Sirolimus and secondary skin-cancer prevention in kidney transplantation

Using omics to explore complications of kidney transplantation

The importance of genetic and biochemical variation in renal transplant outcomes has been clear since the discovery of the HLA in the 1950s. Since that time, there have been huge advancements in both transplantation and omics. In recent years, there has seen an increased number of genome-, proteome- and transcriptome-wide studies in the field of transplantation moving away from the earlier candidate gene/protein approaches. These areas have the potential to lead to the development of personalized treatment depending on individual molecular risk profiles. Here, we discuss recent progress and the current literature surrounding omics and renal transplant complications.

Skin Cancers in Organ Transplant Recipients

Long-term utilization of immunosuppression in organ transplant recipients (OTRs) leads to decreased immune-mediated tumor surveillance and development of malignant tumors. A delicate balance needs to be maintained in the intensity of immunosuppression to keep the risk of malignancy low without jeopardizing life-saving graft function. OTRs are prone to developing skin cancers that exhibit unique epidemiologic, pathophysiologic, and prognostic characteristics. In this review, we discuss the most commonly reported skin cancers in OTRs: squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Kaposi sarcoma, Merkel cell carcinoma, and malignant melanoma (MM). Tumors in this high-risk population are aggressive and may respond poorly to standard therapies; however, new targeted therapies are promising. Checkpoint inhibitor antibodies have been used for treatment of cutaneous SCC, Merkel cell carcinoma, and MM; epidermal growth factor receptor inhibitors have been used for cutaneous SCC; hedgehog pathway inhibitors have been used for BCC; and BRAF and MEK inhibitors are being used increasingly in the management of MM. Guidelines for dermatologic screening are variable and primarily based on expert opinion. Prospective evidence-based trials by multidisciplinary groups are needed to better define surveillance schedules for pre- and posttransplant cutaneous malignancies.

The Effect of Conversion from a Calcineurin Inhibitor to Sirolimus on Skin Cancer Reduction in Post-renal Transplantation Patients

In kidney transplant patients, skin cancer is the most commonly involved neoplasm. More than 90% of post-transplantation skin cancers are nonmelanoma skin cancers (NMSCs). The majority of them are squamous cell carcinomas and basal cell carcinomas. Calcineurin inhibitors (CNIs) such as cyclosporine and tacrolimus are immunosuppressive agents given after solid organ transplantation, but they can also promote tumor growth. Sirolimus is a novel class of immunosuppressants and has been proven to have antineoplastic properties. We review clinical trials and meta-analyses studying if conversion from CNI to sirolimus in post-renal transplantation patients decreases the development of NMSCs. A critical appraisal of the literature demonstrated that, while smaller scale studies tended to yield no clinically significant data, larger clinical trials and meta-analyses supported the conclusion that converting to sirolimus in post-renal transplant patients leads to reductions in skin cancer development. As a result, we conclude that conversion to sirolimus likely reduces NMSC in post-renal transplantation patients. Larger scale clinical trials with more rigorous stratification and less patient dropout rate are needed for more definitive conclusions.

Increasing incidence of melanoma after solid organ transplantation: a retrospective epidemiological study

The risk of melanoma in organ transplant recipients (OTR) is increased compared with the general population. This retrospective study registered all cases of post-transplant melanoma in kidney, heart, lung, and liver transplant recipients followed in our specialized post-transplant Dermatology Clinic since 1991. The yearly prevalence of melanoma and skin carcinoma between 2000 and 2015 was computed and compared in this population. Based on another cohort of kidney transplant recipients grafted since 2005, adjusted age- and sex-standardized incidence ratio (SIR) was calculated using a renal transplantation registry. In our overall OTR cohort, between 1991 and 2000, five melanomas occurred in 1800 OTRs (0.28%), whereas between 1991 and 2015, 53 melanomas were diagnosed in 49 of 4510 OTR (1.09%), representing a 3.9-fold increase in prevalence after 2000. Remarkably, the prevalence of nonmelanoma skin cancers remained unchanged over this period. Two deaths related to melanoma were recorded with an overall follow-up of 62 months. In our cohort of 1102 renal transplant recipients, the SIR of melanoma was 4.52. Our data suggest that contrasting with nonmelanoma skin cancer, the risk of post-transplant melanoma has considerably increased over the last decade.

Risk of Second Malignancies in Solid Organ Transplant Recipients Who Develop Keratinocyte Cancers

Solid organ transplant recipients have increased risk for developing keratinocyte cancers, including cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), in part as a result of immunosuppressive medications administered to prevent graft rejection. In the general population, keratinocyte cancers are associated with increased risks of subsequent malignancy, however, the risk in organ transplant populations has not been evaluated. We addressed this question by linking the U.S. Scientific Registry of Transplant Recipients, which includes data on keratinocyte cancer occurrence, with 15 state cancer registries. Risk of developing malignancies after keratinocyte cancer was assessed among 118,440 Caucasian solid organ transplant recipients using multivariate Cox regression models. Cutaneous SCC occurrence (n = 6,169) was associated with 1.44-fold increased risk [95% confidence interval (CI), 1.31-1.59] for developing later malignancies. Risks were particularly elevated for non-cutaneous SCC, including those of the oral cavity/pharynx (HR, 5.60; 95% CI, 4.18-7.50) and lung (HR, 1.66; 95% CI, 1.16-2.31). Cutaneous SCC was also associated with increased risk of human papillomavirus-related cancers, including anal cancer (HR, 2.77; 95% CI, 1.29-5.96) and female genital cancers (HR, 3.43; 95% CI, 1.44-8.19). In contrast, BCC (n = 3,669) was not associated with overall risk of later malignancy (HR, 0.98; 95% CI, 0.87-1.12), including any SCC. Our results suggest that transplant recipients with cutaneous SCC, but not BCC, have an increased risk of developing other SCC. These findings somewhat differ from those for the general population and suggest a shared etiology for cutaneous SCC and other SCC in the setting of immunosuppression. Cutaneous SCC occurrence after transplantation could serve as a marker for elevated malignancy risk. Cancer Res; 77(15); 4196-203. ©2017 AACR.

