Immune Profiling of Peripheral Blood Mononuclear Cells at Pancreas Acute Rejection Episodes in Kidney-Pancreas Transplant Recipients.

Profiling of circulating immune cells provides valuable insight to the pathophysiology of acute rejection in organ transplantation. Herein we characterized the peripheral blood mononuclear cells in simultaneous kidney-pancreas transplant recipients. We conducted a retrospective analysis in a biopsy-matched cohort (n = 67) and compared patients with biopsy proven acute rejection (BPAR; 41%) to those without rejection (No-AR). We observed that CD3+ T cells, both CD8+ and CD4+, as well as CD19+ B cells were increased in patients with BPAR, particularly in biopsies performed in the early post-transplant period (<3 months). During this period immune subsets presented a good discriminative ability (CD4+ AUC 0.79; CD8+ AUC 0.80; B cells AUC 0.86; p < 0.05) and outperformed lipase (AUC 0.62; p = 0.12) for the diagnosis of acute rejection. We further evaluated whether this could be explained by differences in frequencies prior to transplantation. Patients presenting with early post-transplant rejection (<3 months) had a significant increase in T-cell frequencies pre-transplant, both CD4+ T cells and CD8+ T cells (p < 0.01), which were associated with a significant inferior rejection-free graft survival. T cell frequencies in peripheral blood correlated with pancreas acute rejection episodes, and variations prior to transplantation were associated with pancreas early acute rejection.

Current Trends in Organ Preservation Solutions for Pancreas Transplantation: A Single-Center Retrospective Study.

Due to the high vulnerability of the pancreas to ischemia-reperfusion injury, choices regarding preservation solution markedly affect pancreas transplant success. A retrospective single-center analysis of 380 pancreas transplants (2000-2019) was performed to correlate current preservation solutions with transplant outcomes. Early graft failure requiring transplantectomy within 30 days post-transplant occurred in 7.5% for University of Wisconsin (UW) group (n = 267), 10.8% of Celsior (CS) group (n = 83), 28.5% of Histidine-Tryptophan-Ketoglutarate (HTK) group (n = 7), and none for Institut Georges Lopez-1 (IGL-1) group (n = 23). The most common causes of technical failures in this cohort included abdominal hemorrhage (8.4%); graft pancreatitis (3.7%); fluid collections (2.6%); intestinal complications (6.6%); and vascular thrombosis (20.5%). Although IGL-1 solution provided lower surgical complication rates, no significant differences were found between studied groups. Nevertheless, HTK solution was associated with elevated pancreatitis rates. The best graft survival was achieved at 1 year using UW and IGL-1, and at 3 and 5 years using IGL-1 (p = 0.017). There were no significant differences in patient survival after a median follow-up of 118.4 months. In this setting therefore, IGL-1 solution appears promising for perfusion and organ preservation in clinical pancreas transplantation, compared to other commonly used solutions.

Pancreas outcomes between living and deceased kidney donor in pancreas after kidney transplantation patients.

Background: Pancreas outcomes in pancreas after kidney transplantation (PAK) patients have been reported as being inferior to those of patients who receive simultaneous pancreas and kidney transplantation (SPK). The influence of the kidney donor (i.e. living versus deceased) has never been previously addressed. Methods: We retrospectively analysed all pancreas transplants performed in a single centre since 2007 and compared the outcomes between those patients who had previously received a living-donor kidney transplant (pancreas transplantation after living-donor kidney transplantation, PAldK; n = 18) or a deceased-donor kidney transplant (pancreas transplantation after deceased-donor kidney transplantation, PAddK; n = 28), using SPK (n = 139) recipients as a reference. Results: Pancreas survival was similar between all groups, but inferior for PAldK when including only those with a functioning graft at day 90 post-transplantation (P = 0.004). Pancreas acute rejection was significantly increased in PAldK (67%; 1.8 ± 1.4 episodes/graft) when compared with PAddK (25%) and SPK (32%) (P < 0.05) patients. In a multivariate Cox regression model including known risk factors for pancreas rejection, PAldK was the only predictor of acute rejection (hazard ratio 6.82, 95% confidence interval 1.51-30.70, P < 0.05). No association was found between donor-recipient HLA mismatches and graft rejection. Repeated HLA mismatches between kidney and pancreas donors (0 versus 1-6) did not correlate with pancreas graft rejection or survival in either PAK transplantation group (P > 0.05). Conclusion: Pancreas graft outcomes are worse for PAldK when compared with PAddK and SPK patients.

