Belatacept Combined With Transient Calcineurin Inhibitor Therapy Prevents Rejection and Promotes Improved Long‐Term Renal Allograft Function

Belatacept, a T cell costimulation blocker, demonstrated superior renal function, lower cardiovascular risk, and improved graft and patient survival in renal transplant recipients. Despite the potential benefits, adoption of belatacept has been limited in part due to concerns regarding higher rates and grades of acute rejection in clinical trials. Since July 2011, we have utilized belatacept‐based immunosuppression regimens in clinical practice. In this retrospective analysis of 745 patients undergoing renal transplantation at our center, we compared patients treated with belatacept (n = 535) with a historical cohort receiving a tacrolimus‐based protocol (n = 205). Patient and graft survival were equivalent for all groups. An increased rate of acute rejection was observed in an initial cohort treated with a protocol similar to the low‐intensity regimen from the BENEFIT trial versus the historical tacrolimus group (50.5% vs. 20.5%). The addition of a transient course of tacrolimus reduced rejection rates to acceptable levels (16%). Treatment with belatacept was associated with superior estimated GFR (belatacept 63.8 mL/min vs. tacrolimus 46.2 mL/min at 4 years, p < 0.0001). There were no differences in serious infections including rates of cytomegalovirus or BK viremia. We describe the development of a costimulatory blockade‐based strategy that ultimately allows renal transplant recipients to achieve calcineurin inhibitor–free immunosuppression.     

Incidence of BK with Tacrolimus Versus Cyclosporine and Impact of Preemptive Immunosuppression Reduction

Our purposes were to determine the incidence of BK viruria, viremia or nephropathy with tacrolimus (FK506) versus cyclosporine (CyA) and whether intensive monitoring and discontinuation of mycophenolate (MMF) or azathioprine (AZA), upon detection of BK viremia, could prevent BK nephropathy. We randomized 200 adult renal transplant recipients to FK506 (n = 134) or CyA (n = 66). Urine and blood were collected weekly for 16 weeks and at months 5, 6, 9 and 12 and analyzed for BK by polymerase chain reaction (PCR). By 1 year, 70 patients (35%) developed viruria and 23 (11.5%) viremia; neither were affected independently by FK506, CyA, MMF or AZA. Viruria was highest with FK506-MMF (46%) and lowest with CyA-MMF (13%), p = 0.005. Viruria >/= 9.5 log(10) copies/mL was associated with a 3-fold increased risk of viremia and a 13-fold increased risk of sustained viremia. After reduction of immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction or graft loss. No BK nephropathy was observed. Choice of calcineurin inhibitor or adjuvant immunosuppression, independently, did not affect BK viruria or viremia. Viruria was highest with FK506-MMF and lowest with CyA-MMF. Monitoring and preemptive withdrawal of immunosuppression were associated with resolution of viremia and absence of BK nephropathy without acute rejection or graft loss.     

Prospective study of polyomavirus BK replication and nephropathy in renal transplant recipients in China: a single‐center analysis of incidence,reduction in immunosuppression and clinical course

