A sarcoidosis lung transplant brings high hopes for long-term health
New outcomes study finds greater short-term risks but better survival
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People with pulmonary sarcoidosis who undergo a lung transplant face greater short-term risks after surgery but have better long-term survival compared with individuals undergoing the procedure due to other lung conditions.
Those are the key findings of a large U.S. study that investigated outcomes among people for whom the rare inflammatory disease occurs in the lungs and ultimately requires a transplant. The researchers noted in the study that “sarcoidosis is an uncommon indication” for a lung transplant, and had sought to compare outcomes for these patients relative to those with “more common indications.”
According to the researchers, the data show that “lung transplantation is an efficacious treatment for end-stage pulmonary sarcoidosis.” Indeed, for these patients, “long-term survival exceeded that of … recipients” with two other conditions requiring a transplant, the scientists noted.
The study, “Outcomes of Lung Transplantation for Sarcoidosis in the Lung Allocation Score Era,” was published in the journal Clinical Transplantation by researchers in Arizona.
Sarcoidosis is marked by the formation of small clumps of inflammatory cells, called granulomas, in different tissues and organs. It particularly affects the lungs — when it’s then known as pulmonary sarcoidosis — leading to symptoms such as shortness of breath and cough.
Lung transplant may be needed in very severe sarcoidosis cases
Standard treatment for pulmonary sarcoidosis commonly involves corticosteroids and other immunosuppressive treatments. However, in very severe cases, a lung transplant may be required.
Previous studies have suggested that “pulmonary sarcoidosis accounts for a small fraction, 2.5% to 3.3%, of all indications for lung transplantation,” the researchers wrote, adding that “the literature is limited on short- and long-term outcomes as well as risk factors for mortality in this group in the lung allocation score (LAS) era.”
The LAS, used from 2005 to 2023, prioritized patients for transplant based on disease severity and expected survival, and had replaced an older, first-come, first-served method. In recent years, LAS was replaced by the current system, which uses the Composite Allocation Score and was designed to improve organ distribution to make it more equitable.
To assess the old system, a research team from Creighton University School of Medicine in Phoenix retrospectively analyzed data from the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research file.
The team looked for adults diagnosed with one of three lung diseases — pulmonary sarcoidosis, idiopathic pulmonary fibrosis (IPF), and chronic obstructive pulmonary disease (COPD) — who were listed for lung transplant between May 2005 and March 2023. IPF is a condition marked by lung scarring due to unknown causes, and COPD is characterized by chronic lung inflammation.
A total of 25,169 eligible people were identified, of whom 58% had IPF, 37% had COPD, and 5% had pulmonary sarcoidosis. Of the 20,411 patients who underwent the transplant, 59% had IPF, 36% had COPD, and 5% had pulmonary sarcoidosis.
The median waitlist time for people with pulmonary sarcoidosis — 79 days — was longer than for IPF patients, who waited a median of 33 days, but shorter than for those with COPD, who were on the waitlist for a median of 85 days.
While waiting for a transplant, the mortality was lower in the pulmonary sarcoidosis group than the IPF group (13.7 vs. 26.7 deaths per 100 person-years), but higher than the COPD group (5.5 deaths per 100 person-years). Person-years considers the number of participants and their follow-up time. For instance, a 13.7 mortality rate means that for each 100 patients followed up for one year, 13.7 patients died.
Among those who underwent transplant, pulmonary sarcoidosis patients were significantly younger than those in the other two groups (55 vs. 62-64 years), and significantly more likely to be Black individuals (63% vs. 6%-8%).
Those with sarcoidosis also had significantly higher blood pressure in vessels that supply the lungs (34 vs. 24-25 mmHg) and were significantly more likely to undergo transplant of both lungs (86% vs. 61%-68%).
Long hospital stays, breathing support likely after surgery
After the transplant, pulmonary sarcoidosis patients had significantly longer hospital stays and were significantly more likely to require intensive breathing support. That indicates that pulmonary sarcoidosis patients may have more frequent complications shortly after a transplant, according to the researchers.
Participants with sarcoidosis had significantly worse short-term survival, at one month, three months, and one year compared with those with IPF and COPD. However, “this survival difference disappeared at [three] years posttransplant, and at [five] years, sarcoidosis recipients had better survival than those with COPD or IPF,” the researchers wrote.
These favorable long-term outcomes in the pulmonary sarcoidosis group became more pronounced over time, up to 15 years after the transplant. Still, statistical analyses adjusted for potential influencing factors found no significant difference in mortality between the sarcoidosis group and the other two groups, the researchers noted.
Similar results were seen for graft survival, or when transplanted organs remain functional. On this measure, pulmonary sarcoidosis patients showed lower short-term graft survival, but higher long-term graft survival.
Additional, adjusted statistical analyses showed that high blood levels of creatinine — a marker of kidney damage — at transplant, prior heart surgery, and diabetes were significantly associated with an increased risk of death. In contrast, a better functional status was significantly linked with a lower risk.
“Despite increased [illness around the time of surgery] and worse short-term survival, lung transplant recipients with sarcoidosis experience improved long-term survival comparable to that of COPD and IPF recipients,” the researchers wrote.
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