Real-world evidence of the safety and survival with CD19 CAR-T cell therapy for relapsed/refractory solid organ transplant-related PTLD

Genetic and immunological features of immune deficiency and dysregulation-associated lymphoproliferations and lymphomas as a basis for classification

Immune deficiency and dysregulation-associated lymphoproliferative disorders and lymphomas (IDD-LPDs) encompass a heterogeneous clinical and pathological spectrum of disorders that range from indolent lymphoproliferations to aggressive lymphomas. They arise in a variety of clinical settings and are associated with oncogenic viruses such as the Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus/human herpes virus (KSHV/HHV8) in some, but not all, cases. The recognition of IDD-LPDs as distinct from LPDs in immune competent patients is essential to tailor clinical management options for affected patients. The 5th edition of the World Health Organisation classification has introduced an integrated classification of IDD-LPDs with the goal of standardising diagnoses among different settings to enhance clinical decision support. In parallel, new knowledge in the field, particularly surrounding the role of oncogenic viruses and the tumour microenvironment, has led to clearer understanding of the complex pathogenesis of IDD-LPDs and how these features can be precisely harnessed for therapeutic purposes. In this perspective, we highlight the need for multidisciplinary decision-making to augment patient care as well as key areas where evolving concepts offer challenges and opportunities for clinical management, research and future iterations of the classification.

Applications of cell therapy in the treatment of virus-associated cancers

A diverse range of viruses have well-established roles as the primary driver of oncogenesis in various haematological malignancies and solid tumours. Indeed, estimates suggest that approximately 1.5 million patients annually are diagnosed with virus-related cancers. The predominant human oncoviruses include Epstein-Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV), hepatitis B and C viruses (HBV and HCV), human papillomavirus (HPV), human T-lymphotropic virus type 1 (HTLV1), and Merkel cell polyomavirus (MCPyV). In addition, although not inherently oncogenic, human immunodeficiency virus (HIV) is associated with immunosuppression that contributes to the development of AIDS-defining cancers (specifically, Kaposi sarcoma, aggressive B cell non-Hodgkin lymphoma and cervical cancer). Given that an adaptive T cell-mediated immune response is crucial for the control of viral infections, increasing research is being focused on evaluating virus-specific T cell therapies for the treatment of virus-associated cancers. In this Review, we briefly outline the roles of viruses in the pathogenesis of these malignancies before describing progress to date in the field of virus-specific T cell therapy and evaluating the potential utility of these therapies to treat or possibly even prevent virus-related malignancies.

Cancer Screening and Cancer Treatment in Kidney Transplant Recipients

As the population ages and post-transplant survival improves, pretransplant and post-transplant malignancy are becoming increasingly common. In addition, rapid advances in cancer therapies and improving outcomes prompt us to rethink pretransplant cancer-free wait time and screening strategies. Although kidney transplant recipients (KTRs) are at higher risk of developing cancer, epidemiological data on how to best screen and treat cancers in KTRs are incomplete. Thus, current recommendations are still largely on the basis of studies in the general population, and their validity in KTRs is uncertain. Kidney transplant candidates without prior cancer should be evaluated for latent malignancies even in the absence of symptoms. Conversely, individuals with a history of malignancy require thorough monitoring to detect potential recurrences or de novo malignancies. When treating KTRs with cancer, reducing immunosuppression can enhance antitumor immunity, yet this also increases the risk of graft rejection. Optimal treatment and immunosuppression management remains undefined. As the emergence of novel cancer therapies adds complexity to this challenge, individualized risk-benefit assessment is crucial. In this review, we discuss up-to-date data on pretransplant screening and cancer-free wait time, as well as post-transplant cancer screening, prevention strategies, and treatment, including novel therapies such as immune checkpoint inhibitors and chimeric antigen receptor T-cell therapies.

