Etiology of increased cancer incidence after solid organ transplantation

Unrelated Bone Marrow Transplantation for Chronic Myeloid Leukemia after Liver Transplantation

This report describes the case of a 29-year-old patient with chronic myeloid leukemia in the blast phase who underwent hematopoietic stem cell transplantation (HSCT) after living-donor liver transplantation. Donor selection, conditioning regimens, and graft-versus-host disease (GVHD) prophylaxis are discussed. The patient received a non-myeloablative conditioning regimen and ABO blood group-matched unrelated human leukocyte antigen fully-matched donors. Immunosuppressants tacrolimus and mycophenolate mofetil were administered to prevent GVHD. Maintenance therapy with ponatinib effectively maintained remission. This case highlights the complexities of managing HSCT after solid organ transplantation and suggests strategies for future cases.

Immune checkpoint inhibitor-associated nephritis-treatment standard

Over the last 13 years, the use of immune checkpoint inhibitor (ICI) therapy has grown remarkably, owing to their unprecedented anti-tumor efficacy in certain tumor groups. With increased use of ICIs, we are seeing immune-related adverse events (irAEs) more frequently. Renal irAEs, such as ICI-associated acute kidney injury (ICI-AKI), are reported in 2%-5% of patients treated with ICIs, with acute tubulointerstitial nephritis (ATIN) as the most common histopathologic lesion, though various forms of glomerulonephritis have also been reported. Modifiable risk factors for ICI-AKI include concurrent use of ATIN-associated drugs, like proton pump inhibitors, non-steroidal anti-inflammatory drugs and antibiotics, and dual ICI therapy with both Cytotoxic T-lymphocyte Associated Protein 4 (CTLA-4) and Programmed Cell Death Protein 1 and its ligand (PD1/PDL-1) blockade. Kidney biopsies remain the diagnostic modality of choice, though several promising non-invasive biomarkers, which have not yet been broadly clinically validated have emerged. The treatment of ICI-AKI involves holding ICIs, discontinuation of ATIN-associated drugs and initiation of immunosuppression with corticosteroids as first-line therapy. With prompt treatment initiation, most patients achieve full or partial renal recovery, allowing for re-challenge with ICI. However, a subset of patients will require additional steroid-sparing therapies for corticosteroid-dependent or refractory ICI-AKI. Here we review developments in our understanding of the pathophysiology of ICI-AKI, the approach to diagnosis (with a focus on the emergence of novel diagnostic tools), prognostic factors and the current evidence for establishing treatment standards for ICI-AKI. As the evidence base remains largely retrospective, we identify questions that would benefit from future prospective studies in the diagnosis, management and prognostication of ICI-AKI.

Immune Checkpoint Inhibitor Therapy for Kidney Transplant Recipients - A Review of Potential Complications and Management Strategies

Immune checkpoint inhibitor (ICI) therapy has enabled a paradigm shift in Oncology, with the treatment of metastatic cancer in certain tumor types becoming akin to the treatment of chronic disease. Kidney transplant recipients (KTR) are at increased risk of developing cancer compared to the general population. Historically, KTR were excluded from ICI clinical trials due to concern for allograft rejection and decreased anti-tumor efficacy. While early post-marketing data revealed an allograft rejection risk of 40%-50%, 2 recent small prospective trials have demonstrated lower rates of rejection of 0%-12%, suggesting that maintenance immunosuppression modification prior to ICI start modulates rejection risk. Moreover, objective response rates induced by ICI for the treatment of advanced or metastatic skin cancer, the most common malignancy in KTR, have been comparable to those achieved by immune intact patients. Non-invasive biomarkers may have a role in risk-stratifying patients before starting ICI, and monitoring for rejection, though allograft biopsy is required to confirm diagnosis. This clinically focused review summarizes current knowledge on complications of ICI use in KTR, including their mechanism, risk mitigation strategies, non-invasive biomarker use, approaches to treatment of rejection, and suggestions for future directions in research.

Reconstructive Surgery of the Head and Neck in Organ Transplant Recipients: A Case Report and a Review of the Literature

The number of solid organ transplant recipients (SOTRs) is growing as a consequence of an increase in transplantations and longer survival; these patients, thus, frequently suffer various comorbidities and are subjected to the detrimental effects of immunosuppressive agents, which expose them to a higher risk of developing malignancies. These drugs also complicate the surgical treatment of neoplasms, as they can hinder wound healing, especially when associated with other unfavorable factors (e.g., previous radiotherapy, diabetes, etc.). We herein present our experience with a 74-year-old SOTR who underwent a radical extended parotidectomy and reconstruction with a submental island flap for a persistent cutaneous squamous carcinoma after radiotherapy; his complicated clinical course was characterized by incredibly slow wound healing. The current literature was reviewed to provide a succinct overview of the main difficulties of head and neck surgery in SOTRs. In particular, the immunosuppressive regimen can be tapered considering the individual risk and other elements should be carefully assessed, possibly prior to surgery, to prevent cumulative harm. New developments, including intraoperative monitoring of flap vascularization through indocyanine green fluorescence video-angiography and the prophylactic application of negative pressure wound therapy, when feasible, may be particularly beneficial for high-risk patients.

Cancer risk in people living with HIV and solid organ transplant recipients: a systematic review and meta-analysis

BACKGROUND

Systematic evaluations of cancer risk in people living with HIV or AIDS (PLHIV) and solid organ transplant recipients provide unique insights into the role of the immune system in cancer development. In this systematic review and meta-analysis, we expand previous analyses of cancer risk for these two immunocompromised populations.

METHODS

We considered studies published in English and listed on PubMed or Embase up to July 1, 2022. Studies were eligible for inclusion if they used population-based registries and compared cancer incidence in PLHIV or solid organ transplant recipients with the general population in the same geographical area. We extracted the number of observed site-specific cancers and expected cases and calculated meta-standardised incidence ratios for cancer within PLHIV and solid organ transplant recipients. In solid organ transplant recipients meta-standardised incidence ratios were compared by organ type. This project is registered on PROSPERO, CRD42022366679.

FINDINGS

46 studies in PLHIV and 67 in solid organ transplant recipients were included in the analysis. Meta-standardised incidence ratios for cancers associated with human papillomavirus were increased in both populations; the highest meta-standardised incidence ratio in PLHIV was anal cancer (37·28 [95% CI 23·65-58·75], I2=97·4%), and in solid organ transplant recipients was cutaneous squamous cell carcinoma (45·87 [31·70-66·38], I2=99·0%). Meta-standardised incidence ratios were significantly increased for most non-HPV viral-infection-related cancers in both populations; the highest standard incidence ratios were for Kaposi sarcoma (PLHIV: 801·52 [95% CI 200·25-3208·13], I2=100·0%; solid organ transplant recipients: 47·31 [23·09-96·95], I2=87·7%) and non-Hodgkin lymphoma (32·53 [19·64-53·87], I2=99·8%; 10·24 [8·48-12·35], I2=94·9%). Eight types of cancer with no known viral cause showed an increased risk in solid organ transplant recipients only; no cancer type showed increased risk in PLHIV only.

INTERPRETATION

Cancer risk was increased for a range of infection-related cancers in both PLHIV and solid organ transplant recipients, but divergent results in these and other cancers have emerged. The cancer risk patterns probably reflect variances in the degree of impaired immunity, exposure to carcinogenic viruses, and perhaps exposure to carcinogenic immunosuppressive agents.

FUNDING

US National Cancer Institute, National Institutes of Health.