Epidemiology, risk factors, and impact of bacterial infections on outcomes for pancreatic grafts.

We aimed to determine the epidemiology, risk factors, and impact of bacterial infection on pancreatic function after pancreas transplantation. Data for pancreas transplant recipients were retrospectively reviewed between 2000 and 2014 for at least 1 year. We collected and analyzed post-transplant data for bacterial infection, morbidity, and mortality. During the study period, 312 pancreas transplants were performed. In total, 509 episodes of bacterial infection were diagnosed in 191 patients (61%). Multidrug-resistant (MDR) organisms were present in 173 of the 513 isolated microorganisms (33%). Risk factors independently associated with bacterial infection were acute allograft rejection (OR 1.7, 95%CI 1.1-3), the need for post-transplant hemodialysis, (OR 5.3, 95%CI 1.8-15.7) and surgical re-intervention (OR 2.8, 95%CI 1.5-5.1), which was also considered a risk factor for infections caused by MDR bacteria. Graft survival was associated with the occurrence of one or more episodes of bacterial infection (log-rank test = 0.009). Surgical re-intervention was independently associated with graft loss (OR 2.5, 95%CI 1.3-4.7). To conclude, pancreas recipients frequently experienced bacterial infections associated with the need for hemodialysis or surgical re-intervention. Infection by MDR organisms is a growing concern in these patients and was related to graft survival. Graft loss was independently associated with surgical re-intervention.

Borderline rejection in ABO-incompatible kidney transplantation.

INTRODUCTION: The clinical results of ABO-incompatible (ABOi) and ABO-compatible (ABOc) kidney transplantation (KT) are similar. Protocol kidney biopsies (PKB) of ABOi transplant recipients show positivity for C4d without evidence of antibody-mediated rejection (ABMR), but little is known about the histologic progression. METHOD: We evaluated histologic parameters in PKB at 12 months and also compared clinical outcome at 1 year. This is a prospective observational study conducted between 2009 and 2013. We performed 146/30 ABOc/ABOi consecutive living-donor KT with PKB as well as additional indication biopsies. In the ABOi group, the desensitization protocol consisted of rituximab, plasma exchange or immunoadsorption, and immunoglobulins. RESULTS: In indication biopsies during the first year, T-cell-mediated rejection Banff ≥immunoadsorption was 8.2% vs 6.7% (P=.561) and ABMR 4.8% vs 13.3% (P=.095). At 1 year, PKB (ABOc/ABOi) showed differences in borderline rejection lesions (6.8% vs 23.3% [P=.012]) and in C4d positivity in the ABOi group (P=.001). Interstitial fibrosis and tubular atrophy (IFTA) lesions (ABOc/ABOi) were 68.4% vs 63.2% (P=.348). Transplant glomerulopathy was 0.7% vs 3.3% (P=.373) at 1 year. CONCLUSIONS: Our PKB ABOi series shows at 1 year more borderline lesions independent of ABO titers, HLA incompatibility, and the presence of antidonor antibody, but do not show more IFTA nor transplant glomerulopathy. No clinical differences were observed between ABOi and ABO transplants.

An mTOR-inhibitor-based protocol and calcineurin inhibitor (CNI)-free treatment in kidney transplant recipients from donors after cardiac death: good renal function, but high incidence of conversion to CNI.

Donor after cardiac death (DCD) grafts have excellent survival despite the high incidence of delayed graft function (DGF). We assessed the feasibility of a mammalian target of rapamycin inhibitor (mTOR-I) protocol in uncontrolled DCD kidney transplantation and compared it with brain-dead donor (DBD) transplantation under calcineurin inhibitor (CNI) treatment. This retrospective study (2002-2011) included 109 Maastricht category II DCD patients and 218 standard-criteria DBD as controls. Immunosuppression consisted of polyclonal antibody induction, mycophenolate mofetil, prednisone, and mTOR-I (starting on day 6) in the DCD group and tacrolimus in the DBD group. DGF occurred in 72.5% of the DCD group vs. 26.1% of the DBD group (P = 0.001). Patient survival at 1 year was 99.1% vs. 95.9% (P = 0.112), and graft survival was 89% vs. 92.2% (P = 0.253). Patient survival at 5 years was 85.3% vs. 90.1% (P = 0.340) and graft survival was 85.5% vs. 78.8% (P = 0.166). During the first year, 46.8% (n = 51) of DCD patients were converted to CNI therapy. Serum creatinine at 1 year was 1.5(1.26-2) mg/dl vs. 1.4(1.16-1.8) mg/dl (P = 0.078). At 1 year, the acute rejection rate was 7.3% vs. 12.5% (P = 0.766). mTOR-I-based therapy was not associated with inferior graft function or higher rejection rates than standard CNI therapy. DCD kidney transplantation with an mTOR-I-based protocol is feasible but is associated with a high conversion rate to CNI-based therapy.

