Effects of mTOR-Is on malignancy and survival following renal transplantation: A systematic review and meta-analysis of randomized trials with a minimum follow-up of 24 months

Cellular Immunobiology and Molecular Mechanisms in Alloimmunity-Pathways of Immunosuppression

Current maintenance immunosuppression commonly comprises a synergistic combination of tacrolimus as calcineurin inhibitor (CNI), mycophenolic acid, and glucocorticoids. Therapy is often individualized by steroid withdrawal or addition of belatacept or inhibitors of the mechanistic target of rapamycin. This review provides a comprehensive overview of their mode of action, focusing on the cellular immune system. The main pharmacological action of CNIs is suppression of the interleukin-2 pathway that leads to inhibition of T cell activation. Mycophenolic acid inhibits the purine pathway and subsequently diminishes T and B cell proliferation but also exerts a variety of effects on almost all immune cells, including inhibition of plasma cell activity. Glucocorticoids exert complex regulation via genomic and nongenomic mechanisms, acting mainly by downregulating proinflammatory cytokine signatures and cell signaling. Belatacept is potent in inhibiting B/T cell interaction, preventing formation of antibodies; however, it lacks the potency of CNIs in preventing T cell-mediated rejections. Mechanistic target of rapamycin inhibitors have strong antiproliferative activity on all cell types interfering with multiple metabolic pathways, partly explaining poor tolerability, whereas their superior effector T cell function might explain their benefits in the case of viral infections. Over the past decades, clinical and experimental studies provided a good overview on the underlying mechanisms of immunosuppressants. However, more data are needed to delineate the interaction between innate and adaptive immunity to better achieve tolerance and control of rejection. A better and more comprehensive understanding of the mechanistic reasons for failure of immunosuppressants, including individual risk/benefit assessments, may permit improved patient stratification.

Benefits of Routine Screening for Renal Cell Carcinoma of Native Kidney in Renal Transplant Recipients

BACKGROUND

Renal-cell carcinoma (RCC) is the most common solid organ cancer in kidney transplantation recipients (KTRs).

BACKGROUND

Analyze the incidence, prognosis, and evolution of primitive kidney RCC in KTRs at our institution.

MATERIAL AND METHODS

Observational descriptive retrospective study in which all KTRs from January 2000 to December 2022 were included. We performed an annual abdominal ultrasound in all KTRs. Demographic and clinical data were collected. The surgical approach, location, size, histologic type, and tumor grade were analyzed. We assessed the coexistence of risk factors. We reported the appearance of tumors in other locations, changes in immunosuppressants (IS) after the diagnosis, and survival and recurrence rates observed during follow-up.

RESULTS

Eighteen RCCs of native kidneys were diagnosed with an incidence in our population of 1.08%. The majority were men (77.8%), with a mean age of 59.9 years. The pathologic analysis revealed 11 clear cell carcinomas, 6 papillary carcinomas, and 1 chromophobe cell carcinoma. The median tumor size was 2.7 cm. TNM stage was T1aN0M0 in 15 cases. Laparoscopy was performed to remove the tumor in most cases. All our patients underwent changes in IS therapy, with conversion to mammalian target of rapamycin inhibitors when possible and reduction of IS in all of them. After a mean follow-up of 78.6 months, survival was 100% without tumor recurrence. Seven of the patients were diagnosed with a new tumor in another location.

CONCLUSION

In our experience, annual abdominal ultrasound in KTRs may be an option for the early detection of RCC in native kidneys.

Hyperglycemia and Hyperlipidemia with Kidney or Liver Transplantation: A Review

Although solid organ transplantation in persons with diabetes mellitus is often associated with hyperglycemia, the risk of hyperlipidemia in all organ transplant recipients is often underestimated. The diagnosis of diabetes often predates transplantation; however, in a moderate percentage of allograft recipients, perioperative hyperglycemia occurs triggered by antirejection regimens. Post-transplant prescription of glucocorticoids, calcineurin inhibitors and mTOR inhibitors are associated with increased lipid concentrations. The existence of diabetes mellitus prior to or following a liver transplant is associated with shorter times of useful allograft function. A cycle involving Smad, TGF beta, m-TOR and toll-like receptors has been identified in the contribution of rejection and aging of allografts. Glucocorticoids (prednisone) and calcineurin inhibitors (cyclosporine and tacrolimus) induce hyperglycemia associated with insulin resistance. Azathioprine, mycophenolate and prednisone are associated with lipogenesis. mTOR inhibitors (rapamycin) are used to decrease doses of atherogenic agents used for immunosuppression. Post-transplant medication management must balance immune suppression and glucose and lipid control. Concerns regarding rejection often override those relative to systemic and organ vascular aging and survival. This review focuses attention on the underlying mechanism of relationships between glycemia/lipidemia control, transplant rejection and graft aging.

