Effect of everolimus-based drug regimens on CMV-specific T-cell functionality after renal transplantation: 12-month ATHENA subcohort-study results

Post-transplant cytomegalovirus (CMV) infections and increased viral replication are associated with CMV-specific T-cell anergy. In the ATHENA-study, de-novo everolimus (EVR) with reduced-exposure tacrolimus (TAC) or cyclosporine (CyA) showed significant benefit in preventing CMV infections in renal transplant recipients as compared to standard TAC + mycophenolic acid (MPA). However, immunomodulatory mechanisms for this effect remain largely unknown. Ninety patients from the ATHENA-study completing the 12-month visit on-treatment (EVR + TAC n = 28; EVR + CyA n = 19; MPA + TAC n = 43) were included in a posthoc analysis. Total lymphocyte subpopulations were quantified. CMV-specific CD4 T cells were determined after stimulation with CMV-antigen, and cytokine-profiles and various T-cell anergy markers were analyzed using flow cytometry. While 25.6% of MPA + TAC-treated patients had CMV-infections, no such events were reported in EVR-treated patients. Absolute numbers of lymphocyte subpopulations were comparable between arms, whereas the percentage of regulatory T cells was significantly higher with EVR + CyA versus MPA + TAC (p = 0.019). Despite similar percentages of CMV-specific T cells, their median expression of CTLA-4 and PD-1 was lower with EVR + TAC (p < 0.05 for both) or EVR + CyA (p = 0.045 for CTLA-4) compared with MPA + TAC. Moreover, mean percentages of multifunctional CMV-specific T cells were higher with EVR + TAC (27.2%) and EVR + CyA (29.4%) than with MPA + TAC (19.0%). In conclusion, EVR-treated patients retained CMV-specific T-cell functionality, which may contribute to enhanced protection against CMV infections.

A randomized trial of everolimus-based quadruple therapy vs standard triple therapy early after lung transplantation

Calcineurin inhibitor (CNI) therapy after lung transplantation increases risk of kidney failure. Early everolimus-based quadruple low CNI immunosuppression may improve renal function without compromising efficacy or safety. A prospective, randomized, open-label, 12-month multicenter trial was conducted at 8 German sites. Patients 3-18 months after lung transplantation were randomized (1:1), stratified by baseline estimated glomerular filtration rate (eGFR). In the quadruple low CNI regimen, patients received everolimus (target trough level 3-5 ng/mL) with reduced CNI (tacrolimus 3-5 ng/mL or cyclosporine 25-75 ng/mL) and a cell cycle inhibitor plus prednisone. In the standard triple CNI regimen, patients received tacrolimus (target trough level >5 ng/mL) or cyclosporine (>100 ng/mL) and a cell cycle inhibitor plus prednisone. Of the 180 patients screened, 130 were randomized: 67 in the quadruple low CNI group and 63 in the standard triple CNI group. The primary endpoint (eGFR after 12 months) demonstrated superiority of the quadruple low CNI regimen: 64.5 mL/min vs 54.6 mL/min for the standard triple group (least squares mean, analysis of covariance; P < .001). Key efficacy parameters (biopsy-proven acute rejection, chronic lung allograft dysfunction, and death) and safety endpoints were similar between both groups. Quadruple low CNI immunosuppression early after lung transplantation was demonstrated to be efficacious and safe. Clinical trials registry: ClinicalTrials.gov NCT01404325.

Comparing everolimus-based immunosuppression with reduction or withdrawal of calcineurin inhibitor reduction from six months after heart transplantation: the randomized MANDELA study