Sirolimus Increases T-Cell Abundance in the Sun Exposed Skin of Kidney Transplant Recipients

BACKGROUND

Kidney transplant recipients (KTRs) receiving the mammalian target of rapamycin inhibitor sirolimus may display a reduced risk of skin cancer development compared to KTRs receiving calcineurin inhibitors. Despite studies investigating the effects of these 2 drug classes on T cells in patient blood, the effect these drugs may have in patient skin is not yet known.

METHODS

Fifteen patients with chronic kidney disease (not recipients of immunosuppressive drugs), and 30 KTRs (15 receiving a calcineurin inhibitor, and 15 receiving sirolimus) provided matched samples of blood, sun exposed (SE) and non-SE skin. The abundance of total CD8⁺ and CD4⁺ T cells, memory CD8⁺ and CD4⁺ T cells, and regulatory T (Treg) cells in each sample was then assessed by flow cytometry.

RESULTS

Sirolimus treatment significantly increased absolute numbers of CD4⁺ T cells, memory CD8⁺- and CD4⁺ T cells, and Treg cells in SE skin versus paired samples of non-SE skin. No differences were found in the absolute number of any T cell subset in the blood. Correlation analysis revealed that the percentage of T cell subsets in the blood does not always accurately reflect the percentage of T-cell subsets in the skin of KTRs. Furthermore, sirolimus significantly disrupts the balance of memory CD4⁺ T cells in the skin after chronic sun exposure.

CONCLUSIONS

This study demonstrated that immunosuppressive drug class and sun exposure modify the abundance of multiple T-cell subsets in the skin of KTRs. Correlation analysis revealed that the prevalence of Treg cells in KTR blood does not accurately reflect the prevalence of Treg cells in KTR skin.

Phosphoinositide 3-Kinase-Dependent Signalling Pathways in Cutaneous Squamous Cell Carcinomas

Cutaneous squamous cell carcinoma (cSCC) derives from keratinocytes in the epidermis and accounts for 15–20% of all cutaneous malignancies. Although it is usually curable by surgery, 5% of these tumours metastasise leading to poor prognosis mostly because of a lack of therapies and validated biomarkers. As the incidence rate is rising worldwide it has become increasingly important to better understand the mechanisms involved in cSCC development and progression in order to develop therapeutic strategies. Here we discuss some of the evidence indicating that activation of phosphoinositide 3-kinases (PI3Ks)-dependent signalling pathways (in particular the PI3Ks targets Akt and mTOR) has a key role in cSCC. We further discuss available data suggesting that inhibition of these pathways can be beneficial to counteract the disease. With the growing number of different inhibitors currently available, it would be important to further investigate the specific contribution of distinct components of the PI3Ks/Akt/mTOR pathways in order to identify the most promising molecular targets and the best strategy to inhibit cSCC.

Switch to an everolimus-facilitated cyclosporine A sparing immunosuppression improves glycemic control in selected kidney transplant recipients

BACKGROUND

Mammalian target of rapamycin inhibitors (mToRi) allow calcineurin inhibitor (CNI) sparing therapy in renal transplant recipients with possible beneficial effects on the long-term allograft function and cardiovascular risk. The influence of mToRi on glucose metabolism is still under discussion.

METHODS

In a retrospective analysis, renal allograft recipients switched from a cyclosporine A (CsA) to an everolimus (EVR)-based immunosuppression in the first year after transplantation were compared with patients on continued CsA treatment. At 6-month intervals, the prevalence of impaired fasting glucose (IFG) and new onset of diabetes after transplantation (NODAT) were assessed.

RESULTS

A total of 146 renal transplant recipients were included. The cumulative prevalence of IFG and NODAT 30-months post-transplantation was significantly lower in patients switched to an immunosuppression with EVR compared to patients on continued CsA treatment (10% vs 22%, P=.049). However, patients switched to EVR showed a higher incidence of acute cellular rejections in the first 12 months (23% vs 11%, P=.048).

CONCLUSION

EVR-based immunosuppression was associated with a similar or even improved glycemic control and improved renal function. However, due to higher rejection rates, patients switched to EVR should be carefully selected as rejection therapy with steroids counteracts the benefit in glycemic control.

A potential role of the unfolded protein response in post-transplant cancer

Cancer is one of the major causes of mortality in organ transplant patients receiving immunosuppressive regimen based on Cyclosporin A (CsA). Organ transplantation and chronic immunosuppression are typically associated with skin cancers (both squamous cell carcinoma and melanoma) and renal cell carcinoma (RCC). Recent studies have shown that in addition to its immunosuppressive effects, accounted for by the inhibition of calcineurin and the modulation of the transcriptional programme of lymphocytes, CsA also directly stimulates the growth and aggressive behaviour of various cancer cells. Using renal carcinogenesis as an example, we discuss the current evidence for a role of cellular proteostasis, i.e. the regulation of the production, maturation and turnover of proteins in eukaryotic cells, in tumorigenesis arising under conditions of chronic immunosuppression. We present the recent studies showing that CsA induces the unfolded protein response (UPR) in normal and transformed kidney cells. We examine how the UPR might be important, considering in particular the genomic analyses showing the existence of a correlation between the levels of expression of the actors of the UPR, the chaperones of the endoplasmic reticulum (ER) and the aggressiveness of renal carcinoma. The UPR may offer a possible explanation for how immunosuppressive regimens based on CsA promote renal carcinogenesis. We discuss the opportunities offered by this biological knowledge in terms of screening, diagnosis and treatment of post-transplant cancers, and propose possible future translational studies examining the role of tumour proteostasis and the UPR in this context.