Huang G, Chen L‐Z, Qiu J, Wang C‐X, Fei J‐G, Deng S‐X, Li J, Chen G‐D, Zhang L, Fu Q, Zeng W‐T, Zhao D‐Q. Prospective study of polyomavirus BK replication and nephropathy in renal transplant recipients in China: a single‐center analysis of incidence, reduction in immunosuppression and clinical course.
Clin Transplant 2009 DOI: 10.1111/j.1399‐0012.2009.01141.x
© 2009 John Wiley & Sons A/S. Abstract: Background: BK virus (BKV)‐associated nephropathy (BKVAN) in renal transplant recipients is an important cause of renal transplant dysfunction. Our aim was to determine the kinetics of BKV load within one yr after kidney transplantation under the impact of intensive monitoring and reduction in maintenance immunosuppression, the incidence of BKVAN, and the outcome of BKVAN treatment. Methods: Urine and peripheral blood (PB) were taken from 90 renal transplant recipients for BKV cytological testing and real‐time PCR for BKV DNA at one, three, six, nine, and 12 months after transplantation and treatment. Graft biopsies and urinary sediments of recipients with BKVAN were taken to monitor viral particles by conventional transmission electron microscopy (TEM). Results: By one post‐transplant year, urinary decoy cells (median, 8/10 HPF), BKV viruria (median, 2.60 × 10⁵ copies/mL), viremia (median, 9.65 × 10³ copies/mL ) , and BKVAN occurred in 42.2%, 45.6%, 22.2%, and 5.6% of patients, respectively. The incidence of BK infection was lower in patients who received cyclosporine A (CsA) (28.9%) compared to tacrolimus (FK506) (57.7%) (p = 0.007). An increased hazard of BK infection was associated with the use of FK506 (HR 2.6, p = 0.009) relative to CsA. After reduction in immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction, or graft loss. BKVAN was diagnosed in five patients (5.6%). The treatment of immunosuppression reduction was effective (i.e., decreased the viral load and number of decoy cells, and improved graft function) in our five patients with BKVAN. Quantitative count of decoy cells (e.g., >10 per 10 HPF) as a marker of viremia and BKVAN had increased positive predictive values of 85.7% and 57.1%, respectively. Conclusions: Choice of FK506 as immunosuppressive agent is an independent risk factor affecting BKV infection. Monitoring and pre‐emptive of immunosuppression reduction were associated with resolution of viremia and showed effective in BKVAN recipients at the early stage without acute rejection or graft loss. Quantitative count of urine cytology is a very convenient, useful, and sensitive method for evaluating BKV infection in renal transplant recipients.     

Comparison of alemtuzumab vs. antithymocyte globulin induction therapy in primary non‐sensitized renal transplant patients treated with rapid steroid withdrawal

Alemtuzumab and rabbit antithymocyte globulin (rATG) are commonly used for induction therapy in renal transplantation. This retrospective, single‐center, cohort study evaluated cumulative incidence of one‐yr biopsy‐proven acute rejection (BPAR) among 200 consecutive primary non‐sensitized kidney transplant recipients who received either alemtuzumab (n = 100) or rATG (n = 100) induction followed by rapid steroid taper, tacrolimus, and mycophenolate mofetil. Protocol biopsies, plasma and urine BK virus PCR, serum creatinine and iothalamate glomerular filtration rate (iGFR), were obtained at 1, 4, and 12 months from transplantation. The one‐yr BPAR rates were similar between the alemtuzumab and rATG groups; however, rejection Banff IA and higher was more common in the alemtuzumab arm (18% vs. 5%, p = 0.047). After adjusting for confounding variables, alemtuzumab was still associated with Banff IA and higher rejection (adjusted OR: 3.7, CI: 1.2–10.5, p = 0.02). Despite similar rates of BK viremia, more patients in the alemtuzumab arm developed BK nephropathy (16% vs. 3%, p = 0.046). One‐year iGFR (53.4 ± 20.2 vs. 71.9 ± 27.2 mL/min/1.73 m², p = 0.002) and three‐yr graft survival (89.5% vs. 95%, p = 0.05) were lower in the alemtuzumab group. In low immunological risk kidney transplant recipients on steroid‐free immunosuppression, alemtuzumab was associated with more severe rejection and BK nephropathy compared to rATG.     

Histological Evolution of BK Virus–Associated Nephropathy: Importance of Integrating Clinical and Pathological Findings

