A Combined microRNA and Chemokine Profile in Urine to Identify Rejection After Kidney Transplantation.

There is an unmet need for noninvasive tools for diagnosis of rejection after kidney transplantation. The aim of this study was to determine the discriminative value of a combined cellular and molecular biomarker platform in urine for the detection of rejection. METHODS: First, microRNA (miR) molecules were screened in transplant biopsies and urine sediments of patients with acute rejection and patients without rejection and stable graft function. Second, the expression of 15 selected miRs was quantified in an independent set of 115 urine sediments of patients with rejection and 55 urine sediments of patients without histological signs of rejection on protocol biopsy. Additionally, CXCL-9 and CXCL-10 protein levels were quantified in the urine supernatant. RESULTS: Levels of miR-155-5p (5.7-fold), miR-126-3p (4.2-fold), miR-21-5p (3.7-fold), miR-25-3p (2.5-fold), and miR-615-3p (0.4-fold) were significantly different between rejection and no-rejection urine sediments. CXCL-9 and CXCL-10 levels were significantly elevated in urine from recipients with rejection. In a multivariable model (sensitivity: 89.1%, specificity: 75.6%, area under the curve: 0.94, P < 0.001), miR-155-5p, miR-615-3p, and CXCL-9 levels were independent predictors of rejection. Stratified 10-fold cross validation of the model resulted in an area under the curve of 0.92. CONCLUSIONS: A combined urinary microRNA and chemokine profile discriminates kidney transplant rejection from stable graft conditions.

Long-term cardiovascular outcome of renal transplant recipients after early conversion to everolimus compared to calcineurin inhibition: results from the randomized controlled MECANO trial.

Long-term data on cardiovascular (CV) outcome of renal transplant recipients (RTR) on mTOR-i (mammalian Target Of Rapamycin-inhibitors) are scarce. In a sub-study of the MECANO trial we investigated changes in intima media thickness (IMT), CV risk profile, Major Adverse CV Events (MACE) and survival in RTR on a mTORi versus CNI based regimen. Patients (enrolled 361) were treated with (basiliximab) and triple IS (CsA-Cyclosporine A-(C), MPS (M), prednisolone (P)). At M6 patients were randomized (n = 224) to the CsA group (C, P, N = 89), MPS group (M, P, N = 39) EVL group (Everolimus, P, N = 96). At week 2, M6 and M 24, IMT measurements of the Common Carotid Artery were performed. Cardiovascular risk factors were assessed at baseline, 6 and 24 months of follow-up. Seven years survival and MACE-free survival probability were calculated by the Cardiovascular Risk Calculator for RTR. After 7 years of follow-up, incidence of cardiovascular events and patient survival were assessed. Mean IMT at baseline (N = 192), was 0.64 ± 0.14 mm. At M6 (N = 158), 0.66 ± 0.15, M24 IMT was 0.68 ± 0.15 (N = 95). No significant differences between groups concerning IMT, true CV events and mortality, CV risk profile, predicted MACE/Mortality were found between mTORi and CNI-based regimen after 7 years of follow-up.

Simultaneous pancreas-kidney transplantation in patients with type 1 diabetes reverses elevated MBL levels in association with MBL2 genotype and VEGF expression.

AIMS/HYPOTHESIS: High levels of circulating mannan-binding lectin (MBL) are associated with the development of diabetic nephropathy and hyperglycaemia-induced vasculopathy. Here, we aimed to assess the effect of glycaemic control on circulating levels of MBL and the relationship of these levels with vascular damage. METHODS: We assessed MBL levels and corresponding MBL2 genotype, together with vascular endothelial growth factor (VEGF) levels as a marker of vascular damage, in type 1 diabetes patients with diabetic nephropathy before and after simultaneous pancreas-kidney (SPK) transplantation. We included diabetic nephropathy patients (n = 21), SPK patients (n = 37), healthy controls (n = 19), type 1 diabetes patients (n = 15) and diabetic nephropathy patients receiving only a kidney transplant (n = 15). Fourteen diabetic nephropathy patients were followed up for 12 months after SPK. RESULTS: We found elevated circulating MBL levels in diabetic nephropathy patients, and a trend towards elevated circulating MBL levels in type 1 diabetes patients, compared with healthy control individuals. MBL levels in SPK patients completely normalised and our data indicate that this predominantly occurs in patients with a polymorphism in the MBL2 gene. By contrast, MBL levels in kidney transplant only patients remained elevated, suggesting that glycaemic control but not reversal of renal failure is associated with decreased MBL levels. In line, levels of glucose and HbA1c, but not creatinine levels and estimated GFR, were correlated with MBL levels. VEGF levels were associated with levels of MBL and HbA1c in an MBL-polymorphism-dependent manner. CONCLUSIONS/INTERPRETATION: Taken together, circulating MBL levels are associated with diabetic nephropathy and are dependent on glycaemic control, possibly in an MBL2-genotype-dependent manner.

