Search

Early subclinical inflammation in kidney transplants is associated with later graft fibrosis and dysfunction. Regulatory T cells (Tregs) can reverse established inflammation in animal models. We conducted a pilot safety and feasibility trial of autologous Treg cell therapy in three kidney transplant recipients with subclinical inflammation noted on 6-month surveillance biopsies. Tregs were purified from peripheral blood and polyclonally expanded ex vivo using medium containing deuterated glucose to label the cells. All patients received a single infusion of ~320 × 106 (319, 321, and 363.8 × 106 ) expanded Tregs. Persistence of the infused Tregs was tracked. Graft inflammation was monitored with follow-up biopsies and urinary biomarkers. Nearly 1 × 109 (0.932, 0.956, 1.565 × 109 ) Tregs were successfully manufactured for each patient. There were no infusion reactions or serious therapy-related adverse events. The infused cells demonstrated patterns of persistence and stability similar to those observed in non-immunosuppressed subjects receiving the same dose of Tregs. Isolation and expansion of Tregs is feasible in kidney transplant patients on immunosuppression. Infusion of these cells was safe and well tolerated. Future trials will test the efficacy of polyclonal and donor alloantigen-reactive Tregs for the treatment of inflammation in kidney transplants.

Julio Pascual,1 Titte R Srinivas,2 Steven Chadban,3 Franco Citterio,4 Federico Oppenheimer,5 Helio Tedesco,6 Mitchell L Henry,7 Christophe Legendre,8 Yoshihiko Watarai,9 Claudia Sommerer,10 Po-Chang Lee,11 J Mark Hexham,12 Gaohong Dong,12 Peter Bernhardt,13 Flavio Vincenti14 1Nephrology Department, Hospital del Mar, Barcelona, Spain; 2Division of Nephrology, Medical University of South Carolina, Mt Pleasant, SC, USA; 3Department of Transplantation, Royal Prince Alfred Hospital, Camperdown, NSW, Australia; 4Centro Trapianti d'Organo Istituto di Clinica Chirurgica, Università Cattolica del Sacro Cuore, Policlinico Universitario A Gemelli, Rome, Italy; 5Renal Transplant Unit, Hospital Clínic de Barcelona, Barcelona, Spain; 6Nephrology Division, Hospital do Rim, UNIFESP, São Paulo, Brazil; 7The Comprehensive Transplant Center, The Ohio State University, Wexner Medical Center, Columbus, OH, USA; 8Service de Transplantation Adultes, Université Paris Descartes and Hôpital Necker, Paris, France; 9Department of Transplant Surgery, Nagoya Daini Red Cross Hospital, Nagoya City, Aich, Japan; 10Medizinische Klinik, Sektion Nephrologie, Universitätsklinikum Heidelberg, Heidelberg, Germany; 11Medical College, National Cheng Kung University, Tainan City, Taiwan; 12Biometrics and Statistical Science, Novartis Pharmaceuticals, East Hanover, NJ, USA; 13Research and Development, Novartis Pharma AG, Basel, Switzerland; 14Kidney Transplant Service, University of California San Francisco, San Francisco, CA, USA Abstract: Two well defined, modifiable risk factors for kidney allograft failure are acute rejection and poor graft function at one year post-transplant. Regulatory bodies and expert panels in the USA and Europe have recognized that both acute rejection and one-year graft function should be assessed when evaluating immunosuppressive regimens. TRANSFORM (Clinicaltrials.gov NCT01950819) is one of the first trials to adopt this approach and the first that applies a novel combined clinically meaningful endpoint to take the first step towards changing the paradigm for immunosuppression in kidney transplant patients. Everolimus with reduced-exposure calcineurin inhibitor (CNI) therapy is a strategy designed to reduce the risk of chronic nephrotoxicity and other dose-dependent complications associated with CNI therapy. In TRANSFORM, de novo kidney transplant patients are randomized to everolimus with reduced-exposure CNI, or mycophenolic acid with standard-exposure CNI, both with induction therapy and maintenance steroids. The primary endpoint is a composite of treated biopsy-proven acute rejection or estimated glomerular filtration rate ,50 mL/min/1.73 m2 at month 12 post-transplant, which is expected to be sensitive both to the effects of acute and chronic allograft rejection and nephrotoxic side effects of immunosuppressive therapies. The construct of this endpoint allows the integration of a continuous outcome (graft function) with a logistic outcome (rejection). The trial uses a randomized, multicenter, open-label, two-arm design. After completion of a 2-year core study, patients enter a further 3-year prospective observational study. By capturing follow-up to 5 years, TRANSFORM will provide substantial data on the incidence of graft loss, graft dysfunction, cancer, cardiovascular events, and other patient-relevant outcomes. TRANSFORM will determine whether de novo CNI reduction with an everolimus-based regimen achieves short-term outcomes compared with standard CNI. As the largest clinical trial undertaken to date in kidney transplantation, recruiting more than 2,000 patients, and with extended follow-up to 5 years, TRANSFORM will provide critical data required to help maximize long-term outcomes. Keywords: mTOR inhibitor, calcineurin inhibitor, reduced exposure

David Wojciechowski, Flavio VincentiKidney Transplant Service, University of California, San Francisco, CA, USAAbstract: In June 2011, the US Food and Drug Administration approved belatacept for the prophylaxis of organ rejection in adult kidney transplant recipients. This review discusses the use of belatacept for the prevention of acute rejection as part of a maintenance immunosuppression regimen. Belatacept is a selective costimulation blocker designed to provide effective immunosuppression while avoiding the toxicities associated with calcineurin inhibitors. Phase III trial data have demonstrated that belatacept is noninferior to cyclosporine in 1-year patient and allograft survival. Three-year data demonstrate an ongoing improvement in mean measured glomerular filtration rate in belatacept-treated versus cyclosporine-treated patients. However, the rate of acute rejection was higher in belatacept-treated patients compared with cyclosporine. Specifically, there was a higher incidence of Banff type II rejections in patients treated with belatacept. Despite the higher Banff grade, rejections on belatacept were not associated with other factors associated with poor outcomes, such as the development of donor-specific antibodies or reduced estimated glomerular filtration rate. One safety issue that must be considered when using belatacept is the potential for increased risk of post-transplant lymphoproliferative disease. There were more cases of post-transplant lymphoproliferative disease in belatacept-treated patients, especially in recipients seronegative for Epstein–Barr virus or patients treated with lymphocyte-depleting agents. Therefore, belatacept can be recommended for use in Epstein–Barr virus antibody-positive recipients.Keywords: belatacept, kidney transplant, acute rejection