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

Long-term outcomes of living-donor lobar lung transplantation

OBJECTIVE

Although living-donor lobar lung transplantation (LDLLT) enables an intermediate survival similar to cadaveric lung transplantation, the long-term outcome remains unknown. We examined the long-term outcomes of 30 patients who received LDLLT more than 16 years previously.

METHODS

We retrospectively reviewed the clinical data of 30 patients who underwent LDLLT (bilateral LDLLT, 29 patients; single LDLLT, 1 pediatric patient) between October 1998 and April 2004.

RESULTS

LDLLT was performed for 25 female and 5 male patients ranging in age from 8 to 55 years. The diagnoses included pulmonary hypertension (n = 11), pulmonary fibrosis (n = 7), bronchiolitis obliterans (n = 5), and others (n = 7). At a median follow-up of 205 months, 22 patients were alive and 8 were dead. The causes of death were infection (n = 3), malignancy (n = 2), acute rejection (n = 2), and chronic lung allograft dysfunction (CLAD; n = 1). Unilateral CLAD occurred in 17 patients (56.7%), but only 1 of these patients subsequently developed bilateral CLAD. Two patients underwent bilateral cadaveric lung retransplantations. The 5-, 10-, and 15-year CLAD-free survival rates were 80.0%, 62.8%, and 44.3%, respectively. Malignancy occurred in 7 patients. Two of 5 patients with chronic kidney disease requiring hemodialysis underwent living-donor kidney transplantation. The 5-, 10-, and 15-year overall survival rates were 96.7%, 86.7%, and 73.3%, respectively.

CONCLUSIONS

Although only 2 lobes are implanted, LDLLT provides encouraging long-term outcomes. In patients with unilateral CLAD, the functioning contralateral graft might contribute to a favorable long-term outcome.

Benefit of Belatacept in Cord Blood-Derived Regulatory T Cell-Mediated Suppression of Alloimmune Response

The role of Regulatory T cells (Tregs) in tolerance induction post-transplantation is well-established, but Tregs adoptive transfer alone without combined immunosuppressants have failed so far in achieving clinical outcomes. Here we applied a set of well-designed criteria to test the influence of commonly used immunosuppressants (belatacept, tacrolimus, and mycophenolate) on cord blood-derived Tregs (CB-Tregs). Our study shows that while none of these immunosuppressants modulated the stability and expression of homing molecules by CB-Tregs, belatacept met all other selective criteria, shown by its ability to enhance CB-Tregs-mediated in vitro suppression of the allogeneic response without affecting their viability, proliferation, mitochondrial metabolism and expression of functional markers. In contrast, treatment with tacrolimus or mycophenolate led to reduced expression of functional molecule GITR in CB-Tregs, impaired their viability, proliferation and mitochondrial metabolism. These findings indicate that belatacept could be considered as a candidate in Tregs-based clinical immunomodulation regimens to induce transplant tolerance.

Immunological discrepancy in aged mice facilitates skin allograft survival

More and more aged people are undergoing organ transplantation. Understanding aging effects on immunity will be helpful for post-transplantation care and adjustment of immunosuppressants for aged recipients. A mouse model, using C3H mice as donors and aged/young C57BL/10J mice as recipients, was employed to study aging effects on immunity. The results showed that frequency of myeloid-derived suppressor cells (MDSC) and level of TGF-β was higher in aged mice than in young mice (4.4 ± 1.4% versus 1.6 ± 1.1%, p = 0.026 for MDSC; 21.04 ± 3.91 ng/ml versus 15.26 ± 5.01 ng/ml, p = 0.026 for TGF-β). In vivo, skin allograft survived longer on the aged than on young mice (19.7 ± 5.2 days versus 11.9 ± 4.1 days, p = 0.005). When entinostat was applied to block MDSC, the survival of skin allografts on aged mice was shorten to 13.5 ± 4.7 days which was not different from the survival on young mice (p = 0.359). In conclusion, allogeneic immunity was different in aged from young mice in high frequency of MDSC and high serum level of TGF-β. Blocking the function of MDSC reversed the low immunity in aged mice and caused skin allograft rejection similar to young recipients.

