Question: How are donated lungs allocated for transplantation and what does this mean for patients with Idiopathic Pulmonary Fibrosis (IPF)?

Answer: In May 2005, the Lung Allocation Score (LAS) was initiated. It gives priority to patients on the waiting list who are most severely ill (medical urgency) and who have the best expected outcome during the first year after transplantation. Of these two parameters, medical urgency is given more weight than post transplantation survival. Survival is considered so that futile procedures in particularly impaired patients are not performed. Prior to the LAS system, potential recipients were prioritized only by accrued time on the waiting list. The impetus for LAS was the scarcity of donor lungs and consequent deaths of patients on the waiting list. Before the LAS system, IPF patients had the highest percentage of waiting list deaths (33%) of all diagnostic categories (Egan, 2006).

The LAS is based on a series of parameters including FVC, use of oxygen, 6-minute walk test, pulmonary artery systolic pressure, specific diagnosis, and other indices. The LAS will be evaluated every 6 months following the first three years and the parameters of the score will be adjusted.

In 2007 IPF overtook emphysema/COPD as the most frequent diagnosis of lung transplant recipients and in 2008 approximately one third of lung recipients had a diagnosis of IPF. (http://www.ustransplant.org/annual_reports/current/1204_rec-dgn_lu.htm).

Since illness severity is emphasized in the LAS system, it was expected that more patients with advanced IPF would undergo transplantation. Although patients are more ill pre-transplantation and have more primary graft dysfunction (PGD) and increased ICU stay after the procedure, the 1-year mortality is the same before and after LAS initiation (90%). Adjusting this LAS analysis for specific diagnosis, there is no difference for lung fibrosis in terms of PGD and ICU stay (Kozower, 2007).

Of particular relevance to IPF patients, the LAS can be updated if a patient worsens, which shortens the waiting time. Allocating by severity of illness will permit more ill IPF patients to obtain lungs. Finally, the LAS system should be adapted to include parameters of right heart failure, which would enhance the ability of patients with IPF to get organs.