Pancreatic cancer among solid organ transplant recipients in the United States

INTRODUCTION

Pancreatic cancer (PC) in solid organ transplant (SOT) recipients is not well studied. Some PC cases may be incidentally detected during hepatobiliary imaging.

METHODS

We evaluated PC among 374,106 SOT recipients during 1995-2017 in the United States using linked data from the national transplant registry and multiple state/regional cancer registries. Standardized incidence ratios (SIRs) were used to compare PC risk in recipients to the general population. We used multivariate Poisson regression to identify independent risk factors for PC. We assessed survival after PC diagnosis using Kaplan-Meier curves and log-rank tests.

RESULTS

SOT recipients had elevated incidence for PC compared with the general population (SIR 1.40, 95% CI 1.29-1.52), and this increase was strongest in liver recipients (1.65, 1.41-1.92). Among all recipients, PC incidence was especially increased for cases arising in the head of the pancreas (SIR 1.50, 95% CI 1.34-1.68) and for cases diagnosed at localized stage (1.85, 1.37-2.44). Among SOT recipients, factors independently associated with increased incidence were consistent with those in general population including male sex, older age, non-O blood type, and history of diabetes. Additionally, compared to other organ recipients, liver transplant recipients had higher PC incidence (adjusted incidence rate ratio 1.28; 95% CI 1.06-1.54). Overall survival after PC diagnosis was poor (median 4 months) and similar between liver and other organ transplant recipients (p = 0.08).

CONCLUSIONS

PC incidence is elevated among SOT recipients, and more commonly diagnosed in liver transplant recipients perhaps related to incidental detection. However, survival is poor even in liver recipients, arguing against routine PC screening.

Solid Organ Transplantation Is Associated with an Increased Rate of Mismatch Repair Deficiency and PIK3CA Mutations in Colorectal Cancer

Solid organ transplants are associated with a modestly increased risk of colorectal cancers (CRC). However, the molecular profile of these cancers has not been described. We hypothesized that transplant-related immunosuppression may promote development of more immunogenic tumors as suggested by a high tumor mutation burden or mismatch repair deficiency. We performed an electronic medical record search for patients seen in the Johns Hopkins University Health System (JHHS) between 2017 and 2022 who developed CRC following solid organ transplantation. A comparator cohort of patients treated for CRC at JHHS with molecular profiling data was also identified. In this case, 29 patients were identified that developed post-transplant CRC (renal transplant, n = 18; liver transplant, n = 8; kidney-liver transplantation, n = 3). Compared to the JHHS general population CRC cohort, patients who developed post-transplant CRC had a higher rate of mismatch repair deficiency (41% versus 12%, p-value = 0.0038), and elevated tumor mutation burden (median of 22 mut/Mb versus 3.5 mut/Mb, p-value = 0.033) (range 3.52-53.65). Post-transplant tumors were enriched for PIK3CA mutations (43% versus 24%, p-value = 0.042). Post-Transplant CRCs are associated with clinical and molecular features of immune sensitivity, supporting a potential role for impaired immune surveillance in shaping the landscape of CRCs. These results may help inform the management of patients with post-transplant CRC.

Death With a Functioning Graft Kidney: A Single-Center Experience of More Than 4 Decades

OBJECTIVES

Death with graft function is one of the most catastrophic events after kidney transplant. Various pre and posttransplant risk factors have been linked to death with graft function. Characterization of this event is crucial to set successful preventive measures. Here, we reported on death with graft function among living donor kidney transplant recipients seen at the Urology and Nephrology Centre at Mansoura University (Mansoura, Egypt) throughout a period of >4 decades.

MATERIALS AND METHODS

This single-center study included 2953 patients who received living donor kidney transplant between March 1976 and December 2018. Patient data were retrospectively analyzed. Patients who had death with graft function were compared with other patients with regard to pre- and posttransplant data. Causes of death with graft function were also studied.