The Effect of Corticosteroid Withdrawal on Glucose Metabolism and Anti-GAD Antibodies in Simultaneous Pancreas-Kidney Transplant Patients.

CONTEXT: Corticosteroid withdrawal may reduce insulin resistance; however, it could also influence pancreatic autoantibody profile in simultaneous pancreas-kidney (SPK) transplant patients. OBJECTIVE: To evaluate the effect of corticosteroid withdrawal on glucose metabolism and anti-glutamic acid decarboxylase (GAD) antibody titers in SPK patients with type 1 diabetes after 12 months of follow-up. DESIGN: In this retrospective study, fasting glucose and glycated hemoglobin (A1c) were compared before and after 3, 6, and 12 months of corticosteroid withdrawal in 80 SPK patients. In addition, weight, anti-GAD, and C-peptide levels were compared before and after withdrawal. Finally, fasting and postglucose, insulin, and C-peptide levels were compared before and after withdrawal in 25 patients undergoing oral glucose tolerance test (OGTT). RESULTS: Fasting glucose levels did not change during corticosteroid discontinuation. After 12 months, A1c slightly increased from 4.6% (0.4%) to 4.8% (0.6%) (P < .01) and C-peptide decreased from 2.8 (1.1) ng/mL to 2.4 (1.3) ng/mL (P <. 01). In patients submitted to OGTT, glucose, insulin, and C-peptide levels did not change. There was no alteration in the proportion of anti-GAD positive tests (41% vs 45%). Anti-GAD titers remained stable or decreased in 70% of positive patients. CONCLUSION: Corticosteroid withdrawal has no significant effect on glucose metabolism and on anti-GAD profile among SPK patients.

Incidence and outcome of early Candida peritonitis after liver and pancreas transplantation.

Candida peritonitis is a potentially life-threatening infection after abdominal transplantation, although there is scant information regarding its incidence and outcome. We analysed the incidence rate and outcome of Candida peritonitis in 717 liver or pancreas transplant recipients. Five cases of Candida peritonitis were diagnosed, representing the second most frequent cause of invasive fungal infection in the cohort. The incidence rate of Candida peritonitis during the first 30 days after transplantation was 6.5 cases/10 000 transplant days in pancreas recipients and 1.2 cases/10 000 transplant days in liver recipients (P = 0.035). Four of the five patients received an echinocandin in combination with other antifungal. All patients were alive and with good graft function at 1-year follow-up. In our series, Candida peritonitis in liver and pancreas transplant recipients was not uncommon and had a good prognosis.

Pancreas and kidney transplantation: long-term endocrine function.

OBJECTIVE: To describe the characteristics of metabolic control and beta-cell function in the long-term follow-up of patients with type-1 diabetes (T1D) who have undergone pancreas and kidney transplantation (PKTx). PATIENTS AND METHODS: Twelve patients (eight males/four females) with normal pancreas and kidney graft function for more than 15 yr were included. Patient age at the time of transplantation was 35.8 ± 6.9, with a duration of diabetes of 19.0 ± 4.6 yr and time on dialysis of 18.7 ± 12.4 months. In all the cases, bladder derivation was performed to drain exocrine secretion, with subsequent conversion to the intestinal tract in 42% of the patients. The functional evaluation was made at one, five, 10, and 15 yr after PKTx determining: glycosylated hemoglobin (HbA1c), oral glucose tolerance test (OGTT), measuring insulinemia, and anti-GAD antibody. RESULTS: Comparing the results between one and 15 yr after transplantation: (i) no differences were observed in either HbA1c (4.68% vs. 4.76%) or basal glycemia (71 vs. 79 mg/dL), but an increase was seen in the area under the curve (AUC) of glucose (11,983 vs. 15,875 mg/dL/120', p = 0.02); (ii) a trend to a reduction in basal insulinemia (24 vs. 15 mU/L, p = 0.11) and a trend to a reduction in the AUC of insulinemia (8446 vs. 7057 mU/L/120', p = 0.22) were observed. The OGTT was normal in six patients, intolerant in two and diabetic in four patients. No variations were seen in insulin resistance (FIRI, QUICKI). Anti-GAD antibody became positive in one case. CONCLUSIONS: The results of this study demonstrate that pancreas transplantation has long-term functional viability, being an essential strategy for the treatment of patients with T1D with end-stage renal failure. Nevertheless, lesser response to OGTT can be expected suggesting certain deterioration in the functional capability of the pancreas graft during follow-up.