Differential effect of pretransplant blood transfusions on immune effector and regulatory compartments in HLA-sensitized and nonsensitized recipients.

BACKGROUND: Blood transfusion (BT) may elicit both harmful and beneficial immune responses against a subsequent organ graft. Immune parameters of a single, non leukocyte-depleted BT were investigated in two groups: non-human leukocyte antigen (HLA)-sensitized recipients with a one-HLA-DR matched donor (protocolled BT [PBT]) and females with previous exposure to HLA alloantigens through pregnancy (donor-specific transfusion [DST]). METHODS: Thirty-five percent of DST recipients and 9.5% of PBT recipients developed HLA antibodies after BT.Phenotypic and functional analyses were performed in pre-BT, 2 weeks post-BT, and more than 10 weeks post-BT samples (PBT: n=10; DST: n=14). RESULT: The number of donor-reactive interferon-γ-producing memory T cells increased 2 weeks post-BT, but only in the DST group, increased frequencies persisted beyond 10 weeks (P0.004). In the DST recipients, the proportion of natural killer cells (CD3(-)CD56(+)) significantly increased after BT (P=0.01), whereas in PBT recipients, the proportion of regulatoryT cells (CD4(+)CD25(+)Foxp3(+)CD127 low) significantly increased at 2 weeks post-BT (P=0.039). Microarray analysis confirmed increased activity of genes involved in function of natural killer cells,Tcells, and Bcells in DSTrecipients and increased expression of immune regulatory genes (galectin-1, Foxo3a, and follistatin-like 3) in PBT recipients. Galectin-1 expression by quantitative polymerase chain reaction was significantly enhanced in peripheral blood cells after PBT (P0.05). CONCLUSION: Decreased immune effector mechanisms combined with an increased immune regulatory cell signature after HLA-DR-matched BT in nonsensitized patients is in line with clinical observations of improved outcome of a subsequent graft. Previous sensitization, however, may lead to HLA antibody formation and prolonged donor-specific memory T-cell reactivity after BT.

Minimization of maintenance immunosuppression early after renal transplantation: an interim analysis.

INTRODUCTION: Chronic allograft nephropathy is the main cause of long-term renal transplant failure. Chronic use of calcineurin inhibitors contributes to its pathogenesis. Here, we report on a multicenter randomized trial to study the effects of withdrawal of cyclosporine A (CsA) from a triple immunosuppressive regimen containing CsA, prednisolone (P), and mycophenolate sodium (MPS) early after transplantation. METHODS: Patients continued on P/CsA, P/MPS, or P and everolimus (EVL). Before withdrawal, a transplant biopsy was performed ensuring no subclinical rejection was present. Drug levels were closely monitored. The primary outcome was interstitial graft fibrosis and hyalinosis. Secondary outcome was among others graft rejection. RESULTS: According to trial regulations, an interim analysis was performed after enrollment of half of the intended number of patients (n=113). Mean follow-up was 14+/-5 months from transplantation and 8+/-5 months from conversion. After conversion, acute rejection percentages were 3% in the P/CsA group, 22% in the P/MPS group, and 0% in the P/EVL group (P<0.009). CONCLUSIONS: We conclude that switching immunosuppressive therapy from P/CsA/MPS to therapy with P/CsA or P/EVL at 6 months after renal transplantation is effective in preventing rejection. Double therapy with P/MPS after withdrawal of P/CsA resulted in an increase in severe acute rejection episodes. These results were the immediate reason to halt the P/MPS arm. Serum creatinine values at the latest follow-up (8+/-5 months after conversion and 14+/-5 months after transplantation) in the P/EVL group were lower than in the P/CsA group.

Gallstone formation after pancreas and/or kidney transplantation: an analysis of risk factors.

Pancreas and kidney transplantation (SPK) is the treatment of choice for patients with type 1 diabetes mellitus and end-stage renal failure. Gallstones are common after SPK transplantation but little is known about the true incidence and etiology of gallstones in this group. We therefore evaluated the incidence of gallstones and the presence of transplant-related risk factors in patients after SPK and kidney transplantation alone (KTA). Data were evaluated of 56 consecutive patients who underwent SPK transplantation and compared the results with those of 91 consecutive nondiabetic patients who underwent KTA transplantation at the Leiden University Medical Center between 1987 and 1994. Of the 58 evaluable KTA patients, 20.7% developed gallstones during 7.7 yr of follow-up and in the SPK group 43.9% of the 41 evaluable patients developed gallstones during 7.1 yr of follow-up. Postoperative weight loss and cyclosporin A-related hepatotoxicity correlated with gallstone formation both in SPK and KTA patients. In addition, the duration of postoperative fasting and autonomic neuropathy correlated with gallstones in SPK patients. It is concluded that both in patients after SPK transplantation and in patients after KTA transplantation, the risk to develop gallstones is significantly increased. Physicians should be aware of the high incidence of gallstones in SPK recipients.