While visitors to San Francisco City Hall often see weddings taking place, one held there Monday had a special purpose and a special officiant.

Attorney General Kamala Harris oversaw the renewal of vows for Lateefah Simon and Kevin Weston as part of a campaign aimed to recruit people to join the registry of possible bone marrow donors.

Weston, 44, was diagnosed in August 2012 with an extremely rare form of leukemia and the couple -- who met in Harris' office when she was San Francisco's district attorney -- were initially married the next month while he was in intensive care at a hospital.

Prior to the renewal of their vows late this afternoon, organizers gathered about 85 new potential donors to the registry and are encouraging others, particularly people of color, to sign up as well.

"We've got to increase knowledge about this, we can actually save some lives," said Ayoka Turner, one of the organizers of the campaign. "If you're a person of color, specifically black people, you simply don't have the opportunities to have a match like other races."

According to Be the Match, a group that helps gather potential bone marrow donors, only about 7 percent of the people on the national registry are black.

Weston is a longtime Bay Area journalist and a John S. Knight journalism fellow at Stanford University while Simon is a MacArthur Genius grant recipient for her civil rights work. The couple has a 1-year-old daughter and Weston is stepfather to Simon's teenage daughter.

Harris, who said she has known Simon for nearly 20 years, called them "an extraordinary couple" who has done great work in the community.

"But now the time has come for them to actually advocate not for everybody else but for themselves ... and the need for the marrow donorship base to be expanding because so many other people have the same problem," she said.

More information about the couple's story is available online at www.kevinandlateefah.com.

People interested in joining the bone marrow registry can call (800) MARROW-2 or visit online at www.bethematch.org.