Combination of calcineurin and mTOR inhibitors in kidney transplantation: a propensity score analysis based on current clinical practice.

INTRODUCTION: The TRANSFORM study demonstrated that an immunosuppression based on a combination of calcineurin inhibitors and de-novo mTOR inhibitors (mTORi) is safe and effective in kidney transplant recipients. However, data that validate this approach in clinical practice are currently missing. MATERIALS AND METHODS: Analysis of 401 kidney transplant recipients transplanted from June 2013 to December 2016. All patients received tacrolimus with prednisone in combination with either mycophenolate (n = 186) or mTORi (either everolimus or sirolimus, n = 215). A propensity score to receive mTORi was calculated based on the inverse probability of treatment weighting (IPTW) from the following parameters: age and sex of donor and recipient, BMI, previous transplants, diabetes, cPRA, dialysis before transplantation, dialysis vintage, type of donor, ABO-incompatibility, HLA-mismatches, induction and ischemia time. Median follow-up was 2.6 [1.9; 3.7] years. RESULTS: Cox-regression analysis suggests good results for mTORi versus MPA in terms of 1-year biopsy-proven acute rejection (BPAR, P = 0.063), 1-year graft loss (P = 0.025) and patient survival (P < 0.001). Results observed for BPAR and graft failure were largely attributed to those patients that would have been excluded by the TRANSFORM because of some exclusion criteria (52.9% of the population, P = 0.003 for 1-year BPAR and P = 0.040 for graft loss). In patients who met selection criteria for TRANSFORM, no effect of treatment for BPAR or graft failure was observed, while the beneficial effect on overall survival persisted. CONCLUSIONS: In a real-life setting, a protocol based on de-novo mTORi with tacrolimus and prednisone could be employed as a standard immunosuppressive regimen and was associated with good outcomes.

Sequential quadruple immunosuppression including sirolimus in extended criteria and nonheartbeating donor kidney transplantation.

The aim was to evaluate feasibility and safety of calcineurin inhibitor-free immunosuppression in high-risk donor kidney transplantation with sequential sirolimus introduction. Kidney transplant patients (n=76) with a donor aged >60 years, donor with acute renal failure, or a nonheartbeating donor were included. Immunosuppression consisted of antithymocyte globulin or basiliximab, mycophenolate mofetil, prednisone, and sequential introduction of sirolimus. One-year patient survival was 96.2% and 95.8%; graft survival was 94.2% and 91.7%; acute rejection rates were 21.2% and 12.4%; delayed graft function was 21.2% and 66.7%; and creatinine clearance was 58+/-20 mL/min and 56+/-21 mL/min for the brain-dead donor group and the nonheartbeating donor group, respectively. Most adverse events were infections, but also three lymphoceles, three urinary fistulas, three wound seromas. Sequential sirolimus introduction in high-risk donor kidney transplantation was found to lead to good patient and graft survival and incidence of acute rejection and delayed graft function.

The influence of innate immunity gene receptors polymorphisms in renal transplant infections.

