Steroid regulation: An overlooked aspect of tolerance and chronic rejection in kidney transplantation.

Steroid conversion (HSD11B1, HSD11B2, H6PD) and receptor genes (NR3C1, NR3C2) were examined in kidney-transplant recipients with "operational tolerance" and chronic rejection (CR), independently and within the context of 88 tolerance-associated genes. Associations with cellular types were explored. Peripheral whole-blood gene-expression levels (RT-qPCR-based) and cell counts were adjusted for immunosuppressant drug intake. Tolerant (n = 17), stable (n = 190) and CR patients (n = 37) were compared. Healthy controls (n = 14) were used as reference. The anti-inflammatory glucocorticoid receptor (NR3C1) and the cortisol-activating HSD11B1 and H6PD genes were up-regulated in CR and were lowest in tolerant patients. The pro-inflammatory mineralocorticoid gene (NR3C2) was downregulated in stable and CR patients. NR3C1 was associated with neutrophils and NR3C2 with T-cells. Steroid conversion and receptor genes, alone, enabled classification of tolerant patients and were major contributors to gene-expression signatures of both, tolerance and CR, alongside known tolerance-associated genes, revealing a key role of steroid regulation and response in kidney transplantation

Efficacy of Prolonged- and Immediate-release Tacrolimus in Kidney Transplantation: A Pooled Analysis of Two Large, Randomized, Controlled Trials

Background. Two large, prospective studies (12-03; OSAKA) compared the efficacy and tolerability of prolonged-release versus immediate-release tacrolimus in kidney transplant patients also receiving mycophenolate mofetil and low-dose corticosteroids (without induction therapy). Methods. Data were combined into one database to compare results over 24 weeks using 3 alternative endpoints: biopsy-confirmed acute rejection (BCAR); the Food and Drug Administration composite endpoint (graft loss, SCAR, and loss to follow-up), and the European Medicines Agency composite endpoint (graft loss, BCAR, and graft dysfunction). The 95% confidence intervals were calculated (10% noninferiority margin). Results. Overall, 633 patients received prolonged-release tacrolimus (12-03, n = 331; OSAKA, n = 302) and 645 received immediate-release tacrolimus (n = 336; n = 309). Baseline characteristics were comparable. Proportionately more patients receiving prolonged-release tacrolimus had trough levels of 5-15 ng/mL on day 1 (60.8%) and 2 (56.6%) versus immediate-release tacrolimus (42.5% and 43.9%, respectively, both P < .001). Efficacy of prolonged-release and immediate-release tacrolimus were similar as assessed by BCAR (13.9% vs 14.1%, respectively), European Medicines Agency composite endpoint (40.3% vs 38.3%) and US Food and Drug Administration composite endpoint (21.5% vs 19.8%). Conclusions. Novel efficacy endpoints as required by the European Medicines Agency and US Food and Drug Administration demonstrate noninferiority of prolonged-release versus immediate-release tacrolimus. Significantly more patients treated with prolonged release tacrolimus versus immediate-release tacrolimus achieved trough levels of 5 to 15 ng/mL early after transplantation

Genome-Wide Association Study of Acute Renal Graft Rejection

Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell-mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium.status: publishe