Kathleen Ramos, MD, MS

Kathleen Ramos, MD, MS

Kathleen Ramos, MD, MS

A study led by a CHEST Foundation grant recipient showed that individuals with cystic fibrosis (CF) who are underweight are less likely to receive referrals for critical lung transplants, even though they have similar rates of post-transplant success as other patients with lung disease.

Principal investigator, Kathleen Ramos, MD, MS, used the findings to help increase access to transplants for underweight patients with CF.

As an Assistant Professor at the University of Washington, Dr. Ramos studies the health outcomes of individuals with CF. When she received a research grant from the CHEST Foundation in 2019, she was in the middle of career development awards from the National Institutes of Health and the Cystic Fibrosis Foundation.

“I was thinking a lot about the timing of lung transplant referrals and barriers to referral and transplant,” she said. “The thought process for the research grant was evaluating body mass index in people with cystic fibrosis and its implications for lung transplant referral and listing, and then outcomes after lung transplant.”

The dilemma of transplant referral

Lung transplants can be lifesaving for patients with CF, but the opportunities to receive one are limited.

Before a patient can be considered for placement on the transplant registry, a CF care center must evaluate and refer them to a transplant program. Patients are assessed in many ways, including their likelihood of having a successful transplant outcome.

At this stage, many individuals with CF face a nearly impossible situation. End-stage CF often causes patients to lose a lot of weight, but low BMI typically has been considered a contraindication to lung transplant. Low weight can present concerns about a patient’s likelihood of post-surgery success, and they may be denied a referral to a transplant program.

“Because of this potential contraindication, sometimes the cystic fibrosis program does not even send the person to lung transplant programs because they know—or they think they know—that lung transplant programs will turn down their patients for transplant,” Dr. Ramos said.

Evidence of post-transplant success

Using the grant funding, Dr. Ramos hired a statistician to merge data from the Cystic Fibrosis Foundation Patient Registry and the United Network for Organ Sharing transplant database.

The data showed that underweight individuals with CF were less likely to be referred or listed for lung transplant in the United States from 2005 to 2015.

Dr. Ramos’s findings also provided evidence that underweight patients should be considered for transplant despite low BMI. Her analysis revealed that these individuals had similar or better rates of post-transplant survival compared with patients with other lung diseases.

“We found that the survival after lung transplant—even for the lowest weight patients—was an acceptable level of survival. It was at or above the survival values seen for other lung disease diagnoses that get transplanted,” she said.

Influencing referral decisions worldwide

During the last 3 years, results from the study have been published by the journal CHEST^®, Journal of Cystic Fibrosis, and Annals of the American Thoracic Society.

Dr. Ramos also used the data to help develop the International Society for Heart and Lung Transplantation’s 2021 consensus document for the selection of lung transplant candidates. She helped draft a recommendation that individuals with CF who have malnutrition shouldn’t be denied from lung transplant solely due to their low weight.

“The work from this grant was important when we wrote the expert consensus recommendations for the international transplant community. It’s an impactful document because of how often it’s used clinically and how often it’s cited,” she said. “[The grant] was an excellent opportunity to investigate the effects of low BMI on access to transplant.”

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