BACKGROUND: Genetically defined deficiencies in key components of the innate immune system have been associated with a greater risk of infection. The aim of this study was to assess the influence of genetic variability of innate immune receptors (mannose-binding lectin [MBL], mannose-associated serine-protease-2 [MASP-2], and Toll-like receptors [TLR4]) in the risk of infections after a kidney transplantation. METHODS: All patients undergoing a kidney or kidney-pancreas transplantation during a 3-year period were included. Functionally relevant mutations in MBL2, MASP2, and TLR4 genes were determined by DNA sequencing. The incidence of major bacterial infections, asymptomatic cytomegalovirus (CMV) infection, and CMV disease were compared among groups. RESULTS: There were no differences regarding major transplant characteristics among groups. Older age, requirements for posttransplant hemodialysis, and pretransplant diabetes, but not gene polymorphisms, were associated with a greater number of bacterial infections. In univariate analysis, low-MBL genotypes were associated with CMV disease in pretransplant CMV seropositive patients (P=0.015), whereas the TLR4 mutation was associated with higher risk of CMV primary infection (P=0.024). TLR4 mutation was an independent factor associated with CMV disease (odds ratio 5.84, 95% confidence interval 1.35-25.20, P=0.018). CONCLUSION: Polymorphisms of innate immunity receptors, especially TLR4 mutation, were associated with higher risk of CMV disease, while susceptibility to other infectious disorders was not observed.

Kidney transplant from a living monozygotic twin donor with no maintenance immunosuppression.

UNLABELLED: From a theoretical point of view, an alloimmune response can not take place, still some type of standard immunosuppression is used in about 60% of patients receiving kidney grafts from their monozygotic twins. We aimed at assessing clinical response in patients receiving renal grafts from a living monozygotic twin donor when no immunosuppressive therapy is used. METHODS: This is a retrospective observational study of patients receiving kidney grafts from their monozygotic twins from 1969 to 2013. The following data were recorded: age, renal graft recipient's primary disease, renal function, renal survival and overall survival. Immunosuppressive therapy included a single intraoperative dose of methylprednisolone 500 mg and no maintenance immunosuppression. RESULTS: Five patients with kidney grafts from their monozygotic twins were dentified in our centre. Mean age at transplantation was 33 years (27-39). One-year overall survival and graft survival were 100%. Mean creatinine level was 0.96 ± 0.2 one year after transplantation, and 1.2 ± 0.37 mg/dl at most recent follow-up. Two patients died with a functional graft more than 15 years after kidney transplantation (causes were melanoma and cardiovascular event respectively). Follow-up was lost in a patient one year after transplantation. Two patients are alive with a functioning graft at 18 months and 42.5 years after transplantation respectively. CONCLUSION: Kidney transplantation from a living monozygotic twin is associated to outstanding clinical outcomes. Immunossuppresive therapy to suppress alloimmune response in probably unnecessary 11 zygosity has been confirmed.

DXA variations and fractures after simultaneous pancreas-renal transplantation: results of a long-term follow-up.

Simultaneous pancreas-kidney transplant (SPKT) has been associated with an increased risk of fracture. We prospectively evaluated the long-term effects of SPKT on bone mineral density (BMD) and fracture risk. During 1998 to 1999, 29 participants were consecutively monitored, and 18 completed the 10-year follow-up. Laboratory blood parameters, lumbar-dorsal radiography, and DEXA were determined at baseline, 1 year, and 10 years. The medical record was reviewed for peripheral fragility fractures. The BMD revealed no changes between baseline and 1 or 10 years after SPKT. Lumbar-dorsal radiography showed 0% asymptomatic vertebral fractures at baseline and after 1 year with 16.7% at 10 years. Vertebral asymptomatic fractures were correlated with acute rejection episodes (P = 0.025). During the first year, no nonvertebral fractures were identified. At the end of the follow-up, 5 nonvertebral fractures in 4 patients were reported. Dorsal and lumbar spine fractures correlated with lumbar spine t score (r = -0.591, P =0.022) and peripheral fractures with femoral neck t score (r = -0.633, P = 0.013). Patients with SPKT did not show long-term significant loss of BMD. The incidence of vertebral fractures was low and related to steroid treatment; the incidence of peripheral fractures was higher and independent of clinical or biochemical parameters.

Long-term mycophenolate monotherapy in human leukocyte antigen (HLA)-identical living-donor kidney transplantation.

