A Systematic Review of Immune Checkpoint Inhibitor-Associated Glomerular Disease

Diagnosis and management of immune checkpoint inhibitor-associated nephrotoxicity: a position statement from the American Society of Onco-nephrology

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer and are now the backbone of therapy for several malignancies. However, ICIs can cause a spectrum of kidney immune-related adverse events including acute kidney injury (AKI), most commonly manifesting as acute interstitial nephritis (AIN), although glomerular disease and electrolyte disturbances have also been reported. In this position statement by the American Society of Onco-nephrology (ASON), we summarize the incidence and risk factors for ICI-AKI, pathophysiological mechanisms, and clinicopathologic features of ICI-AKI. We also discuss novel diagnostic approaches and promising biomarkers for ICI-AKI. From expert panel consensus, we provide clinical practice points for the initial assessment and diagnosis of ICI-AKI, management and immunosuppressive therapy, and consideration for rechallenge with ICI following AKI episodes. In addition, we explore ICI use in special populations, such as kidney transplant recipients, and propose key areas of focus for future research and clinical investigation.

SUrvey of renal Biopsy registry database and Anticancer dRUg therapy in Japan (SUBARU-J study)

Background

Kidney complications associated with anticancer drug therapy have greatly increased recently. We aimed to investigate the real-world clinical outcomes of anticancer drug therapy-associated renal complications in Japan using the national kidney biopsy database, Japan Renal Biopsy Registry (J-RBR).

Methods

From 2018 to 2021, 449 cases from 49 facilities identified as 'drug-induced' histopathology in the J-RBR were screened, of which a total of 135 were confirmed as anticancer drug-related cases and included in the analysis. Overall survival rates were estimated using the Kaplan-Meier method and compared by logrank test. The Cox regression model was used to evaluate the association between variables and deaths.

Results

The most common primary sites of malignancies were the lung (33.3%), followed by gastrointestinal (16.3%) and gynaecological (11.1%) cancers. Tubulointerstitial nephritis (TIN; 47.4%) and thrombotic microangiopathy (TMA; 35.6%) were the most frequent diagnoses. All immunoglobulin A nephropathy, minimal change disease and crescentic glomerulonephritis (CrGN) cases were immune checkpoint inhibitor related. All CrGN cases were anti-neutrophil cytoplasmic antibody negative. Antibiotics were most frequently used concomitantly with anticancer drugs in TMA cases among subgroups (TMA versus others: 62.5 versus 27.5%; P < .001). Among TMA cases, the serum lactate dehydrogenase level tended to be higher in cytotoxic agent-associated TMA (CTx-TMA) than in other TMAs, but was not significant between groups (415.5 versus 219.0 U/l; P = .06). Overall survival was worse in CTx-TMA than in other TMAs (P = .007). The Cox model demonstrated proton pump inhibitor (PPI) use (hazard ratio 2.49, P = .001) as a significant prognostic factor, as well as the presence of metastasis and serum albumin level.

Conclusions

Our registry analysis highlighted various presentations of biopsy-proven kidney complications associated with anticancer drug therapy. Clinicians should be aware of worse outcomes associated with CTx-TMA and the prognostic role of PPI use.

Bispecific Antibodies, Immune Checkpoint Inhibitors, and Antibody-Drug Conjugates Directing Antitumor Immune Responses: Challenges and Prospects

Tumor immunotherapy includes bispecific antibodies (BsAbs), immune checkpoint inhibitors (ICIs), vaccines, and adoptive cell immunotherapy. BsAbs belong to the family of antibodies that can specifically target two or more different antigens and are a promising option for tumor immunotherapy. Immune checkpoints are antibodies targeting PD-1, PD-L1, and CTLA4 and have demonstrated remarkable therapeutic efficacy in the treatment of hematological and solid tumors, whose combination therapies have been shown to synergistically enhance the antitumor effects of BsAbs. In addition, the clinical efficacy of existing monoclonal antibodies targeting PD-1 (e.g., ipilimumab, nivolumab, pembrolizumab, and cemiplimab) and PD-L1 (e.g., atezolizumab, avelumab, and durvalumab) could also be enhanced by conjugation to small drugs as antibody-drug conjugates (ADCs). The development of truly effective therapies for patients with treatment-resistant cancers can be achieved by optimizing the various components of ADCs.

