Predictive model for delayed graft function based on easily available pre-renal transplant variables.

Identification of pre-transplant factors influencing delayed graft function (DGF) could have an important clinical impact. This could allow clinicians to early identify dialyzed chronic kidney disease (CKD) patients eligible for special transplant programs, preventive therapeutic strategies and specific post-transplant immunosuppressive treatments. To achieve these objectives, we retrospectively analyzed main demographic and clinical features, follow-up events and outcomes registered in a large dedicated dataset including 2,755 patients compiled collaboratively by four Italian renal/transplant units. The years of transplant ranged from 1984 to 2012. Statistical analysis clearly demonstrated that some recipients' characteristics at the time of transplantation (age and body weight) and dialysis-related variables (modality and duration) were significantly associated with DGF development (p ≤ 0.001). The area under the receiver-operating characteristic (ROC) curve of the final model based on the four identified variables predicting DGF was 0.63 (95 % CI 0.61, 0.65). Additionally, deciles of the score were significantly associated with the incidence of DGF (p value for trend <0.001). Therefore, in conclusion, in our study we identified a pre-operative predictive model for DGF, based on inexpensive and easily available variables, potentially useful in routine clinical practice in most of the Italian and European dialysis units.

Importance of vascular calcification in kidney transplant recipients.

BACKGROUND: Kidney transplantation is the treatment of choice for chronic kidney disease (CKD), but in kidney transplant recipients (KTRs) cardiovascular events are the first cause of death with a functioning graft, ranging from 36 to 55%. The impact of vascular calcification (VC) on morbidity and mortality of KTRs is not appreciated enough nowadays. SUMMARY: This review summarizes 13 important studies on VC in KTRs, comparing the results with CKD and dialysis populations. We focused on VC evaluation and use of coronary artery calcification (CAC) and aorta calcification (AoC) scores. We also evaluated the influence of traditional and non-traditional progression risk factors. KEY MESSAGES: VC strongly predicts cardiovascular events and all-cause mortality in KTRs. VC assessment is important in KTRs and based essentially on multislice computed tomography or electron beam computed tomography recognition of lesions. Quantitative measurement of CAC and AoC scores is essential for a correct definition of the calcium burden before and after kidney transplant. Progression of CAC slows down but does not halt after kidney transplant. A variable association of both traditional and non-traditional risk factors is shown. There is a strong association between baseline CAC score and CAC progression. A significant improvement in secondary hyperparathyroidism after transplantation favorably affects the progression of CAC. Low 25(OH)D3 levels are an independent determinant of CAC progression. Diabetes is a risk factor for the presence of CAC in KTRs, but has not been independently associated with CAC progression. The data published on the use of immunosuppressive drugs as progression factors are few and inconclusive.

MHC class II transactivator is an in vivo regulator of osteoclast differentiation and bone homeostasis co-opted from adaptive immunity.

The molecular networks controlling bone homeostasis are not fully understood. The common evolution of bone and adaptive immunity encourages the investigation of shared regulatory circuits. MHC Class II Transactivator (CIITA) is a master transcriptional co-activator believed to be exclusively dedicated for antigen presentation. CIITA is expressed in osteoclast precursors, and its expression is accentuated in osteoporotic mice. We thus asked whether CIITA plays a role in bone biology. To this aim, we fully characterized the bone phenotype of two mouse models of CIITA overexpression, respectively systemic and restricted to the monocyte-osteoclast lineage. Both CIITA-overexpressing mouse models revealed severe spontaneous osteoporosis, as assessed by micro-computed tomography and histomorphometry, associated with increased osteoclast numbers and enhanced in vivo bone resorption, whereas osteoblast numbers and in vivo bone-forming activity were unaffected. To understand the underlying cellular and molecular bases, we investigated ex vivo the differentiation of mutant bone marrow monocytes into osteoclasts and immune effectors, as well as osteoclastogenic signaling pathways. CIITA-overexpressing monocytes differentiated normally into effector macrophages or dendritic cells but showed enhanced osteoclastogenesis, whereas CIITA ablation suppressed osteoclast differentiation. Increased c-fms and receptor activator of NF-κB (RANK) signaling underlay enhanced osteoclast differentiation from CIITA-overexpressing precursors. Moreover, by extending selected phenotypic and cellular analyses to additional genetic mouse models, namely MHC Class II deficient mice and a transgenic mouse line lacking a specific CIITA promoter and re-expressing CIITA in the thymus, we excluded MHC Class II expression and T cells from contributing to the observed skeletal phenotype. Altogether, our study provides compelling genetic evidence that CIITA, the molecular switch of antigen presentation, plays a novel, unexpected function in skeletal homeostasis, independent of MHC Class II expression and T cells, by exerting a selective and intrinsic control of osteoclast differentiation and bone resorption in vivo.

