Researchers have determined that two commonly used stem cell treatments, often considered interchangeable, contain distinct types of cells.
Researchers from the University of California San Diego discovered that two frequently used stem cell therapies actually consist of different cell types. This challenges the prevailing idea that one type of cell can treat all orthopedic conditions and underscores the importance of thoroughly understanding and characterizing injectable stem cell therapies before they are used on patients.
The study examined the cell populations of autologous bone marrow aspirate concentrate (BMAC) and adipose-derived stromal vascular fraction (ADSVF) from the same individuals. Both therapies, derived from a patient’s own cells (bone marrow for BMAC and adipose tissue for ADSVF), are believed to contain mesenchymal stem/stromal cells (MSCs) that can develop into muscle, bone, and other tissues.
Despite their similarities, these two therapies are often promoted as interchangeable “stem cell therapies” for various musculoskeletal and skin conditions, particularly among professional athletes. However, limited research has been done to analyze the composition and biology of these therapies, hindering thorough clinical investigations into their optimal dosages. This lack of information has led to misinformation in the marketing of these treatments within the lucrative $11.9 billion stem cell industry.
In an effort to address this gap, the researchers examined 62 BMAC cell populations and 57 ADSVF populations to create a detailed cellular atlas showing the cell types, active genes, and present proteins in each therapy.
The atlas indicated that BMAC had very low concentrations of MSCs, and overall, both therapies lacked comparable “stem cell” types. Their compositions differed significantly; BMAC consisted mostly of red and white blood cells, while ADSVF mainly contained connective tissue cells. Furthermore, many proteins associated with regenerative properties were either absent or present in very low amounts in both therapies, raising doubts about their effectiveness and mechanisms of action.
In addition to offering a valuable resource for researchers, the results underscore the need for a more comprehensive definition of the active components in biological therapies like BMAC and ADSVF. They also propose a shift towards standardized cell therapies with accurately quantified clinically necessary cell and protein concentrations.
The study is set to be published on July 12, 2024, in Science Advances, led by Dr. Sam Ward, a professor of orthopedic surgery, radiology, and bioengineering at UC San Diego, and Dr. Severin Ruoss, a project scientist in orthopedic surgery at the same institution.