Proteinuria following administration of immune check point inhibitor: a case-control observational study

PURPOSE

Proteinuria during treatment of immune checkpoint inhibitors (ICIs) was another renal adverse event besides from acute kidney injury. We aim to investigate the incidence and associated factors of proteinuria associated with ICIs.

METHOD

A case-control observational study about ICIs-treated cancer patients was conducted. Clinical and laboratory data at the baseline and during the follow-up was collected. Patients developed proteinuria during ICIs-treatment were classified to the proteinuria group.

RESULTS

Between March 2019 and August 2022, 440 patients were included in the study. Forty-eight patients (10.9%) developed proteinuria after ICIs-treatment. The occurrence of acute kidney injury between the proteinuria group and the control showed no difference[1(2.1%) vs. 9(2.3%), p = 1.000]. By multivariable logistic analysis, accumulative cycle of ICIs-administration (OR 1.079, 95% CI 1.033 to 1.127, p = 0.001) and comorbidity of liver cirrhosis (OR 2.198, 95% CI 1.082 to 4.468, p = 0.030) were associated with occurrence of proteinuria after ICIs-treatment independently.

CONCLUSIONS

Proteinuria could develop during the course of ICIs-therapy. Urinalysis should be monitored, especially for patients received multi-cycle of ICIs-administration and comorbid with liver cirrhosis.

A Case of Rapidly Progressive Glomerulonephritis Associated With Metastatic Melanoma

Pauci-immune glomerulonephritis is a rapidly progressive form of glomerulonephritis. It is distinguished from other rapidly progressive glomerular diseases by the lack of immune deposits seen on renal biopsy, hence the name "pauci-immune." We present a case of pauci-immune glomerulonephritis in a patient with a history of malignancy that was treated with chemotherapy. Notably, the presentation of kidney injury coincided with the discovery of a new metastasis. Prompt treatment of glomerulonephritis is critically important to preserve renal function, though the optimal treatment strategy may not be straightforward in a patient with coexisting malignancy. Ultimately, this case illustrates that collaboration between patients, medical teams, and families is needed to optimize treatment strategy in unique circumstances.

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.

PD-1 immunology in the kidneys: a growing relationship

In recent years, knowledge regarding immune regulation has expanded rapidly, and major advancements have been made in immunotherapy for immune-associated disorders, particularly cancer. The programmed cell death 1 (PD-1) pathway is a cornerstone in immune regulation. It comprises PD-1 and its ligands mediating immune tolerance mechanisms and immune homeostasis. Accumulating evidence demonstrates that the PD-1 axis has a crucial immunosuppressive role in the tumor microenvironment and autoimmune diseases. PD-1 receptors and ligands on immune cells and renal parenchymal cells aid in maintaining immunological homeostasis in the kidneys. Here, we present a comprehensive review of PD-1 immunology in various kidney disorders, including renal cell carcinoma, glomerulonephritis, kidney transplantation, renal aging, and renal immune-related adverse events secondary to PD-1 immunotherapy.

Managing Select Immune-Related Adverse Events in Patients Treated with Immune Checkpoint Inhibitors

The increased use of immune checkpoint inhibitors (ICIs) across cancer programs has created the need for standardized monitoring and management of immune-related adverse events (irAEs). Delayed recognition without appropriate treatment can have serious and life-threatening consequences. The management of irAEs presents a unique set of challenges that must be addressed at a multidisciplinary level. Although various national and international guidelines and working groups provide high-level recommendations for the management of irAEs, practical guidance is lacking. Furthermore, timely collaboration between specialists requires institutional protocols that enable the early recognition, assessment, and treatment of irAEs. Such protocols should be developed by institution specialists and include algorithms for all healthcare providers involved in the care of patients treated with ICIs. At William Osler Health System in Brampton, Ontario, practical step-by-step multidisciplinary treatment approaches with recommendations for the management of irAEs were developed in collaboration with experts across Canada. Here, we provide an in-depth description of the approaches, outlining baseline investigations prior to the initiation of ICIs, as well as the monitoring and management of irAEs based on symptoms, severity, and involved organ systems. We encourage other centres to adapt and modify our approaches according to their specific needs and requirements.