Lactobacillus rhamnosus HN001 facilitates the efficacy of dual PI3K/mTOR inhibition prolonging cardiac transplant survival and enhancing antitumor effect

Solid organ transplantation is a crucial treatment for patients who have reached the end stage of heart, lung, kidney, or liver failure. However, the likelihood of developing cancer post-transplantation increases. Additionally, primary malignant tumors remain a major obstacle to the long-term survival of transplanted organs. Therefore, it is essential to investigate effective therapies that can boost the immune system's ability to combat cancer and prevent allograft rejection. We established a mouse orthotopic liver tumor model and conducted allogeneic heterotopic heart transplantation. Various treatments were administered, and survival curves were generated using the Kaplan-Meier method. We also collected graft samples and measured inflammatory cytokine levels in the serum using an inflammatory array. The specificity of the histochemical techniques was tested by staining sections. We administered a combination therapy of phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) dual inhibitor BEZ235 and Lactobacillus rhamnosus HN001 to primary liver cancer model mice with cardiac allografts. Consistent with our prior findings, L. rhamnosus HN001 alleviated the intestinal flora imbalance caused by BEZ235. Our previous research confirmed that the combination of BEZ235 and L. rhamnosus HN001 significantly prolonged cardiac transplant survival.

IMPORTANCE

We observed that the combination of phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) dual inhibitor BEZ235 and Lactobacillus rhamnosus HN001 notably prolonged cardiac transplant survival while also inhibiting the progression of primary liver cancer. The combination therapy was efficacious in treating antitumor immunity and allograft rejection, as demonstrated by the efficacy results. We also found that this phenomenon was accompanied by the regulation of inflammatory IL-6 expression. Our study presents a novel and effective therapeutic approach to address antitumor immunity and prevent allograft rejection.

TCF1highPD-1+Ly108+CD8+ T Cells Are Associated with Graft Preservation in Sensitized Mice Treated with Non-Fc Receptor-Binding CD3 Antibodies

The non-Fc-binding anti-CD3 Ab [anti-CD3F(ab')2] can induce graft acceptance depending on the therapeutic window in a rodent heart transplant model. The delayed protocol allows for early graft infiltration of lymphocytes, which may behave in an inhibitory manner. We investigated the most effective protocol for anti-CD3F(ab')2 in sensitized conditions to confirm the evidence for clinical application. C57BL/6 mice were sensitized with BALB/c tail skin grafts and transplanted with BALB/c heart grafts at 8-12 wk after sensitization. Fifty micrograms of anti-CD3F(ab')2 was administered daily for 5 consecutive days on days 1-5 (day 1 protocol) or days 3-7 (delayed protocol). In nonsensitized mice, the delayed protocol significantly prolonged graft survival after transplantation from BALB/c to naive B6 (median survival time [MST], >100 d). In contrast, the delayed protocol was unable to prevent graft rejection in sensitized mice (MST, 5 d). A significantly increased percentage of granzyme B+ CD8+ T cells was observed in the graft on day 3 posttransplantation in sensitized conditions. Further, the day 1 protocol significantly prolonged graft survival (MST, 18 d), even in sensitized conditions. Day 1 treatment significantly increased the percentage of Foxp3+CD25+CD4+ T cells and phenotypically changed CD8+ T cells in the graft (i.e., caused a significant increase in the proportion of Ly108+TCF1highPD-1+CD8+ T cells). In conclusion, different timings of delayed anti-CD3F(ab')2 treatment promoted allograft preservation in association with phenotypic changes in CD4+ and CD8+ T cells in the graft under sensitized conditions.

Epithelioid Hemangioendothelioma in a Liver Transplant Recipient: A Case Report of an Extremely Rare Tumor

Epithelioid hemangioendothelioma is a very rare vascular neoplasm, which is often multifocal or metastatic at diagnosis. Most frequently arises in the liver, followed by the lung and bones. The authors present a case of a liver transplant recipient who developed a pattern of hepatic cholestasis associated with the appearance of a proliferative hepatic lesion with infiltrative growth. Histological examination and immunohistochemical study were compatible with the diagnosis of epithelioid hemangioendothelioma. Pulmonary micronodules were detected and lung metastases were hypothesized. Therefore, bronchoscopy was performed, which turned out to be normal, and cytology was negative for neoplastic cells. After a multidisciplinary discussion, liver re-transplantation was decided. After 8 years of follow-up, the patient is clinically stable, with no graft dysfunction, no neoplastic recurrence, and dimensional stability of the pulmonary micronodules. Patients with organ transplant have higher risk of developing carcinoma compared to the general population. The development of cancer is a multifactorial process and little is known about the etiology of epithelioid hemangioendothelioma. No standard treatment strategy has been defined yet, and the natural course of the disease is heterogenous and the individual prognosis unpredictable. Complete surgical resection is offered to patients with unifocal disease, and those with unresectable disease should be evaluated for orthotopic liver transplantation.

Barriers toward xenotransplantation in Arab World

Organ transplant is a crucial therapeutic strategy offering a life-saving and transformative medical intervention. It provides an opportunity to improve their quality of life and increase their lifespan. The shortage of organs remains a critical global challenge, leading to a prolonged waiting times for organ receivers, which contributes to an increase in morbidity and mortality rates. Hence, xenotransplantation offered a promising solution to the global shortage of organs through the use of animal organs, leading to an increase in donor availability, reducing waiting times, minimizing organ trafficking, improving genetic engineering advancements, and driving scientific innovation. Even though xenotransplantation has many benefits in the clinical setting, it has many barriers that are hindering its achievements and constraining its occurrence. Some barriers to xenotransplant are general, such as the immunological barrier, while others are specific to certain regions due to local causes. The Arab region exhibits disparities in clinical settings compared to the global context, marked by the huge economic crisis and a shortage of trained healthcare professionals. Considering the huge resources and advancements needed in the field of xenotransplantation, this review aims to explore the specific barriers toward xenotransplantation in the Arab countries, highlighting the challenges to overcome these barriers.

Cancer mortality after kidney transplantation: A multicenter cohort study in Italy

Kidney transplant (KT) recipients are known to be at risk of developing several cancer types; however, cancer mortality in this population is underinvestigated. Our study aimed to assess the risk of cancer death among Italian KT recipients compared to the corresponding general population. A cohort study was conducted among 7373 individuals who underwent KT between 2003 and 2020 in 17 Italian centers. Date and cause of death were retrieved until 31 December 2020. Indirect standardization was used to estimate standardized mortality ratios (SMRs) and corresponding 95% confidence intervals (CIs). Cancer was the most common cause of death among the 7373 KT recipients, constituting 32.4% of all deaths. A 1.8-fold excess mortality (95% CI: 1.59-2.09) was observed for all cancers combined. Lymphomas (SMR = 6.17, 95% CI: 3.81-9.25), kidney cancer (SMR = 5.44, 95% CI: 2.97-8.88) and skin melanoma (SMR = 3.19, 95% CI: 1.03-6.98) showed the highest excess death risks. In addition, SMRs were increased about 1.6 to 3.0 times for cancers of lung, breast, bladder and other hematopoietic and lymphoid tissues. As compared to the general population, relative cancer mortality risk remained significantly elevated in all age groups though it decreased with increasing age. A linear temporal increase in SMR over time was documented for all cancers combined (P < .01). Our study documented significantly higher risks of cancer death in KT recipients than in the corresponding general population. Such results support further investigation into the prevention and early detection of cancer in KT recipients.

Incidence of renal cell carcinoma after solid organ transplantation: a systematic review and meta-analysis

BACKGROUND

The incidence rate of malignant tumors after solid organ transplantation is higher than the normal population. The aim of our study is to identify the risk of renal cell carcinoma (RCC) after liver, kidney, heart and lung transplantation, respectively, and suggest that transplant patients can be screened early for tumors to avoid risk.

METHODS

PubMed, Embase and the Cochrane Library from their inception until August 16,2023. Retrospective and cohort studies which focus on the statistical data of standardized incidence ratios (SIRs) of RCC after solid organ transplantation (SOT) more than one year have been included and extracted. The study was registered with PROSPERO, CRD4202022343633.