Tumor Recurrence and Graft Survival in Renal Transplant Recipients with a History of Pretransplant Malignancy: A Matched Pair Analysis

Organ scarcity demands critical decision-making regarding eligible transplant candidates and graft allocation to ensure best benefit from renal transplantation (RTx). Among the controversial relative contraindications is a history of pretransplant malignancy (PTM). While oncological outcomes of PTM-RTx recipients are well described, data on graft-specific outcome are scarce. A retrospective double case control matched pair analysis (60 months follow-up) was carried out and RTx-recipients were stratified for history of PTM. First, PTM-RTx recipients were matched according to age, sex and duration of immunosuppressive therapy. Next, PTM-RTx recipients were matched 1:1 for age, sex and cause of end-stage renal disease. Five-year patient and graft survival as well as oncological outcomes were analyzed. A total of 65 PTM-RTx recipients were identified. Post-RTx recurrence rate was 5%, while 20% developed second de novo malignancy, comparable to 14% in the control group. PTM-RTx recipients had a noticeable lower five-year death-censored as well as overall graft survival and Cox proportional hazard modeling showed a correlation between PTM and inferior graft survival. Although underlying reasons remain not fully understood, this study is the first to show inferior graft survival in PTM-RTx recipients and advocates necessity to focus on more meticulous graft monitoring in PTM recipients in addition to heightened surveillance for cancer recurrence.

Considerations for Child Cancer Survivors and Immunocompromised Children to Prevent Secondary HPV-associated Cancers

Survivors of childhood cancer and other immunocompromised children are at high risk for the development of secondary human papillomavirus (HPV)-associated cancers. In this overview, the authors examine the epidemiology of vaccine efficacy, the natural history of HPV infections, and accelerated HPV-associated cancer development in these populations. The authors highlight the opportunities for preventive care and future research directives.

Induction of Allograft Tolerance While Maintaining Immunity Against Microbial Pathogens: Does Coronin 1 Hold a Key?

Selective suppression of graft rejection while maintaining anti-pathogen responses has been elusive. Thus far, the most successful strategies to induce suppression of graft rejection relies on inhibition of T-cell activation. However, the very same mechanisms that induce allograft-specific T-cell suppression are also important for immunity against microbial pathogens as well as oncogenically transformed cells, resulting in significant immunosuppression-associated comorbidities. Therefore, defining the pathways that differentially regulate anti-graft versus antimicrobial T-cell responses may allow the development of regimen to induce allograft-specific tolerance. Recent work has defined a molecular pathway driven by the immunoregulatory protein coronin 1 that regulates the phosphodiesterase/cyclic adenosine monophosphate pathway and modulates T cell responses. Interestingly, disruption of coronin 1 promotes allograft tolerance while immunity towards a range of pathogenic microbes is maintained. Here, we briefly review the work leading up to these findings as well as their possible implications for transplantation medicine.

Resolution of a High Grade and Metastatic BK Polyomavirus-Associated Urothelial Cell Carcinoma Following Radical Allograft Nephroureterectomy and Immune Checkpoint Treatment: A Case Report

BACKGROUND

BK viral infection in the posttransplant setting continues to cause serious morbidity with effects ranging from allograft nephropathy and dysfunction to urothelial malignancy.

RESULTS

In this report, we present a patient that developed BK-associated nephropathy and, 6 years later, locally advanced urothelial malignancy in the renal allograft with nodal, muscle, and extremity involvement. Following radical allograft nephroureterectomy, he was treated with palliative radiation and the immune checkpoint inhibitor atezolizumab. Follow-up imaging at 1 year demonstrated radiographic complete response.

CONCLUSIONS

This report supports the growing body of evidence supporting the association of urothelial malignancy and BK virus infection in renal transplant recipients. Further, it highlights the novel application of immune checkpoint inhibitors in the treatment of advanced posttransplant malignancy, in particular when the allograft is removed and the tumor is possibly of donor origin.

Medication adherence is associated with an increased risk of cancer in kidney transplant recipients: a cohort study

Background

Nonadherence to posttransplant immunosuppressive medication is associated with increased rates of rejection and graft loss, yet it is unknown to what degree ideal adherence is associated with the sequelae of overimmunosuppression. Specifically, we questioned whether excellent adherence increased the posttransplant cancer risk.

Methods

Between August 1998 and August 2006, 195 consenting kidney transplant recipients had electronic monitoring of theirimmunosuppressive medication adherence.

Results

Based on their average quantitative adherence to a single immunosuppressant drug over the first 6 months posttransplant, recipients were grouped into adherence tertiles (highest, >97.9% adherence; middle, 91-97.8%; lowest, <91%). The cumulative incidence of cancer was calculated for patients in each tertile, treating death as a competing risk. The association between adherence and cancer rate was calculated after adjusting for recipient risk factors, using a competing risk proportional hazards model. The median duration of follow-up was 10.1 years. The 10-year estimated cumulative cancer incidence was 59.4% in the most adherent, 36.1% in the middle group and 38.1% in the least adherent group (P = 0.006). Excluding nonmelanocytic skin cancers, cancer incidence remained significantly higher in the highest adherence group (P = 0.002).