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.

Higher Risk of Proteinuria with Atezolizumab plus Bevacizumab than Lenvatinib in First-Line Systemic Treatment for Hepatocellular Carcinoma

Introduction: Proteinuria presents a challenging complication during systemic therapy for hepatocellular carcinoma (HCC). This study aims to identify risk factors for proteinuria in patients with HCC treated with atezolizumab plus bevacizumab (Atezo/Bev) or lenvatinib (LEN) as first-line systemic treatment. Methods: A retrospective analysis was conducted on 622 consecutive patients with unresectable HCC who received Atezo/Bev or LEN as first-line systemic treatment between October 2013 and October 2022. Cumulative incidence of proteinuria was estimated using Kaplan-Meier curves and compared using log-rank tests. Risk factors for proteinuria were identified using Cox proportional-hazard models, along with propensity score-matched and subgroup analyses. Results: Among 367 patients treated with Atezo/Bev and 255 with LEN, the cumulative incidence of proteinuria at 12 months was 27.5%. In the multivariable analysis, Atezo/Bev treatment (adjusted HR [aHR]: 1.57; 95% CI: 1.03–2.42), diabetes (aHR: 1.64; 95% CI: 1.03–2.61), hypertension (aHR: 2.27; 95% CI: 1.04–4.97), Child-Pugh class B (aHR: 3.43; 95% CI: 1.34–8.78), macrovascular invasion (MVI; aHR: 1.58; 95% CI: 1.04–2.38), and an estimated glomerular filtration rate ≤60 mL/min/1.73 m2 (aHR: 3.21; 95% CI: 1.84–5.62) were identified as risk factors for proteinuria. A higher risk of proteinuria in Atezo/Bev patients compared with LEN was consistently observed in the PS-matched cohort, particularly pronounced in subgroups with MVI (HR: 2.84; 95% CI: 1.23–6.54) compared with those without MVI (HR: 1.31; 95% CI: 0.69–2.47). Conclusions: Patients treated with Atezo/Bev as first-line systemic treatment for HCC exhibited a higher risk of proteinuria compared with those with LEN, particularly when accompanied by MVI.

Nivolumab-associated IgA Nephropathy in a Child With Malignant Melanoma

Immune checkpoint inhibitors are humanized antibodies that inhibit downregulatory receptors on T cells, enhancing the antitumor activity of these cells. However, they have been associated with a wide range of systemic immune-related adverse events, including renal toxicities, among others. Most renal immune-related adverse events are acute interstitial nephritis causing acute kidney injury. Recently, immune checkpoint inhibitors-associated glomerular diseases, including IgA nephropathy, have been reported in adults. Most of the adult cases with glomerular involvement had also concomitant acute interstitial nephritis and acute kidney injury. We present the first pediatric case of IgA nephropathy without acute kidney injury during nivolumab treatment.

Two acute kidney injury episodes after ICI therapy: a case report

A 74-year-old Japanese male with lung squamous cell carcinoma received his first dose of immune checkpoint inhibitors (ICIs): ipilimumab and nivolumab. He developed acute kidney injury (AKI) and was admitted to our department. We diagnosed kidney immune-related adverse effects (irAE), and a kidney biopsy revealed acute tubulointerstitial nephritis. We started oral prednisolone (PSL) and his AKI immediately improved. The patient maintained stable findings after PSL was tapered off. However, seven months after the ICI administration, he developed rapid progressive glomerular nephritis and was admitted to our department again. The second kidney biopsy showed findings consistent with anti-glomerular basement membrane glomerulonephritis. Although the patient was treated with pulse methylprednisolone followed by oral PSL and plasma exchange, he became dependent on maintenance hemodialysis. To our knowledge, no case report has described two different types of biopsy-proven nephritis. In cases of suspected relapsing kidney irAEs, both a relapse of previous nephritis and the development of another type of nephritis should be considered.