RESULTS

Sixteen original studies have been included for meta-analysis. Liver transplantation could increase the risk of RCC (SIR = 0.73, 95%CI: 0.53 to 0.93) with no heterogeneity(P = 0.594, I2 = 0.0%). And kidney transplantation could increase the risk of RCC(8.54, 6.68 to 10.40; 0.000,90.0%). Besides, heart and lung transplantation also could increase the risk of RCC(SIR = 0.73, 95%CI: 0.53 to 0.93; SIR = 1.61, 95%CI:0.50 to 2.71). Moreover, significance could also be found in most subgroups, especially the European group and retrospective study group. What's more, after removing studies which have a greater impact on the overall outcome in RCC rate after kidney transplantation, heterogeneity did not solve and significant different was also observed in the European group (7.15, 5.49 to 8.81; 0.000, 78.6%).

CONCLUSION

Liver, kidney, heart and lung transplantation patients have an increased risk of processing RCC compared to the general population and most subgroups, especially in geographic location of European subgroup, which suggested that patients should be screened frequently after transplantation.

HPV38 impairs UV-induced transcriptional activation of the IL-18 pro-inflammatory cytokine

IMPORTANCE

Here, we demonstrate that the direct binding of p53 on the IL-18 promoter region regulates its gene expression. However, the presence of E6 and E7 from human papillomavirus type 38 impairs this mechanism via a new inhibitory complex formed by DNA methyltransferase 1 (DNMT1)/PKR/ΔNp73α, which binds to the region formerly occupied by p53 in primary keratinocytes.

Post-transplant malignancy: Focusing on virus-associated etiologies, pathogenesis, evidence-based management algorithms, present status of adoptive immunotherapy and future directions

Modern immunosuppression has led to a decrease in rejection rates and improved survival rates after solid organ transplantation. Increasing the potency of immunosuppression promotes post-transplant viral infections and associated cancers by impairing immune response against viruses and cancer immunoediting. This review reflects the magnitude, etiology and immunological characteristics of various virus-related post-transplant malignancies, emphasizing the need for future research. A multidisciplinary and strategic approach may serve best but overall literature evidence targeting it is sparse. However, the authors attempted to provide a more detailed update of the literature consensus for the prevention, diagnosis, management and surveillance of post-transplant viral infections and associated malignancies, with a focus on the current role of adoptive immunotherapy and the way forward. In order to achieve long-term patient and graft survival as well as superior post-transplant outcomes, collaborative research on holistic care of organ recipients is imperative.

Incidence of malignancies after lung transplantation and their effect on the outcome. 26 years' experience

Background

Malignancy is a significant, life-limiting complication after lung transplantation (LuTx) and the second common long-term cause of death. We aimed to investigate its incidence and effect on the outcome.

Methods

This is a retrospective observational study. Between 1996 and 2022, n = 627 lung transplantations (LuTx) were performed in our department. We used our institutional database to identify recipients with malignancies after LuTx and examined the malignancies' incidence and mortality.

Results

N = 59 malignancies occurred in n = 55 (8.8%) LuTx recipients. The post-LTx malignancies incidence was 9.4% (59/627). We report the following rates based on their location: n = 17/55 (28,8% of all recipients diagnosed with malignancies) skin, n = 10/55 (16,95%) gastrointestinal, n = 9/55 (15,3%) respiratory, n = 5/55 (8,48%) lymphatic, n = 13/55 (23,6%) other, n = 5 (8,48%) multiple synchronous.During this study period, a total of n = 328 deaths after LuTx was determined. N = 29 (8,84% of all deaths) were malignancy induced, corresponding to a total malignancy-induced mortality of 4.6% (n = 29/627). The majority of deaths were attributed to GI adenocarcinoma and PTLD. Malignancies' origin, primary COPD diagnosis, type, and specific age group were significantly survival-related (p-values <0.05). The most affected organ was skin and showed the best prognosis. PTLD had the fastest and pancreatic the latest onset.

Conclusions

This is the first report of its kind in a large cohort of german LuTx recipients. The prevalence ranking of the three commonest malignancy were skin > colorectal > PTLD. Post-LTx malignancy was the second commonest cause of death. Further studies are needed, while post-LuTx malignomas remain a serious impairment of long-term LuTx survival.

Temporal trends of de novo urological malignancy in renal transplant recipients without a cancer history: A longitudinal cohort study

BACKGROUND

The incidence of malignancies after successful kidney transplantation has historically been higher than in the general population, with adverse impact on clinical outcomes. However, uncertainty remains as to which cancers occur at what time points after kidney transplantation.

METHODS

We conducted a longitudinal cohort study to investigate the temporal trends and topographic patterns of de novo malignancies to optimize surveillance protocols and improve transplant outcome in renal transplant recipients. Measurement of death and cancer events was performed to calculate the cumulative risk of events of interest.

RESULTS

Between 2000 and 2013, 3169 renal transplant recipients were retrospectively screened; 3035 (96%) of them met eligibility criteria and were evaluated with a follow-up of 27612 person-years. There was suboptimal overall survival and malignancy-free survival in renal transplant recipients compared to reference groups (HR: 1.65; 95% CI: 1.50-1.82; p < .001; HR: 2.33; 95% CI: 2.04-2.66; p < .001, respectively). Among renal transplant recipients, urological malignancies were predominant (57.5%), followed by digestive tract malignancies (21.4%). The cancer risks of the urinary bladder and upper urinary tract were lower in male subjects (HR: .48; 95% CI: .33-.72; p < .001; HR: .34; 95% CI: .20-.59; p < .001, respectively). The temporal trends of urological malignancies among renal transplant recipients were expressed in a bimodal pattern, with M-shaped peaks at 3 and 9 years, with gender disparity.

CONCLUSIONS

In renal transplant recipients, cancer occurrences are shown as M-shaped twin peaks. Our study highlights that specific customized 'targeted' strategies for cancer surveillance programs are required to optimize posttransplant care.

A nanotherapeutic strategy that engages cytotoxic and immunosuppressive activities for the treatment of cancer recurrence following organ transplantation

BACKGROUND

Long-term treatment with immunosuppressants is necessary to attenuate allograft rejection following organ transplantation (OT). Consequently, the overall survival of OT recipients with malignancies has been substantially compromised by tumour recurrence. Rapamycin (RAPA) is a clinically approved immunosuppressive agent with antitumour activity that is considered beneficial in preventing posttransplant tumour recurrence. However, the clinical outcome of RAPA is impeded by acquired drug resistance and its poor oral bioavailability.

METHODS

A nanotherapeutic strategy was developed by supramolecular assembly of RAPA into a polymer cytotoxic 7-ethyl-10-hydroxycamptothecin (SN38) prodrug nanoparticle (termed SRNP) for simultaneous codelivery of cytotoxic/immunosuppressive agents. Cell-based experiments were used to evaluate the cytotoxicity of SRNPs against hepatocellular carcinoma (HCC). The therapeutic efficacy of SRNPs was evaluated in multiple preclinical models including an orthotopic HCC mouse model, an orthotopic liver transplantation (OLT) rat model and a clinically relevant cancer-transplant model to examine its antitumour and immunosuppressive activity.

FINDINGS

The combination of SN38 with RAPA resulted in synergetic effects against HCC cells and alleviated RAPA resistance by abrogating Akt/mTOR signalling activation. SRNPs exhibited potent antitumour efficiency in the orthotopic HCC model while substantially prolonging the survival of allografts in the OLT model. In the cancer-transplant model that simultaneously bears tumour xenografts and skin allografts, SRNPs not only effectively inhibited tumour growth but also attenuated allograft damage.

