CF transplant timing not tied to severe COVID-19 outcomes: Study
Poorer lung function before infection more likely to result in hospitalization, death
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In people with cystic fibrosis (CF), the timing of organ transplant — lung, liver, or both — relative to infection with the SARS-CoV-2 virus that causes COVID-19 did not affect the risk of severe outcomes, according to a large international study.
Patients with poorer lung function before infection, however, were more likely to be hospitalized or die, suggesting they may need closer monitoring.
The study, “Outcomes of SARS-CoV-2 infection post-solid organ transplantation in the cystic fibrosis population,” was published in the Journal of Cystic Fibrosis.
Studies in lung transplant recipients have reported mixed results
Since the early stages of the COVID-19 pandemic in March 2020, doctors learned that people with chronic lung disease — and those taking immune-suppressing medications, including solid organ transplant recipients — faced a higher risk of severe illness and death after SARS-CoV-2 infection.
Studies in lung transplant recipients have reported mixed results. Earlier in the pandemic, reports suggested high rates of hospitalization and intensive care, especially soon after transplant. More recent data, collected after vaccination, have generally shown improved outcomes and stable lung function.
For some people with CF, a solid organ transplant — most often for lungs, and in some cases the liver — becomes necessary when complications of the disease can no longer be managed with standard treatments. In this study, an international team of researchers that jointly helped form the CF Registry Global Collaboration, which assessed the impact of SARS-CoV-2 infection on the health of people with CF, examined whether the time since a transplant affected the severity of COVID-19 in CF, and whether infection changed lung function over time after a lung transplant.
Nearly 6% of patients were infected within first year after transplant
The team analyzed data collected between January 2020 and December 2021 from 526 CF patients across 19 countries who had received a solid organ transplant and then had a confirmed SARS-CoV-2 infection. Most had received transplants of both lungs (bilateral, 90.9%), while smaller percentages had a combined lung-liver transplant (2.9%) or a liver-only transplant (6.3%). The median time from transplant to infection was 5.8 years, and 5.7% of patients were infected within the first year after transplant.
Because not all countries had complete clinical data, the final analyses included patients from 15 countries in North America, Europe, and Australia.
For the main goal, the analysis included 319 transplanted patients, of whom 130 (40.8%) were hospitalized and 25 (7.8%) died.
Importantly, time from transplant to infection was not associated with a higher or lower risk of hospitalization or death. In contrast, better lung function before infection, as measured by percent predicted forced expiratory volume in one second (ppFEV1), was associated with a lower risk of severe outcomes. ppFEV1 reflects how much air a person can exhale in one second relative to norms.
Through this work, we demonstrated, in a diverse global population, that the timing of transplantation was not significantly associated with hospitalization/death following SARS-CoV-2 infection in the post-transplant CF population. However, lower baseline ppFEV1 was a risk factor for more severe disease, which is noteworthy
Age, sex, race, year of infection, genetic profile, CF-related diabetes, and pancreatic function were not significantly associated with the risk of hospitalization or death. The results were similar when the researchers examined new oxygen needs, intensive care unit admission, or noninvasive/mechanical ventilation to help with breathing.
To assess lung function over time, the researchers analyzed 236 lung transplant patients (lung-only or lung-liver). After accounting for factors such as age, sex, and whether infection occurred in 2020 versus 2021, they found no statistically significant change in the rate of lung function decline after COVID-19 compared with before infection. Adding CF-related diabetes, pancreatic insufficiency, genetic profile, and race did not change the findings.
Overall, the results suggest that, after a transplant, lung health at the time of transplant, rather than the timing of the transplant, may be more important in shaping COVID-19 outcomes in CF.
“Through this work, we demonstrated, in a diverse global population, that the timing of transplantation was not significantly associated with hospitalization/death following SARS-CoV-2 infection in the post-transplant CF population. However, lower baseline ppFEV1 was a risk factor for more severe disease, which is noteworthy,” the researchers concluded.
They added that “future studies are needed to determine the impact of infection on long-term transplant-specific outcomes.”
