Early kinetics of donor-derived cell-free DNA after transplantation predicts renal graft recovery and long-term function.

BACKGROUND: Ischemia-reperfusion injury (IRI) upon transplantation is one of the most impactful events that the kidney graft suffers during its life. Its clinical manifestation in the recipient, delayed graft function (DGF), has serious prognostic consequences. However, the different definitions of DGF are subject to physicians' choices and centers' policies, and a more objective tool to quantify IRI is needed. Here, we propose the use of donor-derived cell-free DNA (ddcfDNA) for this scope. METHODS: ddcfDNA was assessed in 61 kidney transplant recipients of either living or deceased donors at 24 h, and 7, 14 and 30 days after transplantation using the AlloSeq cfDNA Kit (CareDx, San Francisco, CA, USA). Patients were followed-up for 6 months and 7-year graft survival was estimated through the complete and functional iBox tool. RESULTS: Twenty-four-hour ddcfDNA was associated with functional DGF [7.20% (2.35%-15.50%) in patients with functional DGF versus 2.70% (1.55%-4.05%) in patients without it, P = .023] and 6-month estimated glomerular filtration rate (r = -0.311, P = .023). At Day 7 after transplantation, ddcfDNA was associated with dialysis duration in DGF patients (r = 0.612, P = .005) and worse 7-year iBox-estimated graft survival probability (ß -0.42, P = .001) at multivariable analysis. Patients with early normalization of ddcfDNA (<0.5% at 1 week) had improved functional iBox-estimated probability of graft survival (79.5 ± 16.8%) in comparison with patients with 7-day ddcfDNA ≥0.5% (67.7 ± 24.1%) (P = .047). CONCLUSIONS: ddcfDNA early kinetics after transplantation reflect recovery from IRI and are associated with short-, medium- and long-term graft outcome. This may provide a more objective estimate of IRI severity in comparison with the clinical-based definitions of DGF.

Humoral and Cellular Immune Responses After a 3-dose Course of mRNA-1273 COVID-19 Vaccine in Kidney Transplant Recipients: A Prospective Cohort Study.

In kidney transplant recipients, there is discordance between the development of cellular and humoral response after vaccination against SARS-CoV-2. We sought to determine the interplay between the 2 arms of adaptive immunity in a 3-dose course of mRNA-1273 100 µg vaccine. Methods: Humoral (IgG/IgM) and cellular (N- and S-ELISpot) responses were studied in 117 kidney and 12 kidney-pancreas transplant recipients at the following time points: before the first dose, 14 d after the second dose' and before and after the third dose, with a median of 203 and 232 d after the start of the vaccination cycle, respectively. Results: After the second dose, 26.7% of naive cases experienced seroconversion. Before the third dose and in the absence of COVID-19, this percentage increased to 61.9%. After the third dose, seroconversion occurred in 80.0% of patients. Naive patients who had at any time point a detectable positivity for S-ELISpot were 75.2% of the population, whereas patients who maintained S-ELISpot positivity throughout the study were 34.3%. S-ELISpot positivity at 42 d was associated with final seroconversion (odds ratio' 3.14; 95% confidence interval' 1.10-8.96; P = 0.032). Final IgG titer was significantly higher in patients with constant S-ELISpot positivity (P < 0.001). Conclusions: A substantial proportion of kidney transplant recipients developed late seroconversion after 2 doses. Cellular immunity was associated with the development of a stronger humoral response.

Incidence of severe breakthrough SARS-CoV-2 infections in vaccinated kidney transplant and haemodialysis patients.

INTRODUCTION: Given the increased COVID-19 observed in kidney transplant recipients (KTRs) and haemodialysis patients, several studies have tried to establish the efficacy of mRNA vaccines in these populations by evaluating their humoral and cellular responses. However, there is currently no information on clinical protection (deaths and hospitalizations), a gap that this study aims to fill. METHODS: Observational prospective study involving 1,336 KTRs and haemodialysis patients from three dialysis units affiliated to Hospital Clínic of Barcelona, Spain, vaccinated with two doses of mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 mRNA vaccines. The outcomes measured were SARS-CoV-2 infection diagnosed by a positive RT-PCR fourteen days after the second vaccine dose, hospital admissions derived from infection, and a severe COVID-19 composite outcome, defined as either ICU admission, invasive and non-invasive mechanical ventilation, or death. RESULTS: Six per cent (18/302) of patients on haemodialysis were infected, of whom four required hospital admission (1.3%), only one (0.3%) had severe COVID-19, and none of them died. In contrast, 4.3% (44/1034) of KTRs were infected, and presented more hospital admissions (26 patients, 2.5%), severe COVID-19 (11 patients, 1.1%) or death (4 patients, 0.4%). KTRs had a significantly higher risk of hospital admission than HD patients, and this risk increased with age and male sex (HR 3.37 and 4.74, respectively). CONCLUSIONS: The study highlights the need for booster doses in KTRs. In contrast, the haemodialysis population appears to have an adequate clinical response to vaccination, at least up to four months from its administration.