Clinical features associated with immune checkpoint inhibitor nephritis: a single-center clinical case series

BACKGROUND

Acute kidney injury (AKI) has been well described as a complication of immune checkpoint inhibitor therapy. We present a series of patients, the majority with lung adenocarcinoma, who developed AKI while actively receiving immune checkpoint inhibitors.

METHODS

This is a retrospectively analyzed clinical case series of six patients treated at City of Hope Comprehensive Cancer Center. Data were collected on gender, age, ethnicity, comorbidities, concomitant medications, type of malignancy, treatments, and renal function. All patients underwent renal biopsy for classification of the mechanism of AKI. Comprehensive genomic profiling (CGP) was performed on tumor tissue for all patients.

RESULTS

Patterns of AKI included acute interstitial nephritis and acute tubular necrosis. Contributing factors included the use of concomitant medications known to contribute to AKI. All but two patients had full resolution of the AKI with the use of steroids. There were several mutations found on CGP that was notable including an Exon 20 insertion as well as multiple NF1 and TP53 mutations. There was high PD-L1 expression on tumor tissue noted in two out of six patients. In addition to AKI, a subset of patients had proteinuria with biopsies revealing corresponding glomerular lesions of minimal change disease and focal and segmental glomerulosclerosis.

CONCLUSIONS

Our case series demonstrates that AKI from immune checkpoint inhibitors has a variable presentation that may require an individualized treatment approach. Further studies are needed to identify biomarkers that may help identify those at risk and guide the management of this condition.

Paraneoplastic Syndrome After Kidney Transplantation: Frequency, Risk Factors, Differences to Paraneoplastic Occurrence of Glomerulonephritis in the Native Kidney, and Implications on Long-Term Kidney Graft Function

Posttransplant malignancies are an important complication of solid organ transplantation. Kidney transplant recipients are at particularly high risk of cancer development. The most relevant risk factors of carcinogenesis are the use of immunosuppressive agents and oncogenic viral infections. Additionally, immune dysregulation caused by these factors may predispose to various types of organ damage. Paraneoplastic glomerular diseases are one of the most interesting and understudied cancer manifestations. The appropriate diagnosis of paraneoplastic glomerular damage can be challenging in kidney transplant recipients, due to factors inherent to concomitant medication and common comorbidities. Recent advances in the field of molecular and clinical nephrology led to a significant improvement in our understanding of glomerular diseases and their more targeted treatment. On the other hand, introduction of novel anticancer drugs tremendously increased patients' survival, at the cost of kidney-related side effects. Our review aims to provide insights into diagnosis and treatment of paraneoplastic glomerular diseases, with a special attention to kidney transplant recipients.

Minimal Change Disease

Minimal change disease represents a common cause of nephrotic syndrome in both pediatric and adult patients. Although much remains to be discovered, there have been significant recent advancements in our understanding of the pathophysiology of minimal change disease, including the discovery of antinephrin antibodies as a marker for diagnosis of disease. Here we will review what is known about the pathophysiology, treatment, and prognosis of minimal change disease and the differences between pediatric and adult patients. Recent advances in our understanding of the mechanisms of disease will be noted. We will discuss how this may change the treatment of minimal change disease going forward and what remains to be studied.

Immune checkpoint inhibitors and renal toxicity

Immune checkpoint inhibitors (ICIs) have transformed the management of a broad spectrum of cancers as metastatic melanoma, non-small lung cancer or renal cell carcinoma. These humanized monoclonal antibodies target immune-regulatory receptors expressed on T lymphocytes, antigen presenting cells and tumor cells and induce an immunological anti-tumor response. If on the one hand these molecules have led to considerable improvement in survival outcomes, on the other hand these therapies can be associated with immune-related adverse effects (irAEs). While these side effects have become well known, the best diagnostic and therapeutic approaches are still under investigation. The authors discuss pathophysiology, clinical presentation and histological features of ICIs renal toxicity. Furthermore, we focus on kidney transplant (KT) recipients, including the therapeutic adaptation approach to immunosuppression and the risk of rejection.

