Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tobacco smoke exposure before heart transplantation may increase the risk of transplant failure

27.11.2009
Study provides first direct evidence of cigarette smoke's role in the death of transplanted hearts

A study conducted at the University of Maryland School of Medicine in Baltimore provides the first direct evidence that cigarette smoke exposure prior to a heart transplant in either the donor, recipient, or both, accelerates the death of a transplanted heart.

The study, published this month in the journal Circulation, showed that tobacco smoke leads to accelerated immune system rejection of the transplanted heart, heightened vascular inflammation and increased oxidative stress, and a reduction in the transplanted organ's chance of survival by 33-57 percent.

The study, conducted in rats, involved exposure to levels of tobacco equivalent to that of a habitual, light-to-moderate-range smoker and included comparisons between smoking and non-smoking donors and recipients.

"Our research shows that if a heart donor has been a habitual smoker, and you put that heart in a non-smoking recipient, that heart won't work; it will be rejected," says the study's senior author, Mandeep R. Mehra, M.B.B.S., professor of medicine, head of the Division of Cardiology at the University of Maryland School of Medicine and chief of cardiology at the University of Maryland Medical Center. "This study shows beyond a shadow of a doubt how smoking affects transplantation."

This is the first study to look at the impact of smoking in heart donors, according to the principal investigator, Ashwani K. Khanna, Ph.D., associate professor of medicine at the University of Maryland School of Medicine. "There are already many risk factors that physicians and surgeons must consider when they try to match a donor with a recipient. This study makes clear that smoking in both the donor and the recipient should also become a part of the risk calculus in organ donation," says Dr. Khanna.

Studies from the mid-1990s have shown a connection between cigarette smoking and cardiovascular diseases. More recent studies have found a connection between smoking and the outcome of heart and other organ transplantation in recipients who resumed smoking after their transplants.

"The effects of smoking on heart health are well known and no surprise," says E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and dean of the University of Maryland School of Medicine. "The surprise in this study is the extent of the deleterious effects of smoking on the transplanted heart. Our researchers have discovered a significant connection that may lead to new ways to help patients with heart transplants live longer," he says.

Study design and results

In this study, groups of donor and recipient rats were exposed to tobacco smoke while a control group of donors and recipients did not undergo any tobacco smoke exposure. Drugs are routinely used to prevent the body's immune system from attacking a transplanted organ. To better isolate the effect of smoking exposure from such factors as immunosuppression, the recipient rats in this study were not given medications to suppress their immune systems.

Transplanted hearts not exposed to tobacco were rejected an average of eight days after transplantation. Donor hearts exposed to cigarette smoke were rejected at five days, while recipient smoke exposure elicited rejection at four days. Hearts in which both the donor and recipient were exposed to tobacco smoke lasted just three days before the immune response began destroying the transplant.

The researchers underscore that reduced survival occurred regardless of whether the heart donor or recipient smoked. "This accelerated trajectory of organ loss is similar whether tobacco smoke exposure occurred in donors, recipients, or both before cardiac transplantation," says Dr. Mehra. Further, this reduced survival occurs in the midst of a cascade of processes that add up to a poor outcome: increased inflammation, immune system activation and the resulting destruction of the heart's muscular and vascular systems.

The researchers speculate that this cascade could be interrupted at the time of transplantation with focused drug intervention in the anti-inflammatory and antioxidant pathways. They suggest that an antioxidant such as n-acetyl cysteine or widely prescribed statins (anti-inflammatory drugs) could prove useful in inhibiting these adverse responses. Dr. Khanna says a study of these interventions is being planned.

This work was supported by a grant from the University of Maryland Statewide Health Network and a Tobacco-Related Diseases Research Grant through the Maryland Cigarette Restitution Fund Program.

Khanna AK, Xu J, Uber PA, Burke AP, Baquet C, Mehra MR. "Tobacco Smoke Exposure in Either the Donor or Recipient Before Transplantation Accelerates Cardiac Allograft Rejection, Vascular Inflammation, and Graft Loss." Circulation. Originally published online Oct 19, 2009.

Bill Seiler | EurekAlert!
Further information:
http://www.umm.edu

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>