Newswise — As her husband lay paralyzed with a life-threatening disease, Patricia McElhone said an urgent prayer.

"Please God," she said. "Let him be OK -- I will do anything.'"

Her husband did get better. And later, McElhone would keep her end of the bargain by saving the life of a complete stranger. McElhone did so by donating some of her bone marrow to cancer patient Thomas Yepsen for a bone-marrow transplant. The procedure essentially cured Yepsen of non-Hodgkin lymphoma.

At 2 p.m. Sunday, Sept. 11, Yepsen and McElhone will meet for the first time, during the annual Bone Marrow Transplant Celebration of Survivorship at Loyola University Medical Center's Cardinal Bernardin Cancer Center, 2160 S. First Ave., Maywood.

"She gave me the ultimate gift," Yepsen said. "She gave part of herself to save someone she didn't even know."

Yepsen's physician, Dr. Patrick Stiff, said McElhone "is every much of a hero as the fireman who pulls a person out of a burning building. Because she donated her cells, Mr. Yepsen is alive today." Stiff is director of the Cardinal Bernardin Cancer Center.

Yepsen, 59, of LaSalle, Il., was first diagnosed in 1993 with non Hodgkin lymphoma, a cancer of the immune system's white blood cells. After chemotherapy, Yepsen went into remission, but the cancer came back in 2006. And after it came back a second time, Yepsen's best hope was a bone marrow transplant.

Prior to the transplant, Yepsen underwent high-dose chemotherapy. In the process of killing cancer cells, the chemotherapy also killed his immune system cells. So Yepsen received an infusion of McElhone's bone marrow cells, which developed into healthy new immune system cells.

For a transplant to succeed, a patient requires a close match. No family members fit the bill, so Stiff searched the National Marrow Donor Program's Be the Match® registry. Of the 9 million donors on the registry, only McElhone and one other donor were potentially perfect matches. But the other donor was not available, so that left McElhone as Yepsen's best chance.

McElhone, of St.Augustine, Fla., is a first-grade teacher and the mother of a 10-year-old son and 8-year-old daughter. While McElhone was pregnant with her son, her husband Brian was stricken with a paralyzing condition called Guillain-Barré syndrone. He eventually made a full recovery. And years later, when the marrow donor program contacted McElhone about donating, she said yes. She saw it as an opportunity to give back.

McElhone underwent the procedure at a local hospital. To retrieve marrow cells, a physician inserted a needle in her back and drew out marrow. McElhone spent a night in the hospital, and was bruised and sore for a few days. "But I would do it again if I was called," she said.

Loyola has treated more than 3,000 patients with stem cell transplants, more than any other center in Illinois, and has one of the largest unrelated donor transplant programs in the world. Loyola also is one of the most experienced centers in the world in performing cord blood transplants from cells grown in the laboratory. Such transplants are designed to reduce complications and improve outcomes.

Yepsen underwent a transplant at Loyola in November, 2009. He spent 23 days in the hospital, and another three months in isolation while his immune system was regenerating. During that time, Yepsen and his wife, Sheila, stayed in isolation at a nearby extended-stay hotel."We get along amazingly well," Sheila Yepsen said.Until his new immune system became established, Yepsen was vulnerable to infections. So he had no visitors, and left the hotel only for doctors' visits.

The bone marrow transplant was a success, and now there is only a 1 or 2 percent chance the cancer will come back, Stiff said.

Yepsen, a retired millwright, said it's difficult to put his gratitude in words.

"How do you thank someone for saving your life?" he said.