Since the coronavirus (COVID-19) pandemic emerged, medical researchers and biotech companies around the world have raced to find a solution. While vaccines and antiviral drugs have stolen most of the media spotlight, there is another type of treatment being studied.
Off-the-shelf stem cell therapies may balance and heal the immune system, so now researchers are testing whether or not stem cells treat COVID-19 infections. This includes cases of Acute Respiratory Distress Syndrome (ARDS), a deadly consequence of severe lung inflammation that kills by depleting oxygen. ARDS has rapidly gained attention in recent months as a complication of COVID-19, although it has a wide range of potential causes, including respiratory infections and trauma.
What Are Stem Cells?
Stem cells are undifferentiated cells with two key features: greater capacity for self-renewal and the ability to transform into specific cell types. These properties have created so much hope that degenerative illnesses, serious injuries, and aging itself could be reversed.
But while embryonic stem cells (ESCs) were common in early research, they carry ethical and safety issues. Not only is there the question of whether researchers are killing unborn babies, but ESCs have also been linked to some unwanted health effects like growing tumors.
Adult mesenchymal stem cells (MSCs) are safer and can be isolated from bone marrow, fat tissue, umbilical cords, or menstrual blood. Currently approved stem cell therapies are mostly for rare and serious blood disorders. You only have a 0.46 percent chance of having an approved stem cell treatment by the age of 70.
However, clinical trials for a wider range of conditions are booming worldwide. These include motor neuron disease, age-related frailty, and retinitis pigmentosa. Additionally, more celebrities such as Mike Tyson and Madonna are coming forward with their use of off-label stem cell treatment to heal injuries.
Can Stem Cells Treat COVID-19?
As of mid-2020, the two companies most advanced in their clinical trials are Athersys and Mesoblast. Athersys already has recorded positive results for the use of stem cell therapy in COVID-19 induced ARDS. There results include a lower mortality rate and faster, superior recovery. In late April, Mesoblast revealed that 83 percent or 10 of 12 patients with moderate to severe ARDS survived. This is compared to a 12 percent survival rate among similar cases in New York.
Both Athersys and Mesoblast have now moved onto phase II/III clinical trials. Phase III is the final stage before market approval for new treatments. Hope Biosciences is running three-phase II trials for prevention and treatment. One preventive trial is for frontline healthcare workers and first responders. The other is for people over 50 or with pre-existing conditions.
A successful pilot study from China involving seven hospitalized COVID-19 patients and three untreated controls has already been published. Two patients were moderately serious cases; the other five were severe, including one “critically severe” 65-year-old man. All seven recovered and three were discharged, while one control patient died. Another condition deteriorated into ARDS.
Early research in the UAE tested another type of stem cell treatment. Here, the patients’ own stem cells were extracted, activated, and inhaled in a mist. All 73 patients had moderate to severe COVID-19 symptoms, and all were successfully treated despite one-quarter being in intensive care. Dr. Fatima al-Kaabi said in early May that it could be brought to market in three months if the following trials are successful.
How Stem Cells Could Bring ARDS Under Control
ARDS is caused by a buildup of fluid (edema) in the lungs, leading to reduced oxygen and increased carbon dioxide concentrations. Pneumonia, including that from severe COVID-19 infection; sepsis; injury and inhaling stomach contents can all cause ARDS. Tissue damage accompanies this fluid accumulation, and the immune system creates both during the inflammatory response.
If we leave it alone, the repair is difficult because the lungs are unable to produce their protective surface coating or remove the fluid. The current treatment of ARDS mainly consists of support with a ventilator. Mortality rates are still high, due in part to ventilator-induced lung injury. Ventilators can injure lungs by over-stretching them through repeated opening and collapse of the air sacs where oxygen exchange takes place. This is a more common problem in severe COVID-19 infections, as lung damage is patchy in these cases.
Stem cells could be a more effective, active therapy than supportive care alone. The authors of the Chinese pilot study describe stem cells as able to trigger tissue repair, relieve inflammation, and improve the immune response. They produced high amounts of anti-inflammatory chemicals and growth factors and restored the balance of immune cell types.
Additionally, they showed signs of being able to transform into alveolar cells. These form the lungs’ tiny air sacs where oxygen is exchanged for carbon dioxide. The stem cells did not express the ACE-2 receptor, the point of entry for some coronaviruses such as COVID-19.
Optimizing Our Stem Cells’ Health
Stem cells are at work inside our bodies all the time. Even if you aren’t participating in a clinical trial or having off-label treatment, it’s important to consider the health of your stem cells. The most accessible way to boost them is physical activity, which leads to a short-term rise in partly differentiated stem cells responsible for repairing blood vessels. After a heavy workout, a group of 22 volunteers showed a four-fold increase in these cells and higher levels of growth factors.
Stem cells are harmed by inflammation, which impairs their survival, growth, and differentiation. They also require a high antioxidant status to survive and function, with glutathione (the “master antioxidant”) potentially able to improve stem cell potency. Glutathione status is even more important when it comes to preventing pneumonia, as a deficiency is associated with this condition. Older adults and those with chronic illnesses are most at risk. Additionally, a lab study found that the anti-inflammatory, antioxidant spirulina was able to protect stem cells in the brain.
Do Stem Cell-Enhancing Supplemental Blends Work?
There are several supplemental blends on the market claiming to enhance the function of our stem cells. But do they work?
The evidence so far is still relatively early-stage but looks promising. When the same study above on spirulina and stem cells combined it with a branded blend of blueberry extract, green tea extract, carnosine, and vitamin D3, it increased the growth of blood-forming stem cells.
Another blend combines vitamin D3, beta-1,3-glucan, and ellagic acid with a fermented mix of green tea, goji berry, and astragalus extracts. A small trial of 18 volunteers found that this supplement increased circulation of blood-forming stem cells, with effects lasting for several days. It was less potent than a pharmaceutical stimulant, and therefore likely safer for long-term use.
Boosting cellular energy production may be another way to improve stem cell function. Animal research demonstrated that nicotinamide riboside, a derivative of vitamin B3, helped restore aging stem cells. It prevented deterioration of muscle, brain, and skin stem cells by replenishing NAD+, another product of vitamin B3 used to generate cellular energy. However, more human clinical trials are necessary for this and other potential supplements described above.
Stem cell therapy has progressed from controversy to advanced clinical trials in recent years. If stem cells treat COVID-19 too, the pandemic may turn out to be an example of turning crisis into opportunity. They could go a long way in preventing and treating serious respiratory infections. Their regenerative, anti-inflammatory properties are holistic and versatile instead of microbe-specific, which may open many possibilities in the near future.