MFAT vs. BMAC: Mesenchymal Stem Cell Therapy Showdown for Osteoarthritis Treatment

Review of “Functional Outcomes Following Microfragmented Adipose Tissue Versus Bone Marrow Aspirate Concentrate Injections for Symptomatic Knee Osteoarthritis” from STEM CELLS Translational Medicine by Stuart P. Atkinson

Osteoarthritis, a chronic degenerative disease of the articular cartilage, currently affects an estimated 30 million U.S. adults and costs over $185 billion a year to treat [1]; however, conventional conservative interventions often lack the ability to prevent the progression of osteoarthritis or providing long‐term improvements in pain and function [2]. Recent advances in treatments for osteoarthritis include therapies based on mesenchymal stem cells (MSCs) derived from the bone marrow or adipose tissue; but while both studies and clinical trials have provided evidence of the safety of said strategies [3, 4], we still require further data and well‐conducted trials to confirm their therapeutic utility.

In a recent STEM CELLS Translational Medicine article, researchers from the laboratory of Robert Bowers (Emory University, Atlanta, Georgia, USA) compared symptomatic knee osteoarthritis patients treated with intra‐articular autologous bone marrow aspirate concentrate (BMAC) and microfragmented adipose tissue (MFAT) injections with regards to their ability to provide significant pain and functional improvements [5]. Which of these MSC-based Therapies will win the osteoarthritis treatment showdown?

Mautner et al. retrospectively reviewed data collected from male and female patients of ~60 years of age who received BMAC or MFAT injection for symptomatic knee osteoarthritis and completed both baseline and follow‐up surveys at around six months to two years after treatment. One hundred and ten patients met the inclusion criteria for this study, while seventy-six patients (BMAC 41, MFAT 35) and one hundred and six knees (BMAC 58, MFAT 48) possessed proper follow‐up data.

Encouragingly, both BMAC and MFAT treatments led to significant improvements in improvements in pain and function according to all surveys (Knee Injury and Osteoarthritis Outcome Score questionnaire, Emory Quality of Life questionnaire, and Visual Analog Scale for pain), although there existed no differences between BMAC and MFAT treatments. Of note, these treatment options are not “true” MSC treatments, as MSCs are not isolated and culture-expanded, with clinical effects deriving from the activity of MSCs in combination with angiogenic, anti‐inflammatory, and immune‐modulatory cytokines and growth factors.

While this first-of-its-kind comparison underscores the overall efficacy of these MSC-based treatments for knee osteoarthritis and notes a lack of differences between adipose tissue or bone marrow origin, the authors do highlight significant limitations to their study, including the lack of a control group or randomization and a lack of analysis of BMAC/MFAT content prior to injection. However, the authors hope that these findings will provide the basis for future clinical trials in osteoarthritis patients with randomized and controlled head‐to‐head comparisons of autologous tissue sources, while also factoring in tissue analysis and the exploration of multiple injections and varying MSC doses.

For all the future showdowns of MSC-based treatments for osteoarthritis, stay tuned to the Stem Cells Portal!

References

1. Kotlarz H, Gunnarsson CL, Fang H, et al., Insurer and out-of-pocket costs of osteoarthritis in the US: Evidence from national survey data. Arthritis & Rheumatism 2009;60:3546-3553.
2. Zhang W, Moskowitz RW, Nuki G, et al., OARSI recommendations for the management of hip and knee osteoarthritis, Part I: Critical appraisal of existing treatment guidelines and systematic review of current research evidence. Osteoarthritis and Cartilage 2007;15:981-1000.
3. Yubo M, Yanyan L, Li L, et al., Clinical efficacy and safety of mesenchymal stem cell transplantation for osteoarthritis treatment: A meta-analysis. PLoS One 2017;12:e0175449.
4. Centeno CJ, Al-Sayegh H, Freeman MD, et al., A multi-center analysis of adverse events among two thousand, three hundred and seventy two adult patients undergoing adult autologous stem cell therapy for orthopaedic conditions. International Orthopaedics 2016;40:1755-1765.
5. Mautner K, Bowers R, Easley K, et al., Functional Outcomes Following Microfragmented Adipose Tissue Versus Bone Marrow Aspirate Concentrate Injections for Symptomatic Knee Osteoarthritis. STEM CELLS Translational Medicine 2019;8:1149-1156.