Long‐term clinicopathological studies of BK‐associated nephropathy (PyVAN) are not available. We studied 206 biopsies (71 patients), followed 3.09 ± 1.46 years after immunosuppression reduction. The biopsy features (% immunostain for PyV large T ag + staining and inflammation ± acute rejection) were correlated with viral load dynamics and serum creatinine to define the clinicopathological status (PyVCPS). Incidence of acute rejection was 28% in the second biopsy and 50% subsequently (25% mixed T cell–mediated allograft rejection (TCMR) + antibody‐mediated allograft rejection (AMR); rejection overall affected 38% of patients (>50% AMR). Graft loss was 15.4% (0.8–5.3 years after PyVAN); 76% had complete viral clearance (mean 28 weeks). The only predictors of graft loss were acute rejection (TCMR p = 0.008, any type p = 0.07), and increased “t” and “ci” in the second biopsy (p = 0.006 and 0.048). Higher peak viremia correlated with poorer viral clearance (p = 0.002). Presumptive and proven PyVAN had similar presentation, evolution, and outcome. Late PyVAN (>2 years, 9.8%) justifies BK viremia evaluation at any point with graft dysfunction and/or biopsy evaluation. This study describes the histological evolution of PyVAN and corresponding clinicopathological correlations. Although the pathological features overall reflect the viral and immunological interactions, the PyVAN course remains difficult to predict based on any single feature. Appropriate clinical management requires repeat biopsies and determination of the PyVCPS at relevant time points, for corresponding personalized immunosuppression adjustment.     

Daclizumab Versus Rabbit Antithymocyte Globulin in High‐Risk Renal Transplants: Five‐Year Follow‐up of a Randomized Study

We previously reported a randomized controlled trial in which 227 de novo deceased‐donor kidney transplant recipients were randomized to rabbit antithymocyte (rATG, Thymoglobulin) or daclizumab if they were considered to be at high immunological risk, defined as high panel reactive antibodies (PRA), loss of a first kidney graft through rejection within 2 years of transplantation, or third or fourth transplantation. Patients treated with rATG had lower incidences of biopsy‐proven acute rejection (BPAR) and steroid‐resistant rejection at 1 year. Patients were followed to 5 years posttransplant in an observational study; findings are described here. Treatment with rATG was associated with a lower rate of BPAR at 5 years (14.2% vs. 26.0% with daclizumab; p = 0.035). Only one rATG‐treated patient (0.9%) and one daclizumab‐treated patient (1.0%) developed BPAR after 1 year. Five‐year graft and patient survival rates, and renal function, were similar between the two groups. Overall graft survival at 5 years was significantly higher in patients without BPAR (81.0% vs. 54.8%; p < 0.001). In conclusion, rATG is superior to daclizumab for the prevention of BPAR among high‐immunological‐risk renal transplant recipients. Overall graft survival at 5 years was approximately 70% with either induction therapy, which compares favorably to low‐risk cohorts.     

The impact of surveillance and rapid reduction in immunosuppression to control BK virus‐related graft injury in kidney transplantation

We prospectively screened 609 consecutive kidney (538) and kidney‐pancreas (71) transplant recipients for BK viremia over a 4‐year interval using polymerase chain reaction viral load detection and protocol kidney biopsies. We found that BK viremia is common at our center: total cases 26.7%, cases during first year 21.3% (mean 4 months), and recipients with ≥10 000 copies/ml 12.3%. We found few predictive clinical or demographic risk factors for any BK viremia or viral loads ≥10,000 copies/ml, other than prior treatment of biopsy confirmed acute rejection and/or higher immunosuppressive blood levels of tacrolimus (P = 0.001) or mycophenolate mofetil (P = 0.007). Viral loads at diagnosis (<10 000 copies/ml) demonstrated little impact on graft function or survival. However, rising copy numbers demand early reductions in immunosuppressive drug doses of at least 30–50%. Viral loads >185 000 copies/ml at diagnosis were predictive of BK virus‐associated nephropathy (BKVAN; OR: 113.25, 95% CI: 17.22–744.6, P < 0.001). Surveillance for BK viremia and rapid reduction of immunosuppression limited the incidence of BKVAN to 1.3%. The addition of leflunomide or ciprofloxacin to immunosuppressive dose reduction did not result in greater rates of viral clearance. These data support the role of early surveillance for BK viremia to limit the impact on transplant outcome, although the most effective schedule for screening awaits further investigation.     