Virus-specific T cell therapy to treat refractory viral infections in solid organ transplant recipients

Solid organ transplant recipients require ongoing immunosuppression to prevent acute rejection, which puts them at risk of opportunistic infections. Viral infections are particularly challenging to prevent and treat as many establish latency and thus cannot be eliminated, whereas targets for small molecule antiviral medications are limited. Resistance to antivirals and unacceptable toxicity also complicate treatment. Virus-specific T cell therapies aim to restore host-specific immunity to opportunistic viruses that is lacking due to ongoing immunosuppressive therapy. This minireview will provide a state-of-the-art update of the current virus-specific T cell pipeline and translational research that is likely to lead to further treatment options for viral infections in solid organ transplant recipients.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Role of Radiology in Assessment of Postoperative Complications of Heart Transplantation

Heart transplantation is a pivotal treatment of end-stage heart failure, and recent advancements have extended median posttransplant life expectancy. However, despite the progress in surgical techniques and medical treatment, heart transplant patients still face complications such as rejection, infections, and drug toxicity. CT is a reliable tool for detecting most of these complications, whereas MR imaging is particularly adept at identifying pericardial pathologies and signs of rejection. Awareness of these nuances by radiologists, cardiologists, and surgeons is desired to optimize care, reduce morbidities, and enhance survival.

Successful Treatment of Refractory Post-Transplant Lymphoproliferative Disorder With Chimeric Antigen Receptor T-Cell Therapy in a Heart Transplant Recipient

Post-transplant lymphoproliferative disorders (PTLDs) are opportunistic malignancies that complicate the success of hematopoietic stem cell or solid organ transplantation. These disorders often arise post-transplant due to the immunosuppression required for minimizing the risk of rejection of donor tissue. First-line treatment of these disorders includes limiting immunosuppression when permissible. Subsequent treatment includes the use of monoclonal anti-CD20 antibody (rituximab), and/or combination chemotherapy. Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment paradigm in many lymphoid malignancies. It is not approved for PTLD due to exclusion of PTLD patients from pivotal clinical trials. Also, its utilization post-transplant can be complex and multidisciplinary care is of utmost importance for successful administration of a potentially curative treatment. We present a 68-year-old patient with history of heart transplant for non-ischemic cardiomyopathy, diagnosed with PTLD that was refractory to treatment using current guidelines until successfully receiving CAR T-cell therapy.

Post-transplant lymphoproliferative disorders following kidney transplantation: A literature review with updates on risk factors, prognostic indices, screening strategies, treatment and analysis of donor type

Post-transplant lymphoproliferative disorders (PTLD) is a devastating complication of kidney transplantation with an insidious presentation and potential to disseminate aggressively. This review delineates the risk factors, prognostic indexes, screening, current management algorithm and promising treatment strategies for PTLD. Kidneys from both extended criteria donors (ECD) and living donors (LD) are being increasingly used to expand the donor pool. This review also delineates whether PTLD outcomes vary based on these donor sources. While Epstein-Barr virus (EBV) is a well-known risk factor for PTLD development, the use of T-cell depleting induction agents has been increasingly implicated in aggressive, monomorphic forms of PTLD. Research regarding maintenance therapy is sparse. The international prognostic index seems to be the most validate prognostic tool. Screening for PTLD is controversial, as annual PET-CT is most sensitive but costly, while targeted monitoring of EBV-seronegative patients was more economically feasible, is recommended by the American Society of Transplantation, but is limited to a subset of the population. Other screening strategies such as using Immunoglobulin/T-cell receptor require further validation. A risk-stratified approach is taken in the treatment of PTLD. The first step is the reduction of immunosuppressants, after which rituximab and chemotherapy may be introduced if unsuccessful. Some novel treatments have also shown potential benefit in studies: brentuximab vedotin, chimeric antigen receptor T-cell therapy and EBV-specific cytotoxic T lymphocytes. Analysis of LD v DD recipients show no significant difference in incidence and mortality of PTLD but did reveal a shortened time to development of PTLD from transplant. Analysis of SCD vs ECD recipients show a higher incidence of PTLD in the ECD group, which might be attributed to longer time on dialysis for these patients, age, and the pro-inflammatory nature of these organs. However, incidence of PTLD overall is still extremely low. Efforts should be focused on optimising recipients instead. Minimising the use of T-cell depleting therapy while encouraging research on the effect of new immunosuppressants on PTLD, screening for EBV status are essential, while enabling shared decision-making during counselling when choosing kidney donor types and individualised risk tailoring are strongly advocated.

