LAS System May Fail to Identify Sarcoidosis Patients at Urgent Need of Lung Transplant, Study Finds

LAS System May Fail to Identify Sarcoidosis Patients at Urgent Need of Lung Transplant, Study Finds

The current scoring system used to assess the urgency of lung transplants, called LAS (lung allocation score), fails to predict the risk of death in people with sarcoidosis, a single center study suggests.

The study “Mortality for sarcoidosis patients on the transplant wait list in the Lung Allocation Score era: Experience from a high volume center” was published in the journal Respiratory Medicine.

Over 90% of sarcoidosis patients have impaired lung function, but symptom progression to a risk of death is seen in less than 10% of the cases. About 2.5% to 3.5% of referrals for a possible lung transplant are people with advanced pulmonary sarcoidosis, its researchers noted.

LAS is a measure used to set priorities on lung transplant waiting lists. Established in 2005 by the Organ Procurement Transplantation Network (OPTN), it uses a score from zero to 100 that takes into account the level of lung impairment, and not the time on the list.

Mortality in pulmonary sarcoidosis was determined before the establishment of LAS. But, “during the initial development of the LAS, sarcoidosis data was too sparse to develop disease-specific prognostic factors and therefore [this population] was grouped with COPD (termed Group A) or idiopathic pulmonary fibrosis (IPF),” the study said.

Researchers at the Lewis Katz School of Medicine at Temple University, in Philadelphia, looked at how well LAS predicts lung function decline and mortality risk in sarcoidosis patients.

The team reviewed data from 28 sarcoidosis patients referred for double lung transplant at Temple University Hospital between March 2012 and February 2019.

Results showed that 22 patients survived the transplant, and six died while on a waiting list. This corresponds to a mortality rate of 18.2%. Among the six patients, one died of respiratory failure, one due to ventricular arrhythmia, and one experienced respiratory distress at home. The remaining three patients had no conclusive cause of death since no autopsy was performed.

When researchers compared mortality rates to people diagnosed with chronic lung diseases at the same institute, namely IPF and chronic obstructive pulmonary disease (COPD), they saw that these rates were lower: 12.3% among IPF patients, and 8.7% for COPD patients during the study period.

Median survival rate of sarcoidosis patients who underwent transplant was 70 months, similar to that of other indications.

The LAS scores from patients who survived the transplant showed no significant differences to those who died on the waiting list, with both having a score of 41.

However, lung function markers of advanced lung scarring were associated with a higher death risk on transplant list. Specifically, a low diffusion capacity of the lungs for carbon monoxide (DLCO, 21% or less), and an elevated Composite Physiologic Index (CPI, 67.7% or more) were significant predictors of death among transplant patients.

“Our analysis suggests severe interstitial disease at baseline predicts mortality in this population, and is not necessarily captured by the LAS system. We found that markers of advanced fibrotic disease burden, such as low DLCO and high CPI, were statistical predictors of death, as has been previously observed in non-transplant population,” the researchers wrote.

The levels of bilirubin (the result of the breakdown of red blood cells) had the highest predictive value for death among patients on the transplant list — bilirubin of 0.35 mg/dL or below was the cut-off value to identify those at risk of death with 100% sensitivity.

Overall, the team concluded that “sarcoidosis patients on the lung transplant wait list experience a high mortality, even exceeding mortality for IPF patients at our center. The listing LAS and change in LAS did not predict death.”

Given the results, the researchers suggested that “reconsideration of current referral and transplant candidacy listing recommendations for advanced pulmonary sarcoidosis may be warranted.”

Patricia holds her Ph.D. in Cell Biology from University Nova de Lisboa, and has served as an author on several research projects and fellowships, as well as major grant applications for European Agencies. She also served as a PhD student research assistant in the Laboratory of Doctor David A. Fidock, Department of Microbiology & Immunology, Columbia University, New York.
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Patrícia holds her PhD in Medical Microbiology and Infectious Diseases from the Leiden University Medical Center in Leiden, The Netherlands. She has studied Applied Biology at Universidade do Minho and was a postdoctoral research fellow at Instituto de Medicina Molecular in Lisbon, Portugal. Her work has been focused on molecular genetic traits of infectious agents such as viruses and parasites.
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Patricia holds her Ph.D. in Cell Biology from University Nova de Lisboa, and has served as an author on several research projects and fellowships, as well as major grant applications for European Agencies. She also served as a PhD student research assistant in the Laboratory of Doctor David A. Fidock, Department of Microbiology & Immunology, Columbia University, New York.
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One comment

  1. Alan Bart Cameron MD says:

    When I went on the waiting list for pulmonary transplant my scores were DF 25% PFT also about 35%- dyspnea with talking. After long use of high dose steroids— my DF rose to 85% or more, and PFTs are in the low normal range.. without a transplant. My sarcoidosis is not gone however I am no longer on the transplant list. The thought of a transplant really scared me— but now it looks like it would be really remote now. The waiting list at that time was institution specific, and most people would die waiting for a lung. You had to move to Palo Alto so you could be available if a lung happened to show up. You had to be pretty sick to get on the list, and couldn’t get too sick to stay on it. I am now getting off the steroids and have lost #160 and able to go off insulin, and most other meds for diabetes. Last PET scan shows lots of “hot spots” and biopsy of chest node shows typical sarcoidosis. I am happy to see that someone is actually looking at this issue.

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