RESULTS

Among our patients (1654 male [56%] and 1299 female [44%] patients), death with graft function was reported in 9.9% of patients and responsible for 58.3% of deaths and 24.6% of graft losses. Male sex, pretransplant dialysis and blood transfusion, pre- and posttransplant diabetes and hypertension, high HLA mismatches, antithymocyte globulin induction, steroid and cyclosporine use, steroid dose, acute rejection episodes, and posttransplant infections and malignancy were significantly higher among the death with graft function group. However, multivariate analyses showed that only pretransplant diabetes, steroid dose, and posttransplant infections were risk factors for death with graft function. The most common causes of death with graft function were cardiovascular disease, infections, and malignancy.

CONCLUSIONS

Death with graft function remains a significant hindrance to competent kidney transplant outcomes. We found that the most common contributors to this major event were cardiovascular disease, infections, and malignancy. More attention is needed to modify risk factors of cardiovascular disease, to update implementation policies for posttransplant vaccinations, and to conduct increased malignancy surveillance, as well to adopt less aggressive immunosuppression regimens.

Review of Standardized Incidence Ratios (SIR) of non-lymphoid de novo malignancies after liver transplantation: Structured analysis of global differences

INTRODUCTION

De Novo malignancy after liver transplantation (LTx) is the second most common cause of death in adult LTx recipients. The current report identifies differences in Standardized Incidence Ratios (SIR) for various non-lymphoid de novo malignancies by comparing and analyzing post LTx SIR for non-lymphoid de novo malignancies.

MATERIAL AND METHODS

A thorough search of PubMed and Web of Science databases was conducted; 25 publications describing de novo malignancies post-LTx with SIR were identified.

RESULTS

Overall SIR varied from 1.4 to 11.6 (median 2.4). Oropharyngeal/larynx (OPL), lung, colo-rectal, and kidney malignancies were more prevalent with higher SIR (median = 4.4, 1.9, 2.67, 2.5, respectively). Breast and prostate malignancies were also more prevalent with lower SIR (median = 0.9, 1.0, respectively). Pancreatic, central nervous system (CNS), melanoma, rare cancers and Kaposi's sarcoma were less prevalent (except in Italy and Sweden) but had much higher SIR (median = 2.6, 2.4, 2.02, 22.5 and 53.6, respectively). The overall higher SIR values are related to the age of the recipient, length of follow-up, the grouping of different organ systems, inclusion or exclusion of epidermal non-malacotic skin cancers, lymphoid malignancy, and occurrence of rare malignancies including Kaposi's sarcoma.

CONCLUSION

OPL, lung, gastrointestinal, kidney, and bladder malignancies were more prevalent with higher SIR. Breast and prostate cancers were more prevalent with lower SIR. Pancreatic, CNS, melanoma, rare cancers and Kaposi's sarcoma were less prevalent with higher SIR. Age of the recipients, length of follow-up, and rare cancer types influence overall SIR values with some global differences.

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients. Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.

Conversion From Calcineurin Inhibitors to Mammalian Target of Rapamycin Inhibitors in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

A systematic review and meta-analysis were performed to investigate the efficacy and safety of conversion from calcineurin inhibitors (CNIs) to mammalian target of rapamycin inhibitors (mTORi) in kidney transplant recipients (KTRs).

Methods

MEDLINE, EMBASE, PubMed, and Cochrane Library were searched to identify randomized controlled trials (RCTs) that compared the continuation of CNI with conversion to mTORi therapy.

Results

Twenty-nine RCTs (5,747 KTRs) were included in our analysis. Meta-analysis of the glomerular filtration rate (SMD 0.20; 95%CI 0.10-0.31; P<0.01) and malignancy (RR 0.74; 95%CI 0.55-0.99; P=0.04) demonstrated a significant advantage of mTORi conversion over CNI continuation. However, the risk of acute rejection (RR 1.58; 95%CI 1.22-2.04; P<0.01), infection (RR 1.55; 95%CI 1.01-1.31; P=0.04), proteinuria (RR 1.87; 95%CI 1.34-2.59; P<0.01), leukopenia (RR 1.56; 95%CI 1.27-1.91; P<0.01), acne (RR 6.43; 95%CI 3.43-12.04; P<0.01), and mouth ulcer (RR 11.70; 95%CI 6.18-22.17; P<0.01) were higher in the mTORi group. More patients in the conversion group had to discontinue study medication (RR 2.52; 95%CI 1.75-3.63; P<0.01). There was no significant difference between the two groups with regard to death, graft loss, diabetes, chronic allograft nephropathy, and interstitial fibrosis/tubular atrophy.