Immunogenic and immunotolerogenic effects of extracorporeal photopheresis in high immunological risk kidney recipients. A single center case series.

The immunomodulatory effects of extracorporeal photopheresis (ECP) have been used for the treatment of T-cell mediated disorders, such as rejection in organ transplantation. Currently, it is an established therapy for heart and lung rejection, but not for kidney transplantation (KT), where experience is limited. In addition, some data suggest that ECP could generate an immune response against infections, thus being an alternative for the treatment of rejection in case of active or high-risk of infection. In the present study, we analyze four cases of use of ECP as concomitant therapy in patients with KT and high risk of opportunistic infections due to the high burden of immunosuppression throughout their renal diseases. Two patients had concomitant viral infection (cytomegalovirus and BK virus, respectively) and three patients were on treatment for graft rejection. In the two patients with active viral infection, the infection was successfully controlled during ECP treatment. In all cases, ECP has been shown to be a safe procedure, without complications.

Use of De Novo mTOR Inhibitors in Hypersensitized Kidney Transplant Recipients: Experience From Clinical Practice.

BACKGROUND: It is commonly believed that mTOR inhibitors (mTORi) should not be used in high-immunological risk kidney transplant recipients due to a perceived increased risk of rejection. However, almost all trials that examined the association of optimal-dose mTORi with calcineurin inhibitor (CNI) have excluded hypersensitized recipients from enrollment. METHODS: To shed light on this issue, we examined 71 consecutive patients with a baseline calculated panel reactive antibody (cPRA) ≥50% that underwent kidney transplantation from June 2013 to December 2016 in our unit. Immunosuppression was based on CNI (tacrolimus), steroids and alternatively mycophenolic acid (MPA; n = 38), or mTORi (either everolimus or sirolimus, n = 33, target trough levels 3-8 ng/mL). RESULTS: Demographic and immunological risk profiles were similar, and almost 90% of patients in both groups received induction with lymphocyte-depleting agents. Cox-regression analysis of rejection-free survival revealed better results for mTORi versus MPA in terms of biopsy-proven acute rejection (hazard ratio [confidence interval], 0.32 [0.11-0.90], P = 0.031 at univariable analysis and 0.34 [0.11-0.95], P = 0.040 at multivariable analysis). There were no differences in 1-year renal function, Banff chronicity score at 3- and 12-month protocol biopsy and development of de novo donor-specific antibodies. Tacrolimus trough levels along the first year were not different between groups (12-mo levels were 8.72 ± 2.93 and 7.85 ± 3.07 ng/mL for MPA and mTORi group respectively, P = 0.277). CONCLUSIONS: This single-center retrospective cohort analysis suggests that in hypersensitized kidney transplant recipients receiving tacrolimus-based immunosuppressive therapy similar clinical outcomes may be obtained using mTOR inhibitors compared to mycophenolate.

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.

Effect of mammalian target of rapamycin inhibitors on cytomegalovirus infection in kidney transplant recipients receiving polyclonal antilymphocyte globulins: a propensity score-matching analysis.

Mammalian target of rapamycin inhibitors (mTORi) prevents cytomegalovirus (CMV) infection in kidney transplant (KT) patients. From May 2010 to December 2013, all KT recipients were retrospectively analysed. Maintenance immunosuppression regimen was divided into mTORi or calcineurin inhibitors (CNI)-based regimen. Since June 2011, CMV-seropositive recipients (R+) treated with high-intensity immunosuppression and mTORi did not receive anti-CMV prophylaxis. We analysed 350 consecutive patients, of which 95 (27%) received mTORi and 255 (73%) CNI-based immunosuppression. A Cox-regression multivariate analysis showed that the use of mTORi-based immunosuppression during all follow-up reduced the risk of CMV infection (HR 0.36, 95% CI 0.15-0.89, P = 0.028) and confirmed in a propensity score-matched cohort (HR 0.4, 95% CI 0.1-0.9, P = 0.047). Early discontinuation of mTORi increased the risk of CMV infection (HR 3.2; 95% CI 1.7-6.0) in univariate analysis. The incidence of CMV infection was not higher among CMV R+ patients on mTORi and requiring high-intensity immunosuppression when CMV prophylaxis was not given. The use of mTORi protected for CMV infection in KT patients, allowing to avoid antiviral prophylaxis for R+ patients receiving high-intensity immunosuppression. The increased risk of CMV infection after early discontinuation of mTORi warrants further research.