Influence of the immunogenetic KIR and HLA systems on long-term renal transplant outcome.

BACKGROUND: Numerous studies have established the importance of innate immunity, particularly natural killer (NK) cells, in transplantation tolerance. NK cells express killer cell immunoglobulin-like receptors (KIRs) on their surface. By recognizing and binding major histocompatibility complex class I antigens, KIRs prevent autologous cell killing and promote lysis of non-self antigen-presenting cells. This study investigated the role of 16 KIR genes and donor-recipient KIR/HLA combinations on 5-year outcomes in a population of deceased donor kidney transplant recipients. MATERIAL/METHODS: We genotyped 126 renal transplant patients and their donors for HLA A, B, C, DR, and KIR genes. Patients underwent standardized transplantation and immunosuppressive protocols and were followed-up for 5 years. Graft function was evaluated by serum creatinine level and glomerular filtration rate calculated using the 4-variable modification of diet in renal disease (MDRD) equation. RESULTS: The presence of KIR2DS3 in the recipients was associated with better graft function indexes over time (p<0.05), but this effect was not confirmed by multivariate analysis. Conversely, the presence KIR2DS3 in the recipients combined with the presence of its HLA ligand in the donor had a detrimental effect on the trends of serum creatinine levels and eGFR trends, also confirmed by multivariate analysis. Kidney transplant recipients negative for the KIR2DL1 gene displayed higher creatinine levels after 5 years. Lastly, transplantation of HLA-A3/A11-negative donor kidneys into KIR3DL2-positive patients exerted a protective effect in terms of 5-years outcome (p<0.05). CONCLUSIONS: The present study demonstrates an important role of the KIR immunogenetic system in the long-term immune response to kidney transplantation.

The impact of apoptosis and inflammation gene polymorphisms on transplanted kidney function.

BACKGROUND: The progressive deterioration of kidney allograft function leads in most cases to transplant failure. Polymorphisms in genes encoding for inflammatory and apoptosis molecules may be one possible explanation for interindividual differences in kidney transplant outcomes. The objective of our work was to identify the possible effect of interleukin 6 (IL-6), transforming growth factor beta 1 (TGFB1), and Fas on graft function. MATERIAL AND METHODS: A case-control study was carried out to assess potential associations between polymorphisms in inflammation- and apoptosis-related genes and the risk for chronic impairment of kidney graft function. The study included 376 cadaveric kidney recipients, 256 of them with stable graft function and 120 who experienced renal deterioration during the follow-up period of 2.6 ± 1.4 years. Genotyping of IL-6/G-174C, TGFB1/L10P, TGFB1/R25P, and Fas/G-670A polymorphisms was performed by PCR-RFLP and direct sequencing. RESULTS: Considering the single IL-6, TGFB1, and Fas polymorphisms, we found similar allelic and genotype frequencies between the 2 groups. To test the hypothesis of mutual effects of polymorphisms, multiple logistic regression was performed incorporating data for all the possible dual genotypic associations. The association of IL-6 high producer and Fas low producer genotype resulted in a protective effect against graft dysfunction (OR=0.79; 95% C.I.=0.72-0.86). CONCLUSIONS: This study did not find significant associations of apoptosis and inflammation gene polymorphisms with transplanted kidney function in Italian renal transplant recipients. However, our data seem to indicate that the carriage of IL-6 high producer/Fas low producer genotype has a protective effect against graft function loss.

