The Importance of Harvest Technique: Getting More Stem Cells
Most patients contemplating stem cell therapy have likely never thought about a simple concept that may determine if their cell procedure works or fails-harvest technique. How the cells are obtained by the doctor can make a big difference in how many stem cells the patient receives back. The more cells the doctor is able to get, the more cells the patient will have for the re-injection, so on first principle getting more stem cells is important. I’ve blogged a few times on the differences and capabilities between a research based medical practice with a level III lab vs. a doctor with a bedside kit or centrifuge. Today’s blog is another concrete example. First, bone marrow aspiration is different than a bone marrow biospy-an aspiration is very comfortable for the patient while a biopsy can be painful. We only use bone marrow aspiration. Second, for orthopedic applications, we usually prefer bone marrow over fat as a source for stem cells. Third, bone marrow aspirations have been done the same way for more than 50 years. The skin and area is thoroughly numbed and a needle is poked through the bone and a small amount of the liquid portion of the marrow is pulled out with a syringe. Unlike other clinics who perform the bone marrow aspirate procedure blind, we use imaging guidance to make sure we’re in the right spot-as being off even a little bit will mean no bone marrow aspirate. However, one of our doctors noted that if he performed his bone marrow aspiration in a slightly different way, it seemed he could get more of the nucleated stem cell fraction (the part of the bone marrow that contains stem cells). He knew this because we have a level III lab as part of our medical practice. If instead all we had was a bedside centrifuge or kit, we would be unable to count the cell yield and we would never know how many cells we were able to harvest. When he first brought this to my attention, I was a little doubtful that such a minor tweak in the way a bone marrow aspirate was performed could make such a major difference in the number of cells obtained in the same volume. So we had our lab director run his numbers for yield with his new technique versus another clinic physician using the standard technique. Across 24 patients for the both doctors (16 for the new technique and 8 for the old technique), the doctor was able to document getting approximately 4 times the number of cells compared to the old technique (data above). Why is this really important? We believe that more cells will translate into a better result for patients. In addition, without the data on every patient telling the doctor the cell yield, this breakthrough would have never happened. We’ve also documented multiple times that our bone marrow draw technique produces mesenchymal stem cells that we can culture and identify in the lab. With a bedside centrifuge or a kit (99% of the stem cell work being performed today in the U.S.), the doctor never knows if his cell harvest technique will turn into usable cells for the patient.