Nearly 4,000 Americans are currently waiting for a lung transplant. While the transplant procedure can mean saving a life, the benefits of the procedure are often short-lived.
Lungs are among the most difficult organs to transplant and they have the poorest survival of any solid organ transplant. Three- to four-year survival following a transplant is only about 50 percent.
According to Aldo Iacono, M.D., from the University of Pittsburgh Medical Center, there have not been any advances in therapeutics for lung transplant in the past 10 years.
While doctors are not sure why this is, they suspect that the lung is more immunogenic, which means it stimulates the immune system more than other organs and this causes rejection, a condition known as graft vs. host disease.
What happens is the body identifies the new organ as a foreign object, and creates a cascade of inflammatory compounds to attack it. This eventually destroys the organ and prevents it from working.
Dr. Iacono and colleagues at the University of Pittsburgh have come up with a new treatment approach they say may extend survival in lung transplant recipients. The treatment involves inhaling the drug cyclosporine through a nebulizer for two years following the transplant.
The idea, explains Dr. Iacono, is that if you inhale the drug, it will go directly to the lungs where the rejection takes place. This allows for high concentrations of medication to get where it is needed as opposed to taking medication orally or intravenously where it travels throughout the entire body and only a small concentration gets where it's needed.
The benefits of this are twofold. For one, the drug has a dose-dependent effect, which means the more medication that reaches the organ, the less inflammation and the less rejection one would expect to see.
Secondly, since the drug goes straight to the organ and remains there, there is less toxicity to the rest of the body.
Other drugs that are given orally to prevent rejection have to be given in low doses so they do not affect the body's entire immune system.
Patients inhale the medication three consecutive days in the hospital before being sent home. They then use it three times a week for two years.
The procedure is currently being tested only at the University of Pittsburgh Medical Center, but Dr. Iacono hopes to get it in larger studies. The treatment is being evaluated by a pharmaceutical company for presentation to the FDA for future commercialization.
In a study presented at the annual meeting of the International Society for Heart and Lung Transplant, Dr. Iacono announced the results of a study on 58 patients randomized to receive the cyclosporine or a placebo.