Stem cells are a special type of cells with unique natural and therapeutic properties. They have a remarkable ability to generate the new functionally active cells for replacement of damaged, dying, ageing or diseased ones. In other words, stem cells can be regarded as a natural physiological and reparative regeneration means offering modern medicine a novel, promising and very effective treatment approach.
While modern medicine has just started to appreciate stem cells as a powerful method of treatment, these cells were used by the nature for human body self-repair throughout all history of evolution. From the evolutionary perspective, trade-off between the increasing demand for highly specialized body structures ensuring adaptation to complex and changing environment and the need for self-repair mechanisms resulted in the development of tissue-specific stem cell system. These cells reside in different body tissues throughout the lifespan. Even the long-existing dogma about impossibility of central nervous system regeneration at the cellular level due to absence of neural stem cells in the brain was challenged by the recent research suggesting the presence of “silent” neural stem cells looking like non-neural cells called astrocytes. Tissue-specific stem cells produce new cells with specific functions of the tissue where they reside. However, the number and functional activity of adult tissue-specific stem cells decline with age making elderly people less protected against diseases and conditions associated with the loss of functionally active cells. Therefore, the goal of the regenerative medicine is restoration of the regenerative potential of the body through administration of stem cells.
Being obviously promising for treatment of a wide range of age-related diseases, stem cells were not in the initial focus for COVID-19 treatment because they do not have direct anti-viral effect. The routine treatment strategy for acute respiratory viral infections includes anti-viral medicines, symptomatic treatment and, in some cases, antibiotics for prevention or treatment of complications caused by pathogenic bacteria.
This situation and attitude to stem cells have changed after recent scientific studies that have demonstrated that in COVID-19 not only the viral load, but also dysregulated host immune response substantially contributes to disease severity.
Infection with coronavirus mediated by interaction between viral S protein and angiotensin converting enzyme 2 (ACE2) on the surface of the cells leads to destruction of cells and release of pathogen-associated molecular patters, damage-associated molecular patterns and inflammatory cytokines. In case of well-orchestrated immune response, attraction of the necessary load of active immune cells into the lungs ensures pathogen clearance and recovery of the patient, whereas dysregulated immune response, which is more common for elderly and immunologically compromised people, leads to overproduction of inflammatory cytokines known as cytokine storm or cytokine release syndrome (CRS). Massive recruitment of immune cells results in the decreased number of lymphocytes in the blood and excessive infiltration of the lungs and airways with immune cells. Excessive activity of the immune cells causes damage to the lung tissue, apart from the direct cell-toxic activity of the coronavirus itself. In severe cases, this leads to the extensive inflammation and fluid accumulation in the lung tissue and airspaces resulting in the decline of the vitally important lung function and decrease in blood oxygen level (saturation).
Report of the Oxford University specialists about the RECOVERY trial demonstrating the significant survival rate increase in severely ill COVID-19 patients due to addition of immunomodulatory medicine to the routine treatment protocol was regarded as an important breakthrough of 2020. At the same time, it should be pointed out that 10 years before publication of this influential report the leading Ukrainian scientists working in close collaboration with the founders of the Infinity Clinic in the government-funded scientific research aiming to study mechanisms of severe acute viral lung diseases suggested that immunomodulation should increase positive outcomes in such illnesses. Results of their work were presented at the scientific meeting held in Kiev, Ukraine (2010) by the government, leading academic research institutions of Ukraine and founders of the Infinity Clinic with the goal to improve the recovery of the patients with severe acute viral lung disorders.
After worldwide recognition of the immune-targeting treatment effectiveness in severe cases of COVID-19 preceded by the rationale of anti-inflammatory treatment in severe acute viral respiratory disorders provided by the Ukrainian scientists, stem cell therapy, due to its high immunomodulating potential, received considerable attention and high regard of medical scientific world fighting COVID-19 pandemic.
In 2004, the article published by the Infinity Clinic scientists in the Ukrainian Journal of Transplantology presented evidence about prominent immunomodulatory properties of stem cells. In the following decades, mechanisms of stem cell-mediated immunomodulatory action were the subject of the intensive research in stem cell-focused laboratories all over the world. Joint international effort of stem cell-scientists resulted in the acknowledgement of the fact that stem cells do produce a variety of anti-inflammatory cytokines suppressing overactivity of body cells. Additionally, they facilitate regeneration through the release of factors transforming the functional mode of certain subpopulations of immune cells from inflammatory to regenerative, such as M2 macrophages and Treg cells.
Thus, thank to scientific research on COVID-19 pathogenesis and properties of stem cells, stem cell therapy has emerged as new and highly promising approach for treatment and rehabilitation of severe cases of COVID-19. However, it is obvious that prevention of severe COVID-19 effects and complications is much better than long-lasting treatment and prolonged rehabilitation. This taken into consideration, specialists of the Infinity Clinic have developed and are offering stem cell treatment program aiming at decreasing the risk of severe and life-threatening COVID-19 effects and complications in case of coronavirus infection contraction and as well as the one for quick and the most effective restoration after the disease.