INTERPRETATION

The nanotherapy presented here had enhanced efficacy against tumours and maintained satisfactory immunosuppressive activity and thus has great potential to improve the survival outcomes of patients with a high risk of tumour recurrence following OT.

FUNDING

This work was supported by the National Natural Science Foundation of China (32171368 and 31671019), the Zhejiang Provincial Natural Science Foundation of China (LZ21H180001), the Zhejiang Province Preeminence Youth Fund (LR19H160002), and the Jinan Provincial Laboratory Research Project of Microecological Biomedicine (JNL-2022039c).

Comedications with Immune Checkpoint Inhibitors: Involvement of the Microbiota, Impact on Efficacy and Practical Implications

Immune checkpoint inhibitors (ICIs) have been a major breakthrough in solid oncology over the past decade. The immune system and the gut microbiota are involved in their complex mechanisms of action. However, drug interactions have been suspected of disrupting the fine equilibrium necessary for optimal ICI efficacy. Thus, clinicians are facing a great deal of sometimes contradictory information on comedications with ICIs and must at times oppose conflicting objectives between oncological response and comorbidities or complications. We compiled in this review published data on the role of the microbiota in ICI efficacy and the impact of comedications. We found mostly concordant results on detrimental action of concurrent corticosteroids, antibiotics, and proton pump inhibitors. The timeframe seems to be an important variable each time to preserve an initial immune priming at ICIs initiation. Other molecules have been associated with improved or impaired ICIs outcomes in pre-clinical models with discordant conclusions in retrospective clinical studies. We gathered the results of the main studies concerning metformin, aspirin, and non-steroidal anti-inflammatory drugs, beta blockers, renin-angiotensin-aldosterone system inhibitors, opioids, and statins. In conclusion, one should always assess the necessity of concomitant treatment according to evidence-based recommendations and discuss the possibility of postponing ICI initiation or switching strategies to preserve the critical window.

A rare case of myelolipoma compressing a second-transplanted kidney: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Myelolipoma is a rare benign neoplasm composed of mature elements of fatty and hematopoietic tissues. In addition to its low incidence, myelolipoma in kidney transplant patients is much rarer, with only a few cases of this entity reported in the literature.

CASE PRESENTATION

A 37-year-old diabetic patient was admitted to the hospital due to severe left abdominal pain and elevated creatinine levels of 4.4 mg/dl. The patient has a history of two kidney transplantations. The patient was investigated with different modalities of imaging, which revealed a mass adjacent to the renal graft that was suspicious for malignancy. Histopathological assessment of the resected lesion showed findings consistent with myelolipoma.

CLINICAL DISCUSSION

Although it's uncommon, myelolipoma should be considered in the differential diagnosis of any renal or extra-renal lesion in kidney transplant patients, including those with a history of graft rejection as in our patient.

CONCLUSION

In light of the rarity of the lesions, we affirm the significance of the clinicians' reporting such cases that they encounter in order to better understand the disease's biological behavior.

Variation in Post-Transplant Cancer Incidence among Italian Kidney Transplant Recipients over a 25-Year Period

This cohort study examined 25-year variations in cancer incidence among 11,418 Italian recipients of kidney transplantation (KT) from 17 Italian centers. Cancer incidence was examined over three periods (1997-2004; 2005-2012; and 2013-2021) by internal (Incidence rate ratio-IRR) and external (standardized incidence ratios-SIR) comparisons. Poisson regression was used to assess trends. Overall, 1646 post-transplant cancers were diagnosed, with incidence rates/1000 person-years ranging from 15.5 in 1997-2004 to 21.0 in 2013-2021. Adjusted IRRs showed a significant reduction in incidence rates across periods for all cancers combined after exclusion of nonmelanoma skin cancers (IRR = 0.90, 95% confidence interval-CI: 0.76-1.07 in 2005-2012; IRR = 0.72, 95% CI: 0.60-0.87 in 2013-2021 vs. 1997-2004; P_trend < 0.01). In site-specific analyses, however, significant changes in incidence rates were observed only for Kaposi's sarcoma (KS; IRR = 0.37, 95% CI: 0.24-0.57 in 2005-2012; IRR = 0.09, 95% CI: 0.04-0.18 in 2013-2021; P_trend < 0.01). As compared to the general population, the overall post-transplant cancer risk in KT recipients was elevated, with a decreasing magnitude over time (SIR = 2.54, 95% CI: 2.26-2.85 in 1997-2004; SIR = 1.99, 95% CI: 1.83-2.16 in 2013-2021; P_trend < 0.01). A decline in SIRs was observed specifically for non-Hodgkin lymphoma and KS, though only the KS trend retained statistical significance after adjustment. In conclusion, apart from KS, no changes in the incidence of other cancers over time were observed among Italian KT recipients.

Antithymocyte Globulin Inhibits CD8+ T Cell Effector Functions via the Paracrine Induction of PDL-1 on Monocytes

BACKGROUND

Antithymocyte globulins (ATG) are T cell-depleting antibodies used in solid organ transplantation for induction therapy in sensitized patients with a high risk of graft rejection. Previously described effects besides the depletion of T cells have suggested additional modes of action and identified further cellular targets.

METHODS

We examined the transcriptional changes arising in immune cells from human blood after ex vivo stimulation with ATG at the single-cell level to uncover additional mechanisms by which ATG regulates T cell activity and effector functions.

FINDINGS

Analysis of the paracrine factors present in the plasma of ATG-treated whole blood revealed high levels of chemokines and cytokines, including interferon-γ (IFN-γ). Furthermore, we identified an increase in the surface expression of the programmed death ligand 1 (PDL-1) on monocytes mediated by the released paracrine factors. In addition, we showed that this induction is dependent on the activation of JAK/STAT signaling via the binding of IFN-γ to interferon-γ receptor 1 (IFN-γR1). Lastly, we demonstrated that the modulation of the immune regulatory axis of programmed cell death protein 1 (PD1) on activated CD8⁺ T cells with PDL-1 found on monocytes mediated by ATG potently inhibits effector functions including the proliferation and granzyme B release of activated T cells.

INTERPRETATION

Together, our findings represent a novel mode of action by which ATG exerts its immunosuppressive effects.

Tissue-Targeted Drug Delivery Strategies to Promote Antigen-Specific Immune Tolerance

During autoimmunity or organ transplant rejection, the immune system attacks host or transplanted tissue, causing debilitating inflammation for millions of patients. There is no cure for most of these diseases. Further, available therapies modulate inflammation through nonspecific pathways, reducing symptoms but also compromising patients' ability to mount healthy immune responses. Recent preclinical advances to regulate immune dysfunction with vaccine-like antigen specificity reveal exciting opportunities to address the root cause of autoimmune diseases and transplant rejection. Several of these therapies are currently undergoing clinical trials, underscoring the promise of antigen-specific tolerance. Achieving antigen-specific tolerance requires precision and often combinatorial delivery of antigen, cytokines, small molecule drugs, and other immunomodulators. This can be facilitated by biomaterial technologies, which can be engineered to orient and display immunological cues, protect against degradation, and selectively deliver signals to specific tissues or cell populations. In this review, some key immune cell populations involved in autoimmunity and healthy immune tolerance are described. Opportunities for drug delivery to immunological organs are discussed, where specialized tissue-resident immune cells can be programmed to respond in unique ways toward antigens. Finally, cell- and biomaterial-based therapies to induce antigen-specific immune tolerance that are currently undergoing clinical trials are highlighted.

Evaluation of Routine Ear, Nose, and Throat Screening in Heart Transplant Candidates: A Retrospective Cohort Study

BACKGROUND

Patients with end-stage heart failure refractory to medication can be treated with a heart transplant (HTx). These patients are subjected to a preoperative screening procedure according to International Society for Heart and Lung Transplantation guidelines. Additionally, in our hospital, a routine ear, nose, and throat (ENT) screening is performed, directed toward the identification of asymptomatic infections and head and neck neoplasms. There are no studies demonstrating that this screening has additional value in these patients.