Prediction of three-year outcome of renal transplantation from optimal donors versus expanded criteria donors.

BACKGROUND/AIMS: The shortage in organ supply has required the use of expanded criteria donors (ECD) for kidney transplantation. Current pre-transplant evaluations of ECD organs are based on histological, clinical or mixed criteria. This monocentric study investigates the predictivity of Karpinski's histological score on 3-year graft function in renal transplant. Ex-post classification using Nyberg's score was carried out to assess the reliability of a purely clinical score and its applicability for organ allocation. METHODS: We evaluated 407 deceased donors (251 optimal and 156 ECD) for renal transplants performed between 2001 and 2006. The differences in creatinine levels and MDRD-GFR at transplant and 1, 2 and 3 years post-transplant between optimal donors and ECD were recorded. Amongst ECD organs, the effect of different Karpinski score classes (0-1, 2, 3, 4, double transplants) on 3-year graft outcomes was analyzed. We then compared renal function over time across the Nyberg grades (A, B, C, and D). RESULTS: Karpinski scores 0-1 and 2 and double transplants were associated with improved graft function compared to scores 3 and 4. Nyberg's clinical score shows a good fit with medium-term outcome and Karpinski's score, but among the donors with a high Nyberg grade (C and D), it fails to differentiate between allocable or non-allocable organs (due to Karpinski's score ≥7). CONCLUSIONS: Our data demonstrate a correlation of histological damage at the time of transplant with 3-year graft function, but at present we are unable to provide any supposition on the possible outcome of the discarded kidneys.

Plasma cells require autophagy for sustainable immunoglobulin production.

The role of autophagy in plasma cells is unknown. Here we found notable autophagic activity in both differentiating and long-lived plasma cells and investigated its function through the use of mice with conditional deficiency in the essential autophagic molecule Atg5 in B cells. Atg5(-/-) differentiating plasma cells had a larger endoplasmic reticulum (ER) and more ER stress signaling than did their wild-type counterparts, which led to higher expression of the transcriptional repressor Blimp-1 and immunoglobulins and more antibody secretion. The enhanced immunoglobulin synthesis was associated with less intracellular ATP and more death of mutant plasma cells, which identified an unsuspected autophagy-dependent cytoprotective trade-off between immunoglobulin synthesis and viability. In vivo, mice with conditional deficiency in Atg5 in B cells had defective antibody responses, complete selection in the bone marrow for plasma cells that escaped Atg5 deletion and fewer antigen-specific long-lived bone marrow plasma cells than did wild-type mice, despite having normal germinal center responses. Thus, autophagy is specifically required for plasma cell homeostasis and long-lived humoral immunity.

Risk of de novo cancers after transplantation: results from a cohort of 7217 kidney transplant recipients, Italy 1997-2009.

To assess incidence and risk factors for de novo cancers (DNCs) after kidney transplant (KT), we carried out a cohort investigation in 15 Italian KT centres. Seven thousand two-hundred seventeen KT recipients (64.2% men), transplanted between 1997 and 2007 and followed-up until 2009, represented the study group. Person years (PY) were computed from 30 days after transplant to cancer diagnosis, death, return to dialysis or to study closure. The number of observed DNCs was compared to that expected in the general population of Italy through standardised incidence ratios (SIR) and 95% confidence intervals (CI). To identify risk factors, incidence rate ratios (IRR) were computed. Three-hundred ninety five DNCs were diagnosed during 39.598PYs, with Kaposi's sarcoma (KS), post-transplant lymphoproliferative disorders (PTLD), particularly non-Hodgkin' lymphoma (NHL), lung, kidney and prostate as the most common types. The overall IR was 9.98/1.000PY, with a 1.7-fold augmented SIR (95% CI: 1.6-1.9). SIRs were particularly elevated for KS (135), lip (9.4), kidney carcinoma (4.9), NHL (4.5) and mesothelioma (4.2). KT recipients born in Southern Italy were at reduced risk of kidney cancer and solid tumors, though at a higher KS risk, than those born in Northern Italy. Use of mTOR inhibitors (mTORi) exerted, for all cancers combined, a 46% significantly reduced risk (95% CI: 0.4-0.7). Our study findings confirmed, in Italy, the increased risks for cancer following KT, and they also suggested a possible protective effect of mTORi in reducing the frequency of post transplant cancers.

