SAN FRANCISCO (AP) — In a rare series of interlinked operations, six patients are getting kidney transplants from six donors at a San Francisco hospital.

Dr. William Bry, a surgeon at California Pacific Medical Center, said the "kidney paired donations" are occurring thanks to a woman who started a chain of donations and a computer program that matches donors to recipients, KGO-TV reported Wednesday (http://abc7ne.ws/1B5bshp ).

People in the chain are not compatible with relatives or friends to whom they are willing to give kidneys. So, they donate to strangers they do match.

Zully Broussard of Sacramento agreed to give a kidney to a man with such a relative. That relative, in turn, will donate a kidney to a patient who also has a family member or friend unable to donate because of compatibility issues. This kind of pairing continues down the line four more times until all six kidney patients get transplants, the San Francisco station reported.

The paired kidney exchange happened through computer software developed by David Jacobs, who is a kidney recipient. Its algorithmic program uses a person's genetic profile and finds potential matches.

Once the matches are confirmed, doctors, nurses and case managers work on the logistics of making it a reality.

Broussard said her son died of cancer 13 years ago and her husband passed away 14 months ago, also from cancer.

"I know what it feels like to want an extra day," she said when asked why she volunteered to donate a kidney to a stranger.

Three transplants are planned for Thursday and the remaining three on Friday. Most of those involved are from the San Francisco Bay Area.

"I thought I was going to help this one person who I don't know, but the fact that so many people can have a life extension, that's pretty big," Broussard said.