METHODS

To investigate the yield of protocolled ENT screening in candidates for HTx, we retrospectively reviewed the medical records of patients who were subjected to the screening procedure between 2012 and 2020.

RESULTS

The study population consisted of 251 patients of whom 177 (70.5%) were male with a median age of 52 years (IQR, 45-59 years). Ten patients (4.0%) were diagnosed with an infection (sinus) or a neoplasm, resulting in a number needed to screen of 25. In all cases, ENT consultation or sinus radiography did not influence the decision to list patients for HTx. Furthermore, no major ENT infections or occurrence of de novo head and neck malignant neoplasm were observed during follow-up after HTx.

CONCLUSIONS

The clinically relevant yield of protocolled ENT screening in candidates for HTx is low. Based on these findings, we believe that only patients with abnormal findings on a routine sinus computed tomography scan and/or specific ENT complaints should be referred to an otorhinolaryngologist.

Potential use of multikinase inhibitors in immunosuppressed patients with malignancies including thyroid cancer

In this article, we focus on a variety of immunosuppression scenarios and whether multikinase inhibitors, as systemic therapy for advanced thyroid carcinoma (TC), could be useful for the treatment of immunocompromised patients with TC. Lenvatinib and sorafenib, among other MKIs, have become the standard of care for advanced TC based on their efficacy data and despite their adverse effects. Currently, published data on MKIs in immunosuppressed patients are scarce. Secondary malignancies can arise in immunosuppressed patients who have undergone solid organ transplantation, human immunodeficiency virus-infected patients, and hematopoietic stem cell transplant recipients. This review will explore different immunosuppression settings, the risk of secondary malignancies in immunosuppressed patients, and the special characteristics of this population. Some considerations regarding anticancer treatment in immunosuppressed patients with advanced malignancies are reviewed.

Trends in underlying causes of death in solid organ transplant recipients between 2010 and 2020: Using the CLASS method for determining specific causes of death

Monitoring specific underlying causes of death in solid organ transplant (SOT) recipients is important in order to identify emerging trends and health challenges. This retrospective cohort study includes all SOT recipients transplanted at Rigshospitalet between January 1st, 2010 and December 31st, 2019. The underlying cause of death was determined using the newly developed Classification of Death Causes after Transplantation (CLASS) method. Cox regression analyses assessed risk factors for all-cause and cause-specific mortality. Of the 1774 SOT recipients included, 299 patients died during a total of 7511 person-years of follow-up (PYFU) with cancer (N = 57, 19%), graft rejection (N = 55, 18%) and infections (N = 52, 17%) being the most frequent causes of death. We observed a lower risk of all-cause death with increasing transplant calendar year (HR 0.91, 95% CI 0.86–0.96 per 1-year increase), alongside death from graft rejection (HR 0.84 per year, 95% CI 0.74–0.95) and death from infections (HR 0.86 per year, 95% CI 0.77–0.97). Further, there was a trend towards lower cumulative incidence of death from cardiovascular disease, graft failure and cancer in more recent years, while death from other organ specific and non-organ specific causes did not decrease. All-cause mortality among SOT recipients has decreased over the past decade, mainly due to a decrease in graft rejection- and infection-related deaths. Conversely, deaths from a broad range of other causes have remained unchanged, suggesting that cause of death among SOT recipients is increasingly diverse and warrants a multidisciplinary effort and attention in the future.

Immune Activation, Exhaustion and Senescence Profiles as Possible Predictors of Cancer in Liver Transplanted Patients

Liver transplanted (LT) patients for hepatocellular carcinoma (LT-HCC) or for other causes (LT-no-HCC) may develop post-transplantation malignancies. Although immune activation and senescence are frequently implicated in cancer development, no data is available on their possible role as biomarkers predictive of tumor onset in this setting. A total of 116 patients were investigated: the 45 LT-HCC patients were older than the 71 LT-non-HCC (p=0.011), but comparable for sex, HCV, HBV infection and immunosuppressive treatment. At baseline, the numbers of activated and senescent-like circulating cells were significantly higher in LT-HCC patients than in LT-no-HCC ones. After a median follow-up of 26.8 months, 6 post-transplant malignancies (PTM) occurred: 4 in LT-HCC (8.9%) and 2 in LT-no-HCC (2.8%) patients. Overall, subjects with high percentages of activated and exhausted T and B cells at baseline were at higher risk of PTM. Notably, within the LT-HCC group, a higher percentage of senescence-like T cells was also associated with cancer development. Moreover, patients with PTM had higher telomere erosion and higher levels of circulating PAMPs (16S rDNA) and DAMPs (mtDNA) when compared with matched patients without PTM. Overall, these findings suggest that immune activation and exhaustion may be useful to predict the risk of PTM occurrence, regardless of the cause of transplantation. In LT-HCC, T-cell senescence represents an additional risk factor for tumor onset.

Immunosuppressive treatment and radiotherapy in kidney transplant patients: A systematic review

BACKGROUND

Immunosuppression (IS) therapy may contribute to cancer development. Some authors have proposed to reduce immunosuppression drugs dose in case of viral infections, in immunosuppression-related diseases, and in patients undergoing radiotherapy. The present analysis reports the results of a systematic review on kidney transplant recipients undergoing immunosuppression and radiotherapy.

AIM

To define if it is necessary reduce immunosuppression drugs during radiotherapy.

METHODS

The literature search was based on three electronic databases (Pubmed, Scopus, and Web of Science) using selected keywords linked through the "AND" and "OR" Boolean operators to build specific strings for each electronic search engine. Two researchers independently screened the citations, and disagreement was resolved by discussion or through the intervention of a third author. The review was conducted and reported according to the PRISMA statement. Extracted data were narratively synthesized, and, where possible, frequencies, percentages, and ranges were calculated.

RESULTS

The literature search resulted in 147 citations. After abstracts screening, 21 records were selected for full-text evaluation. Fifteen of these were excluded, leaving six papers considered suitable for analysis. There is still no clear evidence that withdrawing antimetabolites and/or calcineurin inhibitors and/or mammalian target of rapamycin-inhibitors, as opposed to continuing maintenance IS, improves patient survival in kidney transplant recipients with cancer undergoing radiotherapy. Only few retrospective studies on small cancer patient cohorts are available in this setting, but without comparison of different immunosuppression treatments. Even where immunosuppression therapy was described, patient survival seemed to be correlated only with cancer stage and type.

CONCLUSION

The results of this systematic review do not support the reduction of immunosuppression dose in patients undergoing radiotherapy.

Current Status of Malignant Tumors after Organ Transplantation

Objective

To analyze the diagnosis and treatment of patients with concomitant malignant tumors after organ transplantation by compiling data from organ transplantation patients.

Methods

By searching CNKI and PubMed databases, we made a systematic analysis of the studies of postorgan transplantation complicating malignant tumors in the last decade.