Tacrolimus‐ versus sirolimus‐based immunosuppression after simultaneous pancreas and kidney transplantation: 5‐year results of a randomized trial

Tacrolimus, the cornerstone immunosuppression after simultaneous pancreas and ‐kidney (SPK) transplantation, may exert nephrotoxic and diabetogenic effects. We therefore prospectively compared in an open‐label, randomized, monocentric, 5‐year follow‐up study, a tacrolimus‐ and a sirolimus‐based immunosuppressive regimen. Randomization using the block method allowing a blind allocation was done at the time of surgery. All patients received anti‐thymocyte globulin and maintenance therapy with tacrolimus, mycophenolate mofetil, and steroids. At month 3, tacrolimus was continued or replaced by sirolimus. The primary endpoint was kidney and pancreas graft survival at 1 and 5 years. Fifty patients were included in the final analysis in each group. At 1 year, differences for kidney and pancreas graft survival between sirolimus and tacrolimus were 0% (90% confidence interval ?4.61% to 4.61%) and 6% (90% confidence interval ?6.32% to 18.32%), respectively. There was no difference in renal and pancreas graft survival at 5 years. Thirty‐four patients (68%) in the sirolimus group vs three (6%) in the tacrolimus group needed definitive withdrawal of the study drug. Despite noninferiority of sirolimus compared to tacrolimus for kidney and pancreas graft survival, the high rate of sirolimus discontinuation does not favor its use as cornerstone therapy after SPK transplantation (NCT00693446).     

A Double‐Blind,Double‐Dummy,Flexible‐Design Randomized Multicenter Trial: Early Safety of Single‐ Versus Divided‐Dose Rabbit Anti‐Thymocyte Globulin Induction in Renal Transplantation

A previous nonblinded, randomized, single‐center renal transplantation trial of single‐dose rabbit anti‐thymocyte globulin induction (SD‐rATG) showed improved efficacy compared with conventional divided‐dose (DD‐rATG) administration. The present multicenter, double‐blind/double‐dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD‐rATG versus DD‐rATG induction for noninferiority in early (7‐day) safety and tolerability. Ninety‐five patients (randomized 1:1) received 6 mg/kg SD‐rATG or 1.5 mg/kg/dose DD‐rATG, with tacrolimus‐mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12‐month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD‐rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD‐rATG induction to be noninferior to DD‐rATG induction in early tolerability and equivalent in 12‐month safety. (Clinical Trials.gov #NCT00906204.)     

Long‐term graft function with tacrolimus and cyclosporine in renal transplantation: Paired kidney analysis

Aim: The first prospective, randomized trial with paired kidney analysis was conducted to compare the efficacy and safety of tacrolimus with cyclosporine‐based immunosuppressive therapy in renal transplant recipients. This paper reports the long‐term follow‐up results of the authors' previously published study, with the main focus on graft survival and renal function. Methods: Chinese patients transplanted in our centre between June 1998 and June 2005 with their first deceased renal transplant were included. Patients were included if both kidneys were received by the authors' centre, thus allowing a paired analysis. Patients were randomized to receive triple immunosuppressive therapy with either tacrolimus or Neoral cyclosporine, concomitantly with prednisolone and azathioprine therapy. Results: Seventy‐six patients received cadaveric kidneys from 38 donors. Each pair of kidneys was randomly assigned to a separate group (38 subjects/group). The mean follow‐up duration was 6.1 ± 1.8 years. The mean calculated creatinine clearance was significantly higher in patients receiving tacrolimus‐based therapy. The rate of biopsy‐proven acute rejection was lower in the tacrolimus group (18.4% vs 42.1%, P = 0.03). The patient and graft survival were comparable in both treatment arms. Significantly fewer patients on tacrolimus‐based therapy developed hypercholesterolaemia (P = 0.05). However, there was no significant difference in the development of post‐transplant diabetes mellitus, hypertension, opportunistic infection and malignancy between both groups. Conclusion: Using the immunosuppressive regimen, tacrolimus‐based therapy provided adequate immunosuppression with better renal function and less acute rejection, as compared with cyclosporine‐based therapy.     

