Recent Changes in Lung Allocation with Kenneth McCurry, MD & Maryam Valapour, MD, MPP

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During this segment of Lungcast, Valapour and McCurry discussed recent changes made to lung allocation scores as well as the topic of graft rejection.

There are several changes that lung allocation has undergone in the past 2 decades, an example of which included the 2005 addition of the Lung Allocation Score (LAS) that resulted in a massive 40% reduction in waitlist deaths and a doubling of lung transplant successes.

Despite such improvements, there remain consistent initiatives aimed at clinical efficiency and equitable processes of transplantation. This subject was covered in the latest episode of Lungcast, hosted by Al Rizzo, MD, chief medical officer of the American Lung Association (ALA), and his guests Maryam Valapour, MD, MPP, and Kenneth McCurry, MD, from the Cleveland Clinic Lung Transplant Team.

Rizzo first commented on the 2 significant changes in the last couple of decades, including the utilization of the LAS as the primary determinant of donor lung allocation and the change to the primary geographic allocation unit back in 2017. Both changes, he noted, helped improve the allocation system.

“Since our last discussion, there have been further modifications to the lung allocation score, and I believe your research had some bearing on this,” Rizzo said. “And in my readings, terms such as composite allocation score and continuous distribution scoring powered by AI are now being used. Can you tell us how this latest modification of the lung allocation system has impacted patients seeking transplantation?”

Valapour responded that in the nearly 20 years since the LAS’s implementation, clinicians have collectively become better at taking care of complex patients and better at managing donors using advanced techniques.

“Now we don't need to have these strict bounds for geographic distance between the candidate and donor hospitals like we did in the past,” Valapour said. “So it was in response to these new realities that came the 2017 incremental change that would allow us to slightly broaden geographic sharing of donor lungs. The composite allocation score, or the caste system, represents kind of the next step, where we're marrying these 2 priorities.”

After discussing these impacts and others, Rizzo discussed the importance of primary graft dysfunction and chronic inflammation causing rejection. He asked McCurry about changes in how such patients are monitored and generall about the development of chronic graft rejection testing.

“Chronic rejection really remains, sort of, the scourge of transplantation in general,” McCurry explained. “So if you look at all the organs that we transplant, they're all subject to this chronic attrition of graft loss related to chronic allograft rejection. Indeed, if you look at survival contingent on 1 year survival, the curves from that point really haven't changed much in the 25 years that I've been involved in the field…If you look at all the organs that we transplant, the 2 that are most susceptible to this and have the worst long term outcomes are the lung and the intestine. I think many of us conjecture that perhaps it's due to the fact that both of these organs are quite complex, and they're both exposed to the external environment.”

Later, McCurry highlighted the increasing level of data looking at the lung microbiome. He noted that this area holds a lot of interest in terms of new research currently.

Lungcast is a monthly respiratory health podcast series from the ALA produced by HCPLive.

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