Inflammatory responses after intracoronary injection of autologous mononuclear bone marrow cells in patients with acute myocardial infarction.

BACKGROUND

Inflammatory responses after intracoronary injection of autologous mononuclear bone marrow cells (mBMC) are not clarified. The aim of this study was to investigate the influence of intracoronary injection of mBMC on inflammatory mediators in patients with acute myocardial infarction (AMI).

METHODS

Patients with AMI in the ASTAMI trial (N = 100) treated with percutaneous coronary intervention were randomized to intracoronary injections of mBMC or control. Fasting blood samples were drawn the day before stem cell transplantation (baseline 4-5 days after AMI) and 1 day, 3 days, 2 to 3 weeks, and 3 months after transplantation for determination of circulating levels of selected inflammatory markers and mRNA levels in whole blood samples.

RESULTS

From baseline to day 1, the levels of interleukin 6 and the expression of tumor necrosis factor alpha mRNA increased significantly in the mBMC group compared to the control group (P < .05 for both). The decrease in interleukin 6 levels from baseline to 2 to 3 weeks in the mBMC group was less pronounced than in the controls (P < .05), as was also the decrease in C-reactive protein levels from baseline to day 1 and day 3 in the mBMC group (P < .05). However, from baseline to 3 months the levels of tumor necrosis factor alpha and monocyte chemoattractant protein 1 increased less in the mBMC group (P < .05 for both).

CONCLUSION

Intracoronary injection of mBMC in patients with AMI induces a marked short-term inflammatory response, but a slightly reduced inflammation after 3 months which may have implications for the timing of stem cell transplantation in AMI.