Synthetic Peptide Benefits Lung Transplants

By Devaki

Tuesday, May 25, 2010, 14:42

Synthetic peptide can enhance lung transplantation, says the new studies conducted by the scientists.

With in 72 hours of transplant, patients can have the excess fluid and other problems which can significantly reduce short-term survival odds and long-term lung function. Around 10 percent of the lung transplant patients experience an acute lung injury with in the hours after the transplant. This problem leads to the mortality of around 40 percent of those patients, with in 30 days.

Putting TIP peptide in to the trachea of the lungs about half an hour before the transplantation can nullify the bad results, says the studies. This process is called Ischemic Reperfusion injury, which can also improve the oxygenation. The scientists say that the parameters of the transplanted lungs will be almost normal, if this is done.

Reactive oxygen species are natural byproducts of oxygen use that can cause cell damage and death at high levels. Stress, such as putting dormant lungs back to work, can increase their levels. The donor lungs may be preserved in a cool, protective solution for several hours and when the lungs are suddenly put back in a body, the patient get an oxygen supply which by itself causes a lot of damage because of reactive oxygen species production.

A major potential problem immediately after lung transplantation is the dysfunction of sodium channels in alveoli- the tiny air sacs where oxygen uptake occurs, impairing the sacs' ability to clear fluid into the lymphatic system. There can be an immediate invasion of white blood cells called neutrophils, which also produce reactive oxygen species. A tumour necrosis factor, or TNF is an inflammation-producing cytokine that helps the body fight infection, which can be deleterious or even deadly, at high levels. It can be implicated in these early problems of lung transplantation. The lung transplant activates TNF production, causing cells that line the organ's vasculature and air sacs to produce more reactive oxygen species and block sodium channels.

TNF can also have a polar opposite effect, blocking the reactive oxygen species production and increasing sodium uptake. Here the synthetic TIP peptide can help the patients. The levels of reactive oxygen species and neutrophils dropped and sodium channels rebounded, when the scientists conducted the studies in the rats, which underwent lung transplants.

Soluble TNF receptors can block TNF's adverse effects. This method is already being used to treat rheumatoid arthritis, in which the immune system attacks joints. Blocking this site does not block the positive-actions of the sugar-binding site.

We have a physiologically relevant form of this peptide in our body, a cytokine that could help us avoid the problems that lead to ischemic reperfusion injury, says the experts.

The study has appeared in the March issue of Critical Care Medicine.