Detailed analysis of bone marrow from patients with ischemic heart disease and left ventricular dysfunction: BM CD34, CD11b, and clonogenic capacity as biomarkers for clinical outcomes

Abstract

Rationale: Bone marrow (BM) cell therapy for ischemic heart disease (IHD) has shown mixed results. Before the full potency of BM cell therapy can be realized, it is essential to understand the BM niche after acute myocardial infarction (AMI).

Objective: To study the BM composition in patients with IHD and severe left ventricular (LV) dysfunction.

Methods and results: BM from 280 patients with IHD and LV dysfunction were analyzed for cell subsets by flow cytometry and colony assays. BM CD34(+) cell percentage was decreased 7 days after AMI (mean of 1.9% versus 2.3%-2.7% in other cohorts; P<0.05). BM-derived endothelial colonies were significantly decreased (P<0.05). Increased BM CD11b(+) cells associated with worse LV ejection fraction (LVEF) after AMI (P<0.05). Increased BM CD34(+) percentage associated with greater improvement in LVEF (+9.9% versus +2.3%; P=0.03, for patients with AMI and +6.6% versus -0.02%; P=0.021 for patients with chronic IHD). In addition, decreased BM CD34(+) percentage in patients with chronic IHD correlated with decrement in LVEF (-2.9% versus +0.7%; P=0.0355).

Conclusions: In this study, we show a heterogeneous mixture of BM cell subsets, decreased endothelial colony capacity, a CD34+ cell nadir 7 days after AMI, a negative correlation between CD11b percentage and postinfarct LVEF, and positive correlation of CD34 percentage with change in LVEF after cell therapy. These results serve as a possible basis for the small clinical improvement seen in autologous BM cell therapy trials and support selection of potent cell subsets and reversal of comorbid BM impairment.

Clinical trial registrations url: http://www.clinicaltrials.gov. Unique identifiers: NCT00684021, NCT00684060, and NCT00824005.

Keywords: angiogenesis effect; blood cells; bone marrow; myocardial infarction; stem cells.

Conflict of interest statement

Disclosure of Conflicts of Interest: None.

© 2014 American Heart Association, Inc.

Figures

Figure 1. Cell Subsets in the BM of CCTRN Patients

BM-MNCs from subjects enrolled in CCTRN cell therapy trials were immunostained and enumerated by flow cytometry. Lineages are presented in histograms showing cell subsets from most prevalent to least with bars representing mean±SD. In the TIME trial, patients were randomized 1:1 to undergo BM aspirations either (A) 3 days or (B) 7 days after AMI. (C) In the LateTIME trial, all subjects underwent BM aspirations 2-3 weeks after AMI. (D) In the FOCUS trial, BM aspiration was performed on patients with chronic myocardial

Figure 1. Cell Subsets in the BM of CCTRN Patients

BM-MNCs from subjects enrolled in CCTRN cell therapy trials were immunostained and enumerated by flow cytometry. Lineages are presented in histograms showing cell subsets from most prevalent to least with bars representing mean±SD. In the TIME trial, patients were randomized 1:1 to undergo BM aspirations either (A) 3 days or (B) 7 days after AMI. (C) In the LateTIME trial, all subjects underwent BM aspirations 2-3 weeks after AMI. (D) In the FOCUS trial, BM aspiration was performed on patients with chronic myocardial

Figure 1. Cell Subsets in the BM of CCTRN Patients

BM-MNCs from subjects enrolled in CCTRN cell therapy trials were immunostained and enumerated by flow cytometry. Lineages are presented in histograms showing cell subsets from most prevalent to least with bars representing mean±SD. In the TIME trial, patients were randomized 1:1 to undergo BM aspirations either (A) 3 days or (B) 7 days after AMI. (C) In the LateTIME trial, all subjects underwent BM aspirations 2-3 weeks after AMI. (D) In the FOCUS trial, BM aspiration was performed on patients with chronic myocardial

Figure 1. Cell Subsets in the BM of CCTRN Patients

BM-MNCs from subjects enrolled in CCTRN cell therapy trials were immunostained and enumerated by flow cytometry. Lineages are presented in histograms showing cell subsets from most prevalent to least with bars representing mean±SD. In the TIME trial, patients were randomized 1:1 to undergo BM aspirations either (A) 3 days or (B) 7 days after AMI. (C) In the LateTIME trial, all subjects underwent BM aspirations 2-3 weeks after AMI. (D) In the FOCUS trial, BM aspiration was performed on patients with chronic myocardial

Figure 2. Colony Growth from BM-MNCs of CCTRN Subjects with IHD

(A) A representative phase-contrast micrograph of a CFU-Hill colony. (B) A representative phase-contrast micrograph of an ECFC colony. (C) In subjects whose BM generated CFU-Hill colonies, there was no difference in number of colonies between healthy controls (N=9) and IHD patients enrolled in TIME, LateTIME, and FOCUS trials. (D) In patients whose BM generated ECFC colonies, there was a significant decrease in maximum number of ECFC colonies in the LateTIME group, approximately 14 days after AMI.

Figure 3. BM CD 34 + Percentage Among CCTRN Trial Cohorts

Data represent mean ± SD. Percentage of CD34+ cells in the BM of patients 7 days after acute MI (1.9%) was decreased compared to other cohorts of IHD patients (TIME (3), 2.3%; LateTIME, 2.6%; FOCUS, 2.7%).

Figure 4. BM CD34+ Cell Percentage and Change in LVEF at Six Months

BM aspirations were performed in patients presenting with AMI and chronic LVD. CD34+ percentage was quantified by ISHAGE criteria and LVEF was examined at baseline and six months later. (A) Patients with AMI who presented with high BM CD34+ percentage (greater than 2 SD from the mean) showed significantly greater increase in LVEF at six-month follow-up. (B) Likewise, patients with chronic LVD and high BM CD34+ percentage (greater than 2 SD from the mean) also showed significantly greater increase in LVEF at six-month follow-up.