In the 12-month, open-label MANDELA study, patients were randomized at month 6 after heart transplantation to (i) convert to calcineurin inhibitor (CNI)-free immunosuppression with everolimus (EVR), mycophenolic acid and steroids (CNI-free, n=71), or to (ii) continue reduced-exposure CNI, with EVR and steroids (EVR/redCNI, n=74). Tacrolimus was administered in 48.8% of EVR/redCNI patients and 52.6% of CNI-free patients at radomization. Both strategies improved and stabilized renal function based on the primary endpoint (estimated GFR at month 18 post-transplant post-randomization) with superiority of the CNI-free group versus EVR/redCNI : mean 64.1mL/min/1.73m2 versus 52.9mL/min/1.73m2 ; difference +11.3mL/min/1.73m2 (p<0.001). By month 18, estimated GFR had increased by ≥10mL/min/1.732 in 31.8% and 55.2% of EVR/redCNI and CNI-free patients, respectively, and by ≥25 mL/min/1.73m2 in 4.5% and 20.9%. Rates of biopsy-proven acute rejection (BPAR) were 6.8% and 21.1%; all cases were without hemodynamic compromise. BPAR was less frequent with EVR/redCNI versus the CNI-free regimen (p=0.015); 6/15 episodes in CNI-free patients occurred with EVR concentration <5ng/mL. Rates of adverse events and associated discontinuations were comparable EVR/redCNI from month 6 achieved stable renal function with infrequent BPAR. One-year renal function can be improved by early conversion to EVR-based CNI-free therapy but requires close EVR monitoring. This article is protected by copyright. All rights reserved.

Five-year outcomes in kidney transplant patients randomized to everolimus with cyclosporine withdrawal or low-exposure cyclosporine versus standard therapy

HERAKLES was a 1-year randomized, multicenter trial. Patients were randomized at 3 months after kidney transplantation to remain on cyclosporine-based therapy, switch to everolimus without a calcineurin inhibitor (CNI), or switch to everolimus with low-exposure cyclosporine. Overall, 417 of 497 (83.9%) patients from the core study entered a 4-year extension study. The randomized regimen was continued to year 5 in 75.9%, 41.9% and 24.6% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively. Adjusted estimated GFR at year 5 was significantly higher in the CNI-free group versus standard CNI (difference 7.2 mL/min/1.73 m² , P < .001) or low CNI (difference 7.6 mL/min/1.73 m² , P < .001). For patients who continued randomized therapy for 5 years, differences were 14.4 mL/min/1.73 m²  and 10.1 mL/min/1.73 m² , respectively. Biopsy-proven acute rejection occurred during the 4-year extension study in 7.6%, 8.6%, and 9.0% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively (P = .927). In conclusion, conversion to a CNI-free everolimus regimen 3 months after kidney transplantation improved long-term graft function, particularly in patients who continued the CNI-free regimen. Low CNI with everolimus did not improve renal function. Efficacy was comparable between groups but frequent immunosuppression changes should be taken into account.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials

Background

Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes.

Methods

PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497).

Results

There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes).

Conclusions

Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes.

Trial registration

clinicaltrials.gov, NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT (2006-007021-32 and 2004-004346-40).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1031-1) contains supplementary material, which is available to authorized users.

Histological findings to five years after early conversion of kidney transplant patients from cyclosporine to everolimus: an analysis from the randomized ZEUS study

Background

Conversion from calcineurin inhibitor (CNI) therapy to everolimus within 6 months after kidney transplantation improves long-term graft function but can increase the risk of mild biopsy-proven acute cellular rejection (BPAR). We performed a post-hoc analysis of histological data from a randomized trial in order to further analyze histologic information obtained from indication and protocol biopsies up to 5 years after transplantation.

Methods

Biopsy samples obtained up to 5 years post-transplant were analyzed from the randomized ZEUS study, in which kidney transplant patients were randomized at month 4.5 to switch to everolimus (n = 154) or remain on cyclosporine (CsA)-based immunosuppression (n = 146). All patients received mycophenolate and steroids.

Results

At least one investigator-initiated biopsy was undertaken in 53 patients in each group between randomization and year 5, with a mean (SD) of 2.6 (1.7) and 2.2 (1.4) biopsies per patient in the everolimus and CsA groups, respectively. In the everolimus and CsA groups, investigator-initiated biopsies showed (i) BPAR in 12.3 and 7.5% (p = 0.182) of patients, respectively, with episodes graded mild in 22/24 and 18/20 cases (ii) CsA toxicity lesions in 4.5 and 10.3% of patients (p = 0.076) (iii) antibody-mediated rejection in 0.6 and 2.7% of patients (p = 0.204), respectively.