Prevalence and clinical course of BK virus nephropathy in pancreas after kidney transplant patients

The influence of BK virus nephropathy (BKVN) in pancreas after kidney (PAK) transplantation is unclear. A retrospective analysis of PAK transplants performed at our center was conducted to determine the impact of BKVN. Among 40 PAK transplants performed using sequential immunosuppression, four patients developed BKVN, as defined by a >20% rise in serum creatinine and BK viremia (BK plasma load >4 log copies/mL), at a median of 19 months following PAK. In all four patients, treatment of BKVN consisted of reduction in tacrolimus, cessation of mycophenolate mofetil, and introduction of leflunomide. With this approach, two patients experienced improvement or stabilization of renal function. The remaining two patients progressed to dialysis dependence despite treatment. Plasma BK load < or =5 log copies/mL was associated with graft preservation. Gender, age, delay between transplants, cumulative Thymoglobulin dose, and type of kidney donor were not associated with BK virus infection. Pancreas graft rejection or dysfunction was not observed with the above immunosuppression modification. Mean amylase and lipase > or =6 months following BKVN treatment remained normal. BKVN is an important cause of kidney allograft loss in PAK patients. Screening and early treatment of BKVN may enable preservation of kidney and pancreas grafts.     

Complete Avoidance of Calcineurin Inhibitors in Renal Transplantation: A Randomized Trial Comparing Sirolimus and Tacrolimus

Calcineurin inhibitors have decreased acute rejection and improved early renal allograft survival, but their use has been implicated in the development of chronic nephrotoxicity. We performed a prospective, randomized trial in kidney transplantation comparing sirolimus-MMF-prednisone to tacrolimus-MMF-prednisone. Eighty-one patients in the sirolimus group and 84 patients in the tacrolimus group were enrolled (mean follow-up = 33 months; range 13-47 months). At 1 year, patient survival was similar in the groups (98% with sirolimus, 96% with tacrolimus; p = 0.42) as was graft survival (94% sirolimus vs. 92% tacrolimus, p = 0.95). The incidence of clinical acute rejection was 10% in the tacrolimus group and 13% in the sirolimus group (p = 0.58). There was no difference in mean GFR measured by iothalamate clearance between the tacrolimus and sirolimus groups at 1 year (61 +/- 19 mL/min vs. 63 +/- 18 mL/min, p = 0.57) or 2 years (61 +/- 17 mL/min vs. 61 +/- 19 mL/min, p = 0.84). At 1 year, chronicity using the Banff schema showed no difference in interstitial, tubular or glomerular changes, but fewer chronic vascular changes in the sirolimus group. This study shows that a CNI-free regimen using sirolimus-MMF-prednisone produces similar acute rejection rates, graft survival and renal function 1-2 years after transplantation compared to tacrolimus-MMF-prednisone.     

Reduced‐Dose Tacrolimus with Mycophenolate Mofetil vs. Standard‐Dose Tacrolimus in Liver Transplantation: A Randomized Study

We conducted a multicenter randomized study in liver transplantation to compare standard‐dose tacrolimus to reduced‐dose tacrolimus with mycophenolate mofetil to reduce the occurrence of tacrolimus side effects. Two primary outcomes (censored criteria) were monitored during 48 weeks post‐transplantation: occurrence of renal dysfunction or arterial hypertension or diabetes (evaluating benefit) and occurrence of acute graft rejection (evaluating risk). Interim analyses were performed every 40 patients to stop the study in the case of increased risk of graft rejection. One hundred and ninety‐five patients (control: 100; experimental: 95) had been included when the study was stopped. Acute graft rejection occurred in 46 (46%) and 28 (30%) patients in control and experimental groups, respectively (HR = 0.59; 95% CI: [0.37–0.94]; p = 0.024). Renal dysfunction or arterial hypertension or diabetes occurred in 80 (80%) and 61 (64%) patients in control and experimental groups, respectively (HR = 0.68; 95% CI: [0.49–0.95]; p = 0.021). Renal dysfunction occurred in 42 (42%) and 23 (24%) patients in control and experimental groups, respectively (HR = 0.49; 95% CI: [0.29–0.81]; p = 0.004). Leucopoenia (p = 0.001), thrombocytopenia (p = 0.017) and diarrhea (p = 0.002) occurred more frequently in the experimental group. Reduced‐dose tacrolimus with mycophenolate mofetil reduces the occurrence of renal dysfunction and the risk of graft rejection. This immunosuppressive regimen could replace full‐dose tacrolimus in adult liver transplantation.     