Conclusions

These data provide additional support for the need to individualize immunosuppression to minimize both rejection and immunosuppressive drug-related complications including cancer.

Regulatory T cells from patients with end-stage organ disease can be isolated, expanded and cryopreserved according good manufacturing practice improving their function

Background

Here, we isolated, expanded and functionally characterized regulatory T cells (Tregs) from patients with end stage kidney and liver disease, waiting for kidney/liver transplantation (KT/LT), with the aim to establish a suitable method to obtain large numbers of immunomodulatory cells for adoptive immunotherapy post-transplantation.

Methods

We first established a preclinical protocol for expansion/isolation of Tregs from peripheral blood of LT/KT patients. We then scaled up and optimized such protocol according to good manufacturing practice (GMP) to obtain high numbers of purified Tregs which were phenotypically and functionally characterized in vitro and in vivo in a xenogeneic acute graft-versus-host disease (aGVHD) mouse model. Specifically, immunodepressed mice (NOD-SCID-gamma KO mice) received human effector T cells with or without GMP-produced Tregs to prevent the onset of xenogeneic GVHD.

Results

Our small scale Treg isolation/expansion protocol generated functional Tregs. Interestingly, cryopreservation/thawing did not impair phenotype/function and DNA methylation pattern of FOXP3 gene of the expanded Tregs. Fully functional Tregs were also isolated/expanded from KT and LT patients according to GMP. In the mouse model, GMP Tregs from LT or KT patient proved to be safe and show a trend toward reduced lethality of acute GVHD.

Conclusions

These data demonstrate that expanded/thawed GMP-Tregs from patients with end-stage organ disease are fully functional in vitro. Moreover, their infusion is safe and results in a trend toward reduced lethality of acute GVHD in vivo, further supporting Tregs-based adoptive immunotherapy in solid organ transplantation.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2004-2) contains supplementary material, which is available to authorized users.

Pre-transplant CD45RC expression on blood T cells differentiates patients with cancer and rejection after kidney transplantation

Background

Biological biomarkers to stratify cancer risk before kidney transplantation are lacking. Several data support that tumor development and growth is associated with a tolerant immune profile. T cells expressing low levels of CD45RC preferentially secrete regulatory cytokines and contain regulatory T cell subset. In contrast, T cells expressing high levels of CD45RC have been shown to secrete proinflammatory cytokines, to drive alloreactivity and to predict acute rejection (AR) in kidney transplant patients. In the present work, we evaluated whether pre-transplant CD45RC^low T cell subset was predictive of post-transplant cancer occurrence.

Methods

We performed an observational cohort study of 89 consecutive first time kidney transplant patients whose CD45RC T cell expression was determined by flow cytometry before transplantation. Post-transplant events including cancer, AR, and death were assessed retrospectively.

Results

After a mean follow-up of 11.1±4.1 years, cancer occurred in 25 patients (28.1%) and was associated with a decreased pre-transplant proportion of CD4⁺CD45RC^high T cells, with a frequency below 51.9% conferring a 3.7-fold increased risk of post-transplant malignancy (HR 3.71 [1.24–11.1], p = 0.019). The sensibility, specificity, negative predictive and positive predictive values of CD4⁺CD45RC^high<51.9% were 84.0, 54.7, 89.8 and 42.0% respectively. Confirming our previous results, frequency of CD8⁺CD45RC^high T cells above 52.1% was associated with AR, conferring a 20-fold increased risk (HR 21.7 [2.67–176.2], p = 0.0004). The sensibility, specificity, negative predictive and positive predictive values of CD8⁺CD45RC^high>52.1% were 94.5, 68.0, 34.7 and 98.6% respectively. Frequency of CD4⁺CD45RC^high T cells was positively correlated with those of CD8⁺CD45RC^high (p<0.0001), suggesting that recipients with high AR risk display a low cancer risk.

Conclusion

High frequency of CD45RC^high T cells was associated with AR, while low frequency was associated with cancer. Thus, CD45RC expression on T cells appears as a double-edged sword biomarker of promising interest to assess both cancer and AR risk before kidney transplantation.