Conclusions

This analysis of histological findings in the ZEUS study to 5 years after kidney transplantation shows no increase in antibody-mediated rejection under everolimus-based therapy with a lower rate of CNI-related toxicity compared to a conventional CsA-based regimen, and confirms the preponderance of mild BPAR seen in the main study after the early switch to CsA-free everolimus therapy.

Trial registration

ClinicalTrials.gov NCT00154310. Date of registration: September 12, 2005.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0950-1) contains supplementary material, which is available to authorized users.

Everolimus with cyclosporine withdrawal or low-exposure cyclosporine in kidney transplantation from Month 3: a multicentre, randomized trial

Background.

Randomized trials have shown that early adoption of everolimus-based immunosuppressive regimens without a calcineurin inhibitor (CNI) improves long-term kidney graft function, but the optimal strategy for CNI minimization remains uncertain.

Methods.

In a prospective, randomized, multicentre, 12-month trial, 499 de novo kidney transplant patients were randomized at Month 3 to (i) remain on standard CNI (cyclosporine) therapy with mycophenolic acid, (ii) convert to everolimus with mycophenolic acid or (iii) start everolimus with reduced CNI and no mycophenolic acid (clinical trials registry: ClinicalTrials.gov-NCT00514514).

Results.

The primary endpoint, change in estimated glomerular filtration rate (eGFR) (Nankivell) from randomization to Month 12, was significantly greater in the CNI-free arm versus standard CNI therapy: mean difference 5.6 mL/min/1.73 m 2 [95% confidence interval (CI) 2.8-8.3 mL/min/1.73 m 2 , P < 0.001]. The improvement in eGFR in the CNI-free arm was also higher than in the low-CNI group (mean difference 5.5 mL/min/1.73 m 2 , 95% CI 2.8-8.2 mL/min/1.73 m 2 , P < 0.001), while results were similar in the low-CNI and standard CNI arms. The post-randomization incidence of biopsy-proven acute rejection was 11.7%, 8.1% and 7.9% in the CNI-free, low-CNI and standard CNI groups, respectively (CNI-free versus standard CNI, P = 0.27; low-CNI versus standard CNI, P = 1.00). Adverse events led to study drug discontinuation in 28.7%, 15.5% and 15.2% of CNI-free, low-CNI and standard CNI patients, respectively.

Conclusions.

Everolimus initiation with CNI withdrawal at Month 3 after kidney transplantation achieves a significant improvement in renal function at 12 months, with a similar rate of acute rejection.

Direct uptake of Antagomirs and efficient knockdown of miRNA in primary B and T lymphocytes

Depending on their physiological expression level, microRNAs (miRNA) address different target genes, thus have different biological functions. To identify these, the physiological expression has to be blocked. Here, we describe the use of inhibitory cholesterol-modified oligonucleotides (Antagomirs) to inhibit miRNAs selectively in primary human and murine T and B lymphocytes. Due to their lipophilic cholesterol tag Antagomirs enter primary lymphocytes efficiently and quantitatively. We show here that at concentrations of 0.125 to 1μM, Antagomirs selectively inhibit expression of their target miRNA up to 99.5% without affecting cell viability.

miR-148a promotes plasma cell differentiation and targets the germinal center transcription factors Mitf and Bach2

B cells undergo affinity maturation and class switch recombination of their immunoglobulin receptors during a germinal center (GC) reaction, before they differentiate into long-lived antibody-secreting plasma cells (PCs). Transcription factors such as Bach2 and Mitf are essential during this process, as they delay premature differentiation of GC B cells by repressing Blimp-1 and IRF4, two transcription factors required for terminal PC differentiation. Therefore, Bach2 and Mitf expression must be attenuated in activated B cells to allow terminal PC differentiation, but the precise mechanism remains enigmatic. Here, we provide evidence that miR-148a, a small noncoding microRNA, fosters PC differentiation and survival. Next-generation sequencing revealed that miR-148a is the most abundant microRNA in primary human and murine PCs, and its expression is upregulated in activated murine B cells and coincides with Blimp-1 synthesis. miR-148a targets Bach2, Mitf and proapoptotic factors such as PTEN and Bim. When prematurely expressed, miR-148a promotes the differentiation and survival of plasmablasts and reduces frequencies of IgG1(+) cells in primary B-cell cultures. In summary, we propose that miR-148a is a new player in the regulatory network controlling terminal PC differentiation and could, therefore, be a therapeutic target for interfering with PC differentiation and survival.