Reduction of oxidative damage reflects a better kidney transplantation outcome.

BACKGROUND/AIMS: DNA fragmentation is one of the typical features of apoptosis, frequently induced by oxidative stress. Increased oxidative stress is known to be related to several pathological processes. In this study, we assessed oxidative damage in the early follow-up period after kidney transplantation measuring DNA oxidation and fragmentation of mononuclear cells and the circulating levels of inflammatory cytokines. METHODS: Blood samples from 30 kidney transplant recipients were collected before transplantation and after 2 days, 1 month and 6 months. Oxidative DNA fragmentation was measured by Comet Assay, whereas DNA oxidation was evaluated measuring 8-OHdG leukocyte levels. Serum IL-1ß, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF-α were assayed using a multiplex ELISA analysis. RESULTS: At 6 months after transplantation, a significant reduction in DNA fragmentation and IL-6 plasma levels was observed; DNA oxidation was higher in patients with a worse outcome, with delayed graft function and low nutritional status. We also found a correlation of IL-6 and IL-10 levels with DNA fragmentation and of IL-10 levels with DNA oxidation. CONCLUSION: Low levels of oxidation and apoptosis at 6 months after transplantation correlate with a better recovery of renal function in kidney allografts. The measurement of cytokine levels confirmed a reduction of inflammatory parameters within 6 months of follow-up.

Cardiovascular disease in kidney transplant recipients: the prognostic value of inflammatory cytokine genotypes.

BACKGROUND: Cardiovascular disease (CVD) represents the main cause of morbidity and mortality after renal transplantation. In view of the modern paradigm of atherosclerosis as an inflammatory disease, this study investigated the impact of inflammatory cytokine polymorphisms on posttransplant CVD. METHODS: The association between cytokine polymorphisms and CVD was assessed in a case-control study to identify the differences in genotype distributions between kidney allografts with or without posttransplant CVD. To validate our results in two independent groups, we divided a cohort of 798 renal transplant recipients according to geographic area: an evaluation cohort of 478 patients from Emilia-Romagna and a validation cohort of 320 patients from the rest of Italy. Tumor necrosis factor (TNF)-alpha, transforming growth factor-beta1, interleukin (IL)-10, IL-6, interferon-gamma, and IL-8 polymorphisms were analyzed, and thereafter, the cytokine production genotype was assigned. RESULTS: In the evaluation cohort, the patients in the CVD and no-CVD groups differed significantly in TNF-alpha and IL-10 genotype frequencies. Using multivariate analyses to test the association with CVD, the TNF-alpha high-producer genotype was associated with a significantly increased cardiovascular risk (odds ratio [OR]=4.41, 95% confidence interval (CI)=2.53-7.67). Conversely, the IL-10 high-producer genotype resulted protective against CVD (OR=0.07, 95% CI=0.02-0.29). These findings were confirmed in the validation cohort where the carriers of the TNF-alpha high-producer genotype proved to be at 2.45-fold increased cardiovascular risk (OR=2.45, 95% CI=1.29-4.63), whereas the IL-10 high-producer genotype was associated with a 0.08-fold reduced risk (OR=0.08, 95% CI=0.02-0.36). CONCLUSIONS: This work suggests a prognostic value of TNF-alpha and IL-10 genotypes, which might represent cardiovascular risk markers in renal transplant.

Everolimus with very low-exposure cyclosporine a in de novo kidney transplantation: a multicenter, randomized, controlled trial.

