Long-Term Follow-Up of De Novo Use of mTOR and Calcineurin Inhibitors After Kidney Transplantation

The Interferon-Gamma +874 A/T Polymorphism Is Not Associated With CMV Infection After Kidney Transplantation

The +874 A/T polymorphism in the interferon gamma (IFNG) gene has been associated with Cytomegalovirus (CMV) infection risk in lung and kidney transplant recipients. To replicate this association, we performed a retrospective observational study of this polymorphism and immunosuppressive therapies considering the prophylactic treatment in 600 consecutive kidney transplanted recipients. We found no association of the aforementioned polymorphism with CMV infection in univariate and multivariate analyses regardless of the prophylactic treatment. In addition, the immunosuppressive treatment with mammalian target of rapamycin inhibitors (imTOR) showed a protective effect in all patients independently of prophylaxis. Moreover, in the adjusted model, we found interactions between prophylaxis with high-risk (Donor+/Recipient-, D+/R-) status (p-interaction = 0.01), with thymoglobulin induction therapy (p-interaction = 0.03) and with thymoglobulin anti-rejection therapy (p-interaction = 0.002). Data also revealed that prophylaxis was not an advantage in the not D+/R- and without thymoglobulin therapy group (HR = 0.98, p = 0.95). The benefit of prophylaxis was observed in all groups with thymoglobulin therapy, but it was maximal in the high-risk CMV infection group with both thymoglobulin induction therapy and thymoglobulin anti-rejection therapy (HR = 0.01, p < 0.001). In conclusion, the IFNG +874 polymorphism is not a predictive marker of CMV infection. The protective effect of imTOR is not improved with prophylaxis. Interestingly, the thymoglobulin therapy associated with prophylaxis is not a risk factor for CMV infection, and prophylaxis is not effective in recipients with no high-risk CMV status and without thymoglobulin therapy.

Prospective randomized study comparing everolimus and mycophenolate sodium in de novo kidney transplant recipients from expanded criteria deceased donor

The optimal immunosuppressive regimen for recipients of expanded criteria donor (ECD) kidneys has not been identified. In this single-center study, 171 recipients of ECD kidney transplants were randomized to receive antithymocyte globulin induction, and delayed introduction of reduced dose tacrolimus, prednisone and everolimus (r-ATG/EVR, n = 88), or mycophenolate (r-ATG/MPS, n = 83). No cytomegalovirus (CMV) pharmacological prophylaxis was used. The primary endpoint was the incidence of CMV infection/disease at 12 months. Secondary endpoints included treatment failure [first biopsy-proven acute rejection (BPAR), graft loss, or death] and safety. Patients treated with EVR showed a 89% risk reduction (13.6 vs. 71.6%; HR 0.11, 95% CI 0.06-0.220, P < 0.001) in the incidence of first CMV infection/disease. Incidences of BPAR (16% vs. 5%, P = 0.021), graft loss (11% vs. 1%, P = 0.008), death (10% vs. 1%, P = 0.013), and treatment discontinuation (40% vs. 28%, P = 0.12) were higher in the r-ATG/EVR, leading to premature study termination. Mean glomerular filtration rate was lower in r-ATG/EVR (31.8 ± 18.8 vs. 42.6 ± 14.9, P < 0.001). In recipients of ECD kidney transplants receiving no CMV pharmacological prophylaxis, the use of everolimus was associated with higher treatment failure compared with mycophenolate despite the significant reduction in the incidence of CMV infection/disease (ClinicalTrials.gov.NCT01895049).

Everolimus-based Immunosuppression Possibly Suppresses Mean Fluorescence Intensity Values of De Novo Donor-specific Antibodies After Primary Kidney Transplantation

PURPOSE

We evaluated de novo donor-specific antibody (DSA) production of everolimus (EVR)-based immunosuppression for primary kidney transplant recipients involved in the A1202 study at our institute.

METHODS

From March 2008 to August 2009, 24 recipients were prospectively randomized into 2 groups. The EVR group received reduced cyclosporin A and EVR. The standard protocol (STD) group received standard cyclosporin A and mycophenolate mofetil. Both groups received basiliximab and steroids. De novo DSA was identified using LABScreen single antigen beads (One Lambda, Canoga Park, Calif., United States). Mean fluorescence intensity (MFI) values > 1000 were considered positive. P < .05 was considered significant.

