Study shows racial disparity among kidney recipients decreased with transplant p

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http://www.fredericknewspost.com/sections/art_life/display_features.htm?StoryID=129148

Study shows racial disparity among kidney recipients decreased with transplant policy reversal
By Nicholas C. Stern

The racial disparity between the rate at which black and white people receive deceased donor kidney transplants has decreased following a change in the way kidneys are allocated, according to a study published in November in the American Journal of Kidney Diseases.
Until 2003, preference by the United Network for Organ Sharing had been given to potential kidney recipients who matched genetically with the deceased donor in terms of the presence of an antigen -- a foreign molecule that triggers production of an antibody by the immune system -- known as HLA-B, according to Dr. Bernard Jaar, a nephrologist and the medical advisory board chairman for the National Kidney Foundation of Maryland.

HLA-B is involved in the immune response to foreign tissue and tends to be racially clustered, a press release from the National Kidney Foundation of Maryland stated. When combining the HLA-B preference with a higher percentage of white donors, racial disparities were almost inevitable.

Chronic kidney disease affects nearly 20 million people in the United States, the National Kidney Foundation of Maryland website states. Minorities are almost two to four times more likely than non-minorities to reach end-stage renal disease that necessitates dialysis or a kidney transplant. The incidence of kidney failure in the country per million is 783 for African Americans and 295 for whites, for example. The main causes of kidney disease are diabetes and high blood pressure, both of which are more common among minorities.

In the study, Johns Hopkins School of Medicine researchers, led by Dr. Erin Hall, looked at how long 178,902 patients across the country waited from initial placement on the kidney transplant waiting list to the actual transplant, the study's senior author, Dr. Dorry Segev, wrote in an email. Before the 2003 change, African-Americans were 37 percent less likely to receive deceased donor kidney transplants than their white counterparts. After the change, African-Americans were 23 percent less likely to receive the transplants.

Meanwhile, the policy has not affected the transplant success rate, Segev said.

Jaar said improvement in immuno-suppression medications over the past two years has helped prevent patient's bodies' rejection of the organ during transplant.

However, a significant disparity remains, Jaar said.

These may be explained by educational, geographical or physician-related factors, Jaar and Segev said.

For instance, when a patient on the waiting list gets an organ offer, they have to choose whether to accept the offer or wait for another, Segev said. Organs can be below optimal if they come from elderly donors, donors with some level of kidney disease or donors at risk of carrying undetected infections.

"Almost every organ will be right for some patient, but maybe not be for all patients," she wrote in an email. "Patients who are not properly educated about the organ offers and the way the waiting list works, and those who do not have access to a transplant team to help with decision-making, might decline organs based on a misunderstanding of risk, so it is critical that physicians very familiar with transplantation help in these decisions."

Geographical disparities exist because organ allocation occurs in donor service areas and some of these areas either have higher supply and lower demand or vice versa, as in the case of Maryland, she said. Many people on the waiting list die while waiting for a kidney.

Currently, there are about 2,000 people waiting for a kidney transplant in Maryland, Segev said. Last year, 120 donors provided 228 kidneys -- in some people, only one kidney can be transplantable. Typical waiting times for a transplanted kidney in the state can be three to five years or longer, she said.

Nationwide, more than 50,000 patients are waiting for kidney transplants, while only about 14,000 will receive transplants this year because of a shortage of suitable organ donors, the NKF of Maryland reported.

Also, conventional thinking has it that African-Americans do better on dialysis than whites, Segev is quoted as saying in the NKF news release. If a patient or their physician believes they will do fine on dialysis, they may then be more reluctant to accept the initial risk of a transplant.

Yet Segev and Jaar said recent studies show that younger African-American patients do not do better and in fact die more frequently than whites when on dialysis.

"That's a very important factor," Jaar said.

He said more studies about these barriers need to be conducted in order to explain the remaining discrepancies and eventually adjust policy to make transplants more accessible.