Five‐Year Results of a Randomized Trial Comparing De Novo Sirolimus and Cyclosporine in Renal Transplantation: The Spiesser Study

Calcineurin inhibitors improve acute rejection rates and short‐term graft survival in renal transplantation, but their continuous use may be deleterious. We evaluated the 5‐year outcomes of sirolimus (SRL) versus cyclosporine (CsA) immunosuppressive treatment. This observational study was an extension of the SPIESSER study where deceased donor kidney transplant recipients were randomized before transplantation to a SRL‐ or CsA‐based regimen and followed up 1 year. Data from 131 (63 SRL, 68 CsA) out of 133 patients living with a functional graft at 1 year were collected retrospectively at 5 years posttransplant. Seventy percent of CsA patients versus 54% of SRL patients were still on the allocated treatment at 5 years (p = 0.091), most discontinuations in each group being due to safety issues. In intent‐to‐treat, mean MDRD eGFR was higher with SRL: 54.2 versus 45.3 mL/min with CsA (p = 0.019); SRL advantage was greater in on‐treatment analyses. There were no differences for patient survival (p = 0.873), graft survival (p = 0.121) and acute rejection (p = 0.284). Adverse events were more frequent with SRL (80% vs. 60%, p = 0.015). Results confirmed the high SRL discontinuation rate due to adverse events. Nevertheless, a benefit was evidenced on renal function in patients (more than 50%) still on treatment at 5 years.     

Reducing Immunosuppression Preserves Allograft Function in Presumptive and Definitive Polyomavirus‐Associated Nephropathy

Early detection of polyomavirus BK (BKV) viremia and reduction of immunosuppression is recommended for preventing polyomavirus‐associated nephropathy (PyVAN), but systematic histological evaluations were not performed in previous studies. We routinely screen for decoy cells and, if positive, measure plasma BKV‐loads. In a cohort of 203 consecutive renal transplantations performed from 2005–2008, 38 patients (19%) developed BKV‐viremia and were treated with reduction of immunosuppression. Based on subsequent allograft biopsy results and peak BKV‐viremia, patients were assigned to three groups: (i) definitive PyVAN (n = 13), (ii) presumptive PyVAN defined by plasma BKV‐loads of ≥4 log₁₀ copies/ml (n = 17) and (iii) low BKV‐viremia (n = 8). Clearance of BKV‐viremia was achieved in 35/38 patients (92%) and subsequent clinical rejection occurred in 3/35 patients (8.6%), both without any difference among the groups. Patients with definitive PyVAN had higher peak plasma BKV‐loads and required longer time for clearance (8.8 vs. 4.6 vs. 2.9 months; p = 0.001). However, allograft function remained stable from baseline to last follow‐up at 34 months (range 18–60) in all three groups with median serum creatinine of 1.6 mg/dl, 1.6 mg/dl and 1.3 mg/dl, respectively. We conclude that screening for BKV‐replication and reduction of immunosuppression is an effective strategy to preserve medium‐term allograft function even in patients developing definitive PyVAN.     

