Stem Cell Treatment for Arthritis

Mesenchymal stem cells have been shown in recent studies to have significant effects on a variety of conditions including both rheumatoid arthritis and osteoarthritis. As the mechanisms behind these two forms of arthritic degeneration differ, the potential stem cell treatment for arthritis is likely to be administered differently and make use of a variety of properties of stem cells, such as their regenerative abilities, and the capacity for some stem cell types to help regulate immune function. Patients undergoing stem cell treatments for unrelated conditions have reported significant relief from their arthritis after such therapy even though this was not the reason for them obtaining treatment initially; these stories are anecdotal however, and do not constitute evidence for applying treatment more widely. Intravenous stem cell therapy using haematopoietic stem cells has been used extensively in veterinary medicine for a number of years. Often, stem cell treatment for arthritis in companion animals and race horses with signs of the condition (both rheumatoid and osteoarthritis) direct injections of stem cells into the damaged joint have proven effective at inhibiting the autoimmune attacks consistent with RA, reducing inflammation and pain in the joint, and supporting active tissue regeneration.

Stem Cell Treatment for Arthritis brings hope to millions suffering from arthritic conditions

The conditions under which stem cells are implanted appear to make all the difference between active regeneration and hypertrophy of joint tissue. Researchers are wary of the ad hoc use of stem cells for joint repair as it may be that the growth encouraged by stem cells may be adversely influenced by pre-existing pathology in an arthritis patients joints leading to exaggerated tissue growth that may further exacerbate the problems. Using a small number of chondrocytes alongside mesenchymal stem cells may make a significant difference in cultivating healthy cartilage repair without hypertrophy (excessive growth) occurring (Aung, et al, 2011).

A further study by Abedi (et al, 2010) appears to show that the use of scaffolding material alongside mesenchymal stem cell administration improves the healing process in induced articular cartilage defects in animal models (rabbits) in comparison to the stem cells alone. By encouraging differentiation into cartilage tissue types the almost universal progression of articular cartilage damage to osteoarthritis could, theoretically, be prevented using stem cell therapy. MSCs from osteoarthritis patients used in research has also led to the development of intelligent surfaces which can effectively prevent hypertrophy of such stem cells in the laboratory whilst facilitating cartilage regrowth (Petit, et al, 2011); further research in vitro is required to assess their use for therapeutic purposes however. A review of current research into synoviocytes and chondrogenesis has also highlighted a potential source of stem cells which may actively aid repair of avascular meniscal injuries that are otherwise unresponsive to treatment and commonly lead to osteoarthritis (Fox, et al, 2011).

Mesenchymal stem cells, which can differentiate into bone, cartilage, and a number of other cell types appear to hold great potential for easing osteoarthritis joint pain and possibly regenerating damaged tissue. However, MSC therapy alone is unlikely to address the systemic issue of autoimmune rheumatoid arthritis. Just as haematopoietic stem cells can help combat leukaemia, their use following myeloablation (the destruction of the bodys immune-forming cells in the bone marrow) looks promising for treatment of RA (Sykes, et al, 2005).

A study by Bhattacharya (et al, 2001) to test the safety of using umbilical cord blood for those with a variety of conditions found that the transfusions were well tolerated by all 62 of the patients and that the cord blood had the advantages of a higher oxygen carrying capacity, many growth factors and cytokines, and was also less likely to cause an immune reaction than adult whole blood transfusions. The study did not aim to assess the potential benefits of the stem cell treatment, only the safety of such procedures for those with rheumatoid arthritis, arthritis in the neck, ankylosing spondylitis, and systemic lupus erythematosus, amongst other conditions.

The ability to derive stem cells from patients themselves is also opening up a whole new realm of possible treatments which do not require the use of human embryonic stem cells or cord blood stem cells which are less readily available and mired in some ethical controversy. Autologous stem cell transplants are also advantageous as they do not trigger an immune response causing rejection of the material in the body; immunosuppressant drugs are, therefore, not necessary. Jorgensen (et al, 2004) stated that mesenchymal stem cells appeared to be good candidates for the regeneration of arthritic tissue and that more research was required to assess their viability. This research has been carried out in subsequent years by a whole host of scientists such as Mao (2005), Gonzlez (et al, 2009), and Tyndall (et al, 2010).

Some studies have looked at animal models with induced rheumatoid arthritis and their reaction to mesenchymal stem cell transplantation. Across a number of studies the effects have been positive, with the Th1-induced autoimmune response down-regulated by the stem cell treatment. Human adipose-derived mesenchymal stem cells also decreased inflammatory cytokines and chemokines in the mouse models and actively increased the production of antiinflammatory substance interleukin-10 in lymph nodes and joints. A, perhaps unexpected, benefit of human AD-MSCs was the de novo generation of antigen-specific CD4+CD25+FoxP3+ Treg cells, which were then able to suppress those immune system cells which react against the bodys own tissue.

According to Passweg and Tyndall (2007), more than a 1000 patients with autoimmune diseases have been treated with haematopoietic stem cells between 1996 and 2007. Most of these patients had Multiple Sclerosis, systemic lupus erythematosus, RA, or systemic sclerosis and many of those treated have enjoyed long-term disease-free remissions and immune reconstitution since treatment. Unfortunately, there remains a risk of treatment related mortality with such stem cell therapy as it relies on the destruction initially of the patients immune system in order to reset it with the infused stem cells and remove the autoimmune components. This temporarily opens the patients up to increased risks of infection which can be fatal. Improvements in patient care during the treatments have reduced this risk substantially, but it is still a major consideration, particularly for those otherwise doing well on conventional medications. Tyndall and Laar (2010) found that incomplete, low immunoablative intensity, early conditioning was related to patient relapse. This is most likely due to residual lesional effector cells; the patients faulty immune system effectively repopulated itself with self-reactive immune cells when only partially destroyed by initial myeloablative treatment.

Read this article:
Stem Cell Treatment for Arthritis