miR-148a is upregulated by Twist1 and T-bet and promotes Th1-cell survival by regulating the proapoptotic gene Bim

Repeatedly activated T helper 1 (Th1) cells present during chronic inflammation can efficiently adapt to the inflammatory milieu, for example, by expressing the transcription factor Twist1, which limits the immunopathology caused by Th1 cells. Here, we show that in repeatedly activated murine Th1 cells, Twist1 and T-bet induce expression of microRNA-148a (miR-148a). miR-148a regulates expression of the proapoptotic gene Bim, resulting in a decreased Bim/Bcl2 ratio. Inhibition of miR-148a by antagomirs in repeatedly activated Th1 cells increases the expression of Bim, leading to enhanced apoptosis. Knockdown of Bim expression by siRNA in miR-148a antagomir-treated cells restores viability of the Th1 cells, demonstrating that miR-148a controls survival by regulating Bim expression. Thus, Twist1 and T-bet not only control the differentiation and function of Th1 cells, but also their persistence in chronic inflammation.

Five-year outcomes in kidney transplant patients converted from cyclosporine to everolimus: the randomized ZEUS study

ZEUS study was an open-label, 12-month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five-year follow-up data were available for 245/269 patients (91.1%) who completed the core 12-month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m(2) with everolimus versus 60.9 mL/min/1.73 m(2) with CsA; the mean difference was 5.3 mL/min/1.73 m(2) in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent-to-treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m(2) (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy-proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long-term graft function.

Renal function to 5 years after late conversion of kidney transplant patients to everolimus: a randomized trial

BACKGROUND

Few trials have investigated late preemptive conversion of kidney transplant patients from a calcineurin inhibitor (CNI) to an mTOR inhibitor.

METHODS

In an open-label, 12-month, prospective, randomized, parallel-group study, maintenance kidney transplant patients (>6 months post-transplant) either switched from CNI to everolimus or continued their current CNI regimen. Patients who completed the core study were followed to 5 years post-randomization.

RESULTS

Of 93 randomized patients, 78 completed the core study and 67 attended the final 60-month study visit. Mean time post-transplant at baseline was 82.6 months and 70.5 months in the everolimus and CNI groups, respectively. At month 60, adjusted mean eGFR (Nankivell) was 63.0 (95% CI 57.8, 68.2) mL/min/1.73 m(2) in the everolimus group versus 57.9 (95% CI 52.6, 63.1) mL/min/1.73 m(2) in the CNI group, a difference of 5.1 (95% CI -0.6, 10.8) mL/min/1.73 m(2) (p = 0.076). Among patients who remained on randomized study drug at month 60, mean eGFR (Nankivell) was 71.6 (95% CI 64.2, 79.0) mL/min/1.73 m(2) in everolimus-treated patients (n = 21) versus 60.6 (95% CI 55.1, 66.1) mL/min/1.73 m(2) in CNI-treated patients (n = 29) (mean difference 11.0; 95% CI 3.6, 18.5 mL/min/1.73 m(2); p = 0.005). No cases of BPAR occurred from randomization to month 60 in either group. Graft loss occurred in three everolimus-treated patients and one CNI-treated patient. No unexpected safety concerns were observed in either group.

CONCLUSION

Late preemptive conversion of maintenance kidney transplant patients from CNI to everolimus may be associated with improved long-term renal function and preserves immunosuppressive efficacy. Patient numbers were low, but these findings merit further investigation.