Conclusions

Posttransplant patients have a better graft function and lower incidence of malignancy after conversion from CNI to mTORi therapy. However, this conversion strategy may be prevented by the higher drug discontinuation rate due to mTORi-associated adverse events, such as more acute rejection, infection, proteinuria, leukopenia, acne, and mouth ulcer, indicating that conversion therapy may only be a treatment option in selected patients.

Sex differences in cancer risk and outcomes after kidney transplantation

Kidney transplant recipients (KTRs) experience a two- to four-fold increased risk of developing and dying from cancer compared with the general population. High cancer risk results from the interaction of both modifiable and non-modifiable factors. This mapping review explores the impact of sex disparity on cancer's increased incidence and mortality after kidney transplantation (KT). In terms of age, population-based studies indicate that younger recipients of both sexes experience a higher risk of cancer, but this is more pronounced in young women. On the contrary, older men are more likely to be diagnosed with cancer, although their increased risk is not statistically significant compared with the general population. Regarding cancer type, studies show an increased risk of Kaposi sarcoma, gynecologic and lung cancer in women, and bladder and kidney cancer in men. Immune-related cancers such as pos-transplant lymphoproliferative disorders and melanoma are increased in both sexes. Mortality also shows differences between sexes. Although cancer is the second cause of death in both male and female KTRs, studies show higher overall mortality in men and elderly recipients. However, the relative risk of cancer mortality compared with the general population is higher at a younger age, with disparate results regarding sex. Female KTRs appear to die at a younger age than males when compared with the general population. Differences in cancer rates by sex after renal transplantation need further studies. A better understanding of sex-specific differences in cancer epidemiology after KT could help nephrologists to better address pre-transplant counseling, to establish early surveillance programs, and to plan modifiable risk factors such as immunosuppression.

Association of HLA mismatch and MTOR inhibitor regimens with malignancy and mortality after kidney transplantation

Background The association of mammalian target of rapamycin inhibitors (MTORI) with malignancies and mortality in kidney transplant recipients (KTR) with different degrees of human leukocyte antigen mismatch (HLA-mm) at transplant has not been previously studied. Methods Our observational cohort study included 166, 256 adult KTRs in 2000-2018. Immunosuppression in the first post-transplant year were MTORIs in 13,056 (7.85%) and non-MTORIs in 153,200 (92.15%). We used Cox multivariable regression models to determine the cause-specific hazard ratio (HRcs) of non-melanoma skin cancer (NMSC),solid organ malignancies (SOM)] and all-cause death (death_ac); and the HR of the composite outcomes of NMSC or death_ac and SOM or death_ac associated with MTORI versus non-MTORI regimens in the overall study sample and the 0, 1-3, and 4-6 HLA-A, B and DR mm subgroups. Results NMSC risk was lower with MTORI than non-MTORI in all HLA-mm subgroups [(0 mm, HRcs = 0.67; 95% CI = 0.46-0.97, 1-3 mm, HRcs = 0.73; 95% CI = 0.61-0.87, 4-6 mm, HRcs = 0.69; 95% CI = 0.62-0.76)]. SOM risks were similar between regimens in the 0 HLA mm subgroup (HRcs = 1.10 (95% CI = 0.78-1.57) and lower with MTORI than non-MTORI in the 1-3, and 4-6 HLA-mm subgroups, [(HR = 0.84; (95% CI = 0.71-0.99), and (HR = 0.86; 95% CI = 0.78-0.94); respectively]. Risks of death_ac and composite outcomes (NMSC or death_ac and SOM or death_ac) were higher with MTORI than non-MTORI in almost all HLA-mm subgroups. Conclusion MTORIs are associated with protection from NMSC and SOM in almost all HLA-mm subgroups ca; however, their association with increased all-cause mortality in adult kidney transplant recipients needs further investigation.

