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Stem cells: A possible treatment for severe respiratory failure, a COVID-19 complication

New study to test stem cells’ ability to treat patients with acute lung injury

New clinical trial aims to boost survival chances for patients with acute respiratory distress syndrome

(SACRAMENTO) — UC Davis Health scientists have joined a landmark multicenter clinical trial to test whether a type of stem cell may help reduce inflammation in the lungs of patients with acute respiratory distress syndrome (ARDS), a life-threatening lung injury. They will study the potential role these cells play in reducing the severity of ARDS in patients with and without COVID-19.


New study to test stem cells’ ability to treat patients with acute lung injury

The phase III trial, sponsored by the U.S. Department of Defense and the California Institute of Regenerative Medicine (CIRM), is led by Michael Matthay, a professor of pulmonology at UCSF. At UC Davis Health, it is co-managed by critical care specialists Rachael Callcut, associate professor of surgery and vice chair of clinical sciences, and Timothy Albertson, chair of internal medicine and professor of pulmonology.

Mesenchymal stromal cells, a type of stem cell, are found in the bone marrow. In laboratory testing, these cells have shown potential benefits for treating lung failure from ARDS. Two prior safety trials, completed in 2015 and 2018, indicated the cells are safe. The current study is to see how effective the cells are for ARDS treatment.

“We will test if these cells can reduce inflammation associated with ARDS and help damaged lungs to repair themselves,” said Callcut. “The aim is to give extremely ill patients an increased chance of survival.”

The deadly outcome of acute respiratory distress syndrome

Patients with ARDS have difficulty breathing. Their lungs fill with fluids, blocking oxygen from getting into the body. Without enough oxygen, the body can begin to shut down, leading to death.

There are many causes for ARDS, such as traumatic injury and pneumonia - including those associated with COVID-19. Once a patient develops ARDS, their risk of death becomes high. The mortality rate among trauma patients is three times higher in those who develop ARDS than those who do not. The mortality rate is at least 40% among COVID-19 patients who develop ARDS.

“For ARDS, aside from supportive care with lung-protective ventilation, there are virtually no treatments that reduce mortality,” Callcut said. “This is why this trial is so important.”

The researchers hope that the cell infusion could decrease the severity of ARDS and lead to improved health outcomes.

The UC Davis Health team recently enrolled their first patient for this trial. Recruitment continues among hospitalized patients with significant lung failure due to infection, trauma or other acute illness.

“We are fortunate to work on this trial with our partners at the CIRM Alpha Stem Cell Clinic at UC Davis,” Callcut said. “We are especially excited to bring this potential therapy for COVID-19 patients to UC Davis.”

For more information, contact Callcut at