In the current transplantation methodology, the patient’s hair is taken from the back and/or side of the scalp to be grafted into the recipient area. The coverage obtainable is limited, of course, to the amount available in donor area. According to a new study, it seems possible that follicles can be harvested and transplanted into the scalp between two different subjects.
These investigations could increase the number of people who can access a transplant; in fact, the hair transplant has historically always been at the mercy of genetics, as it is dictated greatly by the number of follicles possessed by the patient in donor area.
Researchers at the Seoul National University Hospital (SNUH) have discovered a method that could allow balding patients to receive healthy hair follicles from other patients, without taking immunosuppressant drugs.
The study from Seoul National University Hospital
Currently, patients with hair loss undergo drug therapy in the early stage. However, if hair loss progresses to the point where treatment with medication is difficult, patients consider the option of transplantation.
Current hair transplantation is called autologous hair transplantation. With it, only the patient’s existing hair follicles are used, but without generating new ones. To solve these problems, the team, led by Professor Kwon Oh-sang of Seoul Hospital’s department of dermatology, focused on dendritic cells involved in human immune processes.
The dendritic cells recognize abnormal cells as tumors in the human body. In doing so, they order immune T cells to attack them. Unfortunately, the immune system also attacks transplanted organs, after recognizing them as a foreign body.
The researchers focused on the fact that donor dendritic cells play an important role in acute immune rejection. The team used ultraviolet B irradiation, widely used in dermatological therapies, to remove all dendritic cells present in donor hair follicles.
Subsequently, the researchers performed allogeneic grafting on 24 laboratory mice. These had the same level of the human immune system, thanks to a hematopoietic stem cell transplant.
As a consequence, the transplanted hair follicles produced new hairs. It was, moreover, observed that these could survive for more than six months without an immune rejection response.
According to the team, hair follicles have a behavior similar to the cornea of the human eye. They possess a kind of “immune privilege,” in that they are less likely to be rejected by the immune system than other organs such as the heart, kidneys and so on.
Researchers may be able to reproduce the same state for follicles by removing the donor dendritic cells involved in direct antigen activity.
“Through this research, we have obtained a new medical basis for hair transplantation without the use of immunosuppressants,” said professor Kwon. “Applying this finding to clinical practice in humans would be a challenge. The research is significant in that it can use new resources that were previously impossible.”