Stem Cell Therapy and ARDS
Acute respiratory distress syndrome, or ARDS, was a relatively rare condition until the advent of the novel coronavirus and COVID-19. Prior to the global pandemic of 2020, ARDS affected fewer than 200,000 individuals per year, but that number has risen significantly.
What Is ARDS?
ARDS is an acronym for acute respiratory distress syndrome. It’s also known as acute lung injury and noncardiac pulmonary edema. The National Heart, Lung, and Blood Institute defines it as,
“a serious lung condition that causes low blood oxygen. People who develop ARDS are usually ill due to another disease or a major injury. In ARDS, fluid builds up inside the tiny air sacs of the lungs, and the surfactant breaks down. Surfactant is a foamy substance that keeps the lungs fully expanded so that a person can breathe.”
What Causes ARDS?
As mentioned, those who develop ARDS usually have another injury or health condition that precipitates the condition. The American Lung Association states,
“Acute respiratory distress syndrome (ARDS) usually occurs when our lungs are severity injured, often by infection or trauma”.
COVID-19 is just such an infection, which is the reason that many patients struggling with the virus eventually develop ARDS. The American Lung Association goes on to explain that while ARDS usually results from another condition, that specific condition is not always clear or definable.
However, some of the most common conditions known to result in ARDS include the following:
- Blood transfusions
- Chest injuries
- Head injuries
- Inhaling harmful substances
What Are the Symptoms of ARDS?
ARDS causes fluid to leak into the lungs, which can lead to a wide range of symptoms, including the following:
- Shortness of breath
- Reduced blood pressure
- Exhaustion/extreme tiredness
- Labored breathing
- Unusually rapid breathing
Note that the symptoms of ARDS can vary significantly from patient to patient, and even with the same patient over time. In addition, the intensity of symptoms can vary depending on the underlying cause and whether there is any preexisting lung or heart disease.
Who Is Most at Risk for ARDS?
ARDS primarily affects patients who are already critically ill, the majority of whom are hospitalized at the time it develops. However, because of their existing illness, these patients are at particular risk from the disease. In addition to critically ill patients, others who are most at risk include the following:
- Those suffering from chronic alcoholism
- Those with sepsis
- Elderly patients
- Patients with a history of tobacco use (not just smoking)
- Those who have undergone high-risk surgery
- Those with chronic lung disease
- Those with a history of illicit drug use
- Those with genetic lung conditions
What Are the Common Treatments for ARDS?
The primary concern with ARDS is the lack of oxygen entering the body due to the presence of fluid in the lungs and the breakdown of the surfactant that enables lungs to remain inflated. The most common treatment for ARDS is oxygen therapy via nasal tubing, a face mask, or a throat tube. Many patients will be treated with non-invasive ventilation, but severe cases will require the patient to be placed on a ventilator.
In addition to oxygen therapy, some medications may be used to help alleviate symptoms and/or to treat the underlying condition causing ARDS. Some of the more commonly used medications include the following:
- Acid reducers
- Blood thinners
- Muscle relaxants
- Pain medications
What Role Might Stem Cells Play in Treating ARDS?
While oxygen therapy provides hope for some patients, ARDS is often fatal. Even in cases where patients survive, they may be left with serious complications, including life-threatening blood clots or lung scarring, or they may be at greater risk for additional infections. Survivors also frequently report ongoing breathing problems, reduced cognitive ability, reduced energy levels, and depression. Because of this and the increasing number of ARDS patients due to the global COVID-19 pandemic, stem cells are being researched for their use in treating ARDS.
Several studies have been conducted using mesenchymal stem cells to treat ARDS with positive results. In one study, published in the journal Respiratory Research in 2014, 12 adult patients were given stem cell therapy. The results were positive, with a reduction in serum SP-D levels at day five in comparison to day zero, and reduced IL-6 levels.
Another study, published in the American Journal of Respiratory and Critical Care Volume (196, Number 3, August 1, 2017), found that
“cell-based therapies offer promise for the treatment of ARDS,”
although the authors noted at the time that additional studies were necessary.
A third study, this one published by the National Institutes of Health in January 2015, found that a primary infusion of mesenchymal stem cells resulted in favorable changes in LIS and SOFA scores for several patients receiving higher doses of stem cells and inflammation markers reduced across all patients.
Allogeneic Stem Cells versus Autologous Stem Cells
In the realm of stem cell therapy, there are two types used. Autologous stem cells are sourced from the patient’s own body, while allogeneic stem cells are sourced from banked umbilical cord blood and tissue.
Of the two, allogeneic stem cells show the greatest promise in therapeutic use. Autologous stem cells are the same age as the patient, and often have significant accumulated damage and mutations that limit their ability to multiply and change into other types of cells. Considering ARDS patients are often elderly, their stem cells should be considered insufficient.
In comparison, allogeneic stem cells are youthful and highly energetic. They are easily able to multiply and transform into multiple types of tissue, including lung tissue. This makes allogeneic stem cells better suited for therapy with ARDS patients.
While all stem cell therapy in the US is considered experimental, and no such therapy has been endorsed by the FDA, there may be hope for ARDS sufferers. Patients are urged to work with a physician experienced in using allogeneic stem cells and who has significant experience with this form of treatment.