1. Assessment of the Monocyte Subpopulations and M1/M2 Macrophage Ratio in Concentrated Bone Marrow Aspirate.
- Author
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Butler JJ, Dankert JF, Keller LE, Azam MT, Dahmen J, Kerkhoffs GMMJ, and Kennedy JG
- Abstract
Objective: The purpose of this study was to determine the M1/M2 macrophage ratio in concentrated bone marrow aspirate (cBMA) in patients undergoing surgical intervention augmented with cBMA for osteochondral lesions of the talus (OLTs)., Design: Samples of peripheral blood (PB), bone marrow aspirate (BMA), and cBMA were collected during the procedure. The samples were analyzed by automated cell counting and multicolor fluorescence-activated cell sorting with specific antibodies recognizing monocytes (CD14+ CD16+) and the M1 (CD86+) and M2 (CD163+CD206+) populations within that monocyte population. Cytokine concentrations within the samples were evaluated with enzyme-linked immunosorbent assay (ELISA). The composition of cBMA was compared between 2 commercially available BMA concentration systems., Results: Thirty-eight patients with a mean age of 43.2 ± 10.1 years old undergoing a surgical procedure for the treatment of OLTs involving the use of cBMA were included. cBMA had a mean fold increase of 4.7 for all white blood cells, 6.1 for monocytes, 7.9 for lymphocytes, 2.4 for neutrophils, and 9.6 for platelets when compared to BMA. The mean M1/M2 ratio for PB, BMA, and cBMA was 15.2 ± 12.0, 20.8 ± 13.3, and 22.1 ± 16.0, respectively. There was a statistically significant higher concentration of interleukin-1 receptor antagonist (IL-1Ra) in the cBMA sample (8243.3 ± 14,837.4 pg/mL) compared to both BMA (3143.0 ± 2218.5 pg/mL) and PB (1847.5 ± 1520.4 pg/mL) samples. The IL-1Ra/IL-1β ratio for PB, BMA, and cBMA was 790.6 ± 581.9, 764.7 ± 675.2, and 235.7 ± 192.1, respectively. There was no difference in the cBMA M1/M2 ratio (19.0 ± 11.1 vs 24.0 ± 18.3) between the Magellan (Isto Biologics, Hopkinton, Massachusetts) and Angel systems (Arthrex Inc, Naples, Florida)., Conclusion: This prospective study found that the M1/M2 ratio in cBMA was 22.1 ± 16.0, with significant patient to patient variation observed. Overall, there was no statistically significant difference in the M1/M2 ratio across PB, BMA, and cBMA samples. This is the first study to characterize the macrophage subpopulation within cBMA, which may have significant clinical implications in future studies., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: J.G.K. is a consultant for Arteriocyte, In2Bones, and Arthrex. J.G.K. receives financial support from the Ohnell Family Foundation, Mr Winston Fischer and Tatiana Rybak.
- Published
- 2024
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