Men's scalp hair transplanted into geneticaly incompatible woman might foretell new hair loss treatments.

Scalp hair from men has been successfully transplanted into the forearm of a genetically unrelated and immunologically incompatible woman, according to a report in the November 4 issue of Nature.

Durham University researchers in Durham, UK transplanted human follicle dermal sheath tissue from the scalp of a male scientist into the forearm of a female coinvestigator who differed both in blood group and major histocompatibility complex (MHC) type. Five months after the first transplant, the researchers transplanted additional grafts of follicle dermal sheath and dermal papilla from the same male to the same female. And in a third experiment, they transplanted dermal sheath from a second genetically unrelated male donor into the same woman's forearm.

Not only did all the wound sites heal without gross evidence of rejection, but "remarkably, each of the sites of dermal sheath implantation produced new follicles and fibers 3 to 5 weeks after the graft," wrote lead author Colin Jahoda, PhD and colleagues. The new hairs resembled scalp hairs--large, thick, mostly pigmented, and growing in all directions--rather than the soft unpigmented vellus hairs on the untouched forearm surround the grafts. Biopsies taken 41 and 77 days posttransplant showed no histologic signs of rejection. DNA testing confirmed that the grafted papilla cells were male, while the surrounding epidermis contained only female cells, the authors said.

These findings "...indicate that the follicle-end bulb dermal sheath is among a restricted group of immunoprivileged tissues that can be transplanted to foreign sites without being rejected," the research team wrote. "This mini-organ morphogenesis shows how adult cells with inductive properties might be used in tissue and organ engineering and, more immediately, might be used in new treatments for hair loss."