Doctors are interested in using stem cells to treat a variety of conditions, including arthritis. Scientists believe that stem cells are very important to the body’s ability to repair damaged cells (such as healing after an injury). Stem cell therapy is being evaluated in clinical trials for arthritis as an alternative to knee replacements, biologics, and more.

What are stem cells?

Stem cells are defined as cells that can both:

  1. Divide and duplicate themselves: This is called self-renewal, and means a small amount of these cells can divide to form more cells.

  2. Differentiate: Stem cells can develop into different types of cells (such as a blood, bone, or cartilage cell).

Mesenchymal stem cells

While there are multiple types of stem cells, the most common type used in therapy are mesenchymal stem cells (also known as adult stem cells). This is because they seem to have both the best effect and least risk compared to other types of stem cells.

Many researchers believe mesenchymal stem cells have the potential to repair and replace the damage caused by arthritis because they have the potential to develop into musculoskeletal cells, such as fat, bone, or cartilage cells.

Mesenchymal stem cells are usually collected from the patient's:

  • Fat tissue, which are collected by surgery or liposuction
  • Blood, which have the potential to grow into cartilage cells
  • Bone marrow, which are the most studied and considered to have the best potential for becoming cartilage cells

Once they're harvested, stem cells are either cultured in a lab, or processed into a concentrated solution.

How have stem cells been used to treat arthritis?

Physicians believe that when stem cell therapy is applied to a joint, the cells may develop into the cartilage cells that are needed, suppress inflammation, and release proteins that decrease pain.

While there have been many individual cases reported where patients have received positive results from stem cell therapy from clinics, in 2016, researchers at the Mayo Clinic campus in Florida organized the world's first ever blinded, placebo-controlled clinical study on the benefit of bone marrow stem cells for treating osteoarthritis in the knees. Each of the 25 patients who participated in the study had two knees with arthritis, and had tried at least one other standard arthritis treatment for over weeks. Only one knee received the stem cell treatment, but none of the participants knew which knee received the therapy.

The treatment was given in Mayo Clinic’s Human Cell Therapy Lab. Doctors extracted 60 to 90 milliliters of bone marrow from each patient, and processed it into a solution which contained tens of thousands of stem cells. This solution was then injected into a patient’s knee using ultrasound-guided imagery.

  • Measures of safety, pain, and function were tracked after 1 week, 3 months, and 6 months after the procedure was finished.
  • Before the study, 100% of patients were using over-the-counter or prescription medications for pain, but at the 3 month time check-in, only 24% were.
  • The team also found that patients not only had a significant improvement in the knee that received stem cells, but also in the other knee which had not received the therapy at all.

A follow up study will be done to evaluate how the stem cell injection in a single knee relieves pain in both affected knees. One theory they have is that the stem cells can travel to areas where they will be the most useful. This matches the fact that researchers have found stem cells injected intravenously in cancer treatments go to the patients’ bone marrow where they are needed.

For rheumatoid arthritis, researchers have shown in animal studies that mesenchymal stem cells (MSCs) are very effective for reducing RA inflammation. The team compared MSCs to hematopoietic stem cells (HSCs) and methotrexate, and found that MSCs were most effective in reducing swelling and different scores of RA disease activity (such as IL-6, IL-10, TNF-α, and rheumatoid factor).

What does this mean for you as a arthritis patient?

Stem cell therapies have primarily been studied for osteoarthritis, but they are now being evaluated in additional clinical trials, including for patients with early rheumatoid arthritis and knee osteoarthritis.

As these studies progress, they will be able to identify more areas where stem cell treatments can provide patients alternatives for the currently available therapies.


Are you or a loved one interested in exploring alternative treatments for arthritis available in clinical trials? Let us know! We'll help you every step of the way. Sign up for Clara now or follow this link to learn more about how Clara supports patients through the clinical trials process.