Are there stem cell therapies available for arthritis?
Currently, there are no Health Canada or U.S. Food and Drug Administration approved stem cell therapies for treating arthritis. Patients researching their options may come across companies with Web sites that say otherwise and offer fee-based stem cell treatments. Many of these claims are not supported by sound scientific evidence, so patients are encouraged to review some of the links below before making crucial decisions about their treatment plan.
For more about stem cell clinical trials for arthritis click here. (For printed version: http://1.usa.gov/1O6onFa)
How close are we? What do we know about arthritis?
- There are over 100 different conditions that could lead to arthritis, which means “inflammation of the joints.”
- Arthritis is categorized as degenerative or inflammatory.
- The most common degenerative form is osteoarthritis. Primary osteoarthritis is linked to genetic or familial factors while secondary osteoarthritis is associated with mechanical stresses from deformity, misalignment of limbs or acute injury.
- The most common inflammatory form is Rheumatoid arthritis, caused by an autoimmune attack on the lining of the joints. Scientists think genetic and environmental factors are also involved. Other types of inflammatory arthritis are lupus, ankylosing spondylitis, psoriatic arthritis, juvenile idiopathic arthritis, and gout.
- Arthritis can affect people of any age and ethnicity, but the hardest hit are people over 60.
- Osteoarthritis is on the rise in West, in part because of the aging population but also because of obesity, which strains the joints by increasing the load they carry.
- The underlying symptoms of arthritis are chronic pain in the joints, muscles and bones, stiffness and swelling.
- Treatments for arthritis aim to alleviate pain and minimize loss of function. Exercise improves muscle strength and conditioning, drugs reduce inflammation and control pain, and surgical procedures realign, redesign, or replace damaged joints. autologous chondrocyte implantation (ACI), a cell transplant therapy using the patient’s own cells, is also now widely used to replace cartilage, the paper-thin tissue layer that covers joints and eases the friction between moving joints.
- The long-term effectiveness of the current treatments is unknown, leaving the door open to exploring other potential therapies like stem cells.
How can stem cells play a part?
The clinical application of stem cells to cure arthritis is some time off, but there are good reasons to think that they could help. Stem cells have anti-inflammatory and regenerative capacities. For example, some stem cells have been shown to dampen the immune system response, inhibit inflammation, stimulate blood vessel formation, repair tissue and help transplanted stem cells to engraft. Stem cells can also make cartilage.
Are there lots of groups working on developing a stem cell therapy?
Many research teams around the globe are working to develop stem cell therapies for arthritis. They are trying to identify how stem cells work, which stem cells are the most anti-inflammatory and are best suited to making chondrocytes (cells found in healthy cartilage), how best to safely administer stem cells, and how to scale up cell numbers for larger trials if they are warranted.
The stem cell field is ready to move forward: there are now better cell culture techniques for growing stem cells into chondrocytes, and researchers have developed bioengineered scaffolds to expand chondrocyte numbers and help them to engraft. Researchers have also learned that some stem cells possess anti-inflammatory properties that might buffer against the immune components contributing to arthritis.
Stem cell research on arthritis is moving down a number of different avenues and some successes have yielded early Phase 1/2 clinical trials using mesenchymal stem/stromal cells to assist cell regeneration and reduce inflammation. Researchers are also investigating the use of or adipose (fat) derived stem cells.
What research is underway?
Before basic stem cell research can be transferred to the clinic for patients, it must be rigorously tested. For arthritis, this involves validating stem cell therapies in animals first and then translating these discoveries to the clinical setting.
Cartilage lining the head of the joints that move (called articular cartilage) lacks both blood vessels and nerves, so it is very slow to repair itself following acute injury or chronic inflammation. Cartilage tissue has a very low cell content, with chondrocytes accounting for only about 5% of the tissue (the remainder is extracellular matrix and water). Stem cells can make chondrocytes and chondrocytes make cartilage, so it makes sense that scientists are trying to find ways to direct stem cells to make patient-derived chondrocytes for transplanting.
Current research using mesenchymal stem/stromal cells
Mesenchymal stem/stromal cells (MSCs) have tremendous flexibility to make a variety of different cell types, including bone, fat, muscle, cartilage, bone marrow and tendon. They can dampen the immune system response, inhibit inflammation, stimulate blood vessel formation, repair tissue and help transplanted stem cells to engraft. Transplanted MSCs do not lead to extensive graft rejection even when the donor and recipient are unrelated. And MSCs are easily collected from bone marrow, fat, and umbilical cord.</>
Researchers have designed innovative ways to harvest MSCs, expand them in the laboratory, and stimulate them to make chondrocytes. They have also developed a method for engineering a layer of cartilage by seeding MSCs onto a three-dimensional scaffold that can be used to replace damaged tissue. Pre-clinical studies transplanting chondrocytes made from MSCs into animals with osteoarthritis and Rheumatoid arthritis have proven benefits, and the evolution to clinical trials is promising.
Researchers are also using MSCs as anti-inflammatories to support the regeneration of cartilage in affected joints, and the results so far are positive. Some researchers are also packaging MSCs as “extra strength” anti-inflammatories by loading them with genes that block inflammation. This approach is being tested in animals. Going forward, scientists agree that to design better clinical trials it will be crucial to be able to distinguish various MSC subtypes and to understand how they are different. Scientists are also exploring novel, easy access sources for obtaining MSCs, such as the gums (gingiva).
Current research using adipose (fat) derived stem cells
Fat stem cells can make fat cells, bone, cartilage, muscle cells, and even promote the formation of new blood vessels. These stem cells are isolated through minimal liposuction techniques and then put through a series of purification steps in the laboratory. In preclinical testing, a single dose of fat stem cells injected into animals with osteoarthritis suppressed inflammation that causes cartilage destruction and damage to the ligaments holding the joints together. Clinical trials testing whether the same holds true for human joints with osteoarthritis are underway.
Current research using embryonic stem cells
Applying embryonic stem cells (ESCs) to the problem of arthritis is still at pre-clinical stage and a lot of work will be needed to evaluate the safety of the chondrocytes made from ESCs before they can be approved for human use. The ultimate goal is to use ESCs to make “off the shelf” chondrocytes to be used as donor transplants for many different patient populations.