BACKGROUND: In combination with everolimus (EVL), cyclosporine A (CsA) may be used at low exposure, so reducing the risk of renal dysfunction in renal transplant recipients (RTR). We evaluated whether higher exposure of EVL could allow a further reduction of CsA. METHODS: De novo RTR were randomized to standard exposure EVL (C0 3-8 ng/mL) with low-concentration CsA (C2 maintenance levels 350-500 ng/mL, group A) or higher EVL exposure (C0 8-12 ng/mL) with very low-concentration CsA (C2 maintenance levels 150-300 ng/mL, group B). The primary endpoints were 6-month creatinine clearance (CrCl) and biopsy-proven acute rejection (BPAR) rate. After 6 months, patients were followed up (observational extension) to 12 months. RESULTS: Two hundred eighty-five RTR (97% from deceased donors) were enrolled. Two patients per group died (1.4%). The 6-month death-censored graft survival was 90.2% in group A and 97.9% in group B and was unchanged at 12 months (P=0.007). There was no significant difference between groups at 6 months in CrCl (59.9 vs. 57.8 mL/min) and BPAR rates (14.7% vs. 11.9%) and also at 12 months (CrCl 62.5+/-20.7 vs. 61.3+/-22.0 mL/min, BPAR 14.7% vs. 14.1%). No significant differences were seen in treated acute rejections, steroid-resistant acute rejections, treatment failures, or delayed graft function, although there was a trend to better results in group B. CONCLUSIONS: EVL given at higher exposure for 6 months plus very low CsA concentration may obtain low acute rejection rate and good graft survival in De novo renal transplantation. However, there was no difference between groups in CrCl.

Chronic allograft nephropathy--a clinical syndrome: early detection and the potential role of proliferation signal inhibitors.

Chronic allograft nephropathy (CAN) leads to the majority of late graft loss following renal transplantation. Detection of CAN is often too late to permit early intervention and successful management. Most current strategies for managing CAN rely on minimizing or eliminating calcineurin inhibitors (CNIs) once CAN has become established. The proliferation signal inhibitors everolimus and sirolimus have potent immunosuppressive and antiproliferative actions, with the potential to alter the natural history of CAN by reducing CNI exposure whilst avoiding acute rejection. Whilst data will be forthcoming from a number of clinical trials investigating this potential, we discuss early detection of CAN and the rationale for a role for this class of agent.

[Clinical evaluation of living donor]. / La valutazione clinica del donatore vivente.

When possible, living donor transplantation represents the best therapeutic strategy for patients suffering from chronic renal failure. Studying the donor allows a complete and thorough clinical, laboratory and instrumental assessment that guarantees good organ function whilst protecting the health of the donor. The main parameters considered within this framework are age, renal function, nephrological complications, comorbidities (diabetes, hypertension, obesity, etc.), malignancies, and infection. Moreover, particular attention is paid to the sociopsychological aspects of the donation, particularly related to the donor, the recipient, and the entire family situation.

An in vivo autotransplant model of renal preservation: cold storage versus machine perfusion in the prevention of ischemia/reperfusion injury.

There is increasing proof that organ preservation by machine perfusion is able to limit ischemia/reperfusion injury in kidney transplantation. This study was designed to compare the efficiency in hypothermic organ preservation by machine perfusion or cold storage in an animal model of kidney autotransplantation. Twelve pigs underwent left nephrectomy after warm ischemic time; the organs were preserved in machine perfusion (n = 6) or cold storage (n = 6) and then autotransplanted with immediate contralateral nephrectomy. The following parameters were compared between the two groups of animals: hematological and urine indexes of renal function, blood/gas analysis values, histological features, tissue adenosine-5'-triphosphate (ATP) content, perforin gene expression in kidney biopsies, and organ weight changes were compared before and after preservation. The amount of cellular ATP was significantly higher in organs preserved by machine perfusion; moreover, the study of apoptosis induction revealed an enhanced perforin expression in the kidneys, which underwent simple hypothermic preservation compared to the machine-preserved ones. Organ weight was significantly decreased after cold storage, but it remained quite stable for machine-perfused kidneys. The present model seems to suggest that organ preservation by hypothermic machine perfusion is able to better control cellular impairment in comparison with cold storage.

Expanding the evidence base in transplantation: the complementary roles of randomized controlled trials and outcomes research.