Pregnancy in a renal transplant recipient with HIV-1 infection: a case report.

We report the first case of a pregnancy in a renal transplant recipient with HIV infection. She underwent renal transplantation in 2005 and became pregnant in 2009. The patient underwent vaginal delivery and a healthy full-term, female baby was born. Almost 6 years after delivery, both mother and child were doing well. The management of concurrent renal transplantation, HIV infection and pregnancy was extremely challenging. Women with HIV infection who have undergone renal transplantation should be accurately informed of the potential health risks for them and their offspring. Multidisciplinary teams are mandatory in order to properly manage these patients.

Pre-implantation analysis of kidney biopsies from expanded criteria donors: testing the accuracy of frozen section technique and the adequacy of their assessment by on-call pathologists.

Pre-implantation renal biopsies of expanded criteria donors are one of the criteria used for allocation decisions, but there are concerns about the impact of the interobserver variability and the technique to be used. The aim was (i) to compare the original report performed by on-call pathologists using frozen sections (FS) to a retrospective analysis carried out by a trained pathologist using the same frozen section, and (ii) to compare the same FS to subsequently obtained paraffin sections (PS) by the same pathologist. A total of 92 biopsies, 78 from transplanted and 14 from nontransplanted cases, were analyzed. Agreement between observers using the same FS was weaker than the correlation between FS and PS in all the examined parameters (Kendall's Tau b for the Remuzzi score 0.104 vs. 0.306). According to the Remuzzi score, the revised FS analysis would have resulted in a higher rate of organ discard (n = 19) than PS (n = 14) and the original report (n = 6). However, kidneys that would have been discarded according to the retrospective analysis showed adequate outcomes in terms of graft survival and function. Accordingly, the impact of interobserver and technique-related variability can be minimized by the use of a relatively low threshold (RS ≤ 4) for organ acceptance.

Enteric-coated mycophenolate sodium immunosuppression in renal transplant patients: efficacy and dosing.

Mycophenolate mofetil (MMF), a mycophenolic acid (MPA) formulation, has improved both short- and long-term outcomes following renal transplantation, but is often associated with gastrointestinal (GI) complications that can lead to dose reduction or discontinuation, potentially jeopardizing patient outcomes. Enteric-coated mycophenolate sodium (EC-MPS) delivers equivalent MPA exposure to MMF and offers the potential to reduce GI burden (while maintaining patient safety). Here we review the efficacy of EC-MPS compared with MMF in renal transplant patients in terms of biopsy-proven acute rejection and graft loss, and examine the use of EC-MPS in newer regimens such as intensified dosing and calcineurin inhibitor minimization.

Enteric-coated mycophenolate sodium in de novo and maintenance kidney-pancreas transplant recipients.

BACKGROUND: Our objective was to describe efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS) in de novo and maintenance recipients of kidney-pancreas transplant in the clinical practice. METHODS: Observational, multicentre, prospective, 12-month study. RESULTS: We included 24 de novo and 24 maintenance patients. EC-MPS mean (± SD) doses at initiation in de novo patients were 1440 ± 0 vs. 1268 ± 263 mg/d at month 12 (M12). Patient and renal graft survival at one yr were 100%, and pancreatic graft survival was 83.3% (two losses owing to technical failure and two owing to rejection). In the maintenance cohort, EC-MPS was introduced at a median (P25-P75) of 30 (6-71) months after transplant. Baseline doses were 585 ± 310 vs. 704 ± 243 mg/d at M12. In this group, a significant increase in creatinine clearance was observed (65 ± 22 at baseline vs. 74 ± 20 mL/min at M12, p = 0.011). Patient, renal, and pancreatic graft survival were 100%, 95.8%, and 100%, respectively (one kidney graft loss owing to rejection). During follow-up, one patient from each group discontinued EC-MPS. CONCLUSIONS: The efficacy of EC-MPS in the clinical practice of kidney-pancreas transplantation is good, with high patient and grafts survival at 12 months, and good safety profile. The maintenance group displayed an improvement in renal function.

Effect of thymoglobulin induction on HIV-infected renal transplant recipients: differences between HIV-positive and HIV-negative patients.

