Analysis of Ambient Influences Affecting Interleukin-6 Secretion in the Context of Clinical Trials of Stem Cell Therapy for Myocardial Infarction.

Abstract

Contradictory results of large clinical trials of stem cell therapy in acute myocardial infarction (AMI) have impeded a wider clinical use. As signalling via paracrine factors in AMI has received more and more attention recently, we sought to compare processing protocols with special emphasis on interleukin-6 (IL-6), a factor of major relevance for triggering cardioprotective signals via STAT3 and PI3K. Bone marrow and peripheral blood mononuclear cells were processed according to protocols used in the REPAIR-AMI and ASTAMI study. Keeping cells at higher temperatures significantly boosted secretion of IL-6. Moreover, the use of autologous serum and X-Vivo medium was superior over reagents used in the protocol of the ASTAMI study. External influencing factors (higher temperature, use of a modern cell culture medium supplemented with serum) led to higher concentrations of IL-6. These results could provide an explanation for the superior results found in the REPAIR-AMI study.