Optimal Dose of Stem Cell Infusion

When it comes to stem cell therapy, there's a misconception that throwing more cells at a problem will always yield better results. However, factors such as the quality of stem cells and how they're prepared are much more important when it comes to therapeutic success.

Understanding Passages and Quality

Stem cells are like the body's natural repairmen, capable of regenerating and healing damaged tissues. But not all stem cells are equal. The way they're handled and cultured in the lab can significantly affect their potency and effectiveness.

Passages of the cells

The passage refers to the number of times a cell population has been subcultured or passaged in the laboratory. Each passage involves the process of detaching cells from the culture vessel, usually a flask or a dish, and then reseeding them into new culture vessels to allow them to proliferate further.

Each time stem cells are cultured, they can lose some of their potency. This means that high-passage stem cells, which have been grown and passed through many generations in the lab, may not be as effective as freshly isolated cells:

1. With each passage, there is a risk of genetic and phenotypic drift. This means that cells may accumulate mutations or undergo changes in gene expression patterns over successive passages. These alterations can affect the behavior and functionality of the cells.
2. Passage number can also influence the cellular senescence rate. As cells undergo multiple passages, they may reach a state of replicative senescence, where they lose their ability to divide and function effectively.

Studies have proven that the therapeutic efficacy of low-passage MSCs (passage 3) is much greater than high-passage MSCs (passage 10). These studies found that low-passage MSCs exhibited greater differentiation potential and immunomodulatory effects compared to high-passage MSCs. This suggests that passage number significantly influences the potency and functionality of MSCs in regenerative medicine applications.

Human trials show the importance of passage number in stem cell therapy. In studies focusing on conditions like liver cirrhosis and rheumatoid arthritis, some patients experienced improvements in symptoms and quality of life following the infusion of 200 million high-passage cells, and these results were fairly similar to other patients which received 50 million low-passage cells. This shows that outcomes aren't solely due to the number of cells infused; they're also a result of the strength of the cells.

Quality of the cells

Would you rather eat tons of bad food or the right amount of premium food? When it comes to stem cell treatments, the answer is the same. We want good quality and excellent results, so we need to find the right amount of the best quality.

The quality of cells used in treatments has a huge influence on treatment outcomes. These are the main items to consider:

1. Cell Viability and Functionality: Healthy cells with robust viability possess the metabolic activity and functional integrity needed to fulfill their roles in the body. High-quality cells ensure their survival and persistence post-administration. On the other hand, cells with reduced viability or impaired functionality due to storage issues or suboptimal culture conditions will fail to produce the desired therapeutic effects.
2. Genetic Stability and Integrity:Genetic alterations or mutations in administered cells can lead to adverse outcomes such as abnormal immune responses. High-quality cells maintain genomic integrity, reducing the risk of genetic alterations that could compromise treatment safety and efficacy. Rigorous quality control measures, such as genomic profiling and karyotype analysis, ensure the genetic stability of therapies.
3. Differentiation Potential: Stem cells with strong differentiation capabilities can transform into specialized cell types necessary for tissue repair and regeneration. High-quality stem cells retain their differentiation potential, enabling them to undergo lineage-specific differentiation and contribute effectively to tissue regeneration. Inferior cells may exhibit diminished differentiation capacity, limiting their therapeutic efficacy in vivo.
4. Immunomodulatory Properties: Many cell-based therapies, including those utilizing MSCs, rely on their immunomodulatory properties to modulate inflammatory responses and promote tissue healing. High-quality MSCs exhibit potent immunomodulatory capabilities, secreting anti-inflammatory cytokines and suppressing immune cell activation. These functions are crucial for mitigating inflammation and facilitating tissue repair in various pathological conditions.
5. Consistency and Reproducibility: Variability in cell quality can lead to inconsistent treatment outcomes and hinder the translation of experimental findings into clinical practice. High-quality cells demonstrate consistent performance and reproducible therapeutic effects across patient populations. Standardized manufacturing processes and stringent quality control measures ensure the uniformity and reproducibility of cell-based therapies.

So how many stem cells should I get?

Every condition and patient require different number of cells. Some studies suggest the ideal dose of stem cells is 1 million cells for each kilogram of body weight. But there’s a way to optimize this number:

1. Condition and specific needs of the patient: The same dose of cells can have very different impact on a 45 Kg old person with lung issues, compared to a healthy young 90 Kg person with a knee issue. While an excessively high dose of stem cells will result in a reduced number of effective stem cells migrating to the site of injury, a very low dose of stem cells cannot fully exert the repair effect because there is not enough dose of stem cells to reach the damaged site.

The standard dose of low-passage MSCs in IV is 40 million, and from there the amount will increase or decrease depending on the specific situation.

1. Quality, passage and number of infusions of the cells: For most conditions, fewer high-viability low-passage stem cells are required to achieve great results. The main advantage of working with stronger cells at passage 3 or 4 compared to much higher passages, is that the patient needs less amount of cells. If we consider the possibility of having treatments in various days, the effect of these stem cells can be exponential.

There are studies confirming the higher success rate when splitting treatments throughout a few days. These studies prove that the repeated infusion of stem cells generally achieves better results that a single infusion. Due to the low survival rate of allogeneic cells, the repeated infusion of these cells will lead to higher cell survival efficiency and increase its immunomodulatory effects.

1. Method of infusion: Intravenous infusions of stem cells usually contain higher amounts of cells such as 30, 40, 50 million or more. Intra-articular and intrathecal injections are done with lower amounts, from 5 to 20 million cells depending on the condition.

It’s important to consider the side effects, especially when it comes to local injections of stem cells. Studies have shown that too high dose of cell injections can trigger a strong inflammatory response, thus reducing the repair effect of stem cells.