[Cutaneous squamous cell carcinoma]

Squamous cell carcinoma (SCC) of the skin accounts for 20 % of non-melanoma skin cancer and is one of the most frequent types of cancer in Caucasian populations. Diagnosis is based on the clinical features and should be histopathologically confirmed to adequately address the prognosis and treatment. Complete surgical excision with histopathological control of excision margins is the gold standard in the treatment of primary SCC. Sentinel lymph node biopsies (SLNB) can be considered in SCC with a tumor thickness of >6 mm but there is currently no evidence concerning prognostic and therapeutic effects. Radiotherapy can be discussed as an alternative to surgery for inoperable tumors or as adjuvant therapy for a high risk of recurrence. In SCC with distant metastases various chemotherapeutic agents are used; however, there is no standard regimen. The epidermal growth factor receptor (EGFR) inhibitors and immune checkpoint blockers can be discussed as treatment options, preferentially in clinical trials. There is no standard follow-up schedule for patients with SCC. A risk-adapted follow-up is recommended based on the risk of metastatic spread or development of new lesions primarily by dermatological control and supplemented by ultrasound investigations in high risk patients.

Hormesis and Defense of Infectious Disease

Infectious diseases are a global health burden and remain associated with high social and economic impact. Treatment of affected patients largely relies on antimicrobial agents that act by directly targeting microbial replication. Despite the utility of host specific therapies having been assessed in previous clinical trials, such as targeting the immune response via modulating the cytokine release in sepsis, results have largely been frustrating and did not lead to the introduction of new therapeutic tools. In this article, we will discuss current evidence arguing that, by applying the concept of hormesis, already approved pharmacological agents could be used therapeutically to increase survival of patients with infectious disease via improving disease tolerance, a defense mechanism that decreases the extent of infection-associated tissue damage without directly targeting pathogenic microorganisms.

Daunting but Worthy Goal: Reducing the De Novo Cancer Incidence After Transplantation

Solid-organ transplant recipients are at increased risk of developing de novo malignancies compared with the general population, and malignancies become a major limitation in achieving optimal outcomes. The prevention and the management of posttransplant malignancies must be considered as a main goal in our transplant programs. For these patients, immunosuppression plays a major role in oncogenesis by both impairement of immunosurveillance, enhancement of chronic viral infection, and by direct prooncogenic effects. It is essential to manage the recipient with a long-term adapted screening program beginning before transplantation to use a prophylaxis to decrease infection-related cancer, to propose a viral monitoring, and to modulate the immunosuppression toward lower doses especially for calcineurin inhibitors. Indeed, strategies to induce tolerance or to allow a dramatic reduction of the immunosuppression burden are the more promising approaches for the reduction of the posttransplant malignancies.

Renal association clinical practice guideline in post-operative care in the kidney transplant recipient

These guidelines cover the care of patients from the period following kidney transplantation until the transplant is no longer working or the patient dies. During the early phase prevention of acute rejection and infection are the priority. After around 3-6 months, the priorities change to preservation of transplant function and avoiding the long-term complications of immunosuppressive medication (the medication used to suppress the immune system to prevent rejection). The topics discussed include organization of outpatient follow up, immunosuppressive medication, treatment of acute and chronic rejection, and prevention of complications. The potential complications discussed include heart disease, infection, cancer, bone disease and blood disorders. There is also a section on contraception and reproductive issues.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and AD depending on the quality of the evidence that the recommendation is based on.

Cancer and mTOR Inhibitors in Transplant Recipients

Malignancy is the second most common single cause of death observed in organ transplant recipients. The excess cancer risk is related to intensity and duration of immunosuppressive therapy and inversely to recipient age. Immunodeficiency and (chronic/oncogenic) viral infections together constitute a major risk. Nonmelanoma skin cancer, Kaposi sarcoma, and posttransplant lymphoproliferative disease have standardized incidence ratios exceeding 10- or 50-fold. The mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, are increasingly used after organ transplantation with potential advantages in virus-associated posttransplant malignancies as well as anti-cancer properties. Despite a seemingly clear mechanism of action and solid rationale for their use in cancer therapy, mTORis have met only modest success rates in clinical trials with advanced malignancies except for specific tumors, such as Kaposi sarcoma and mantle cell lymphoma. Because mTORis are primarily cytostatic, not cytotoxic, the observed clinical efficacy is a reflection of disease stabilization rather than tumor regression. Nonmelanoma skin cancers, in particular cutaneous squamous cell carcinoma, have the highest standardized incidence ratios in transplant recipients. Recent meta-analyses and randomized trials on secondary prevention of squamous cell carcinoma observed a reduction in cumulative tumor load, suggesting most benefit to be gained by early conversion to an mTOR inhibitor-based maintenance regime. There is ongoing debate on the mechanisms involved including withdrawal of the carcinogenic effects of calcineurin inhibitors and/or their impact on chronic (oncogenic) viral infections. At present, there is, however, insufficient evidence for the primary use of mTORis as protective agents against most other cancer types.

Clinical and Economic Consequences of Early Cancer After Kidney Transplantation in Contemporary Practice

BACKGROUND

Current clinical and economic consequences of cancer after kidney transplantation are incompletely defined.

METHODS

We examined United States Renal Data System records of Medicare-insured kidney transplant recipients in 2000 to 2011 to determine clinical and economic impacts of cancer diagnosed within the first 3 years posttransplantation. Cancer diagnoses were identified using Medicare billing codes and categorized as nonmelanoma skin cancer (NMSC), viral-linked and "other" cancers. Associations of cancers with mortality and graft loss were estimated by time-varying Cox regression. Impacts of cancer diagnoses on inpatient and outpatient costs within each year were quantified by multivariate linear regression modeling.