Efficacy and safety of conversion from cyclosporine to everolimus in living-donor kidney transplant recipients: an analysis from the ZEUS study

Conversion of living-donor kidney transplant patients from calcineurin inhibitor therapy to an mTOR inhibitor is poorly documented. In the prospective, multicentre ZEUS study, 300 kidney transplant recipients without prior rejection (Banff grade >1) and serum creatinine ≤265 μmol/l were randomized to continue cyclosporine or convert to everolimus at 4.5 months post-transplant. In a post hoc analysis of 80 living-donor recipients, adjusted estimated GFR (Nankivell) at month 12 (the primary endpoint) was 74.3 (95% CI [70.7, 77.9]) ml/min/1.73 m(2) with everolimus versus 63.8 (95% CI [60.0, 67.7]) ml/min/1.73 m(2) ) with cyclosporine, a difference of 10.5 ml/min/1.73 m(2) in favour of everolimus (P < 0.001). From randomization to month 12, adjusted estimated GFR increased by a mean of 9.8 (95% CI [6.2, 13.4]) ml/min/1.73 m(2) with everolimus versus -0.7 (95% CI [-4.6, 3.1]) ml/min/1.73 m(2) ) (P < 0.001) with cyclosporine. There were six biopsy-proven acute rejection episodes in everolimus-treated patients (five Banff grade I) and one episode in cyclosporine-treated patients (Banff grade 1). Overall safety profile was similar between groups. Discontinuation due to adverse events occurred in three everolimus patients (7.1%) and five cyclosporine patients (13.2%) between randomization and month 12. Initiation of everolimus with early elimination of calcineurin therapy is associated with a significant renal benefit at 12 months post-transplant that is observed in both living and deceased-donor recipients. (clinicaltrials.gov NCT00154310).

Contribution of microRNA 24-3p and Erk1/2 to interleukin-6-mediated plasma cell survival

Plasma cells can survive for long periods and continuously secrete protective antibodies, but plasma cell production of autoantibodies or transformation to tumor cells is detrimental. Plasma cell survival depends on exogenous factors from the surrounding microenvironment, and largely unknown intracellular mediators that regulate cell homeostasis. Here we investigated the contribution of the microRNA 24-3p (miR-24-3p) to the survival of human plasma cells under the influence of IL-6 and SDF-1α (stromal cell derived factor 1), both of which are bone marrow survival niche mediators. Deep sequencing revealed a strong expression of miR-24-3p in primary B cells, plasma blasts, plasma cells, and in plasmacytoma cells. In vitro studies using primary cells and the plasmacytoma cell line RPMI-8226 revealed that (i) expression of miR-24-3p mediates plasma cell survival, (ii) miR-24-3p is upregulated by IL-6 and SDF-1α, (iii) IL-6 mediates cell survival under ER stress conditions via miR-24-3p expression, and (iv) IL-6-induced miR-24-3p expression depends on the activity of the MAP kinase Erk1/2. These results suggest a direct connection between an external survival signal and an intracellular microRNA in regulating plasma cell survival. miR-24-3p could therefore be a promising target for new therapeutic strategies for autoimmune and allergic diseases and for multiple myeloma.

HnRNP L and L-like cooperate in multiple-exon regulation of CD45 alternative splicing

CD45 encodes a trans-membrane protein-tyrosine phosphatase expressed in diverse cells of the immune system. By combinatorial use of three variable exons 4–6, isoforms are generated that differ in their extracellular domain, thereby modulating phosphatase activity and immune response. Alternative splicing of these CD45 exons involves two heterogeneous ribonucleoproteins, hnRNP L and its cell-type specific paralog hnRNP L-like (LL). To address the complex combinatorial splicing of exons 4–6, we investigated hnRNP L/LL protein expression in human B-cells in relation to CD45 splicing patterns, applying RNA-Seq. In addition, mutational and RNA-binding analyses were carried out in HeLa cells. We conclude that hnRNP LL functions as the major CD45 splicing repressor, with two CA elements in exon 6 as its primary target. In exon 4, one element is targeted by both hnRNP L and LL. In contrast, exon 5 was never repressed on its own and only co-regulated with exons 4 and 6. Stable L/LL interaction requires CD45 RNA, specifically exons 4 and 6. We propose a novel model of combinatorial alternative splicing: HnRNP L and LL cooperate on the CD45 pre-mRNA, bridging exons 4 and 6 and looping out exon 5, thereby achieving full repression of the three variable exons.