BOSTON (Reuters) - A federally mandated change in the way doctors test for compatibility in kidney transplants has increased the number of organs going to minorities by about 7.2%, according to a study reported this week in The New England Journal of Medicine.

Under the previous system, whites were twice as likely to receive a donated kidney than were non-whites.

The policy calls for ignoring part of the scoring system that determines whether a donated kidney and a would-be recipient are a good match.

The scoring criteria were changed last May by the U.S. Department of Health and Human Services after it received advance results of The New England Journal of Medicine study.

The study, led by Dr. John Roberts of the University of California at San Francisco, predicted that a small change would increase the transplant rate for non-whites by 6.3% while lowering the chance of a transplant for whites by 4%.

The study also concluded the new rule would increase the failure rate for each transplant, regardless of race, by 2%.

"This has been a delicate balance. Should we give up a perfect match in return for reducing the imbalance over who gets a transplant?" said Friedrich Port, who co-authored the study. "We were happy to see that the price for improving the balance was very small."

Data from the first 4 months after the new scoring system was adopted showed a 7.2% increase in transplants for minorities. There have not been enough cases to provide a good breakdown among individual races, Port said.

Dr. Roberts said it's probably too early to gauge the full impact of the change.

BLACKS AT A DISADVANTAGE

"It will probably take a few years for it to work its way through the system, but it's one step to getting rid of the disparity," he said.

Blacks, for example, are at a disadvantage for getting a kidney transplant because they are more likely than whites to develop serious kidney problems. Finding a good match for a black patient also is more challenging because blacks are more genetically diverse than whites, Roberts said.

"The white population tends to be more homogeneous so they're a relatively easy match," he explained.

Transplant rules are controversial because there are not enough transplantable kidneys available to meet the demand.

Whether someone gets a kidney depends on the amount of time they spend on a waiting list and whether they have a correct tissue match, which is determined through HLA typing.

To develop its recommendation, the Dr. Roberts' team used success rates for 32,609 transplants that were done from 1995 to 2001. They studied what would happen if certain HLA types were ignored.

They found that by not including matching of HLA type B, minorities would have a better chance for a new kidney.

"We said, 'Let's eliminate B. It doesn't matter much and it hurts blacks,"' Dr. Roberts said.

The study "is an important step toward the formulation of a just and scientific system of distributing kidney allografts," according to an editorial in the Journal by Jon van Rod of the Europdonor Foundation in Leiden, Netherlands.

Copyright © 2003 Reuters Limited. All rights reserved. Republication or redistribution of Reuters Limited content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters Limited. Reuters Limited shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.