Mesenchymal stromal cell-based therapy in kidney diseases and transplantation

Intense investigation in pre-clinical models of kidney disease and transplantation showed that mesenchymal stromal cell (MSC) therapy acts on renal and inflammatory cells in multiple, complex and integrated ways, resulting in cell repair and regeneration, in the inhibition of inflammatory cells, and in the development of cells endowed with their own anti-inflammatory and immuneregulatory properties. These encouraging data paved the way for exploring the use of MSC in clinics as innovative therapeutic tools for patients with renal diseases and transplantation. In this review, we describe the available results of clinical studies of MSC in patients with post-cardiac surgery, acute kidney injury, chronic kidney diseases - including diabetes, renovascular disease and lupus nephritis - and in kidney transplant recipients, with a particular focus on our experience with MSC therapy as a pro-tolerogenic strategy in kidney transplantation. The available studies, mainly phase 1, indicated that MSC therapy is safe and feasible and not associated with adverse events, at least in the short- and mid-term. Encouraging results have been reported in renovascular disease and kidney transplantation, while studies in acute kidney injury and chronic kidney disease had contrasting outcomes. The relevant issues and the knowledge gap that still limit the translation of MSC cell therapy into clinical practice are discussed briefly.