Acute kidney injury associated with anti-PD-1 and anti-PD-L1 drugs: a meta-analysis of randomized clinical trials

BACKGROUND

Immune Checkpoint Inhibitors (ICI) have been widely used in treating different types of cancer. They increase survival in many oncologic patients and enable cancer-specific therapy. Acute Kidney Injury (AKI) is one of the adverse effects associated with using ICI, where knowledge of the prevalence and renal histological findings are still reasons for discussion.

OBJECTIVE

Therefore, this meta-analysis evaluates the association between ICI use and AKI.

METHODS

The search was performed in PubMed, Lilacs, and Cochrane platforms. Studies published up to December 1, 2022, were included.

RESULTS

A total of 16 studies met the established PICOT criteria and were included in this review. Comparing the ICI plus chemotherapy against chemotherapy alone, the relative risk (RR) for AKI's development with ICI use was 2.89 (95%CI 1.37-6.10). In the analyses by class and drug type, programmed cell death 1 monoclonal antibody (anti-PD-1) showed an increased risk of 2.11 (95%CI 1.26-3.52), and pembrolizumab demonstrated a risk of AKI (RR= 2.77, 95%CI 1.46-5.26). Likewise, regarding the severity of AKI, AKI grade 3 or higher was more common in the ICI plus chemotherapy compared to the chemotherapy group: 3.66 (95%CI 1.19-11.30), while the subgroup analyses pooled studies comparing ICI alone versus chemotherapy alone in the control group did not demonstrate an association with AKI.

CONCLUSIONS

These findings suggest that ICI use is associated with an increased risk of AKI and that anti-PD-1 use is associated with a higher incidence of renal adverse events than programmed cell death ligand 1 monoclonal antibody (anti-PD-L1). Studies with adequate power and well-defined criteria for acute interstitial nephritis, nowadays taken as a synonym for AKI related to ICI, are necessary.

Immune checkpoint inhibitor therapy associated with IgA nephropathy: a case report and literature review

Immune checkpoint inhibitors (ICIs) dramatically improve the prognosis of many malignancies but at the cost of numerous side effects, which may limit their benefits. Acute kidney injury associated with immune checkpoint inhibitors most frequently are acute tubulointerstitial nephritis (ATIN), but various cases of glomerulonephritis have also been reported. Herein, we report a case of severe IgA nephropathy (IgAN) associated with ICIs and carry out a literature review. IgAN was diagnosed in a median time of 5 months (range 1-12 months) after the initiation of ICIs, with heterogeneous severity, and usually treated by corticosteroid and discontinuation of ICIs. In contrast to our case, renal outcomes in literature were often favorable, with recovery of renal function and a reduction in proteinuria on treatment. Although IgAN related to ICIs is a much rarer complication than ATIN, it may still be underdiagnosed. Careful questioning and screening for asymptomatic hematuria should be performed before using ICIs.

Cancer drugs and acute kidney injury: new therapies and new challenges

PURPOSE OF REVIEW

Cancer therapies continue to evolve at a rapid pace and although novel treatments, including immunotherapies and targeted therapies have allowed for substantial improvements in cancer survival, they carry associated risks of acute kidney injury (AKI). We aim to summarize the existing literature on AKI associated with the spectrum of systemic cancer treatments, including conventional chemotherapies, newer immunotherapies, and the growing number of targeted cancer therapies, which may be associated with both AKI and 'pseudo-AKI'.