Comparison of two strategies based on mammalian target of rapamycin inhibitors in secondary prevention of non-melanoma skin cancer after kidney transplantation, a pilot study

After kidney transplantation, withdrawal of calcineurin inhibitors (CNI) and conversion to sirolimus (SRL) may reduce the occurrence of new non-melanoma skin cancer (NMSC). Conversely, a reduced CNI exposure with everolimus (EVR) is an alternative strategy that has not been thoroughly evaluated. We retrospectively compared the occurrence of newly diagnosed NMSCs in two cohorts of kidney transplant recipients (KTR) with at least one NMSC: 35 patients were converted to EVR with reduced CNI exposure (CNI/EVR group), whereas 46 patients were converted to SRL in association with mycophenolic acid (MPA) (SRL/MPA group). Two years after conversion, survival free of new NMSC was similar between the two cohorts (p = .37), with 19 KTR (54.3%) in the CNI/EVR group and 22 (47.8%) in the SRL/MPA group being diagnosed of at least one new NMSC. Half of the KTR from both groups showed adverse events, leading to mTORi discontinuation for 37.1% of KTR in the CNI/EVR group and 21.7% in the SRL/MPA group (p = .09). The incidence of rejections was similar between the two groups. In a retrospective cohort of KTR with at least one post-transplant NMSC, the outcome of the patients converted to a CNI/EVR regimen was not different from those converted to a SRL/MPA regimen.

Timing of mTORI usage and outcomes in kidney transplant recipients

The introduction of mammalian target of rapamycin inhibitors (mTORi) as immunosuppressive agents has changed the landscape of calcineurin inhibitor-based immunosuppressive regimens. However, the timing of mTORi conversion and its associated outcomes in kidney transplantation have conflicting results. This study investigated the effect of early or late mTORi post-transplant initiation on major transplant outcomes, including post-transplant malignancy, in kidney transplant recipients in our center. We enrolled 201 kidney transplant recipients with surviving function grafts of >3 months between 1983 and 2016. Patients were divided into three groups: early mTORi (initiated within 6 months of kidney transplantation), late mTORi, (mTORi initiation >6 months after kidney transplantation) and no mTORi. The mean creatinine at conversion was 1.46 ± 0.48 mg/dL and 1.30 ± 0.53 mg/dL for the early and late mTORi groups, respectively. During the study period, 10.5% of mTORi users and 19.2% of mTORi nonusers developed malignancy, mainly urothelial carcinoma. After adjustment for confounding factors, mTORi users were found to have a lower incidence of post-transplant malignancy than did nonusers (adjusted OR: 0.28, P = 0.04). No significant difference was observed between early and late mTORi users. Our results verified the potential advantages of mTORi usage in reducing cancer incidence after kidney transplantation. However, no significant result was found related to the timing of mTORi introduction. Future studies should include a longer observation period with a larger cohort.

The previously common post-kidney transplant Kaposi sarcoma has become non-existent for a decade: an Egyptian experience

BACKGROUND

De novo malignancy is a worrying complication after kidney transplantation; the type of which may vary due to factors such as the prevalence of viral infection and race. Kaposi sarcoma used to be the most common malignancy among our patients constituting more than one-third of cancers. Nevertheless, we noticed that Kaposi sarcoma has not been observed for a long period. Therefore, we conducted this study to explore such observation.

METHODS

Data of all kidney transplant recipients were retrieved and retrospectively analyzed. Their total number was 3126 patients. Their mean age was 28.71 ± 10.97 years and of them, 823 (26.3%) were females. The pattern of Kaposi sarcoma throughout the last decade as well as the preceding three decades was studied. The possible relation between the disappearance of Kaposi sarcoma and three paradigm shifts in our practice, namely the use of mTOR inhibitors, steroid-free regimen and CMV prophylaxis was explored.

RESULTS

Since 2010, no new cases of Kaposi sarcoma have been observed. In addition, patients who have been transplanted after 2006 did not develop such malignancy. Patients who received CMV prophylaxis and/or were maintained on mTOR inhibitor or steroid-free regimens have not developed Kaposi sarcoma. Moreover, CMV prophylaxis had a statistically significant difference when compared to a homogenous group without CMV prophylaxis. However, Kaplan-Meier analysis of patients of the three policies and their counterpart groups showed comparable results.

CONCLUSION

Kaposi sarcoma, which was previously the most common malignancy, is no longer observed for almost a decade among our kidney transplant recipients. m-TOR inhibitors, steroid-free regimen and CMV prophylaxis policy are possible contributing factors. Nevertheless, only CMV prophylaxis policy had a statistically significant relation to the disappearance of Kaposi sarcoma.