UNLABELLED: Although recipients of a first HLA-identical living-donor kidney transplant seem to need less immunosuppression, there are no guideline recommendations for these patients, and few prospective trials are available. METHODS: We analyzed all PRA-negative patients who received a first kidney transplant from an HLA-identical living donor. The patients received no antibody induction. An intraoperative bolus of 500 mg of methylprednisolone was administered. Then, steroid therapy was withdrawn within one week. Tacrolimus and mycophenolate treatment were started 3 days before transplantation with tacrolimus target levels of 4 to 8 ng/mL. In the absence of rejection, tacrolimus was withdrawn between 3 and 12 months post-transplant to reach mycophenolate mofetil monotherapy of 2 g/day or equivalent. RESULTS: Six patients were treated with the above protocol. At last follow-up, graft and patient survival were 100%. MDRD glomerular filtration rates were 54, 60, and 62 mL/min at 3 months, 12 months and last follow-up, respectively. None of the patients developed PRA post-transplant. One episode of acute rejection Banff IA occurred 9 years after transplantation due to non-adherence with good outcome after treatment. The mean number of concomitant drugs given with mycophenolate was 2.6. Four patients needed antihypertensive drugs. CONCLUSION: Steroid-free de novo treatment and calcineurin-inhibitor weaning with mycophenolate monotherapy is feasible in first HLA-identical kidney transplantation from a living sibling.

Preservation of pancreas graft function after complete venous thrombosis: report of four cases treated conservatively.

BACKGROUND: Pancreas graft thrombosis is the most common cause of technical graft failure, with an incidence of up to 20% is some series. In most instances, vascular thrombosis of the graft will require immediate removal to avoid further abdominal complications. We present a total of four cases of complete venous thrombosis with preservation of function that were managed conservatively, resulting in long-term graft function. METHODS: Retrospective analysis of our case series over 10 years was carried out, obtaining patients with complete graft thrombosis by Doppler ultrasound. We included in the study only those patients who remained asymptomatic with preserved graft function. The clinical status of the patients, radiological findings, and therapeutic approach are evaluated. Patient and graft outcomes are analyzed. RESULTS: Retrospective evaluation of 227 transplants, a total of four patients were found to have complete thrombosis of the graft, remaining asymptomatic and preserving function without complications. Graft thrombosis was found on routine Doppler ultrasound evaluation of the transplanted organs at a median time of 19 days (range, 11-28 days), angiographic confirmation was obtained in all cases. The clinical condition and the presence of collateral flow allowed for conservative treatment. Median hospital stay was 29 days (range, 16-38 days), with a median follow-up of 106 months (range, 24-110 months), all patients are alive with a functioning graft. CONCLUSIONS: In rare instances with complete thrombosis of the pancreas transplant in absence of clinical manifestations, the grafts can be closely monitored and treated with systemic anticoagulation, allowing long-term patient and graft survival.

Trasplante renal de donante vivo entre gemelos monocigotos sin inmunosupresión de mantenimiento / Kidney transplant from a living monozygotic twin donor with no maintenance immunosuppression

Los pacientes trasplantados de riñón de gemelo monocigótico reciben en un 60% de los casos algún tipo de inmunosupresión estándar a pesar de la imposibilidad teórica para generar una respuesta aloinmune. El objetivo de este estudio es evaluar la respuesta clínica de los receptores renales de donante vivo de gemelo monocigoto sin tratamiento inmunosupresor. Método: Estudio observacional retrospectivo entre 1969 y 2013 de pacientes trasplantados renales de donante vivo entre gemelos monocigotos. Se ha recogido edad y enfermedad primaria del receptor, función renal, supervivencia renal y global. El protocolo inmunosupresor consistía en la administración de una dosis única intraoperatoria de 500mg de metilprednisolona sin otra inmunosupresión de mantenimiento. Resultados: Se identificó a 5 receptores renales de gemelos idénticos en nuestro centro. Edad media en el momento del trasplante 33 años (27-39). La supervivencia a un año de los pacientes y el injerto fue del 100%. La creatinina media al año fue de 0,96±0,2 y al último seguimiento de 1,2±0,37mg/dl. Dos pacientes fallecieron con injerto funcional más de 15 años después del trasplante (uno debido a melanoma y otro debido a un evento cardiovascular). Se perdió el seguimiento de un paciente al año del trasplante. Los 2 pacientes restantes están vivos 18 meses y 42,5 años después del trasplante, respectivamente, con injerto funcionante. Conclusión: El trasplante renal entre gemelos monocigotos ofrece excelentes resultados clínicos. Probablemente el tratamiento inmunosupresor para inhibir la respuesta aloinmune es innecesario en estos casos cuando se haya comprobado la cigosidad (AU)