RESULTS

Among 67 157 recipients, by 3 years posttransplant, NMSC was diagnosed in 5.7%, viral-linked cancer in 1.9%, and "other" cancers in 6.3%. Viral-linked cancer was associated with more than 3-fold increased risk in subsequent mortality until the third transplant anniversary, and nearly twice the mortality risk after year 3. "Other" cancers had similar associations with death and graft loss, whereas NMSC was associated with 33% higher mortality beyond the third year posttransplant. Viral-linked cancer had the largest inpatient and outpatient cost impacts per case, followed by "other" cancer, whereas NMSC impacted only outpatient costs. Care of new cancer diagnoses was generally more costly than care of previously established diagnoses. Cancer accounted for 3% to 5.5% of total inpatient Medicare expenditures and 1.5% to 3.3% of outpatient expenditures in the first 3 years posttransplant.

CONCLUSIONS

Early posttransplant malignancy is an expensive and morbid condition that warrants attention in efforts to improve pretransplant screening and management protocols before and after transplant.

While reinforcing cell cycle arrest, rapamycin and Torins suppress senescence in UVA-irradiated fibroblasts

Sunlight predisposes to skin cancer and melanomas. Ultraviolet A (UVA), a long wave component of sunlight, can reach dermal fibroblasts. Here we studied UVA-induced senescence in human fibroblasts in vitro. It is known that senescence occurs, when cell cycle is arrested, but mTOR is still active, thus converting arrest to senescence (geroconversion). We showed that, while arresting cell cycle, UVA did not inhibit mTOR, enabling geroconversion. In UVA-treated cells, mTOR remained fully active. Rapamycin and Torins 1/ 2 prevented UVA-induced senescent phenotype, although they further re-enforced cell cycle arrest. Given that senescent stromal fibroblasts support tumorigenesis, we envision that mTOR inhibitors may potentially be used to prevent sunlight-caused tumors as well as skin photo-aging.

Rate of regional nodal metastases of cutaneous squamous cell carcinoma in the immunosuppressed patient

PURPOSE

Immunosuppressed solid organ transplant recipients (SOTRs) have an increased risk of developing cutaneous squamous cell carcinomas (cSCCs) with metastatic potential. This study sought to determine the rate of regional lymph node involvement in a large cohort of solid organ transplant patients with cutaneous head and neck squamous cell carcinoma.

MATERIALS AND METHODS

A retrospective chart review was performed on solid organ transplant patients with head and neck cutaneous squamous cell carcinoma treated at a tertiary academic medical center from 2005 to 2015.

RESULTS

130 solid organ transplant patients underwent resection of 383 head and neck cutaneous squamous cell carcinomas. The average age of the patient was 63. Seven patients (5%) developed regional lymph node metastases (3 parotid, 4 cervical lymph nodes). The mean time from primary tumor resection to diagnosis of regional lymphatic disease was 6.7months. Six of these patients underwent definitive surgical resection followed by adjuvant radiation; one patient underwent definitive chemoradiation. 6 of the 7 patients died of disease progression with a mean survival of 15months. The average follow up time was 3years (minimum 6months).

CONCLUSIONS

Solid organ transplant recipients with cutaneous squamous cell carcinoma of the head and neck develop regional lymph node metastasis at a rate of 5%. Regional lymph node metastasis in this population has a poor prognosis and requires aggressive management and surveillance.

Renal Tumor in Allogeneic Kidney Transplant Recipient

BACKGROUND

Malignancies will be a leading cause of mortality in renal transplant recipients in the next 20 years. Renal cell cancer (RCC) is the most common urologic cancer in kidney transplant recipients. The risk of RCC development in kidney transplant recipients is 15-100 times higher than in the general population. The purpose of the current retrospective study was to assess the frequency of nephrectomies performed because of renal tumors in the native kidneys in kidney transplant recipients in the Department of General and Transplantation Surgery at the Medical University of Warsaw between 2010 and 2014 year; the identification of kidney recipients diagnosed with RCC; and epidemiologic, clinical, and histopathological aspects associated with RCC.

PATIENTS AND METHODS

A total of 319 nephrectomies were performed in the Department of General and Transplantation Surgery at the Medical University of Warsaw between 2010 and 2014 year. Renal tumors were diagnosed in 25 renal transplant recipients.

RESULTS

Among malignant tumors, 13 cases of RCC and 1 case of post-transplant lymphoproliferative disorder (PTLD) were observed. There was no significant difference between age and duration of pretransplantation dialysis in patients with RCC and patients with benign tumors (P = .14 and P = .91, respectively). Body mass index was significantly higher in patients with RCC than in patients with benign tumors (P = .04).

CONCLUSIONS

Renal cell cancer is more common among male kidney recipients. There is a good Polish screening system allowing detection of kidney cancer in native kidney. We recommend performing periodic screening for kidney cancers to obtain an early diagnosis.

Everolimus-Induced Systemic Serositis After Simultaneous Liver and Kidney Transplantation: A Case Report

Although everolimus, a mammalian target of rapamycin inhibitor, has been used as a potent immunosuppressive agent in organ transplantation, data regarding its adverse effect profile compared with that of sirolimus in clinical circumstances are limited. A 50-year-old man who underwent simultaneous liver and kidney transplantation 14 months previously was admitted with large pleural effusion, pericardial effusion, and ascites. Laboratory findings and cultures for possible infectious causes were all negative. Pericardial window surgery with drainage of the pericardial fluid was performed on day 3. Pleural and pericardial biopsy revealed non-specific inflammation without evidence of malignant cells. Everolimus was discontinued and replaced by mycophenolate mofetil on day 4. Significant clinical improvement was observed after discontinuation of everolimus, and follow-up echocardiography and chest radiography showed no recurrence of the pericardial or pleural effusion after discharge.

High-risk cutaneous malignancies and immunosuppression: Challenges for the reconstructive surgeon in the renal transplant population

Renal transplantation is the most frequently performed transplant procedure. Immunosuppressive therapies have dramatically increased survival rates in transplant recipients but are associated with an increased risk of skin cancers. Recent changes in immunosuppressive strategies have been adopted with the aim of reducing this challenging adverse effect. Despite these new strategies, cutaneous malignancies tend to be numerous, aggressive and associated with a higher risk of local and distant dissemination than in the non-transplant population. This represents a significant workload for transplant physicians, dermatologists, and head and neck and plastic surgeons. This review highlights key concepts in the pathogenesis of skin cancer in transplant patients, the impact current and evolving immunosuppressive strategies and regimens will have on the epidemiology, and the management of cutaneous malignancies in renal transplant patients, with particular focus on the implications for the plastic surgery community.