Everolimus Initiation With Early Calcineurin Inhibitor Withdrawal in De Novo Heart Transplant Recipients: Long-term Follow-up From the Randomized SCHEDULE Study

BACKGROUND

A calcineurin inhibitor (CNI)-free immunosuppressive regimen has been demonstrated to improve renal function early after heart transplantation, but long-term outcome of such a strategy has not been well described.

METHODS

In the randomized SCHEDULE trial, de novo heart transplant recipients received (1) everolimus with reduced-exposure CNI (cyclosporine) followed by CNI withdrawal at week 7-11 posttransplant or (2) standard-exposure cyclosporine, both with mycophenolate mofetil and corticosteroids; 95/115 randomized patients were followed up at 5-7 years posttransplant.

RESULTS

Mean measured glomerular filtration rate was 74.7 mL/min and 62.4 mL/min with everolimus and CNI, respectively. The mean difference was in favor of everolimus by 11.8 mL/min in the intent-to-treat population (P = 0.004) and 17.2 mL/min in the per protocol population (n = 75; P < 0.001). From transplantation to last follow-up, the incidence of biopsy-proven acute rejection (BPAR) was 77% (37/48) and 66% (31/47) (P = 0.23) with treated BPAR in 50% and 23% (P < 0.01) in the everolimus and CNI groups, respectively; no episode led to hemodynamic compromise. Coronary allograft vasculopathy (CAV) assessed by coronary intravascular ultrasound was present in 53% (19/36) and 74% (26/35) of everolimus- and CNI-treated patients, respectively (P = 0.037). Graft dimensions and function were similar between the groups. Late adverse events were comparable.

CONCLUSIONS

These results suggest that de novo heart transplant patients randomized to everolimus and low-dose CNI followed by CNI-free therapy maintain significantly better long-term renal function as well as significantly reduced CAV than patients randomized to standard CNI treatment. Increased BPAR in the everolimus group during year 1 did not impair long-term graft function.

Monoclonal gammopathy of undetermined significance coexisting in patients undergoing kidney transplantation does not adversely influence post-graft clinical outcome

Background

Management of patients with oncohaematological disorders such as monoclonal gammopathy of undetermined significance (MGUS) is a frequent problem in pre-transplant work-up. Insights on disease progression and long-term functional outcomes are still lacking in this setting.

Methods

This was a retrospective analysis on all patients with MGUS who underwent kidney transplant (KT) at our centre between 1 January 2000 and 31 December 2017 (cases, n = 65). Patients were matched with a control group (KTs with similar characteristics but without history of haematological disease, controls, n = 1079). Primary endpoints were graft and patient survival; secondary endpoints were causes of graft failure, patient death, occurrence of allograft rejection, post-transplant neoplasia (not correlated to previous disorder) and/or infectious episodes.

Results

The MGUS and control groups had a similar mean age [60 (29–79) versus 55.2 (19.3–79.5) years, respectively] and percentage of males (69.2% versus 64.6%, respectively). Median follow-up time since KT was 3.5 years (0–14) in cases and 8.3 years (0–14.9) in controls. All MGUS patients underwent KT following extensive multidiscliplinary investigations. No differences were found between cases and controls regarding patient and graft survival or post-transplant complications except for lower incidence of infections (58.7% versus 69.8%, P = 0.019) and increased use of mTOR inhbitors (30.3% versus 14.7%, P = 0.001) in MGUS. MGUS isotype did not influence graft and patient survival. The absence of difference in patients and graft survival was also confirmed in an adjunctive analysis where MGUS were compared with controls (ratio 1:2) matched for recipient age, gender, number of transplantations and transplant period.

Conclusion

Patients with MGUS may undergo KT without significantly increased risks of complications, provided that appropriate diagnostic procedures are carefully followed. Multidiscipline-based studies are crucial for establishing well designed pre- and post-transplant protocols for the best management of patients with coexisting MGUS and end-stage renal disease.

