Recently a patient e-mailed me that he discovered an article ( http://www.ncbi.nlm.nih.gov/pubmed/23694810 )that stated fat stem cells ( AT-MSCs) were much more effective than bone marrow stem cells (BM-MSCs). It seems that this has been an ongoing controversy for years. The patient felt relieved that he could get a treatment to improve his knee by only using fat and bypassing bone marrow stem cells. I told him otherwise.
When looking at this article at face value the uninitiated would think the fat derived stem cells would give much better results than the bone marrow. There is no doubt that fat contains much more in the way of mesenchymal stem cells when compared to bone marrow. In this study the mesenchymal stem cells from bone marrow were compared to those derived from fat. The perimeters that were looked at were the immunomodulatory effect of the cells. The immunomodulatory effects concern getting the stem cells niche (environment) more conducive allow other stem cells to help repair the tissue. Without the immunomodulatory effects repair will not take place and damage will continue unabated.
Now comes the very interesting aspect of this study. When compared in equal numbers the mesenchymal stem cells from fat showed more potent immunomodulatory effects as compared with the bone marrow derived stem cells. When comparing the two cells, assays of the cytokines produced were studied. Remember that the cytokines are growth factors and interleukins which help accomplish repair. They can turn off inflammation and help form collagen and other important tissue. The comparison between the two types of cells showed that the mesenchymal stem cells derived from fat were more metabolically active. From these studies we conclude that the immunomodulatory capacities of bone marrow and fat derived mesenchymal stem cells are similar, but that differences in cytokine secretion cause fat mesenchymal stem cells to have more potent immunomodulatory effects than bone marrow derived stem cells. Therefore, lower numbers of AT-MSCs evoke the same level of immunomodulation. Here is a quote from the article ” these data indicate that AT-MSCs can be considered as a good alternative to BM-MSCs for immunomodulatory therapy”.
There is no doubt that the fat stem cells win out on the aspect of immuomodulation but that is only half the story. We must remember that this does not imply that fat is a good alternative to bone marrow for regeneration. On the contrary, they are both needed for regeneration to occur. Bone marrow supplies the much needed hematopoietic stem cells which are the drivers of tissue regeneration while the fat provides the mesenchymal stem cells which drives immunomodulation which is the step needed before regeneration. Together they are a powerful army.
What other aspects can be learned from this study? One thing that is for sure is that fat derived stem cells may actually work better for many of the auto immune inflammatory diseases. I myself stick to musculoskeletal conditions and let some of my colleagues treat these diseases. It seems to make sense to use these cells to treat a condition where the body is essentially attacking itself. In another words the inflammation that the body is experiencing is causing damage. If the damage is turned off than the patient will feel better. Many of the medicines used today to treat Rheumatoid arthritis basically try to quell the the immune response. The problem with these drugs is that they can quill the immune response in the body so much they can leave the patient open to a number of serious problems including certain types of infections and cancers. On the other hand fat stem cells seem to be more target specific. They will affect the inflammatory process but not at the cost of sacrificing the body’s immune defenses for a variety of problems.
Right now we are only touching the tip of the ice berg. Fat offers some exciting possibilities in treating a variety of diseases but I feel bone marrow will be needed also to eventually cure the disease. If I had to go to a deserted island and I could only take one or the other I would make some type of deal so that I could have some of both.
Thanks Dr. P