Results

There were 10 articles on malignant tumors after renal transplantation, 8 articles on liver transplantation, 2 articles on heart transplantation, and 1 article on lung transplantation. The incidence of malignant tumors complicating renal transplantation is 10.4% in Europe, with skin cancer and Kaposi's sarcoma being common; the incidence in the United States is 3.4%, with PTLD having the highest incidence; the incidence of malignant tumors is relatively lowest in Asia, with gastrointestinal malignancies being the main ones. The mean time to complication of malignancy after renal transplantation is 3.83 years. The incidence of concurrent malignancies after liver transplantation is 8.8% in Europe, where skin cancer and Kaposi's sarcoma are common; 5.6% in Asia, where gastrointestinal tract tumors are prevalent; and 4.5% in the United States, where gastrointestinal tract tumors, PTLD, and hematologic diseases are predominant. The mean time to complication of malignancy after liver transplantation is 4.79 years. The incidence of malignancy after heart transplantation is 6.8-10.7%. The incidence of malignancy after lung transplantation is about 10.1%. Minimization of immunosuppression or modification of immunosuppression regimens may be a key component of cancer prevention. mTOR inhibitors and phenolate (MMF) reduce the incidence of de novo malignancies in patients after solid organ transplantation. Surgical treatment improves survival in patients with early malignancies. The use of external beam radiation therapy in the treatment of hepatocellular carcinoma is limited due to the risk of radiation liver disease.

Conclusions

The risk of concomitant malignancy needs to be guarded for 5 years of immunosuppressive therapy after organ transplantation surgery. Adjusting the immunosuppressive treatment regimen is an effective way to reduce concurrent malignancies. Systemic chemotherapy or radiotherapy requires vigilance against the toxic effects of drug metabolism kinetics on the transplanted organ.

Cancer risk and mortality after solid organ transplantation - A population-based 30-year cohort study in Finland

Cancer is a significant cause of morbidity and mortality after solid organ transplantation (SOT) and related to lifelong immunosuppression. This retrospective registry study assessed for the first time in Finland population‐based cancer risk and cancer mortality after all SOTs (lung and childhood transplantations included) as standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs). Data from transplant registries were linked with the data of Finnish Cancer Registry and Statistics Finland. We followed 6548 consecutive first SOT recipients from 1 January 1987 to 31 December 2016 translating to 66 741 person‐years (median follow‐up time 8.9 years [interquartile range 4.0‐15.1]). In total, 2096 cancers were found in 1483 patients (23% of all patients). Majority of cancers (53%) were nonmelanoma skin cancers (NMSCs). The overall SIR was 3.6 (95% confidence interval [CI]: 3.5‐3.8) and the SIR excluding NMSCs was 2.2 (95% CI: 2.0‐2.3). SIR for all cancers was highest for heart (5.0) and lowest for liver (2.7) recipients. Most common cancer types after NMSCs were non‐Hodgkin lymphoma (NHL), SIR 9.9 (95% CI: 8.5‐11.4) and kidney cancer, SIR 7.3 (95% CI: 6.0‐8.8). Cancer‐related deaths were 17% (n = 408) of all deaths after first month post transplantation. SMR for all cancers was 2.5 (95% CI: 2.2‐2.7) and for NHL 13.6 (95% CI: 10.7‐16.8). Notably, overall SIR for cancer was lower in later period (2000‐2016), 3.0 (95% CI: 2.8‐3.2), than in earlier period (1987‐1999), 4.3 (95% CI: 4.0‐4.5), P < .001. Decrease in cancer incidence was temporally associated with major changes in immunosuppression in the 2000s.

Desmoid tumour of the chest wall in paediatric post-operatory of heart transplant

We will report a case of a desmoid tumour (DT), which developed at the surgical site of the pacemaker after a late childhood heart transplant. Patients with idiopathic dilated cardiomyopathy followed up in the paediatric cardiology service. It evolved with the dissociation of ventricular rhythm caused by severe heart failure, which led to the implantation of a cardiac resynchronization device prior to heart transplantation. The progression to end-stage heart disease culminated in a heart transplant at 12 years old. One year after the transplant, at the age of 13 years, he presented a progressively growing mass on the generator site of the resynchronization device. The initial decision was to remove the device. During the removal surgery, there was no haematoma or fluid collection. However, there was a progression of the lesion. The lesion was biopsied with the anatomopathological diagnosis of a DT. Resection surgery happened 4 months after the start of the mass growth. At that time, the tumour reached 20 cm in diameter. The lesion infiltrated the pectoralis major muscle and this muscle was resected partially en bloc with the lesion. The defect had primary closure. The patient evolved without postoperative complications and was discharged on the 14th postoperative day. The surgical specimen came with negative circumferential margins. However, the deep margin was microscopically positive. Due to deep involvement, the patient underwent adjuvant radiotherapy. Currently, the patient is under clinical follow-up and has no evidence of tumour recurrence. DT is a rare tumour, with unpredictable courses. Surgery can be considered in the progression of lesions. Treatment is justified by long survival after a heart transplant and in DT patients. DT is a differential diagnosis to be considered in progressive growth lesions.

Current trends in candidate selection, contraindications, and indications for lung transplantation

Lung transplantation is an established treatment option that can improve quality of life and prolong survival for select patients diagnosed with end-stage lung disease. Given the gaps in organ donation and failures to make effective use of available organs, careful selection of candidates for lung transplant remains one of the most important considerations of the transplant community. Toward this end, we briefly reviewed recent trends in pretransplant evaluation, candidate selection, organ allocation, and organ preservation techniques. Since the latest consensus statement regarding appropriate selection of lung transplant candidates, many advances in the science and practice of lung transplantation have emerged and influenced our perspective of 'contraindications' to transplant. These advances have made it increasingly possible to pursue lung transplant in patients with risk factors for decreased survival-namely, older recipient age, increased body mass index, previous chest surgery, poorer nutritional status, and presence of chronic infection, cardiovascular disease, or extrapulmonary comorbid conditions. Therefore, we reviewed the updated evidence demonstrating the prognostic impact of these risk factors in lung transplant recipients. Lastly, we reviewed the salient evidence for current trends in disease-specific indications for lung transplantation, such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, emphysema due to alpha-1 antitrypsin deficiency, and pulmonary arterial hypertension, among other less common end-stage diseases. Overall, lung transplant remains an exciting field with considerable hope for patients as they experience remarkable improvements in quality of life and survival in the modern era.

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.

The Role of CTLA4 and Its Polymorphisms in Solid Organ and Haematopoietic Stem Cell Transplantation

HLA matching, transplantation technique, or underlying disease greatly influences the probability of long-term transplantation success. It has been hypothesised that genetic variation affecting antigen presentation also contributes to the outcomes of both solid organ transplantation and allogeneic haematopoietic stem cell transplantation (AHSCT). Those genes, along with those responsible for innate and adaptive immunity, have become targets of investigation. In this review, we focus on the role of CTLA4 in the process of acute graft rejection and summarise the progress in our understanding of its role in predicting the outcome. We present the results of the latest studies investigating the link between CTLA4 gene variability and AHSCT, as well as organ transplantation outcomes. While some studies found a link between +49 A/G and −318 C/T and transplantation outcomes, comprehensive meta-analyses have failed to present any association. The most recent field reviews suggest that the −1772 T/C (rs733618) CC genotype is weakly associated with a lower risk of acute graft rejection, while +49 A/G might be clinically meaningful when investigated in the context of combinations with other polymorphisms. Studies verifying associations between 12 CTLA4 gene SNPs and AHSCT outcomes present inexplicit results. Some of the most commonly studied polymorphisms in this context include +49 A/G (rs231775) and CT60 A/G (rs3087243). The results signify that, in order to understand the role of CTLA4 and its gene polymorphisms in transplantology, further studies must be conducted.

The role of radiotherapy in patients with solid tumours after solid organ transplantation: a systematic review

For patients diagnosed with cancer who have previously received an organ transplant, radiotherapy represents a challenging clinical scenario without well established care algorithms. Immunosuppressive therapy can be a cause for concern among clinicians treating this category of patients. Potential immune modulation following irradiation could affect recipient organ tolerance and the outcomes of the transplantation itself. The main aim of this systematic review was to define the safety and effectiveness of radiotherapy in patients diagnosed with cancer who have previously received an organ transplant. We searched PubMed and Embase for articles published between Jan 1, 1995, and April 30, 2020 for studies in patients who had undergone radiotherapy for post-transplantation malignancies. The Review is framed by the PICO (population, intervention, control, and outcomes) criteria, and primarily focuses on modern treatment techniques.