Risk of Aggressive Skin Cancers After Kidney Retransplantation in Patients With Previous Posttransplant Cutaneous Squamous Cell Carcinomas: A Retrospective Study of 53 Cases

BACKGROUND

The course of skin cancer after retransplantation in organ-transplant recipients who have already developed posttransplant skin cancer has not been assessed.

METHODS

This retrospective multicentric study included 53 patients with a history of cutaneous squamous cell carcinoma (SCC) after a first kidney transplantation who received a second kidney transplantation. The primary endpoint was the occurrence of aggressive cutaneous SCC after the second transplantation. Secondary endpoints included the course of skin cancers over 3 periods (first transplantation, return to dialysis, second transplantation), the time to occurrence, and risk factors for aggressive SCC after retransplantation.

RESULTS

The first SCC developed in 47 patients with a functional graft and in 6 after return to dialysis. After the first transplantation, 17 (33.3%) patients developed SCC in dialysis and 39 (73.6%) after the second transplantation, respectively. Twenty aggressive SCC developed over the study period. They occurred in 14 (26.4%) patients after retransplantation vs 5 (9.4%) after the first transplantation with a median delay of 50 months and were responsible for 5 deaths. Fair skin type, multiple tumors before retransplantation, treatment with azathioprine, T cell-depleting antibodies, and delayed revision of immunosuppression were associated with an increased risk of aggressive cutaneous SCC after retransplantation.

CONCLUSIONS

Candidates to retransplantation with a history of posttransplant SCC have a high risk of aggressive SCC. Our data suggest that the risk could be reduced by a tailored immunosuppression. A wait period may be required depending on the clinicopathological characteristics of the previous SCC and discussed on an individual patient basis.

Alloantigen gene transfer to hepatocytes promotes tolerance to pancreatic islet graft by inducing CD8+ regulatory T cells

BACKGROUND & AIMS

Induction of donor-specific immune tolerance is a good alternative to chronic life-long immunosuppression for transplant patients. Donor major histocompatibility complex (MHC) molecules represent the main targets of the allogeneic immune response of transplant recipients. Liver targeted gene transfer with viral vectors induces tolerance toward the encoded antigen. The aim of this work was to determine whether alloantigen gene transfer to hepatocytes induces tolerance and promotes graft acceptance.

METHODS

C57BL/6 (H-2b) mice were treated with adeno-associated viral (AAV) vector targeting the expression of the MHC class I molecule H-2K^d to hepatocytes, before transplantation with fully allogeneic pancreatic islet from BALB/c mice (H-2d).

RESULTS

AAV H-2K^d treated mice were tolerant to the alloantigen, as demonstrated by its long-term expression by the hepatocytes, even after a highly immunogenic challenge with an adenoviral vector. After chemical induction of diabetes, the AAV treated mice had significantly delayed rejection of fully allogeneic pancreatic islet grafts, with more than 40% of recipients tolerant (>100days). AAV-mediated expression of H-2K^d in the liver induced the local expansion of CD8⁺ T lymphocytes with allo-specific suppressive properties. The adoptive transfer of these liver-generated CD8⁺ Tregs into naive diabetic mice promoted the long-term survival of allogeneic pancreatic islet grafts.

CONCLUSION

AAV-mediated long-term expression of a single MHC class I molecule in the liver induces the generation of a subset of allo-specific CD8⁺ Treg cells, which promote tolerance toward fully allogeneic graft. Liver gene transfer represents a promising strategy for in vivo induction of donor-specific tolerance.

LAY SUMMARY

The liver has a special immune system, biased toward tolerance. In this study, we investigated the possibility of harnessing this property of the liver to induce tolerance to an allogeneic transplantation. We demonstrate for the first time that the in vivo gene transfer of an allogeneic antigen with an adeno-associated viral vector to mouse hepatocytes induces the expansion of a population of CD8⁺ regulatory T lymphocytes. These Tregs are then instrumental in preventing the rejection of allogeneic pancreatic islets transplanted in these animals. Allogeneic transplantation is the main treatment for the end-stage diseases of a number of organs. Life-long immunosuppressive treatments are still required to limit graft rejection, and these treatments exhibit serious side effects. Our present findings open a new avenue for promoting allo-specific tolerance via in vivo induction of CD8⁺ Treg expansion.

The risk of cancer in kidney transplant recipients may be reduced in those maintained on everolimus and reduced cyclosporine

Kidney transplant recipients are at a high risk of developing cancers after transplantation. Switching from calcineurin inhibitors to sirolimus has been shown to prevent secondary nonmelanoma skin cancer but whether everolimus with reduced exposure to calcineurin inhibitors has similar anti-cancer effects remains unknown. Therefore, we compared the risk of incident cancer over seven years of follow-up among kidney transplant recipients randomized to everolimus plus reduced exposure cyclosporine versus mycophenolate sodium and standard exposure cyclosporine. Using the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA), we assessed the seven-year risk of incident cancer and other graft outcomes among a subgroup of recipients who had participated in the A2309 study using adjusted Cox proportional hazard models. Of 95 recipients, 66 were randomized to everolimus (1.5 mg or 3 mg) with reduced cyclosporine and 29 received mycophenolate sodium and standard exposure cyclosporine. Compared to mycophenolate sodium and standard exposure cyclosporine, everolimus treatment was associated with unadjusted hazard ratios of 0.28 (95% confidence interval 0.11-0.74), 0.39 (0.16-0.98) and 0.41 (0.23-0.71), respectively for nonmelanoma skin cancer, non-skin cancers and any cancers. Interestingly, the adjusted hazard ratios were 0.34 (0.13-0.91), 0.35 (0.09-1.25) and 0.32 (0.15-0.71), respectively. There was no association between treatment groups and rejection, graft loss or death. Compared to standard-exposure cyclosporine, everolimus with reduced exposure to cyclosporine may be associated with a reduced risk of cancer, particularly for non-melanoma skin cancer. Thus, if confirmed in larger patient cohorts, de novo use of everolimus with reduced exposure to calcineurin inhibitors may enable a reduction in cancer burden after transplantation.