RECENT FINDINGS

Conventional cytotoxic chemotherapies (e.g. cisplatin and other platinum-based agents, methotrexate, pemetrexed, ifosfamide, etc.) with well recognized nephrotoxicities (predominantly tubulointerstitial injury) remain in widespread use. Immunotherapies (e.g., immune checkpoint inhibitors and CAR-T therapies) may be associated with kidney immune-related adverse events, most often acute interstitial nephritis, and rarely, glomerular disease. Recently, multiple targeted cancer therapies have been associated with reduced renal tubular secretion of creatinine, causing elevations in serum creatinine and apparent 'pseudo-AKI'. To complicate matters further, these agents have had biopsy-proven, 'true' kidney injury attributed to them in numerous case reports.

SUMMARY

Clinicians in nephrology and oncology must be aware of the various potential kidney risks with these agents and recognize those with clinically meaningful impact on both cancer and kidney outcomes.

How to deal with renal toxicities from immune-based combination treatments in metastatic renal cell carcinoma. A nephrological consultation for Oncologists

We are witnessing a revolution in the treatment of metastatic renal cell carcinoma (mRCC). Indeed, several immune-based combinations (ICI [immune checkpoint inhibitor] + ICI, or ICI + antiangiogenic agents) have been approved as first-line therapy for mRCC after demonstrating superior efficacy over the previous standard. Despite all the improvements made, safety remains a critical issue, adverse events (AEs) being the main reason for drug discontinuations or dose reductions, ultimately resulting in an increased risk of losing efficacy. Thus, a good understanding of the AEs associated with the use of immune-based combinations, their prevention, and management, are key in order to maximize therapeutic effectiveness. Among these AEs, renal ones are relatively frequent, but always difficult to be diagnosed, not to take into account that it is often difficult to determine which drug is to blame for such toxicities. Chronic kidney disease (CKD) is a common finding in patients with RCC, either as a pre-existing condition and/or as a consequence of cancer and its treatment; furthermore, CKD, especially in advanced stages and in patients undergoing dialysis, may influence the pharmacokinetics and pharmacodynamics properties of anticancer agents. Finally, managing cancer therapy in kidney transplanted patients is another challenge. In this review, we discuss the therapy management of immune-based combinations in patients with CKD, on dialysis, or transplanted, as well as their renal toxicities, with a focus on their prevention, detection and practical management, taking into account the crucial role of the consulting nephrologist within the multidisciplinary care of these patients.

Pharmacotherapy considerations in patients who develop acute kidney injury during anti-cancer therapy

INTRODUCTION

Acute kidney injury (AKI) frequently develops in patients receiving cancer therapy and requires a wide differential diagnosis due to possible role of unique cancer and drug-related factors, in addition to common pre- and post-renal causes. Rapid development of new molecular targeted anti-cancer drugs and immunotherapies has opened unprecedented possibilities of treatment at the price of an increased spectrum of renal side effects.

AREAS COVERED

The present review aims at providing a state-of-the-art picture of AKI in cancer patient (PubMed and Embase libraries were searched from inception to January 2024), with a focus on differential diagnosis and management of diverse clinical settings. Reports of parenchymal AKI due to glomerular, microvascular, tubular and interstitial damage have been constantly increasing. Complex electrolyte and acid-base disorders can coexist. The role of renal biopsy and possible therapeutic approaches are also discussed.

EXPERT OPINION

Onconephrology has become an important subspecialty of clinical nephrology, requiring constantly updated skills and a high degree of interdisciplinary integration to tackle diagnostic challenges and even therapeutic and ethical dilemmas. Integrated onconephrological guidelines and availability of biomarkers may provide new tools for management of this unique type of patients in the near future.

Onconephrology: mitigation of renal injury in chemotherapy administration

PURPOSE OF REVIEW

Onconephrology was first coined as a name for the intersection of cancer medicine and nephrology in the early 2010s. It was recognized then that beyond and understanding of kidney physiology, a new generation of nephrologists skilled in both molecular biology and precision medicine were needed to deal with the challenges of emerging cancer therapies. Stem cell transplants, biologic agents, adjuvants blocking basic cellular signaling pathways, immunotherapy were found to promote novel anticancer outcomes, but also to pose new risks to the kidneys. The field rapidly overlapped with emerging expertise in vascular glomerular disease, glomerular disease, and the same biologic agents now applied to auto immune systemic and kidney diseases.

