 12 weeks, but they will not be immunosuppressed long term.
They were carefully selected for treatment, which took place in the US. One had dry age related macular degeneration. The other, who was younger, had Stargardt’s macular dystrophy. Both had severely impaired vision at the time of the procedure. Visual acuity improved slightly over four months in the treated eye of both patients. The authors also report slight improvement in the untreated eye of the patient with age related macular degeneration.
Visual improvements were subjective, say the authors. It is too early to say whether this treatment works. For now, all we can say is that the treatment is possible and seems to be well tolerated in the short term.
Dutasteride for men with low risk prostate cancer?
Inhibitors of 5α-reductase, such as GlaxoSmithKline’s dutasteride, are best known as treatments for benign prostatic hyperplasia. These agents can shrink the prostate …