Role of surgery in treating epstein-barr virus-associated smooth muscle tumor (EBV-SMT) with central nervous system invasion: A systemic review from 1997 to 2019

Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) is a rare mesenchymal tumor occurred almost exclusively in immunocompromised hosts. This article provides a systematic review of literature under PRISMA guideline on clinical features, treatment modalities, roles of surgical intervention, and outcomes of all 65 reported EBV-SMTs with central nervous system (CNS) invasion. Over 95% of reported cases were immunocompromised, while human immunodeficiency virus infection and post-organ transplantation were the most commonly associated underlying causes (near 90%). Despite a heterogeneous follow-up period, a 1-year survival rate of 76.0% and 5-year survival rate of 59.6% may support the indolent and non-deadly nature of EBV-SMT even with CNS invasion. Immune survey and reconstruction should be conducted for every patient with CNS EBV-SMT. Surgical resection is mostly adopted as primary treatment to obtain diagnosis and relieve compressive effect. A total resection of tumor may be beneficial if tumor was symptomatic and had intracranial invasion.

Acute renal transplant rejection following nivolumab therapy for metastatic melanoma

Cancers can develop the ability to evade immune recognition and destruction. Immune checkpoint inhibitors (ICIs) are drugs targeting these immune evasion mechanisms. ICIs have significantly improved outcomes in several cancers including metastatic melanoma. However, data on toxicities associated with allograft transplant recipients receiving ICI is limited. We describe a case of a 71-year-old woman who was diagnosed with metastatic melanoma 13 years after renal transplantation. She was commenced on the ICI nivolumab. She developed acute renal transplant rejection 15 days after administration of the first dose. She continues on haemodialysis but has demonstrated complete oncological response. This case demonstrates the risk of acute renal transplant rejection versus improved oncological outcomes. Patients and clinicians must consider this balance when initiating ICI therapy in allograft transplant recipients. Patients should be fully consented of the potential consequences of acute renal transplant rejection including lifelong dialysis.

Intratumoral immunotherapy with anti-PD-1 and TLR9 agonist induces systemic antitumor immunity without accelerating rejection of cardiac allografts

Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) blockades, have revolutionized the field of cancer immunotherapy. However, there is a growing concern whether PD-1 inhibitors can be administered safely to transplant recipients with advanced cancer, as the T cells activated by checkpoint inhibitors may become reactive not only toward tumor antigens but also toward donor alloantigen, thereby resulting in allograft rejection. Here, immunotherapy with anti-PD-1/toll like receptor 9 agonist was administered to C57BL/6 mice bearing a cardiac allograft that were receiving maintenance immunosuppression or a PI4KIIIβ inhibitor-based tolerogenic regimen. Intratumoral (i.t.), but not systemic, immunotherapy promoted potent anti-tumor responses, but did not accelerate allograft rejection. This effect was associated with a pro-immunogenic effect induced by i.t. immunotherapy resulting in systemic cellular and humoral immune anti-tumor responses. Furthermore, when the tumor and cardiac allograft shared major histocompatibility complex (MHC) antigens, i.t. immunotherapy promoted immune responses directed against tumor and the cardiac allograft resulting in allograft rejection. The anti-tumor effect was compromised by maintenance immunosuppression with cyclosporin A, indicating that an optimal balance between enhanced anti-tumor immunity and decreased transplant immunoreactivity is critical. A clinically relevant approach could be to temporarily withdraw maintenance immunosuppression and/or replace it with a PI4KIIIβ inhibitor-based tolerance-inducing regimen to allow for effective immunotherapy to take place.

The clinical and pathological features of plasma cell myeloma post solid organ transplantation

Plasma cell neoplasms (PCNs), comprising plasma cell myelomas (PCMs) and plasmacytomas, which occur after solid organ transplantation, represent rare subtypes of monomorphic post-transplant lymphoproliferative disorders (M-PTLDs). Data regarding the clinical and pathological features of post-transplant (PT)-PCMs are limited. To gain a better understanding of disease biology, we performed comprehensive immunophenotypic analysis, reviewed cytogenetic analysis results and evaluated clinical outcomes of PT-PCMs diagnosed and treated at our institution. Fifteen PT-PCM (M: F - 4:1) and two PT-MGUS (two males) cases were identified. The median age of PT-PCM patients was 68 years (29-79 years) and PCMs presented at a median of 9.7 years (0.5-24.7 years) after transplantation. The PT-PCMs accounted for 11.6% of all M-PTLDs and the period prevalence was 9/3108 (0.29%), 3/1071 (0.28%), 2/1345 (0.15%) and 1/878 (0.11%) post kidney, heart, liver and lung transplantation. Lytic bone disease was observed in 1/11 (9%) patients. Marrow plasma cell infiltration ranged from 10%-70% (median 20%), with 10/15 (67%) and 5/15 (33%) cases manifesting immature and plasmablastic morphology. The immunophenotype of all cases and cytogenetic abnormalities, identified in 60% of cases, were similar to multiple myeloma (MM) of immunocompetent individuals. All PT-PCMs were EBER negative. Ten of 11 (91%) patients with active MM were treated, all with proteasome inhibitor-based therapy. Treatment response and 5-year overall survival (54.5%) was comparable to MM of immunocompetent individuals. However, the survival of patients with plasmablastic PCMs was inferior to those with immature PCMs. 0ur findings indicate PT-PCMs to be predominantly late onset PTLDs that have similar clinicopathologic characteristics as conventional MM.

Heart transplantation in patients with localized prostate cancer-Are we denying a life-saving therapy due to an indolent tumor?

BACKGROUND

Prostate cancer (PC) is the most common non-cutaneous cancer in men. Approximately 90% of these cancers are localized (LPC) with a cancer-specific survival rate of 99% at 10 years. Some heart transplant centers (HTCs) regard PC as an absolute contraindication to heart transplantation (HT). This study aims to understand the current status of HT in patients with advanced heart failure (AHF) and concurrent LPC in the United States.

METHODS

Adult HTCs in the United States were asked to fill out an email questionnaire addressing their current approach to HT in AHF patients with concurrent LPC.

RESULTS

Fifty of the 90 HTCs that received the questionnaire responded. Only 16% of HTCs had a formal policy regarding HT in patients with LPC, while only 10% had patients with LPC on the HT waitlist at the time of the survey. Overall, 84% of the HTCs had never performed HT in a patient with LPC in the history of their transplant program.

CONCLUSION

An overwhelming majority of HTCs in the United States do not consider HT an option for AHF patients with concurrent LPC and lack a formal policy regarding the same.

Donor-specific chimeric antigen receptor Tregs limit rejection in naive but not sensitized allograft recipients

Cell therapy with autologous donor-specific regulatory T cells (Tregs) is a promising strategy to minimize immunosuppression in transplant recipients. Chimeric antigen receptor (CAR) technology has recently been used successfully to generate donor-specific Tregs and overcome the limitations of enrichment protocols based on repetitive stimulations with alloantigens. However, the ability of CAR-Treg therapy to control alloreactivity in immunocompetent recipients is unknown. We first analyzed the effect of donor-specific CAR Tregs on alloreactivity in naive, immunocompetent mice receiving skin allografts. Tregs expressing an irrelevant or anti-HLA-A2-specific CAR were administered to Bl/6 mice at the time of transplanting an HLA-A2⁺ Bl/6 skin graft. Donor-specific CAR-Tregs, but not irrelevant-CAR Tregs, significantly delayed skin rejection and diminished donor-specific antibodies (DSAs) and frequencies of DSA-secreting B cells. Donor-specific CAR-Treg-treated mice also had a weaker recall DSA response, but normal responses to an irrelevant antigen, demonstrating antigen-specific suppression. When donor-specific CAR Tregs were tested in HLA-A2-sensitized mice, they were unable to delay allograft rejection or diminish DSAs. The finding that donor-specific CAR-Tregs restrain de novo but not memory alloreactivity has important implications for their use as an adoptive cell therapy in transplantation.