The best immunosuppressive regimen in HIV-infected renal transplant recipients has not been established. Thymoglobulin has been associated with an increased risk of serious bacterial infections in HIV-negative patients and, for this reason, there is some concern over its use in the HIV-infected population. We describe three consecutive HIV-infected renal transplant recipients who received thymoglobulin as induction therapy, and we compared their progress with a cohort of 23 HIV-negative recipients. Median follow-up was 24 and 11 months, respectively. Nadir lymphocytopenia was observed at 1 week in both groups, and their absolute lymphocyte count recovery was similar. An early and deep (<30 cells/mm(3)) CD4(+) T cell lymphocytopenia was seen in two of the three HIV-infected patients. No opportunistic infections were diagnosed in HIV-positive patients. One HIV-positive patient had a bacterial infection and five HIV-negative patients had one or more bacterial infections. Thymoglobulin was safe in our three HIV-infected renal transplant recipients. Until those data are confirmed in larger studies, close monitoring is recommended during the thymoglobulin-induced CD4(+) T cell lymphocytopenia period.

Efficacy and safety of enteric-coated mycophenolate sodium in renal transplant patients with diabetes mellitus: post hoc analyses from three clinical trials.

To examine the efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS, myfortic) in renal transplant patients with diabetes mellitus, six- and 12-month data from three clinical trials with EC-MPS (Studies B301, B302, and myPROMS) were analyzed post hoc. Studies B301 (de novo patients) and B302 (maintenance patients) followed a randomized double-blind design whereas myPROMS was an open-label study in de novo and maintenance renal transplant patients in which all patients received EC-MPS as part of their immunosuppressive regimen. In studies B301 and B302, diabetic patients were compared against mycophenolate mofetil (MMF, CellCept), the reference drug. For myPROMS, data from diabetic and non-diabetic patients were compared. In total, 246 diabetic patients receiving EC-MPS were analyzed. In study B301, the efficacy failure rate [biopsy-proven acute rejection (BPAR), graft loss, death or loss to follow-up] in diabetics at 12 months was 17.6% (EC-MPS) vs. 26.2% (MMF), and of BPAR alone 14.7% vs. 19.0% (both n.s.). In de novo patients from myPROMS, the treatment failure rate was similar in diabetic (20.3%) and non-diabetic patients (27.1%), as was the incidence of BPAR (17.7% vs. 23.1%, both n.s.). The overall incidence, severity and pattern of AEs were comparable between EC-MPS and MMF in de novo patients. This was supported by the safety results assessed in maintenance patients (B302) indicating no increased safety risk with the use of EC-MPS in the diabetic patient population, if compared with MMF. Likewise, apart from a higher incidence of severe/serious infections in diabetics, the safety profile of EC-MPS was not different to non-diabetics in myPROMS. In conclusion, preliminary data suggest that EC-MPS in combination with cyclosporine (+/- steroids) can be used efficiently and safely for the prophylaxis of organ rejection in diabetic renal transplant patients. Moreover, diabetic patients can apparently be safely converted from MMF to EC-MPS. More data from prospective studies are needed to fully judge the efficacy and safety profile of EC-MPS in the diabetic transplant population.

Randomized double-blind study of immunoprophylaxis with basiliximab, a chimeric anti-interleukin-2 receptor monoclonal antibody, in combination with mycophenolate mofetil-containing triple therapy in renal transplantation.

BACKGROUND: Acute rejection remains a major problem in renal transplantation. Immunoprophylaxis with basiliximab (Simulect) has achieved significant reductions in acute rejection episodes in renal allograft recipients receiving dual immunosuppression. This study explored the tolerability and cumulative benefit of combining basiliximab with triple-drug therapy-cyclosporine (USP Modified, Neoral), mycophenolate mofetil, and steroids. METHODS: In a randomized, double-blind, placebo-controlled, multicenter study, 123 kidney transplant recipients received either basiliximab at 20 mg before transplantation (day 0) and 20 mg on day 4 (n=59), or placebo (n=64). All received triple-drug immunosuppression and were followed for 6 months. RESULTS: Tolerability of basiliximab was equivalent to placebo, with no increase in serious adverse events, infection, malignancy, or posttransplant lymphoproliferative disorder. At 6 months, there were trends in favor of basiliximab over placebo in the incidences of first biopsy-confirmed acute rejection (15.3% vs. 26.6%, P=NS) and of acute rejection treated with antibody (5.1% vs. 15.6%, P=NS). Kaplan-Meier estimates at 4 weeks and 6 months were significantly in favor of basiliximab treatment for first acute rejection, biopsy-confirmed rejection, rejection episodes treated with antibody therapy, and treatment failure. Renal function improved more rapidly in the basiliximab group, with mean creatinine clearance at week 2 being 54.7 mL/min versus 43.2 mL/min for placebo (P=0.034). At 12 months, patient survival was 100% in both groups; graft survival was 94.9% with basiliximab and 92.2% with placebo. CONCLUSIONS: Basiliximab immunoprophylaxis is safe, well tolerated, and shows a trend toward reduction in number of acute rejection episodes in renal transplant patients receiving cyclosporine, mycophenolate mofetil, and steroids.