RESULTS

Graft survival was 100% in the EVR group and 90.9% in the STD group. All patients remained on the primary protocol in the EVR group, but 3 patients in the STD group (27.3%) were converted to tacrolimus due to DSA and non-adherence. Estimated glomerular filtration rate was similar in both groups. No EVR group recipients and 9.1% of STD group recipients were treated for T-cell-mediated rejection. No recipients of the EVR group exhibited peritubular capillaritis, while 9.1% in STD group developed chronic active antibody-mediated rejection. LABScreen revealed an accumulative class II DSA production rate of 15.4% in the EVR group and 18.3% in the STD group at 10 years. When the MFI cut-off level was set to 6000, anti-HLA antibody and de novo DSA-free survival was significantly better in the EVR group.

CONCLUSIONS

EVR-based immunosuppression provided equivalent or even better clinical outcomes. EVR suppressed de novo DSA production at 10 years follow-up; however, further follow-up is inevitable.

An open-label, randomized trial indicates that everolimus with tacrolimus or cyclosporine is comparable to standard immunosuppression in de novo kidney transplant patients

This is a randomized trial (ATHENA study) in de novo kidney transplant patients to compare everolimus versus mycophenolic acid (MPA) with similar tacrolimus exposure in both groups, or everolimus with concomitant tacrolimus or cyclosporine (CsA), in an unselected population. In this 12-month, multicenter, open-label study, de novo kidney transplant recipients were randomized to everolimus with tacrolimus (EVR/TAC), everolimus with CsA (EVR/CsA) or MPA with tacrolimus (MPA/TAC), with similar tacrolimus exposure in both groups. Non-inferiority of the primary end point (estimated glomerular filtration rate [eGFR] at month 12), assessed in the per-protocol population of 338 patients, was not shown for EVR/TAC or EVR/CsA versus MPA/TAC. In 123 patients with TAC levels within the protocol-specified range, eGFR outcomes were comparable between groups. The mean increase in eGFR during months 1 to 12 post-transplant, analyzed post hoc, was similar with EVR/TAC or EVR/CsA versus MPA/TAC. The incidence of treatment failure (biopsy proven acute rejection, graft loss or death) was not significant for EVR/TAC but significant for EVR/CsA versus MPA/TAC. Most biopsy-proven acute rejection events in this study were graded mild (BANFF IA). There were no differences in proteinuria between groups. Cytomegalovirus and BK virus infection were significantly more frequent with MPA/TAC. Thus, everolimus with TAC or CsA showed comparable efficacy to MPA/TAC in de novo kidney transplant patients. Non-inferiority of renal function, when pre-specified, was not shown, but the mean increase in eGFR from month 1 to 12 was comparable to MPA/TAC.

Polymorphisms in mTOR and Calcineurin Signaling Pathways Are Associated With Long-Term Clinical Outcomes in Kidney Transplant Recipients

Monitoring of immunosuppressive drugs, such as calcineurin and mTOR inhibitors, is essential to avoid undesirable kidney transplant outcomes. Polymorphisms in pharmacokinetics-related genes have been associated with variability in blood levels of immunosuppressive drugs and adverse effects, but influence of pharmacodynamics-related genes remains to be elucidated. The influence of polymorphisms in genes of the mTOR and calcineurin signaling pathways on long-term clinical outcomes was investigated in Brazilian kidney transplant recipients within the 1-year post-transplant. Two-hundred and sixty-nine kidney transplant recipients were enrolled at a kidney transplant center in São Paulo city, Brazil, and treated with tacrolimus plus everolimus or mycophenolate sodium (clinical trial NCT01354301). Clinical and laboratory data, including renal function parameters and drug blood levels were recorded. Genomic DNA was extracted from blood samples. Polymorphisms in MTOR rs1057079 (c.4731G>A), rs1135172 (c.1437T>C), and rs1064261 (c.2997C>T); PPP3CA rs3730251 (c.249G>A); FKBP1A rs6033557 (n.259+24936T>C); FKBP2 rs2159370 (c.-2110G>T); and FOXP3 rs3761548 (c.-23+2882A>C) and rs2232365 (c.-22-902A>G) were analyzed by real-time PCR. Frequencies of gene polymorphisms did not differ among the treatment groups. Analysis of primary outcomes showed that patients carrying MTOR c.1437CC and FOXP3 c.-23+2882CC genotypes had higher serum creatinine than non-carriers (p < 0.05) at 1-year post-transplant. MTOR c.4731G allele (AG+GG genotype) was associated with increased risk for acute rejection (OR = 3.53, 95% CI = 1.09-11.48, p = 0.037). Moreover, 1-year cumulative incidence of rejection was higher in MTOR c.4731G allele carriers compared to AA genotype carriers (p = 0.027). Individually, analysis of secondary outcomes revealed that FKBP2 c.-2110GG genotype carriers had higher risk of leukopenia, FKBP1A n.259+24936C allele carriers had increased risk of constipation, and FOXP3 c.-22-902A or c.-23+2882A allele had higher risk of gastrointestinal disorders (p < 0.05). However, these results were not maintained in the multivariable analysis after p-value adjustment. In conclusion, variants in genes of mTOR and calcineurin pathways are associated with long-term impaired renal function, increased risk of acute rejection, and, individually, with adverse events in Brazilian kidney transplant recipients.

