Human mesenchymal stromal cells inhibit platelet activation and aggregation involving CD73-converted adenosine.

BACKGROUND: Mesenchymal stromal cells (MSCs) are promising cell therapy candidates. Clinical application is considered safe. However, minor side effects have included thromboembolism and instant blood-mediated inflammatory reactions suggesting an effect of MSC infusion on hemostasis. Previous studies focusing on plasmatic coagulation as a secondary hemostasis step detected both procoagulatory and anticoagulatory activities of MSCs. We now focus on primary hemostasis and analyzed whether MSCs can promote or inhibit platelet activation. METHODS: Effects of MSCs and MSC supernatant on platelet activation and function were studied using flow cytometry and further platelet function analyses. MSCs from bone marrow (BM), lipoaspirate (LA) and cord blood (CB) were compared to human umbilical vein endothelial cells or HeLa tumor cells as inhibitory or activating cells, respectively. RESULTS: BM-MSCs and LA-MSCs inhibited activation and aggregation of stimulated platelets independent of the agonist used. This inhibitory effect was confirmed in diagnostic point-of-care platelet function analyses in platelet-rich plasma and whole blood. Using inhibitors of the CD39-CD73-adenosine axis, we showed that adenosine produced by CD73 ectonucleotidase activity was largely responsible for the LA-MSC and BM-MSC platelet inhibitory action. With CB-MSCs, batch-dependent responses were obvious, with some batches exerting inhibition and others lacking this effect. CONCLUSIONS: Studies focusing on plasmatic coagulation suggested both procoagulatory and anticoagulatory activities of MSCs. We now show that MSCs can, dependent on their tissue origin, inhibit platelet activation involving adenosine converted from adenosine monophosphate by CD73 ectonucleotidase activity. These data may have strong implications for safety and risk/benefit assessment regarding MSCs from different tissue sources and may help to explain the tissue protective mode of action of MSCs. The adenosinergic pathway emerges as a key mechanism by which MSCs exert hemostatic and immunomodulatory functions.

Health claims data as a strategy and tool in disease management.

A comprehensive definition of disease management provides an opportunity to track a population of patients across the entire continuum of a condition, from wellness through disease and disability, so that improvements in health status and quality of life and efficiencies in the application of health care resources can be demonstrated. The need is great for information systems that can computerize clinical encounter, summarize, and apply the information to help identify opportunities for improvement in the performance of quality and cost control, monitor processes of care, and report outcomes that are meaningful to the organization. By tracking health care charges as a proxy for the application of health care resources, health claim data analyses can identify conditions for disease management, facilitate provider buy-in, develop the disease management program, monitor interventions, and report outcomes.