Single gene variant in donors may affect survival of transplanted kidneys

ScienceDaily (Oct. 11, 2012) — A single genetic variant in kidney donors' cells may help determine whether their transplanted organs will survive long term, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings provide new information that might be used to improve transplant longevity by revealing that the genetic make-up of kidney transplant donors affects the survival of transplanted organs.
A transplant recipient must take lifelong immunosuppressive drugs to prevent rejection of the new organ, but these drugs can have serious side effects, including kidney damage. So, ironically, the very drugs needed to prevent kidney rejection can also be toxic to the kidneys. Research suggests that how well certain proteins pump these drugs out of kidney cells may influence the drugs' kidney toxicity.
Richard Borrows, MB (Queen Elizabeth Hospital Birmingham, in the UK) and his colleagues looked to see if variants in the genes that encode such pumps might influence the health of transplanted kidneys. They investigated the links between donor and recipient gene variants with kidney outcome among 811 immunosuppressant-treated kidney transplant recipients.
Among the major findings:
One particular variant within the multidrug resistance 1 (MDR-1) gene in donors was linked to a 69% increased risk for long-term failure of transplanted organs.The researchers validated the link in another 3,660 donors, making this the largest study of its kind.This variant affects the expression of the protein that the MDR-1 gene encodes, the drug transporter P-glycoprotein.No other genetic variants in donors or recipients were linked with organ survival or failure.
"The study of donor, as opposed to recipient, gene variation is relatively uncommon in the field of transplantation, and it certainly warrants more attention," said Dr. Borrows. He added that a single genetic variant probably has limited effect on its own, but when combined, multiple genetic variants may play an important role in transplant longevity.
Study co-authors include Jason Moore, MBBS, Amy Jayne McKnight, PhD, Bernd Döhler, PhD, Matthew Simmonds, PhD, Aisling Courtney, PhD, Oliver Brand, PhD, David Briggs, PhD, Simon Ball, PhD, Paul Cockwell, PhD, Christopher Patterson, PhD, Alexander Maxwell, PhD, Stephen Gough, PhD, and Gerhard Opelz, PhD.
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The above story is reprinted from materials provided by American Society of Nephrology (ASN), via Newswise.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
Richard Borrows et al. Donor ABCB1 Variant Associates with Increased Risk for Kidney Allograft Failure. Journal of the American Society of Nephrology, 2012; DOI: 10.1681/ASN.2012030260
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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Cyberbullying Rarely Single Factor in Teen Suicides: Study

SATURDAY, Oct. 20 (HealthDay News) -- Cyberbullying is rarely the only factor behind teen suicides, according to a small study.

The researchers found that most teen suicide victims are bullied both online and in school, and that many also suffer from depression.

For the study, the investigators analyzed 41 suicide cases in Australia, Canada, the United Kingdom and the United States. There were 24 female and 17 male victims, ages 13 to 18.

Twenty-four percent of the teens were the victims of homophobic bullying. Of those, half were identified as homosexual and the other half were identified as heterosexual or of unknown sexual preference.

Seventy-eight percent of the teens were bullied both at school and online. Just 17 percent were targeted online only. Thirty-two percent of the victims had been diagnosed with a mood disorder and 15 percent with depression symptoms.

The study was scheduled for presentation Saturday at the American Academy of Pediatrics' national conference in New Orleans.

"Cyberbullying is a factor in some suicides, but almost always there are other factors such as mental illness or face-to-face bullying," study author Dr. John LeBlanc said in an academy news release. "Cyberbullying usually occurs in the context of regular bullying."

He and his colleagues found that cyberbullying occurred through various media, with Formspring and Facebook specifically mentioned in 21 cases, and text or video messaging noted in 14 cases.

"Certain social media, by virtue of allowing anonymity, may encourage cyberbullying," LeBlanc said. "It is difficult to prove a cause-and-effect relationship, but I believe there is little justification for anonymity."

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

-- Robert Preidt Copyright © 2012 HealthDay. All rights reserved. SOURCE: American Academy of Pediatrics, news release, Oct. 20, 2012

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