How to Escape the Immune Response: What Tumors Teach to Transplant Physicians/Immunologists

Recent progress in deciphering the mechanisms underlying the concepts of tumor immunosurveillance and immunoevasion has opened new opportunities for the development of effective antitumor therapies. Transplant physicians and immunologists have much to learn from those direct clinical translations of basic science. The 2016 Beaune Seminar in Transplant research brought together researchers from both fields to explore and discuss significant advances in cancer biology, immunotherapies and their potential impacts for the management of cancer in transplant recipients.

More than skin deep? Potential nicotinamide treatment applications in chronic kidney transplant recipients

Non-melanoma cutaneous carcinomas, or skin cancers, predominantly squamous cell carcinomas (SCCs), are the most common malignancies occurring in kidney transplant recipients (KTRs). Squamous cell carcinoma risk is dramatically elevated in KTRs, occurring at rates of up 45-250 times those reported in general populations. New non-melanoma skin cancers in KTRs with a prior non-melanoma skin cancer also develop at 3-times the rate reported in non-KTRs with the same clinical history. The unique aggressiveness of SCCs in KTRs increases patient morbidity, due to the high rate of new lesions requiring treatment, frequently surgical excision. Oral nicotinamide shows promise in the chemoprevention of the especially aggressive non-melanoma skin cancers which occur in KTRs. This benefit might be conferred via its inhibition of sirtuin enzymatic pathways. Nicotinamide’s concurrent hypophosphatemic effect may also partially ameliorate the disturbed calcium-phosphorus homeostasis in these patients-a putative risk factor for mortality, and graft failure. Conceivably, a phase 3 trial of nicotinamide for the prevention of non-melanoma skin cancers in KTRs, lasting at least 12-mo, could also incorporate imaging and laboratory measures which assess nicotinamide’s impact on subclinical cardiovascular and chronic kidney disease risk, and progression.

Impact of mTOR Inhibitors on Cancer Development in Kidney Transplantation Recipients: A Population-Based Study

BACKGROUND

The mammalian target of rapamycin (mTOR) inhibitor is an immunosuppressive drug used in kidney transplantation. Whether the mTOR inhibitor is associated with reduced risk of cancer development and mortality after kidney transplantation is controversial.

METHODS

We conducted a nationwide population-based study. Patients who did not have malignancy history and received kidney transplantation between 2010 and 2013 were enrolled. Recipients who had mTOR inhibitors (n = 430) for more than 30 days comprised the study group; 1720 recipients who did not have mTOR inhibitors comprised the control group. The primary outcome is the development of cancer after kidney transplantation. These patients were followed until the first-time admission with diagnosis of cancer, death, or the end of 2014. A Cox proportional-hazard model was used to determine the risk of cancer development and all-cause mortality.

RESULTS

During the 35-month median duration of observation, there were 16 and 61 patients with cancer development in the study group and the control group, respectively. The cancer incidence was 12.8 and 12.4 per 1000 person-years. There were 10 and 135 mortality cases, with the incidence rate of 7.8 and 26.9 per 1000 person-years. After multivariable adjustment, the mTOR inhibitors users were not associated with reduced risk of new cancer development as compared with control (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.46-1.60; P = .63), nor risk of all-cause mortality (HR, 0.70; 95% CI, 0.33-1.46; P = .34).

CONCLUSIONS

The use of mTOR inhibitors was not associated with a reduction in the risk of cancer development and all-cause mortality in kidney transplantation recipients.

Everolimus and Advagraf Ab Initio in Combined Liver and Kidney Transplant With Donor-Specific Antibodies: A Case Report

Although donor-specific antibodies are regarded as a contraindication for kidney transplantation, the data available for combined liver and kidney transplantation (cLKTx) are scarce, and there is no established therapeutic approach for this category of transplant recipients. De novo use of everolimus and a reduced dose of calcineurin inhibitor reportedly provides excellent kidney function compared with a standard regimen containing a calcineurin inhibitor. This strategy, however, has been applied in only some recipient categories. Here we report a case of A highly sensitized male patient who underwent a cLKTx and received everolimus with low-dose tacrolimus (once-daily prolonged-release formulation) as ab initio immunosuppressive treatment. The pretransplant panel-reactive antibody estimate was 97%, and multiple anti-HLA antibodies were detected at the time of transplantation. Thus far, patient and allograft survival have reached 2 years, with the recipient remaining on a regimen of immunosuppression with everolimus and low-dose tacrolimus, with no episodes of rejection.

Azathioprine and Risk of Skin Cancer in Organ Transplant Recipients: Systematic Review and Meta-Analysis

Azathioprine, a purine antimetabolite immunosuppressant, photosensitizes the skin and causes the production of mutagenic reactive oxygen species. It is postulated to increase the risk of squamous cell carcinoma (SCC) and other skin cancers in organ transplant recipients (OTRs), but evidence from multiple, largely single-center studies to date has been inconsistent. We aimed to resolve the issue of azathioprine's carcinogenicity by conducting a systematic review of the relevant literature and pooling published risk estimates to evaluate the risks of SCC, basal cell carcinoma (BCC), keratinocyte cancers (KCs) overall and other skin cancers in relation to azathioprine treatment. Twenty-seven studies were included in total, with risk estimates from 13 of these studies able to be pooled for quantitative analysis. The overall summary estimate showed a significantly increased risk of SCC in relation to azathioprine exposure (1.56, 95% confidence interval [CI] 1.11-2.18). No significant associations between azathioprine treatment and BCC (0.96, 95% CI 0.66-1.40) or KC (0.84, 95% CI 0.59-1.21) risk were observed. There was significant heterogeneity between studies for azathioprine risk estimates and the outcomes of SCC, BCC and KC. The pooled findings of available evidence support the contention that treatment with azathioprine increases the risk of SCC in OTRs.