Transplantation offers a unique opportunity to demonstrate the complementary roles of randomized controlled trials and outcome research. The surgery and collaboration necessary for the transplant procedure makes randomization and blinding difficult. Because essentially every recipient is included in a transplant registry, sampling bias is minimized. Regulatory agencies generally do not consider outcomes research when assessing efficacy of new drugs or medical interventions. This workgroup summary examines the suitability of outcomes research to complement results of randomized controlled trials and related issues: efficacy versus effectiveness, internal versus external validity, data types, limitations, and analysis methodologies. Many advances in outcomes research have been pioneered in transplantation. A case is made for regulatory and reimbursement authorities to use outcomes research when making efficacy, effectiveness, and coverage decisions in transplantation.

Tubular dysfunction after peritonectomy and chemohyperthermic treatment with cisplatin.

Peritoneal carcinomatosis has always been regarded as a contraindication in traditional cancer surgery treatment; however, good results have been reported by using new combined medical-surgical loco-regional techniques. Peritonectomy and chemohyperthermic perfusion with cisplatinum (CIIP) seem to play a central role in obtaining a better survival rate than with the traditional procedures, even though there is a cisplatinum nephrotoxic effect. The aim of this study was to investigate entity and type of renal injury after CIIP. Forty-two patients (12 males and 30 females) with recurrent or primary peritoneal carcinomatosis who underwent peritonectomy and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy with cisplatin were enrolled. A significant worsening in renal function was observed on the third post-operative day and this condition then persisted for three months. A reduction in estimated-Glomerular Filtration Rate (e-GFR) and an alteration in the albumin:creatinine ratio proved tubular injury. On the third post-operative day after cisplatinum administration, a high toxicity peak was found following platinum free fraction excretion. Proximal tubular injury was confirmed even at the three month analysis. A significant correlation between the total protein reduction rate and the decrease in renal function was established. In relation to that, the platinum free fraction could increase because of a binding protein shortage and the nephrotoxic effect could be enhanced due to platinum accumulation within the post-operative period. This finding suggests that the higher the protein reduction is, the lower the e-GFR determination is at three months.

Clinical outcomes during the first three months posttransplant in renal allograft recipients managed by C2 monitoring of cyclosporine microemulsion.

BACKGROUND: MO2ART (monitoring of 2-hr absorption in renal transplantation) is the first prospective, multicenter trial of cyclosporine (CsA) blood level 2 hr postdose (C2) monitoring in de novo kidney recipients receiving CsA microemulsion (ME) (Neoral; Novartis, Basel, Switzerland). Efficacy and safety results from the first 3 months are presented here. METHODS: MO2ART is a 12-month, open-label, randomized study involving 296 patients. In all patients, the dose of CsA-ME was adjusted to achieve protocol-defined C2 targets of 1.6 to 2.0 microg/mL for the first month, with subsequent tapering. Randomization into two target groups occurred at 3 months. All patients received steroids and mycophenolate mofetil (89%) or azathioprine. For patients with delayed graft function, the protocol permitted reduced C2 targets and prophylactic administration of antibodies. RESULTS: At 3 months, overall incidence of biopsy-proven acute rejection was 11.5%. Median serum creatinine was 132 micromol/L. Patient and graft survival were 96.6% and 91.2%, respectively. C2 levels greater than 1.6 microg/mL were achieved within 5 days by 60.6% of patients with immediate graft function and 19.5% of patients with delayed graft function. Prophylactic antibodies were used in 15% of the total population. Twenty-four patients (8.1%) experienced serious adverse events with a suspected relation to CsA, and 26 patients (8.8%) discontinued the study because of adverse events (n=15) or after a switch in immunosuppression after rejection episodes (n=11). CONCLUSIONS: Patient management by C2 monitoring resulted in a low incidence of biopsy-proven acute rejection in standard risk de novo kidney recipients, 85% of whom did not receive prophylactic antibodies. CsA-ME with C2 monitoring provides excellent short-term efficacy and safety among de novo renal transplant patients.