Late conversion of tacrolimus to sirolimus in a prednisone‐free immunosuppression regimen in renal transplant patients

Chhabra D, Grafals M, Cabral B, Leventhal J, Parker M, Gallon L. Late conversion of tacrolimus to sirolimus in a prednisone‐free immunosuppression regimen in renal transplant patients.
Clin Transplant 2009: DOI: 10.1111/j.1399‐0012.2009.01047.x
© 2009 John Wiley & Sons A/S. Abstract: Background: One of the most important causes of graft loss is chronic nephrotoxicity from calcineurin inhibitors. The aim of this study was to evaluate the feasibility and to assess the impact on rejection risk, graft loss and renal allograft function of converting patients from tacrolimus (Tac) to sirolimus (SRL) at one yr post‐transplantation (Tx) using a prednisone‐free immunosuppressive regimen. Methods: Two hundred fifty‐five kidney transplant patients were induced with Alemtuzumab and maintained on a steroid‐free regimen with Tac and mycophenolate mofetil. Thirty‐seven stable patients (14%) were converted from Tac to SRL at one yr post‐Tx. Results: The two groups were demographically similar. Mean post‐tx follow‐up was 2.8 ± 0.2 yr. Patient and graft survival were not statistically different. There was no significant difference in acute rejection episodes between the SRL and Tac groups (21% vs. 15%, p = 0.2). Calculated glomerular filtration rate (GFR), in the SRL group at 2.8 yr post‐tx, was 69 ± 13 mL/min from the one month post‐tx GFR of 53 ± 19 and 59 ± 23 mL/min from the one month post‐tx GFR of 56 ± 21 mL/min in the Tac group. Conclusions: Using a prednisone‐free regimen, the conversion of Tac to SRL at one yr post‐Tx was not associated with an increased risk of acute rejection or graft loss.     

Complete Steroid Avoidance Is Effective and Safe in Children With Renal Transplants: A Multicenter Randomized Trial With Three‐Year Follow‐Up

To determine whether steroid avoidance in pediatric kidney transplantation is safe and efficacious, a randomized, multicenter trial was performed in 12 pediatric kidney transplant centers. One hundred thirty children receiving primary kidney transplants were randomized to steroid‐free (SF) or steroid‐based (SB) immunosuppression, with concomitant tacrolimus, mycophenolate and standard dose daclizumab (SB group) or extended dose daclizumab (SF group). Follow‐up was 3 years posttransplant. Standardized height Z‐score change after 3 years follow‐up was –0.99 ± 2.20 in SF versus –0.93 ± 1.11 in SB; p = 0.825. In subgroup analysis, recipients under 5 years of age showed improved linear growth with SF compared to SB treatment (change in standardized height Z‐score at 3 years –0.43 ± 1.15 vs. –1.07 ± 1.14; p = 0.019). There were no differences in the rates of biopsy‐proven acute rejection at 3 years after transplantation (16.7% in SF vs. 17.1% in SB; p = 0.94). Patient survival was 100% in both arms; graft survival was 95% in the SF and 90% in the SB arms (p = 0.30) at 3 years follow‐up. Over the 3 year follow‐up period, the SF group showed lower systolic BP (p = 0.017) and lower cholesterol levels (p = 0.034). In conclusion, complete steroid avoidance is safe and effective in unsensitized children receiving primary kidney transplants.     

Randomized controlled trial assessing the impact of everolimus and low‐exposure tacrolimus on graft outcomes in kidney transplant recipients

This was a single‐center, randomized controlled trial assessing the impact of a 3‐month (10‐16 weeks) conversion to everolimus with low‐exposure tacrolimus, as compared to remaining on full exposure tacrolimus with mycophenolate (NCT 02096107). Adult kidney transplant recipients with a functioning graft were eligible for participation. Goal troughs in the intervention arm were 2‐5 ng/mL for tacrolimus and 3‐8 ng/mL for everolimus, with tacrolimus maintained at 5‐12 ng/mL in the control arm; 60 were randomized (30 in each arm) and were well matched at baseline; mean age was 51 years and 57% were African‐American. At 12‐months, fibrosis scores (27.8% tacrolimus/mycophenolate vs 22.9% tacrolimus/everolimus, P = .391), acute rejection rates (7% tacrolimus/mycophenolate vs 3% tacrolimus/everolimus, P = .554), and graft function (mean eGFR tacrolimus/mycophenolate 56 ± 15 vs tacrolimus/everolimus 59 ± 14 mL/min/1.73 m², P = .465) were similar between arms. The everolimus arm had significantly lower rates of CMV infection, severe BK infection, and improved BK viral clearance kinetics, as compared to the MPA arm. In this population, including a significant number of African‐Americans, an immunosuppression regimen of everolimus with low‐exposure tacrolimus provided similar efficacy to tacrolimus and mycophenolate, with significantly lower rates of BK and CMV.     