ACR Appropriateness Criteria(®) Aggressive Nonmelanomatous Skin Cancer of the Head and Neck

BACKGROUND

Aggressive nonmelanomatous skin cancer (NMSC) of the head and neck presents an increasingly common therapeutic challenge for which prospective clinical trials are lacking.

METHODS

The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

RESULTS

The American College of Radiology Expert Panel on Radiation Oncology - Head and Neck Cancer developed consensus recommendations for guiding management of aggressive NMSC.

CONCLUSION

Multidisciplinary assessment is vital to guiding the ideal use of surgery, radiation, and systemic therapy in this disease.

Mammalian Target of Rapamycin Inhibitors and Clinical Outcomes in Adult Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

Emerging evidence from recently published observational studies and an individual patient data meta-analysis shows that mammalian target of rapamycin inhibitor use in kidney transplantation is associated with increased mortality. Therefore, all-cause mortality and allograft loss were compared between use and nonuse of mammalian target of rapamycin inhibitors in patients from Australia and New Zealand, where mammalian target of rapamycin inhibitor use has been greater because of heightened skin cancer risk.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our longitudinal cohort study included 9353 adult patients who underwent 9558 kidney transplants between January 1, 1996 and December 31, 2012 and had allograft survival ≥1 year. Risk factors for all-cause death and all-cause and death-censored allograft loss were analyzed by multivariable Cox regression using mammalian target of rapamycin inhibitor as a time-varying covariate. Additional analyses evaluated mammalian target of rapamycin inhibitor use at fixed time points of baseline and 1 year.

RESULTS

Patients using mammalian target of rapamycin inhibitors were more likely to be white and have a history of pretransplant cancer. Over a median follow-up of 7 years, 1416 (15%) patients died, and 2268 (24%) allografts were lost. There was a higher risk of all-cause mortality with time-varying mammalian target of rapamycin inhibitor use (hazard ratio, 1.47; 95% confidence interval, 1.23 to 1.76) as well as in the fixed time model analyses comparing mammalian target of rapamycin inhibitor use at baseline (hazard ratio, 1.54; 95% confidence interval, 1.22 to 1.93) and 1 year (hazard ratio, 1.63; 95% confidence interval, 1.32 to 2.01). Time-varying mammalian target of rapamycin inhibitor use was associated with higher risk of death because of malignancy (hazard ratio, 1.37; 95% confidence interval, 1.09 to 1.71). There were no statistically significant differences in the risk of all-cause (hazard ratio, 0.98; 95% confidence interval, 0.85 to 1.12) and death-censored (hazard ratio, 0.85; 95% confidence interval, 0.69 to 1.03) allograft loss between the mammalian target of rapamycin inhibitor use and nonuse groups in the time-varying model as well as the fixed time models.

CONCLUSIONS

Mammalian target of rapamycin inhibitor use was associated with a higher risk of all-cause mortality but not allograft loss.

Checkpoint inhibitors in chronic kidney failure and an organ transplant recipient

BACKGROUND

Immune-checkpoint inhibitors have been approved for the treatment of metastatic melanoma based on several phase III trials. Patients after organ transplantation and patients with impaired renal function were excluded from these studies. Recently, allograft rejections were reported in organ transplant recipients receiving PD-1 blocking antibodies.

PATIENTS AND FINDINGS

Four patients with metastatic melanoma and impaired kidney function (baseline serum creatinine 1.79-2.59 mg/dl) were treated with immune-checkpoint blockers, of which one was a kidney-transplant recipient receiving immunosuppressive therapy with tacrolimus and prednisolone. The patient was initially treated with the anti-CTLA-4 antibody ipilimumab after detailed explanation of the potential risk of allograft rejection. Upon disease progression, therapy was switched to the anti-PD-1 antibody nivolumab. The other three patients were treated with nivolumab or pembrolizumab, two of them after previous therapy with ipilimumab.

RESULTS

The patients received a median of six doses (range 3-21) of anti-PD-1 antibodies and 3-4 doses of ipilimumab. Kidney function tests remained stable throughout the course of checkpoint blockade. In the kidney transplant recipient, neither ipilimumab nor nivolumab led to an allograft rejection. Responses to anti-PD-1 treatment were divergent with two patients showing disease progression, one achieving a mixed response and one experiencing a complete response.

CONCLUSION

These cases show that checkpoint inhibitors can be a safe therapeutic option in patients with impaired kidney function. Furthermore, we report the first organ transplant patient with malignant melanoma who received ipilimumab followed by nivolumab without experiencing a kidney allograft rejection.

Dual mTORC1/C2 inhibitors suppress cellular geroconversion (a senescence program)

In proliferating cells, mTOR is active and promotes cell growth. When the cell cycle is arrested, then mTOR converts reversible arrest to senescence (geroconversion). Rapamycin and other rapalogs suppress geroconversion, maintaining quiescence instead. Here we showed that ATP-competitive kinase inhibitors (Torin1 and PP242), which inhibit both mTORC1 and TORC2, also suppressed geroconversion. Despite inhibition of proliferation (in proliferating cells), mTOR inhibitors preserved re-proliferative potential (RP) in arrested cells. In p21-arrested cells, Torin 1 and PP242 detectably suppressed geroconversion at concentrations as low as 1-3 nM and 10-30 nM, reaching maximal gerosuppression at 30 nM and 300 nM, respectively. Near-maximal gerosuppression coincided with inhibition of p-S6K(T389) and p-S6(S235/236). Dual mTOR inhibitors prevented senescent morphology and hypertrophy. Our study warrants investigation into whether low doses of dual mTOR inhibitors will prolong animal life span and delay age-related diseases. A new class of potential anti-aging drugs can be envisioned.