From a theoretical point of view, an alloimmune response can not take place, still some type of standard immunosuppression is used in about 60% of patients receiving kidney grafts from their monozygotic twins. We aimed at assessing clinical response in patients receiving renal grafts from a living monozygotic twin donor when no immunosuppressive therapy is used. Methods: This is a retrospective observational study of patients receiving kidney grafts from their monozygotic twins from 1969 to 2013. The following data were recorded: age, renal graft recipient's primary disease, renal function, renal survival and overall survival. Immunosuppressive therapy included a single intraoperative dose of methylprednisolone 500mg and no maintenance immunosuppression. Results: Five patients with kidney grafts from their monozygotic twins were dentified in our centre. Mean age at transplantation was 33 years (27-39). One-year overall survival and graft survival were 100%. Mean creatinine level was 0.96±0.2 one year after transplantation, and 1.2±0.37mg/dl at most recent follow-up. Two patients died with a functional graft more than 15 years after kidney transplantation (causes were melanoma and cardiovascular event respectively). Follow-up was lost in a patient one year after transplantation. Two patients are alive with a functioning graft at 18 months and 42.5 years after transplantation respectively. Conclusion: Kidney transplantation from a living monozygotic twin is associated to outstanding clinical outcomes. Immunossuppresive therapy to suppress alloimmune response in probably unnecessary 11 zygosity has been confirmed (AU)

The utility of the C-peptide in the phenotyping of patients candidates for pancreas transplantation.

It is not unusual for simultaneous pancreas and kidney transplantation (SPK) to be performed in patients with type 2 diabetes (T2D), clinically classified as having type 1 diabetes (T1D). C-peptide determination is useful to identify these patients. We describe the prevalence and characteristics of patients with C-peptide levels >3 ng/mL, classified with T2D in 172 patients referred for SPK from 1998-2006. Nine patients (5.2%) fulfilled this criteria (mean free C-peptide 9.08 ng/mL) and were older at diabetes onset (23.5 vs. 12 yr, p < 0.001) and at assessment (42.2 vs. 37.6 yr, p = 0.047) with shorter time between diabetes onset and renal failure (17.8 vs. 22.7 yr, p = 0.3) compared with T1D patients (mean free C-peptide 0.24 ng/mL). In our experience the prevalence of T2D in candidates for SPK is not negligible. Despite some clinical differences with T1D these T2D patients can phenotypically be confounded with T1D in the absence of C-peptide determination.

Influence of sirolimus on proteinuria in de novo kidney transplantation with expanded criteria donors: comparison of two CNI-free protocols.

BACKGROUND: The contribution of mammalian target of rapamycin (mTOR) inhibitors to proteinuria is controversial. The aim was to analyse proteinuria in suboptimal kidney calcineurin inhibitor-(CNI) free de novo immunosuppression. METHODS: All patients from our centre with donors >60 years and CNI-free treatment were included (n = 108). Patients were divided into two groups: (i) SRL group: sirolimus (SRL) + prednisone + mycophenolate mofetil (MMF) + antiCD25; (ii) MMF group: prednisone + MMF w/ or w/o antiCD25 (n = 75). Follow-up was 12 months. RESULTS: Donors were slightly younger in the SRL group (68 vs 71 years; P < 0.05), receptor age (67 vs 65 years) was not significantly different. Patient survival in the MMF group was 88 vs 94% in the SRL group, however, these differences did not reach statistical significance. One-year graft survival censored for death was 83% in the MMF group and 94% in the SRL group. Acute rejection rate was 45% in the MMF and 15% in the SRL group (P < 0.01). The incidence of CNI introduction was higher in the MMF-group (35 vs 5; P < 0.05). The intention-to-treat analysis revealed significant differences of proteinuria [SRL vs MMF at 12 months: 461 (163-6988) vs 270 (53-3029) mg/day], which did not exist in the on-therapy (OT) analysis [SRL vs MMF at 12 months: 357 (199-1428) vs 279 (53-3029) mg/day]. New onset nephrotic range proteinuria seemed to occur slightly more frequently in SRL patients (3/33 vs 1/75; P = 0.049), however, all four cases occurred in a context of recurrent disease, or previous drug-independent damage or non-adherence. All of these patients were converted to CNI. CONCLUSION: SRL-based compared with MMF-based treatment in kidney transplantation with advanced age donors is associated with an acceptable outcome, however, with increased proteinuria in the intention-to-treat analysis. A large subgroup of the patients in the MMF group experienced acute rejection and required conversion to CNI.