Hair Fall and Stem Cells

There was a very interesting news item in field of hair transplant which I would like to share. This concerns cause of male pattern alopecia.
It is a known fact that in male pattern balding (Androgenetic alopecia), hair follicles don't disappear. They become so small by a process called “miniaturization” that they are not visible to naked eye. Although, we know that DHT is responsible for this process, how exactly it causes miniaturization of hair roots is still not known.

One theory of miniaturization says that DHT causes stem cell depletion in hair follicles of bald areas. A new study, published in the Journal of Clinical Investigation, tries to shed some light on this.  The research team led by Dr. Costarelis, MD collected cell samples from bald and non bald areas from the same persons and counted the number of stem cells present. They were surprised to find that bald areas had the same number of stem cells as hair bearing areas. When they looked further, they found that another cell type, which develops from stem cell, called progenitor cell was deficient in miniaturized follicle.

Dr Costarelis says that, "This implies that there is a problem in the activation of stem cells converting to progenitor cells in bald scalp." As of now, why or what causes the arrest in progression of stem cells to progenitor cells is not known. "However, the fact that there are normal numbers of stem cells in bald scalp gives us hope for reactivating those stem cells," notes Costarelis.
The logical next step would be to identify the factors that arrest this progression and to remove them. A locally applied agent or growth factors that can help stem cells to get converted to progenitor cells would also be very useful.
I have used growth factors injections in some of my patients. The results, especially when used with PRP are good but temporary. The repeated injections overcome the cost benefit. The big break will be an agent that can grow hair permanently. Till then we have hair transplants.