Clinical Outcomes of Everolimus With Reduced-Dose Tacrolimus vs Mycophenolate Mofetil With Standard-Dose Tacrolimus in De Novo ABO-Incompatible Kidney Transplant Recipients: 1-Year Follow-up

BackgroundOne of the major barriers for long-term renal graft survival is considered to be calcineurin inhibitor nephrotoxicity, contributing to chronic graft dysfunction. Thus, recent immunosuppressive strategies are focused on regimens that can reduce or avoid exposure to calcineurin inhibitors. Herein, we carried out a small-scale pilot study to assess whether everolimus (EVR) with reduced-dose tacrolimus (Tac) is an acceptable immunosuppressive regimen for patients with de novo ABO-incompatible kidney transplant compared with mycophenolate mofetil (MMF) with standard-dose Tac.MethodsThis retrospective single-center cohort study included patients who underwent ABO-incompatible kidney transplant at our institution between January 2016 and December 2019. Those whose immunosuppressive regimen was changed by reasons other than rejection during the 1-year follow-up period were excluded.ResultsA total of 24 patients were enrolled in this study: 10 patients who received an EVR with reduced-dose Tac regimen and 14 patients who received an MMF with standard-dose Tac regimen. Tac trough levels in the EVR group were significantly lower than those in the MMF group (P < .001). No patients died or lost their grafts during the follow-up period. There were no significant differences in renal function, proteinuria, and prevalence of hyperlipidemia between the 2 groups at 1 year after transplant. There were no significant differences in the incidence of rejection (acute cellular rejection, steroid-resistant acute cellular rejection, acute antibody-mediated rejection) and infection (cytomegalovirus viremia, cytomegalovirus disease, BK viremia, BK virus nephropathy) between the 2 groups.ConclusionsComparable with MMF with standard-dose Tac, EVR with reduced-dose Tac might be an acceptable immunosuppressive regimen for patients with de novo ABO-incompatible kidney transplant.     

Pathology of Resolving Polyomavirus‐Associated Nephropathy

Control of polyomavirus BK (BKV) is achieved by reducing immunosuppression allowing an effective BKV‐specific T‐cell response. The morphology of resolving BKV‐associated nephropathy (PyVAN) has not been systematically investigated. Ninety‐nine surveillance biopsies of 35 patients with BKV viremia treated exclusively by immunosuppression reduction were scored according to Banff criteria and grouped relative to BKV viremia as pre‐, increasing, decreasing and post‐BKV viremia. Thirty‐four of 35 patients (97%) cleared BKV viremia after a median of 9 months posttransplantation. The tubulitis score, extent of tubules with intraepithelial lymphocytes, and interstitial inflammation significantly increased from the time of increasing to decreasing viremia. Tubulointerstitial inflammation, to a lower extent, persisted after clearance. The number of SV40+ tubules correlated with the BKV load in plasma, but SV40 immunohistochemistry was frequently negative (60%). During decreasing viremia, 31% of PyVAN cases were plasma cell‐rich and 40% showed tubular HLA‐DR expression. Compared to baseline 1 month posttransplantation, allograft function remained stable or improved in 29/35 patients (83%) after a median follow‐up of 48 months. Within 1 year after clearance of BKV viremia, clinical rejection occurred in 2/35 patients (6%). Our data suggest that resolving PyVAN is typically characterized by a self‐limiting acute interstitial nephritis, morphologically indistinguishable from interstitial rejection.