Mesenchymal stromal cell and mononuclear cell therapy in heart disease

Stem cell therapy to treat heart ischaemia: implications for diabetes cardiovascular complications

Diabetes mellitus is a well-known risk factor for coronary artery disease (CAD), which can lead to acute myocardial infarction, chronic myocardial ischaemia and heart failure. Despite the advantages in medical treatment, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), morbidity and mortality is still high in patients with CAD. Along with PCI and CABG or in patients without options for revascularization, stem cell regenerative therapy in controlled trials is a possibility. Stem cells are believed to exert their actions by angiogenesis and regeneration of cardiomyocytes. Recently published clinical trials and meta-analysis of stem cell studies have shown encouraging results with increased left ventricle ejection fraction and reduced symptoms in patients with CAD and heart failure. There is some evidence of mesenchymal stem cell being more effective compared to other cell types and cell therapy may be more effective in patients with known diabetes mellitus. However, further investigations are warranted.

Stem cells therapy for cardiovascular repair in ischemic heart disease: How to predict and secure optimal outcome?

Coronary artery disease is a growing problem worldwide. Early treatment with stabilizing drugs and revascularization by percutaneous coronary intervention or by-pass surgery has reduced the mortality significantly, but it is still the most common cause of death and a major cause of hospital admissions in industrialized countries. Treatment with stem cells with the potential to regenerate the damaged myocardium is a relatively new approach. However, the results from clinical studies on stem cell therapy for cardiac regeneration in patients with acute or chronic ischemic heart disease have been inconsistent. Some of the discrepancy could be due differences in study designs or patient selection. The review will based on conducted clinical stem cell trials try to elucidate how to predict and personalize this new treatment approach.

Serial in vivo imaging of the porcine heart after percutaneous, intramyocardially injected 111In-labeled human mesenchymal stromal cells

This pilot trial aimed to investigate the utilization of (111)In-labeling of mesenchymal stromal cells (MSC) for in vivo tracking after intramyocardial transplantation in a xenotransplantation model with gender mismatched cells. Human male MSC were expanded ex vivo and labeled with (111)In-tropolone. Ten female pigs were included. The labeled cells were transplanted intramyocardially using a percutaneous injection system. The (111)In activity was determined using gamma camera imaging. Excised hearts were analyzed by fluorescence in situ hybridization (FISH) and microscopy. Gamma camera imaging revealed focal cardiac (111)In accumulations up to 6 days after injection (N = 4). No MSC could be identified with FISH, and microscopy identified widespread acute inflammation. Focal (111)In accumulation, inflammation but no human MSC were similarly seen in pigs (N = 2) after immunosuppression. A comparable retention of (111)In activity was observed after intramyocardial injection of (111)In-tropolone (without cells) (N = 2), but without sign of myocardial inflammation. Injection of labeled non-viable cells (N = 1) also led to high focal (111)In activity up to 6 days after intramyocardial injection. As a positive control of the FISH method, we identified labeled cells both in culture and immediately after cell injection in one pig. This pilot trial suggests that after intramyocardial injection (111)In stays in the myocardium despite possible disappearance of labeled cells. This questions the clinical use of (111)In-labeled cells for tracking. The results further suggest that xenografting of human MSC into porcine hearts leads to inflammation contradicting previous studies implying a special immunoprivileged status for MSC.