Novel non-cystic features of polycystic kidney disease: having new eyes or seeking new landscapes

For decades, researchers have been trying to decipher the complex pathophysiology of autosomal dominant polycystic kidney disease (ADPKD). So far these efforts have led to clinical trials with different candidate treatments, with tolvaptan being the only molecule that has gained approval for this indication. As end-stage kidney disease due to ADPKD has a substantial impact on health expenditures worldwide, it is likely that new drugs targeting kidney function will be developed. On the other hand, recent clinical observations and experimental data, including PKD knockout models in various cell types, have revealed unexpected involvement of many other organs and cell systems of variable severity. These novel non-cystic features, some of which, such as lymphopenia and an increased risk to develop infections, should be validated or further explored and might open new avenues for better risk stratification and a more tailored approach. New insights into the aberrant pathways involved with abnormal expression of PKD gene products polycystin-1 and -2 could, for instance, lead to a more directed approach towards early-onset endothelial dysfunction and subsequent cardiovascular disease. Furthermore, a better understanding of cellular pathways in PKD that can explain the propensity to develop certain types of cancer can guide post-transplant immunosuppressive and prophylactic strategies. In the following review article we will systematically discuss recently discovered non-cystic features of PKD and not well-established characteristics. Overall, this knowledge could enable us to improve the outcome of PKD patients apart from ongoing efforts to slow down cyst growth and attenuate kidney function decline.

Early conversion to a CNI-free immunosuppression with SRL after renal transplantation-Long-term follow-up of a multicenter trial

Introduction

Early conversion to a CNI-free immunosuppression with SRL was associated with an improved 1- and 3- yr renal function as compared with a CsA-based regimen in the SMART-Trial. Mixed results were reported on the occurrence of donor specific antibodies under mTOR-Is. Here, we present long-term results of the SMART-Trial.

Methods and materials

N = 71 from 6 centers (n = 38 SRL and n = 33 CsA) of the original SMART-Trial (ITT n = 140) were enrolled in this observational, non-interventional extension study to collect retrospectively and prospectively follow-up data for the interval since baseline. Primary objective was the development of dnDSA. Blood samples were collected on average 8.7 years after transplantation.

Results

Development of dnDSA was not different (SRL 5/38, 13.2% vs. CsA 9/33, 27.3%; P = 0.097). GFR remained improved under SRL with 64.37 ml/min/1.73m² vs. 53.19 ml/min/1.73m² (p = 0.044). Patient survival did not differ between groups at 10 years. There was a trend towards a reduced graft failure rate (11.6% SRL vs. 23.9% CsA, p = 0.064) and less tumors under SRL (2.6% SRL vs. 15.2% CsA, p = 0.09).

Conclusions

An early conversion to SRL did not result in an increased incidence of dnDSA nor increased long-term risk for the recipient. Transplant function remains improved with benefits for the graft survival.

From Cancer to Immune-Mediated Diseases and Tolerance Induction: Lessons Learned From Immune Oncology and Classical Anti-cancer Treatment

Success in cancer treatment over the last four decades has ranged from improvements in classical drug therapy to immune oncology. Anti-cancer drugs have also often proven beneficial for the treatment of inflammatory and autoimmune diseases. In this review, we report on challenging examples that bridge between treatment of cancer and immune-mediated diseases, addressing mechanisms and experimental models as well as clinical investigations. Patient-derived tumor xenograft (PDX) (humanized) mouse models represent useful tools for preclinical evaluation of new therapies and biomarker identification. However, new developments using human ex vivo approaches modeling cancer, for example in microfluidic human organs-on-chips, promise to identify key molecular, cellular and immunological features of human cancer progression in a fully human setting. Classical drugs which bridge the gap, for instance, include cytotoxic drugs, proteasome inhibitors, PI3K/mTOR inhibitors and metabolic inhibitors. Biologicals developed for cancer therapy have also shown efficacy in the treatment of autoimmune diseases. In immune oncology, redirected chimeric antigen receptor (CAR) T cells have achieved spectacular remissions in refractory B cell leukemia and lymphoma and are currently under development for tolerance induction using cell-based therapies such as CAR Tregs or NK cells. Finally, a brief outline will be given of the lessons learned from bridging cancer and autoimmune diseases as well as tolerance induction.

Arteriovenous graft in kidney transplant patients: Lookout for the rare but fearsome angiosarcoma

INTRODUCTION

Angiosarcomas are rare tumors, comprising less than 1% of all sarcomas. However, they portend a poor prognosis, as they tend to metastasize early, being of uttermost importance a prompt diagnosis and treatment.

