A 21-year-old leukemia patient underwent pioneering surgery in a Shanghai hospital Wednesday, when doctors transfused 30 milliliters of umbilical-cord blood donated by a Shanghai cord bank. Today they will transplant a batch of his father's stem cells, which are an imperfect match.

This combination of umbilical-cord blood and half-matched stem cells can offer lifesaving transplant opportunities to many more patients than traditional methods, which require a perfect match between patient and donor, said doctors from Shanghai No. 1 People's Hospital.

It will be a month before results of the transplant are determined.

About 40,000 to 50,000 people on China's mainland are diagnosed with leukemia every year - alf of them children. Only about 1,000 are able to receive a stem-cell transplant because of the difficulty of finding a matching donor.

The chances of finding a perfectly matched donor are as little as one in 100,000, when direct blood-relatives are not available. The possibility of an exact match is one in four between immediate relatives.

The chances of finding a donor of umbilical-cord blood is 50 to 100 times higher because this sort of transfusion is less prone to rejection. However, one unit of umbilical-cord blood is usually not enough to treat an adult patient.

Stem cells, from which all other cells in the body grow, are found in umbilical-cord blood, bone marrow and peripheral blood. With this new procedure, umbilical-cord blood is used to reduce the chance of the body rejecting half-matched stem cells.

"Without a perfectly matched donor, the recipient will develop severer rejection and could die," said Chen Liyun, a Shanghai Cord Bank official. "In cord blood, there's a special type of cell that can curb rejection. The method uses this kind of cell to control rejection."

Medical experts said hospitals in Beijing were the first in the nation to begin the practice four or five years ago.

The new transplant method offers options to patients who previously had none.

Dr Chen Jing from Shanghai Children's Medical Center said the technology is still new in clinical practice and there hasn't been a lot of data collected to confirm its effects.

"However, it is a solution for some patients who can't find a perfectly matched donor," Chen Jing said.

(Shanghai Daily April 9, 2009)