Factors Influencing the Yield of Progenitor Cells in Bone Marrow Aspiration Concentrate-A Retrospective Analysis of 58 Patients

Abstract

This study aims to identify the role of subjective factors (age, sex, and comorbidities) and procedure-specific factors (aspiration volume) in influencing the yield of progenitor cells in bone marrow aspiration concentrate (BMAC) harvested from the iliac crest. A retrospective analysis was conducted on 58 patients (male:female = 31:27; mean age: 52.56 ± 18.14 years) who underwent BMAC therapy between January 2020 and June 2021. The factors analyzed include individual factors such as age, sex, and comorbid conditions, and procedural factors such as aspirate volume. The mononuclear cell (MNC) count and colony-forming unit (CFU) assay were used to assess the yield of progenitors in the aspirate. Pearson's correlation test was performed for the age, aspirate volume, and outcome parameters, such as MNC and CFU. We used the chi-square test to analyze the role of sex and comorbidities on cellular yield. The mean volume of aspirate used for BMAC therapy was 66.65 (±17.82) mL. The mean MNC count of the BMAC was 19.94 (±16.34) × 10⁶ cells, which formed 11 (±12) CFUs. Evidence of statistically significant positive associations was noted between the CFUs developed from the BMAC and the MNC count within them (r = 0.95, p < 0.001). The sex of the individual did not play any significant role in MNC count (p = 0.092) or CFUs formed (p = 0.448). The age of the individual showed evidence of a statistically significant negative association with the MNC count (r = -0.681, p < 0.001) and CFUs (r = -0.693, p < 0.001), as did the aspiration volume with the MNC count (r = -0.740, p < 0.001) and CFUs (r = -0.629, p < 0.001). We also noted a significant reduction in the MNC count (p = 0.002) and CFUs formed (p = 0.004) when the patients presented comorbidities. Individual factors such as age, comorbid conditions, and procedure factors such as aspirate volume significantly affected the yield of progenitor cells in the BMAC. The sex of the individual did not influence the yield of progenitor cells in BMAC.

Keywords: BMAC; bone marrow aspiration concentrate; cellular yield; colony-forming unit; mononuclear cell; progenitor cells; regenerative medicine.

Figure 1

Microscopic appearance of the colonies in the CFU assay (200×). Red circles mark the identified colonies at 7 day culture.

Figure 2

Schematic representation of bone marrow aspirate concentrate isolation and culture. ASIS: anterior superior iliac spine, MNC: mononuclear cell, CFU: colony-forming unit.

Figure 3

(A) Association scatter plot of age of the patient and MNC count of the formed BMAC. (B) Association scatter plot of age of the patient and formed CFU count.

Figure 4

ROC curve estimation of the cut-off to analyze the relationship of the MNC count and CFU with categorical variables such as comorbidities. (A) ROC curve for MNC count and comorbid illness. (B) ROC curve for CFU count and comorbid illness.

Figure 5

(A) Association scatter plot of aspiration volume of bone marrow and MNC count of the formed BMAC. (B) Association scatter plot of aspiration volume of bone marrow and formed CFU count.

Figure 6

Correlation scatter plot of the MNC count of the BMAC and the CFUs formed from them.