Review Article

Safety and Efficacy Endpoints for Mesenchymal Stromal Cell Therapy in Renal Transplant Recipients

Table 1

Objectives of currently registered and performed trials with autologous MSCs in renal transplantation.

Trial/study phase/outcomePrimary endpointSecondary endpoints

Induction therapy with autologous MSCs in living-related kidney transplants; phase II 

Lower incidence of BPAR, decreased risk of infections compared to IL-2RB induction [18].
(i) BPAR  
(ii) Renal function (MDRD)
(i) Patient and graft survival 
(ii) Adverse events

Autologous MSCs to induce tolerance in living-donor kidney transplant recipients; phase I 

Recruiting. ClinicalTrials.gov identifier: NCT02012153
Adverse events(i) T cell counts (flow cytometry) 
(ii) Functional assays (ELISPOT in MLR) 
(iii) Regulatory T cell counts (flow cytometry) 
(iv) Urinary Foxp3 mRNA expression (qPCR)

Autologous MSCs under Basiliximab/low-dose RATG to induce renal transplant tolerance; phase I 

MSC administered at day 7 induced graft dysfunction. Not observed when MSCs were given day 1. Expansion of regulatory T cells and control of memory CD8+ T cell function [12, 13].
Safety related to MSC infusion (i) Immunophenotyping T cells (Flow cytometry) 
(ii) Functional assays (ELISPOT for IFN-γ and Granzyme-B, cell-mediated lympholysis, HLA specific antibodies)  
(iii) Histology and Immunohistochemistry (graft infiltrating cells, MSC localization, complement deposition)

Autologous MSCs and subclinical rejection; phase I 

Feasible and safe. MSCs had immunosuppressive effects (3 patients suffered from opportunistic infections, 5 patients displayed downregulation of MLR), resolution of tubulitis [14].
(i) Adverse events  
(ii) Number of expanded MSCs 
(iii) Number of passages required
(i) Late acute rejections 
(ii) Histology  
(iii) Immunophenotyping T cells (flow cytometry) 
(iv) Functional assays (MLR, cytokines, HLA specific antibodies)

Autologous MSCs in combination with Everolimus to preserve renal structure and function in renal transplant recipients; phase II 

Recruiting [11]. ClinicalTrials.gov identifier: NCT02057965
Histology (fibrosis by Sirius red) (i) Adverse events including (opportunistic) infections 
(ii) BPAR 
(iii) Graft and patient survival 
(iv) Renal function (iohexol, MDRD) 
(v) Immune monitoring (One study) 
(vi) Cardiovascular endpoints

Autologous MSC transplantation in the treatment of chronic allograft nephropathy; phases I-II 

Status unknown. ClinicalTrials.gov identifier: NCT00659620
Renal function  
(Cr and CrCl)
(i) Patient and graft survival  
(ii) Proportion of renal biopsies after 12 months 
(ii) Adverse events including (opportunistic) infections

Safety and efficacy of autologous MSCs transplantation in patients undergoing living-donor kidney transplantation; phase I 

Safe and feasible. Expansion of regulatory T cell population and reduced T cell proliferation [17].
Adverse events(i) Immunophenotyping T cells (flow cytometry) 
(ii) Functional assays (proliferation assay) 
(iii) Renal function (Cr)

MSCs: mesenchymal stromal cells; BPAR: biopsy proven acute rejections; IL-2RB: interleukin-2 receptor blocker; RATG: rabbit antithymocyte globulin; Cr: creatinine; CrCl: creatinine clearance; MDRD: modification of diet in renal disease; HLA: human leukocyte antigen; MLR: mixed lymphocyte reaction; PCR: polymerase chain reaction; qPCR: quantitative PCR.