Roles of mTOR complexes in the kidney: implications for renal disease and transplantation

The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.

Rejuvenating immunity: "anti-aging drug today" eight years later

The 2014 year ended with celebration: Everolimus, a rapamycin analog, was shown to improve immunity in old humans, heralding ‘a turning point’ in research and new era in human quest for immortality. Yet, this turning point was predicted a decade ago. But what will cause human death, when aging will be abolished?

Cyclosporine A immunosuppression drives catastrophic squamous cell carcinoma through IL-22

Immune-suppressed organ transplant recipients (OTRs) can develop catastrophic squamous cell carcinoma (SCC), characterized by multiple primary tumors, extensive body surface area involvement, or metastases. There are currently no curative systemic therapies available. We previously showed that IL-22 enhances SCC proliferation. Herein, we examined links between cyclosporine (CSA), IL-22, and SCC in patients, cell lines, and mice with UV light-induced SCC. Eighteen of 114 OTRs developed catastrophic SCC, which was strongly associated with CSA treatment. We found that CSA drives T cell polarization toward IL-22-producing T22 cells, and CSA treatment increased IL-22 receptor in SCC cells. SCC tissue from OTRs showed increased expression of IL-22RA1. CSA potentiated rescue by IL-22 of serum-starved SCC cells; treatment of SCC cells with IL-22 and CSA increased both their migratory and invasive capacity. In a UV-induced model of SCC in SKH-1 immunocompetent mice, treatment with anti-IL-22 antibody reduced tumor number and tumor burden. We found that catastrophic SCC in OTRs is associated with CSA use, which may be acting by favoring T22 polarization. Since anti-IL-22 antibody administration decreased tumor number and tumor burden in vivo, blockade of the IL-22 axis may be developed as a viable therapeutic option for catastrophic SCC.

Immunosuppression with mammalian target of rapamycin inhibitor and incidence of post-transplant cancer in kidney transplant recipients

BACKGROUND

Evidence is limited regarding the effect of de novo therapy with mammalian target of rapamycin (mTOR) inhibitors on cancer risk after kidney transplantation.

METHODS

Collaborative Transplant Study data from 78 146 adult recipients of first deceased-donor kidney transplants (1999-2013) were analysed (4279 mTOR inhibitor, 73 867 no mTOR inhibitor) using standard methods. Propensity score matching was performed for analysis of basal cell and squamous cell skin cancer.

RESULTS

Standardized incidence ratios (SIR) versus a matched non-transplant population showed reduced tumour incidence in recipients with de novo mTOR inhibitor therapy compared with no mTOR inhibitor for non-melanoma skin cancer (NMSC) (SIR 5.1 versus 6.1; P =0.019) but not non-NMSC cancers (SIR 1.6 versus 1.7; P =0.35). Within propensity score-matched groups (n = 4265), multivariable Cox regression analysis showed a trend to reduced NMSC with mTOR inhibition [hazard ratio (HR) 0.77; P =0.063] but not for all non-NMSC tumours (HR 0.94; P= 0.59). A significant effect for mTOR inhibition was observed for basal cell carcinoma of the skin (HR 0.56; P= 0.004) but not squamous cell carcinoma (HR 0.87; P= 0.54).

CONCLUSIONS

De novo mTOR inhibition was associated with a substantially and significantly reduced risk of basal cell carcinoma of the skin after kidney transplantation. A significant reduction of the incidence of other cancers was not found.

Regulatory T cells and cancer: an undesired tolerance

The incidence of cancer is markedly increased in organ transplant patients. A better understanding of underlying mechanisms and the identification of biomarkers for diagnosis and prognosis are major challenges. Hope et al. report expansion of regulatory T cells to be associated with the presence and severity of cancer. Although relevant, these results raise several questions.

What is the best immunosuppressant combination in terms of antitumor effect in hepatocellular carcinoma?

AIM

Despite its known anticancer benefits, monotherapy with sirolimus is not sufficient to achieve optimal immunosuppression to prevent rejection. However, there is no published prospective study to compare the anticancer effect between various immunosuppressive combinations. Therefore, we analyzed the anticancer effects of various immunosuppressive regimens in order to provide experimental evidence for selecting an optimal immunosuppressive regimen after liver transplantation for hepatocellular carcinoma (HCC).

METHODS

The Huh7 cell line was used as a model for HCC in both in vitro and in vivo mouse experiments. The immunosuppressant regimens tested were: tacrolimus, sirolimus, MMF, sirolimus plus tacrolimus, and sirolimus plus MMF. 3-(4 5-Dimethylthiazol-2-yl)-2 5-diphenyltetrazolium bromide assays showed that the sirolimus plus MMF combination appeared to be synergistic in its cell suppressive effects, achieving statistically significant lowest cell viability.

RESULTS

In vitro western blot analysis showed that there were lower levels of expression of phosphorylated mammalian target of rapamycin, p70S6K and p4EBP1, transforming growth factor-β and pSmad3 expression in the cells treated with sirolimus, MMF and sirolimus plus MMF. Finally, in the mouse model of tumorigenesis, the sirolimus plus MMF and sirolimus plus tacrolimus showed the most suppressive effect in terms of tumor volume.

CONCLUSION

Throughout both the in vitro and in vivo experiments, the sirolimus and MMF combination had the most consistent and greatest antiproliferative effects.

De Novo Malignancies After Transplantation: Risk and Surveillance Strategies

De novo malignancies are one of the leading causes of late mortality after liver and kidney transplantation. Nonmelanoma skin cancer is the most common malignancy, followed by posttransplant lymphoproliferative disorder and solid organ tumors. Immunosuppression is a key factor for cancer development, although many other transplant-related and traditional risk factors also play a role. In this review, the authors summarize risk factors and outcomes of frequently encountered de novo malignancies after liver and kidney transplantation to stratify recipients at highest risk. Future efforts in prospectively validated, cost-effective surveillance strategies that improve survival of these complex patients are greatly needed.