Fewer women receive lung transplants despite policy changes, study finds

New research from UCLA Health reveals that women continue to face barriers in accessing lung transplants compared to men, despite recent national policy changes aimed at making organ distribution more equitable.

“Female lung transplant candidates have historically faced unique challenges in organ allocation due to a combination of biological and social factors,” said Dr. Abbas Ardehali, director of the UCLA Heart, Lung, and Heart-Lung Transplant Programs at UCLA Health and senior author of the study, published in the Annals of Thoracic Surgery.

Women often have a smaller body size, which limits the number of donor lungs that are physically compatible. They are also more likely to develop antibodies from prior pregnancies, blood transfusions, or autoimmune conditions, making it harder for their bodies to accept many potential donor organs. Together, these factors significantly narrow the pool of compatible donors, Ardehali said.

Efforts to reduce these disparities have been ongoing. The Lung Allocation Score (LAS) system, introduced in 2005, prioritized transplants based on medical urgency but did not fully account for biological differences that affect women.

To improve fairness, the Organ Procurement and Transplantation Network (OPTN) implemented the Composite Allocation Score (CAS) system in March 2023. The new system added variables such as height, blood type, and immune sensitivity to better match donors and recipients.

However, researchers found that even with this improved system, inequities remain. Before CAS was implemented, women were 32% less likely than men to receive a lung transplant. After CAS went into effect, women were 16% less likely to undergo transplantation.

“There was a modest improvement in narrowing the gap, but we still have a lot of work to do,” Ardehali said. “Further refinements to the scoring system are needed to ensure a fair and effective organ allocation system for all patients, regardless of gender.”