Courtesy of Dr. Alvi Armani
Hair Transplant in Incompatible Hosts
Auto-transplantation of hair normally provides satisfactory correction of baldness and hair loss. In a normal hair transplant redistribution of hair follicles from one part to another occurs in the same individual.
Allo-transplantation of hair is the transplantation of hair from one individual to another. Allo-transplantation of hair has not been attempted because hair is considered strongly antigenic. Rosati et al. reported the case that the bone marrow transplant patients could undergo an allotransplant of hair from the same bone marrow donor. Jahoda et al.
Reported for the first time in 1999 that the human follicle cells can be induced to grow in an incompatible host of the other sex. With these recent advances in follicle cell transplants in incompatible hosts we considered it necessary to evaluate an allogenic hair transplant. We wanted to determine whether the allotransplant is successful or not. If it is not successful the reasons behind it and how to overcome the obstacles.
Objective: We performed an allo-transplant in two unrelated individuals. We observed the growth of hair in the incompatible hosts over a period of 14 months.
Material and/or Methods: To test this hypothesis we selected two different male donors AA and FA. Hair follicles from AA was taken and successfully transplanted on FA and similarly in an another operation hair follicles from FA was taken and transplanted on AA.
We provided each of the subjects pre-op medications and an area of scalp measuring 6x1cm was shaved and anesthetized. Then the skin with the hair follicles were removed. The hair grafts were cut into smaller single, double and triple grafts. In the first operation 586 grafts of AA were transplanted on FA and in the second operation 594 grafts of FA were transplanted on AA.
The transplants were performed on both temple angles of both individuals. This would give us clear observation of hair growth. The hair color on AA is black and the hair color on FA is brown. This would facilitate the identification of hair growth. Post surgery growth was measured at 9 months and 14 months.
were taken at different
intervals to monitor growth.
• Grafting was done on temple areas for better visibility
• AA has black hair - FA has light brown hair
• Color difference would facilitate identification of hair growth.
4 months post surgery
Discussion / Results:
Post surgery growth was measured at 9 months and 14 months. At 9 months on FA 45 of 586 grafts were counted as surviving grafts.
We were not able to determine the amount of surviving grafts on AA. At 14 months there were no surviving grafts on FA.
Jahoda et al. reported for the first time in 1999 that the human follicle cells can be induced to grow in an incompatible host of the other sex. The anagen hair bulb constitutes one of the few immunologically privileged tissues of the mammalian body. The absence of MHC Class I expression as well as the virtual absence of MHC Class II presenting Langerhans cells in the hair bulb, together with the virtual absence of CD4+ cells and lack of CD8+ T cells and Natural Killers (NK) in hair follicle contribute to this immune-privileged concept. The lack of MHC Class II presenting Langerhans Cells in the hair bulb can play an important role in tolerance of allogenic transplant. The death of the allo-grafts is the result of a strongly antigenic skin. The hair is not antigenic.
Conclusion: This study shows that allo-hair transplants do not work in the traditional format. Even though the dermal sheath of the follicle is immuneprivileged the tissue surrounding the graft does not have the same properties. Therefore there is no survival of the graft.
It will be necessary to introduce modifications to the way the grafting is done to remove the non immune-privileged elements that surround the dermal sheath of the follicle. We hypothesize that if skin antigenicity can be limited this can present a new approach to the treatment of hair loss.
The above is provided by courtesy of Dr. Alvi Armani