�A Johns Hopkins enquiry team reports it may have an explanation for at least some of the higher organ rejection rates seen among black as compared to tweed kidney graft recipients.
In a study of 50 goodly adult hands, 25 black and 25 white, importantly different amounts of certain immune arrangement cells were found between the races.
These cells, known as human leukocyte antigen-specific, or HLA-specific B cells, when "hypersensitive" produce antibodies linked to transplanted kidney rejection, says Andrea Zachary, professor of medicine at Johns Hopkins and lead researcher of the study.
It's been foresightful known that HLA-reactive antibodies produced by B cells are one of the ways that transplanted organs are jilted. Zachary developed a novel method for counting HLA-specific B cells more accurately, leading to the hypothesis that B cell book of Numbers make a difference in transplant retentivity and rejection.
"Now that we have an accurate way to bet these cells, we ar able to confirm what we tenacious suspected, that blacks might have a bigger army of HLA-specific B cells," says Zachary who presented her findings at the Congress of the International Transplant Society in Sydney, Australia on Aug. 12.
Zachary says that patients turn sensitized when exposed to HLA in blood or tissue that is non their have. Sensitized HLA-specific B cells then produce antibodies that attack transplanted organs containing foreign HLA. Patients tin become sensitised from a blood blood transfusion, transplantation or pregnancy.
"If the recipient is not hypersensitized, B cells represent simply a patient's potential for making antibodies," says Zachary. "However around a third of patients in motive of a kidney are sensitized since they're often on their second or third transplanting and may have undergone transfusions. In the written report, Zachary and her squad gathered blood samples from 25 adult black males and 25 adult albumen males. They were all healthy and all non-sensitized. They as well gathered stock samples from 10 sensitized adult disastrous males and 25 supersensitive white males.
Results showed that the bleak non-sensitized males tested had an average of 17.2 per centum more HLA-sensitive B cells than the white non-sensitized males time-tested. Among the sensitized chemical group, black males had an average of 22.9 percent more HLA-sensitive B cells than white males.
HLA antigens are proteins that sit on the surface of origin and tissue paper cells. Each person has a specific set, standardized to a fingerprint. Rejection of a transplant occurs when the recipient's immune system sees the donor's HLA antigens as alien and attacks those antigens with cells or antibodies. The amount of antibody made depends on the number of B cells a recipient has.
"Knowing that blacks have an increased number of HLA-specific B cells - which increases their opportunity for antibody-mediated rejection - we may be able to custom-make treatments for black recipients to account for these differences and lessen the likelihood that the organ will be rejected," says Zachary.
Additional Johns Hopkins researchers who worked on this study ar Mary S. Leffell, Ph.D.; and Dessislava Kopchaliifka, Ph.D., of the Department of Medicine and J. Keith Melancon, M.D., of the Department of Surgery.
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Tuesday 9 September 2008
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