Malignancy after lung transplantation

Lung transplantation is an established therapeutic option for selected patients with advanced lung diseases. As early outcomes after lung transplantation have improved, chronic medical illnesses have emerged as significant obstacles to long-term survival. Among them is post-transplant malignancy, currently representing the 2^nd most common cause of death 5–10 years after transplantation. Chronic immunosuppressive therapy and resulting impairment of anti-tumor immune surveillance is thought to have a central role in cancer development after solid organ transplantation (SOT). Lung transplant recipients receive more immunosuppression than other SOT populations, likely contributing to even higher risk of cancer among this group. The most common cancers in lung transplant recipients are non-melanoma skin cancers, followed by lung cancer and post-transplant lymphoproliferative disorder (PTLD). The purpose of this review is to outline the common malignancies following lung transplant, their risk factors, prognosis and current means for both prevention and treatment.

Bilateral Nephrectomy for Adult Polycystic Kidney Disease Does Not Affect the Graft Function of Transplant Patients and Does Not Result in Sensitisation

BACKGROUND

Native nephrectomy in Adult Polycystic Kidney Disease (ADPKD) patients is a major operation with controversy related to timing and indications. We present our single centre experience in transplanted patients and future candidates for transplantation.

METHODS

Retrospective analysis from an anonymised database of bilateral nephrectomies for ADPKD patients. Results were reported as median, range, and percentage. Differences between groups were tested using ANOVA and t-test. Surgery was performed between January 2012 and July 2018.

RESULTS

Thirty-three patients underwent bilateral native nephrectomy for APKD. 18 had a functioning kidney transplant (transplant group, 55%) while 15 patients were on dialysis (dialysis group, 45%) at the time of surgery; 8 patients of the latter group (24% of the whole cohort) were eventually transplanted. 53% were males, with median age of 55 years (27-71). Indications to surgery were the following: space (symptoms related to the size of the native kidneys or need to create space for transplantation) (59%), recurrent cyst infection (36%), haematuria (15%), pain (24%), and weight loss associated with cystic alteration on imaging (3%). In the transplant group, postoperative kidney function was not affected; haemoglobin serum levels significantly dropped in the whole cohort: 121 (82-150) g/L, versus 108 (58-154) g/L (p<0.001), with 14 patients being transfused perioperatively. Elevation of anti-HLA antibodies was noted in one female patient on dialysis, with no change in DSA levels and no rejection after transplant for all 26 transplanted patients. Median postoperative length of hospital stay was 9 days (6-71). One patient died (3%) after six months. Median follow-up for the whole cohort was 282 days (13-1834). Histopathological examination revealed incidental renal neoplasms in five cases (15%): 1 pT1a papillary renal cell carcinoma and 4 papillary adenomas.

CONCLUSIONS

Native nephrectomy for ADPKD could be safely performed in case of refractory symptoms, suspect of cancer or to create space for transplantation. It does not affect graft function or DSA status of transplanted patients or the prospect of transplantation of those on the waiting list.

Programmed Cell Death 1 (PD-1) Inhibitors in Renal Transplant Patients with Advanced Cancer: A Double-Edged Sword?

Given advancements in cancer immunity, cancer treatment has gained breakthrough developments. Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) inhibitors, are the most promising drugs in the field and have been approved to treat various types of cancer, such as metastatic melanoma, head and neck squamous cell carcinoma, and urothelial carcinoma. However, whether PD-1 inhibitors should be administered to renal transplant patients with advanced cancer remains unclear because the T-cells produced after administration of these inhibitors act against not only tumor antigens but also donor alloantigens. Thus, the use of PD-1 inhibitors in kidney-transplanted patients with advanced cancer is limited on account of the high risk of graft failure due to acute rejection. Hence, finding optimal treatment regimens to enhance the tumor-specific T-cell response and decrease T-cell-mediated alloreactivity after administration of a PD-1 inhibitor is necessary. Thus far, no recommendations for the use of PD-1 inhibitors to treat cancer in renal transplant patients are yet available, and very few cases reporting kidney-transplanted patients treated with PD-1 inhibitors are available in the literature. Therefore, in this work, we review the published cases and suggest feasible approaches for renal transplant patients with advanced malignancy treated by a PD-1 inhibitor. Of the 22 cases we obtained, four patients maintained intact grafts without tumor progression after treatment with a PD-1 inhibitor. Among these patients, one maintained steroid dose before initiation of anti-PD1, two received immunosuppressive regimens with low-dose steroid and calcineurin inhibitor (CNI)-elimination with sirolimus before initiation of anti-PD-1 therapy, and one received combined anti-PD-1, anti-vascular endothelial growth factor (VEGF), and chemotherapy with unchanged immunosuppressive regimens. mammalian target of rapamycin (mTOR) inhibitors and anti-VEGF may act as regulators of tumor-specific and allogenic T-cells. However, more studies are necessary to explore the optimal therapy and ensure the safety and efficacy of PD-1 inhibitors in kidney-transplanted patients.

Dissecting the Multiplicity of Immune Effects of Immunosuppressive Drugs to Better Predict the Risk of de novo Malignancies in Solid Organ Transplant Patients

De novo malignancies constitute an emerging cause of morbidity after solid organ transplant (SOT), significantly affecting the long-term survival of transplant recipients. Pharmacologic immunosuppression may functionally impair the immunosurveillance in these patients, thereby increasing the risk of cancer development. Nevertheless, the multiplicity and heterogeneity of the immune effects induced by immunosuppressive drugs limit the current possibilities to reliably predict the risk of de novo malignancy in SOT patients. Therefore, there is the pressing need to better characterize the immune dysfunctions induced by the different immunosuppressive regimens administered to prevent allograft rejection to tailor more precisely the therapeutic schedule and decrease the risk of de novo malignancies. We herein highlight the impact exerted by different classes of immunosuppressants on the most relevant immune cells, with a particular focus on the effects on dendritic cells (DCs), the main regulators of the balance between immunosurveillance and tolerance.

Promoting vascularization for tissue engineering constructs: current strategies focusing on HIF-regulating scaffolds

INTRODUCTION

Vascularization remains one of the greatest yet unmet challenges in tissue engineering. When engineered tissues are scaled up to therapeutically relevant dimensions, their demand of oxygen and nutrients can no longer be met by diffusion. Thus, there is a need for perfusable vascular structures. Hypoxia-inducible factors (HIF) act as transcriptional oxygen sensors and regulate a multitude of genes involved in adaptive processes to hypoxia, including angiogenesis. Thus, targeting HIFs is a promising strategy to induce vascularization of engineered tissues.

AREAS COVERED

Here we review current vascularization strategies and summarize the present knowledge regarding activation of HIF signaling by ions, iron chelating agents, α-Ketoglutarate (αKG) analogues, and the lipid-lowering drug simvastatin to induce angiogenesis. Specifically, we focus on the incorporation of HIF-activating agents into biomaterials and scaffolds for controlled release.

EXPERT OPINION

Vascularization of tissue constructs through activation of upstream regulators of angiogenesis offers advantages but also suffers from drawbacks. HIFs can induce a complete angiogenic program; however, this program appears to be too slow to vascularize larger constructs before cell death occurs. It is therefore crucial that HIF-activation is combined with cell protective strategies and prevascularization techniques to obtain fully vascularized, vital tissues of therapeutically relevant dimensions.