Case Report: Post-transplant lymphoproliferative disorder as a serious complication of vascularized composite allotransplantation

Vascularized composite allotransplantation (VCA) is an emerging field in transplant surgery. Despite overall positive outcomes, VCA confers risk for multiple complications related to the procedure and subsequent immunosuppression. Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoproliferative disorders occurring after solid organ and hematopoietic stem cell transplant. A patient with PTLD after bilateral upper extremity transplantation is presented as well as a review of all known cases of PTLD after VCA, with a focus on the unique epidemiology, presentation, and treatment in this population.

How I treat posttransplant lymphoproliferative disorder

Posttransplant lymphoproliferative disorder (PTLD) is an important and potentially life-threatening complication of solid organ transplant and hematopoietic stem cell transplant (HSCT). Given the heterogeneity of PTLD and the risk of infectious complications in patients with immunosuppression, the treatment of this disease remains challenging. Monomorphic PTLD and lymphoma of B-cell origin account for the majority of cases. Treatment strategies for PTLD consist of response-adapted, risk-stratified methods using immunosuppression reduction, immunotherapy, and/or chemotherapy. With this approach, ∼25% of the patients do not need chemotherapy. Outcomes for patients with high risk or those who do not respond to frontline therapies remain dismal, and novel treatments are needed in this setting. PTLD is associated with Epstein-Barr virus (EBV) infection in 60% to 80% of cases, making EBV-directed therapy an attractive treatment modality. Recently, the introduction of adoptive immunotherapies has become a promising option for refractory cases; hopefully, these treatment strategies can be used as earlier lines of therapy in the future.

Integrated genetic analyses of immunodeficiency-associated Epstein-Barr virus- (EBV) positive primary CNS lymphomas

Immunodeficiency-associated primary CNS lymphoma (PCNSL) represents a distinct clinicopathological entity, which is typically Epstein-Barr virus-positive (EBV+) and carries an inferior prognosis. Genetic alterations that characterize EBV-related CNS lymphomagenesis remain unclear precluding molecular classification and targeted therapies. In this study, a comprehensive genetic analysis of 22 EBV+ PCNSL, therefore, integrated clinical and pathological information with exome and RNA sequencing (RNASeq) data. EBV+ PCNSL with germline controls carried a median of 55 protein-coding single nucleotide variants (SNVs; range 24-217) and 2 insertions/deletions (range 0-22). Genetic landscape was largely shaped by aberrant somatic hypermutation with a median of 41.01% (range 31.79-53.49%) of SNVs mapping to its target motifs. Tumors lacked established SNVs (MYD88, CD79B, PIM1) and copy number variants (CDKN2A, HLA loss) driving EBV- PCNSL. Instead, EBV+ PCNSL were characterized by SOCS1 mutations (26%), predicted to disinhibit JAK/STAT signaling, and mutually exclusive gain-of-function NOTCH pathway SNVs (26%). Copy number gains were enriched on 11q23.3, a locus directly targeted for chromosomal aberrations by EBV, that includes SIK3 known to protect from cytotoxic T-cell responses. Losses covered 5q31.2 (STING), critical for sensing viral DNA, and 17q11 (NF1). Unsupervised clustering of RNASeq data revealed two distinct transcriptional groups, that shared strong expression of CD70 and IL1R2, previously linked to tolerogenic tumor microenvironments. Correspondingly, deconvolution of bulk RNASeq data revealed elevated M2-macrophage, T-regulatory cell, mast cell and monocyte fractions in EBV+ PCNSL. In addition to novel insights into the pathobiology of EBV+ PCNSL, the data provide the rationale for the exploration of targeted therapies including JAK-, NOTCH- and CD70-directed approaches.