Stem Cell Mythbusters: Harvest and Stem Cell Injection
I’m busy this week preparing for 4 lectures in the last 2 weeks of April covering Beunos Aires, Florida, Las Vegas, and Pittsburgh. In preparing for one of those lectures and hunting for an interesting picture for a slide, I came across these pictures from the blog of a paraplegic patient who traveled to Europe for stem cell therapy. I thought they were such great examples of some of the problems we see with stem cell therapy, I would quickly blog on the issue. As I have blogged before, a procedure to harvest stem cells from bone marrow needs imaging guidance. This is because the area at the back of the hip where these cells are taken is very tricky. If you’re in exactly the right spot, you get stem cells, if you’re in the wrong spot (where the bone is paper thin and just a quarter of an inch from the right spot) you get blood and not many stem cells. The image on the left of the doctor taking a bone marrow aspirate shows that no imaging guidance was used to confirm where the needle was placed. If you ask pathologists about this issue (the doctors that examine these samples under a microscope for diagnosis), they will tell you this is a big problem-as often they get blood when they should get marrow because the doctor assumed he was in the right spot. Realize again that the stem cells this doctor is interested in are in the marrow . The image on the right is equally concerning. Here the doctor is inserting the cells in the spine of the patient. Knowing the clinic, it’s likely they’re trying to get these cells “intrathecal“, meaning inside the covering of the spinal cord. Again, no imaging is being used to make sure the cells in the stem cell injection are really getting there. This is concerning for a few reasons. The first is that the doctor may not be in the space he thinks he’s accessing (to hit this space being a few millimeters too shallow or deep can mean not getting the cells to the injured area). Even if he’s in that space, he’s got no way of knowing if the cells will ever make it to the injury site, because he has no way of observing where cells will go. Will the cells travel up, down, right, or left? Will they all get stuck in one spot which is nowhere near the lesion? If this injection of stem cells had just used a simple fluoroscopy unit (one can be purchased for about the cost of 3-4 treatments at this center) and some radiographic contrast (which can be seen on x-ray), the doctor could observe that the cells are likely or not likely to make it to the injury site. Obviously, if the cells can’t make it to the area in need of repair, then injecting stem cells may do no good. The upshot? Imaging needs to be used with a marrow aspiration and a stem cell re-injection to make sure that the doctor is actually harvesting the right tissue and re-injecting the cells in the right spot.