Millions of bald and balding men may have a chance at a full head of hair in the not-too-distant future, a new study suggests. Researchers said that their study, published in this week's international journal Nature, shows for the first time that adults can grow additional hair follicles from the transplanted hair of other adults.

The study confirms what many hair researchers have suspected: Hair follicles have a special status among parts of the human body and can be transplanted from one person to another without triggering an immune reaction, said research team member Angela Christiano, Ph.D., a molecular biologist at Columbia University in New York City.

"There's this principle of immune privilege that's thought to be associated with hair follicles," Christiano said. "It's been assumed, but this is the first proof."

Although hair transplant surgery has become increasingly sophisticated in recent years, no one has found a way yet to increase a person's allotment of hair follicles, she said. Current methods of surgery merely redistribute the existing follicles, which limits how effective they are for people who have lost hair follicles from injury or disease.

A genetic mix

But the husband-wife research team from Durham University in England, Amanda Reynolds and Colin Jahoda, may have opened the way for new hair-loss treatments. Trying to grow a new follicle, the researchers took a small plug of hair from Jahoda's head. The team then implanted parts of a special area of the follicle -- just a few cells' worth -- into tiny cuts on Reynolds' inner forearm.

Three weeks later, she had new hairs where the cells had been implanted -- thicker and darker than other hairs on her arm. DNA analysis of the new hair follicles revealed that the new hairs matched neither his nor her own natural hairs, but a genetic mix of donor and recipient.

An organ transplant between Jahoda and Reynolds would normally fail, said Christiano, because -- unlike twins or close relatives -- the couple carry different genes, which makes them immunologically incompatible. But in this case, even 77 days after the graft, the researchers didn't see any signs that Reynolds' body was rejecting the new hair.

To test these results further, the research team did another follicle transplant into Reynolds five months later. This time they used hair from two different men, Jahoda and another. That transplant, too, showed no signs of rejection.

"This particular piece of work that Colin and Amanda did -- it's a unique piece of work," said Maria Hordinsky, M.D., a dermatologist who specializes in hair loss at the University of Minnesota Academic Health Center in Minneapolis. "In theory, it's wonderful, it's exciting."

Applying the research, though, will take more work, Hordinsky said. "I'd like to see it repeated on the scalp and on different body parts. And if you have injured skin, say from radiation treatment or a burn -- will it work?"

Other researchers have tried to "clone" hair follicles before, but with limited success, said Gary Hitzig, M.D. Hitzig is a hair transplant surgeon in the New York City area, and medical director for the American Hair Loss Council, a non-profit organization of professionals who treat hair loss. The new research, he said, suggests that others might have been using the wrong parts of the hair follicle.

Even so, the new finding won't change hair transplant procedures right away, said George Cotsarelis, M.D., director of the Hair and Scalp Clinic at the University of Pennsylvania Medical Center in Philadelphia.

"If someone thinks this is going to lead to a baldness cure in a year or two, that's completely unrealistic. I think seven to 10 years is more realistic."