Fri., 10/19/07 Basic Science, Paper #42, 4:36 pm OTA-2007
Cigarette Smoking Is Associated with Lower Concentration of Bone Marrow Mesenchymal Stem Cells
Shaul Beyth, MD (a-Hadassah); Anat Daskal, MSc (n); Amal Khoury, MD (n);
Rami Mosheiff, MD (n); Meir Liebergall, MD (a-Teva);
Hadassah University Medical Center, Jerusalem, Israel
Purpose: Cigarette smoking is associated with musculoskeletal degenerative disorders and increased risk of fracture delayed union and nonunion. Mesenchymal stem cells (MSC) reside within the bone marrow and play a key role in regeneration and healing of musculoskeletal tissues following traumatic injuries. A lower-than-average concentration of MSC may be the reason for the reduced regenerative potential. We hypothesized that fresh bone marrow obtained from cigarette smokers will have lower-than-average concentration of MSC.
Methods: In an IRB-approved clinical trial, 20 mL of fresh bone marrow samples were processed and MSC were isolated. FACS analysis was used both to assess the purity of the separation process and to evaluate the number of MSC recovered from each sample. Demographic and hematologic data were also collected. Differences in continuous outcomes between smoking and nonsmoking groups were assessed by two-tailed t test and difference between categorical outcomes was measured by chi-square test.
Results: Thirteen smoking subjects and 13 nonsmoking subjects participated in the study. Groups were not significantly different with regard to demographic and hematologic parameters. The average concentration of MSC was 352.04 • 103/mL for nonsmokers and 131.23 • 103/mL for smokers (standard deviations were 245.72 • 103/mL and 161.54 • 103/mL, respectively). The difference between the two groups was found to be significant (t = 3.2 P = 0.004).
Conclusions: MSC throughout the body and specifically in the bone marrow serve as a reservoir for skeletal tissue repair and regeneration. The deleterious effect of cigarette smoking on mesenchymal tissues’ regenerative properties is well documented. The present study indicates that cigarette smokers have lower-than-average concentration of MSC in their bone marrow. Our data suggest that delayed union and nonunion of fractures in smokers may be related to decreased MSC concentration.
Significance: Our findings may contribute to understanding and prevention of delayed union and nonunion. Further investigation is currently underway to address the issue of bone marrow recovery after smoking cessation.
If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing.