Stem the Joint-Aging Tide

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Trail running is one of the best ways to stave off the effects of aging. It keeps our cardiovascular systems young, our brains healthy and it even keeps cartilage intact. And yet, according to the Arthritis Foundation, over half of us will experience some age-related joint degeneration, like osteoarthritis, during our lives.

Osteoarthritis is the loss of the protective cushions of cartilage in joints like the knee. Once cartilage is damaged, it gets inflamed, which causes more damage and a painful cycle ensues. Previous injuries as well as a history of running hard and long can also increase your chances of developing arthritis.

Treatments like physical therapy, anti-inflammatory drugs or steroids can keep a lot of runners going, but there is no specific cure. Eventually, many people choose to have a joint replacement to escape the bone-on-bone pain.

This is one reason stem-cell treatments don’t work equally well for everyone. Growth factors and other essential ingredients may not be present in adequate amounts in different preparations.

Since about 2010, a different, non-surgical option has come onto the scene with much intrigue: stem-cell injections.

Stem cells are the building blocks our bodies use to build and repair all of our tissues—muscles, bones, even nerves.

How Do Stem Cells Work?

Cuts, abrasions, fractures, tears and stresses send a signal into your blood calling for help. The first step in the healing process is to get more blood flow to the area. This brings immune cells to pick off any bacteria that may have sneaked in. The immune cells also signal local stem cells to begin dividing to make more cells that will fill in the holes. In just a day or so, these little cell factories scab over the scrapes and grow new skin.

Shirley G, an avid hiker and biker, says the pain in her knees was so bad she could barely walk. After several bone-marrow MSC injections, she said, ‘I got my knees back!’

Almost every tissue in an adult body has its own type of stem cell for repairing itself; however, as we get older, we have fewer of them and they don’t work as well. So, just shoot some more into an arthritic joint, right? Not quite.

The repair process requires a specific set of signals. Like when baking cookies, you have to add specific ingredients (stem cells and growth factors as well as other things, typically proteins), in a certain sequence or else they’ll turn out like sad pancakes.

When stem cells are injected, all of the required signals need to be in place in the right order. If everything is a go, the stem cells will divide to produce more cartilage (or whatever tissue is needed). Figuring out which signals are used in which tissues is a big research area right now, but it’s not well understood.

This is one reason stem-cell treatments don’t work equally well for everyone. Growth factors and other essential ingredients may not be present in adequate amounts in different preparations.

What Kinds Are Available?

There are two types of stem cells that can be used in treatments: MSC (Mesenchymal stromal cell, an adult stem cell, producing bone, cartilage, muscle, fat and a few other cell types) and FS (Fetal stem cell, producing almost all types of adult cells).

The FS stem cells are found in amniotic fluid, umbilical cords and in placentas. As you may know, these tissues are produced by a growing fetus. You may not know that there is a developing industry in obtaining, harvesting and selling these stem cells—mostly from placentas.

MSC are pre-specialized to divide into cartilage-producing cells and can come from bone marrow or be purified from fat. In fact, it’s become popular to go in for liposuction and pull out MSC.

MSC living in fat don’t have the same environmental triggers for developing into cartilage as those in bone marrow; however, getting the cells from fat is a lot less painful than sticking a giant needle into your hip bone.

There are about 50 published studies following osteoarthritis patients injected with these two types of MSC. The results were all good when patients were compared with untreated controls, but all of the studies had pretty small samples and short follow-ups. Bottom line: some of the good outcomes could be due to placebo, and others might wear off. It’s unknown at this point.

Nonetheless, this is sounding promising right?

U.S. versus Abroad

Bone marrow is probably a better source of MSC if we want to stack the deck for stem cells to grow into cartilage. The bad news is that you don’t get that many cells from an aspiration of the hip—maybe 10,000 to 100,000. Although this sounds like a lot, you can get a lot more from placentas. In clinical trials, most of which have been done outside the U.S., the MSC are put into test tubes and grown in a lab for a few weeks. Then the cell count goes way up, into the millions. One of the findings of the clinical trials is, the more stem cells you put in, the better results you get.

But it gets trickier. Even though the bone marrow pulled from a hip has a lot of MSC, it also contains other types of stem cells. Some tricks have to be used to pick out just the MSC before they are injected.

In the U.S., the FDA restricts what clinics can do with stem cells. When the cells are withdrawn, they can only be “minimally manipulated” and must be re-injected in the same day. This means the bone marrow can be centrifuged to pull out the stem cells but not grown for weeks or treated to isolate the MSC. What’s more, the injected cells are supposed to have the same basic function as the tissue into which they are being injected. One example of this would be a cornea transplant. This equivalency is really hard to define for stem cells because they can grow into so many other types of cells.

Not surprisingly, there are a lot of gray areas in these regulations. This ambiguity allowed explosive growth in the number of stem-cell clinics in recent years. In the past few months, however, the FDA has been more aggressive about shutting down clinics with egregious violations.

To Inject or Not to Inject?

Stem-cell therapy is promising, but, like other treatments, it has certain risks. Educate yourself and ask the relevant questions of any stem-cell-therapy provider.

There is also a lot of anecdotal evidence—on both sides.

Personally, if I had the money for a European stem-cell vacation, I might go for it. The methods used there for concentrating cells—which give you a better chance for a good outcome—are just not available in clinics in the U.S.

I spoke with several athletes (who were reluctant to use their full names) who went to local clinics for stem-cell injections into their knees. Shirley G, an avid hiker and biker, says the pain in her knees was so bad she could barely walk. After several bone-marrow MSC injections, she said, “I got my knees back!”

Anne B had to give up running due to osteoarthritis. She says, “My knees have improved significantly, but I don’t know if it was the stem cells, the PT or the alignment work.”

Finally, be aware that there are changes in the works at the FDA. This spring, they released a statement saying they will start to “expedite” the regulatory process. But, no further changes have been made at this time.

Current FDA stem-cell guidelines:⁄guidancecomplianceregulatoryinformation/guidances/cellularandgenetherapy/ucm585403.pdf

Beth Bennett has her Ph.D. in genetics and taught biochemistry physiology at the University of Colorado for 25 years.

This article originally appeared in the December issue of Trail Runner. To get quality content like this delivered right to your door, click here.

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