Ganciclovir-Resistant Cytomegalovirus Infection in Abdominal Solid Organ Transplant Recipients: Case Series and Review of the Literature

Ganciclovir-resistant cytomegalovirus (GR-CMV) is emerging as a significant infection in the abdominal transplant population. GR-CMV is difficult to manage, and treatment options are limited. We report a descriptive case series of 15 patients who had documented GR-CMV at our center and review the literature on treatment of GR-CMV. The first case in this series was detected in 2012; the majority of cases occurred after January 1, 2014, with approximately 50% occurring in 2015. UL97 and UL54 viral genome mutations were present in 100% and 40% of CMV-infected patients, respectively. GR-CMV infection occurred ≤ 1 year posttransplantation in 11 patients (73%). All patients experienced dose reduction of valganciclovir (the oral prodrug of ganciclovir) before the development of GR-CMV. Initial treatment for GR-CMV included a variety of regimens, all including reduction in maintenance immunosuppression. Of the 6 patients with detectable GR-CMV by polymerase chain reaction (PCR) who were discharged without GR-CMV treatment and had a length of stay (LOS) less than 14 days, 83% were subsequently readmitted for treatment of GR-CMV within 2 months (60% in < 20 days); none received leflunomide. Of six patients with a LOS ≥ 14 days, 80% had CMV PCR below quantification on hospital discharge, and only one patient was readmitted in less than 20 days; 83% received leflunomide. Following GR-CMV, there was a 50% rejection incidence, 27% graft loss, and 20% mortality. For patients with more than three admissions for GR-CMV treatment, 100% had a major complication: 60% rejection, 20% graft loss, and 40% mortality. Common clinical characteristics of patients with GR-CMV included high-risk serostatus, lymphocyte depletion, and history of valganciclovir dose reduction. Overall, outcomes were poor. It appears that hospital readmission rate was reduced when CMV was treated to negativity with an initial treatment regimen of reduced immunosuppression, foscarnet, intravenous immunoglobulins, and leflunomide.

Induction Immunosuppressive Therapy With Everolimus and Low-Dose Tacrolimus Extended-Release Preserves Good Renal Function at 1 Year After Kidney Transplantation

BACKGROUND

Utilization of everolimus (EVR) has been increasing in recent years for patients undergoing renal transplantation to reduce calcineurin inhibitor (CNI) levels. However, an optimum regimen has yet to be established.

METHODS

We retrospectively examined 12 renal transplant recipients who underwent an induction immunosuppressive protocol; the protocol comprises 5 agents, including EVR plus low-dose tacrolimus extended-release (TAC-ER) treatment. We compared those findings from those of 14 patients who underwent a conventional protocol without EVR. Clinical outcome and pathologic changes were assessed by using protocol graft biopsy findings obtained at 3 months and 1 year after transplantation.

RESULTS

The estimated glomerular filtration rate was significantly higher for the EVR group at both 3 months and 1 year compared with the conventional group (P < .01 and P = .03, respectively). TAC-ER trough levels were also significantly lower at 3 months and 1 year (both, P < .01). Histologic findings of the 3-month protocol biopsy samples in the EVR group revealed 4 cases of borderline change and 2 of acute cellular-mediated rejection. The findings from the 1-year biopsy samples revealed 10 cases with normal findings with no evidence of CNI toxicity. Patients in the EVR group developed subclinical borderline change and acute cellular-mediated rejection after 3 months at a significantly higher rate than the conventional group (P = .02).

CONCLUSIONS

Use of the present therapeutic strategy successfully maintained the trough of each drug at a lower level, and it also kept renal function stable up to 1 year after transplantation.