CASE DESCRIPTION

We present the case of a 55-year-old female with history of kidney transplantation, immunosuppressed with tacrolimus, prednisolone, and mofetil mycophenolate. Fifteen years after the transplant, she developed an ulcerated lesion on the site of a nonfunctioning arteriovenous graft, which was excised. Histology was compatible with a high grade angiosarcoma that invaded the margins, and immunosuppression was switched to everolimus. Staging imaging exams revealed lymph node, muscle, and lung metastases. Shortly after, nodular lesions appeared compatible with local recurrence of the disease, and the patient showed severe deterioration of her clinical condition, being proposed for palliative chemotherapy. However, the disease showed an explosive progression and the patient died before starting the treatment.

CONCLUSION

This case emphasizes the importance of including inspection of the vascular access (functioning or not) in regular post-transplant consultation and value any alterations in the attempt of a timely diagnosis. Although rare, angiosarcoma is an important entity that should be considered in the differential diagnosis of soft tissue masses arising from a vascular access, especially in immunocompromised patients. Aggressive treatment should be offered whenever possible.

Assessment of kidney transplant suitability for patients with prior cancers: is it time for a rethink?

Kidney transplant recipients have up to a 100-fold greater risk of incident cancer compared with the age/sex-matched general population, attributed largely to chronic immunosuppression. In patients with a prior history of treated cancers, the type, stage and the potential for cancer recurrence post-transplant of prior cancers are important factors when determining transplant suitability. Consequently, one of the predicaments facing transplant clinicians is to determine whether patients with prior cancers are eligible for transplantation, balancing between the accelerated risk of death on dialysis, the projected survival benefit and quality of life gains with transplantation, and the premature mortality associated with the potential risk of cancer recurrence post-transplant. The guidelines informing transplant eligibility or screening and preventive strategies against cancer recurrence for patients with prior cancers are inconsistent, underpinned by uncertain evidence on the estimates of the incidence of cancer recurrence and the lack of stage-specific outcomes data, particularly among those with multiple myeloma or immune-driven malignancies such as melanomas. With the advent of newer anti-cancer treatment options, it is unclear whether the current guidelines for those with prior cancers remain appropriate. This review will summarize the uncertainties of evidence informing the current recommendations regarding transplant eligibility of patients with prior cancers.

Preformed Donor-Specific HLA Antibodies in Living and Deceased Donor Transplantation: A Multicenter Study

BACKGROUND AND OBJECTIVES

The prognostic value of preformed donor-specific HLA antibodies (DSA), which are only detectable by sensitive methods, remains controversial for kidney transplantation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The outcome of 4233 consecutive kidney transplants performed between 2012 and 2015 in 18 German transplant centers was evaluated. Most centers used a stepwise pretransplant antibody screening with bead array tests and differentiation of positive samples by single antigen assays. Using these screening results, DSA against HLA-A, -B, -C, -DRB1 and -DQB1 were determined. Data on clinical outcome and possible covariates were collected retrospectively.

RESULTS

Pretransplant DSA were associated with lower overall graft survival, with a hazard ratio of 2.53 for living donation (95% confidence interval [95% CI], 1.49 to 4.29; P<0.001) and 1.59 for deceased donation (95% CI, 1.21 to 2.11; P=0.001). ABO-incompatible transplantation was associated with worse graft survival (hazard ratio, 2.09; 95% CI, 1.33 to 3.27; P=0.001) independent from DSA. There was no difference between DSA against class 1, class 2, or both. Stratification into DSA <3000 medium fluorescence intensity (MFI) and DSA ≥3000 MFI resulted in overlapping survival curves. Therefore, separate analyses were performed for 3-month and long-term graft survival. Although DSA <3000 MFI tended to be associated with both lower 3-month and long-term transplant survival in deceased donation, DSA ≥3000 MFI were only associated with worse long-term transplant survival in deceased donation. In living donation, only strong DSA were associated with reduced graft survival in the first 3 months, but both weak and strong DSA were associated with reduced long-term graft survival. A higher incidence of antibody-mediated rejection within 6 months was only associated with DSA ≥3000 MFI.

CONCLUSIONS

Preformed DSA were associated with an increased risk for graft loss in kidney transplantation, which was greater in living than in deceased donation. Even weak DSA <3000 MFI were associated with worse graft survival. This association was stronger in living than deceased donation.