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) for Peritoneal Metastases in Solid Organ Graft Recipients: First Experience

BACKGROUND Therapy of peritoneal metastases (PM) in solid organ transplant recipients is challenging. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) might constitute a new therapeutic opportunity for these patients. MATERIAL AND METHODS This was a single-center, retrospective analysis of prospective registry data (NCT03210298) in a tertiary care center between 1.7.2016 and 31.12.2017. Intraperitoneal administration of oxaliplatin 92 mg/m² body surface or a combination of cisplatin 7.5 mg/m² and doxorubicin 1.5 mg/m², repeated every 6 weeks. Objective tumor response was documented via histology (Peritoneal Regression Grading Score, PRGS), adverse events according to Common Terminology Criteria for Adverse Events (CTCAE) 4.0. RESULTS Out of 71 consecutive patients treated with PIPAC, 2 patients (2.8%) were solid organ transplant recipients. The first patient had metachronous PM of colonic cancer origin after liver transplantation. The second patient had synchronous PM of pancreatic cancer origin after combined kidney-pancreas transplantation. After repeated combined systemic and PIPAC chemotherapy, objective histological response was documented in both patients. No adverse events >CTCAE 2 were recorded. There was no measurable liver or renal toxicity. PIPAC procedures could be repeated (2, resp. 3 cycles) without any interruption of immunosuppressive medication or impairment of respective plasmatic drug levels. The first patient passed away 7 months after the first PIPAC, the second patient was still alive after 8 months. CONCLUSIONS PIPAC can induce objective regression of PM in solid organ transplant recipients without inducing organ toxicity or interfering with immunosuppressive therapy.

Common viral infections in kidney transplant recipients

Infectious complications have been considered as a major cause of morbidity and mortality after kidney transplantation, especially in the Asian population. Therefore, prevention, early detection, and prompt treatment of such infections are crucial in kidney transplant recipients. Among all infectious complications, viruses are considered to be the most common agents because of their abundance, infectivity, and latency ability. Herpes simplex virus, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, hepatitis B virus, BK polyomavirus, and adenovirus are well-known etiologic agents of viral infections in kidney transplant patients worldwide because of their wide range of distribution. As DNA viruses, they are able to reactivate after affected patients receive immunosuppressive agents. These DNA viruses can cause systemic diseases or allograft dysfunction, especially in the first six months after transplantation. Pretransplant evaluation and immunization as well as appropriate prophylaxis and preemptive approaches after transplant have been established in the guidelines and are used effectively to reduce the incidence of these viral infections. This review will describe the etiology, diagnosis, prevention, and treatment of viral infections that commonly affect kidney transplant recipients.

Posttransplant Malignancy

Posttransplant malignancy is a leading cause of death after solid organ transplantation (SOT). Recipients of SOT are at significantly higher risk of multiple cancers compared with the general population, most notably nonmelanoma skin cancer and posttransplant lymphoproliferative disorders. Risk factors for posttransplant malignancy include history of malignancy, immunosuppression, oncogenic viral infections, sun exposure, and disease-specific associations. Early detection and treatment of malignancies can improve survival.

How to obtain and maintain favorable results after heart transplantation: keys to success?

We compared survival in our heart recipients with survival rates reported by the International Society of Heart and Lung Transplantation (ISHLT) Registry. As recipient and donor characteristics are changing over time, we studied four different eras. In order to differentiate between short- and long-term survival, we analyzed both overall survival and survival at one year. Obviously, this exercise is only relevant when baseline donor and recipient characteristics are comparable, as these differences may affect the outcome in opposite directions. To overcome this potential bias as much as possible, we calculated the Index for Mortality Prediction After Cardiac Transplantation (IMPACT)-scores and the Donor Risk Index (DRI). Looking to our results, we found that our DRIs in the different eras are almost equal to those obtained from the United Network for Organ Sharing database in the very same eras. Our IMPACT-scores, on the other hand, seem higher than those reported by ISHLT. Survival after transplantation and conditional on 1-year survival was higher than the outcome reported by the ISHLT Registry. As our operation technique and post-transplant immunosuppressive schedule did not differ from most centers, we speculated on potential factors that might contribute to our positive results. Patient selection and a relatively short waiting time are important contributors to the overall survival benefit. Our centralized follow-up may also have played an important role. Finally, the indefinite compulsory health insurance coverage in our country and easy access to different screening programs might also have influenced our outcome in a positive way. We are well aware that with challenges like donor organ shortage, more and more patients on mechanical circulatory support (MCS) will affect outcomes in the future.