RECENT FINDINGS

Many categories of chemotherapeutic agents have been discovered to have adverse renal side effects. In this review, we address classic chemotherapeutic nephrotoxicity and oncologic clinical situations leading to acute kidney injury. We also review the frontiers of nephrotoxicity reported with cell cycle inhibitors, diverse classes of tyrosine kinase inhibitors, immune checkpoint inhibitors, chimeric antigen receptor T-cell therapy, anticancer vaccines, and thrombotic microangiopathies triggered by malignancy and chemotherapy. The aim will be to focus on published strategies to mitigate nephrotoxicity.

SUMMARY

As onconephrology expands into its own field, it gives birth to new subdisciplines. An understanding that patient populations want the benefits of chemotherapy without the renal (and other) systemic toxicities is emerging. A need to develop a new class of molecular and genetic experts in onconephrology to mitigate nephrotoxicity from chemotherapy is apparent and urgent.

Drug-induced glomerular diseases

Drug-induced kidney diseases represent a wide range of diseases that are responsible for a significant proportion of all acute kidney injuries and chronic kidney diseases. In the present review, we focused on drug-induced glomerular diseases, more precisely podocytopathies - minimal change diseases (MCD), focal segmental glomerulosclerosis (FSGS) - and membranous nephropathies (MN), from a physiological and a pharmacological point of view. The glomerular filtration barrier is composed of podocytes that form foot processes tightly connected and directly in contact with the basal membrane and surrounding capillaries. The common clinical feature of these diseases is represented by the loss of the ability of the filtration barrier to retain large proteins, leading to massive proteinuria and nephrotic syndrome. Drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), D-penicillamine, tiopronin, trace elements, bisphosphonate, and interferons have been historically associated with the occurrence of MCD, FSGS, and MN. In the last ten years, the development of new anti-cancer agents, including tyrosine kinase inhibitors and immune checkpoint inhibitors, and research into their renal adverse effects highlighted these issues and have improved our comprehension of these diseases.

Nephrotoxicity in the Age of Immune Checkpoint Inhibitors: Mechanisms, Diagnosis, and Management

Immune checkpoint inhibitors (ICI) revolutionized cancer therapy by augmenting anti-tumor immunity via cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death-1/programmed death-ligand 1 (PD-1/PD-L1). However, this breakthrough is accompanied by immune-related adverse effects (irAEs), including renal complications. ICI-related nephritis involves complex mechanisms like auto-reactive T cells, auto-antibodies, reactivation of drug-specific T cells, and cytokine-driven inflammation culminating in AKI. ICI-AKI typically manifests weeks to months into treatment, often with other irAEs. Timely detection relies on monitoring creatinine levels and urine characteristics. Biomarkers, like soluble interleukin-2 receptor (sIL-2R) and urine cytokine levels, provide non-invasive insights, while renal biopsy remains the gold standard for confirmation. Management of ICI-AKI requires a balance between discontinuing ICI therapy and prompt immunosuppressive intervention, typically with corticosteroids. Some cases permit ICI therapy resumption, but varying renal recovery rates highlight the importance of vigilant monitoring and effective therapy. Beyond its clinical implications, the potential of irAEs to predict positive treatment responses in certain cancers raises intriguing questions. Data on nephritis-treatment response links are limited, and ongoing research explores this complex interaction. In summary, ICI therapy's transformative impact on cancer treatment is counterbalanced by irAEs, including nephritis. Early recognition and management are vital, with ongoing research refining diagnostic and treatment strategies.

Efficacy and safety of immune checkpoint inhibitors combined with anti-VEGF therapy in the treatment of unresectable or advanced liver cancer: a systematic review

OBJECTIVE

This study aimed to evaluate the clinical effects and safety of immune checkpoint inhibitors (ICIs) combined with anti-VEGF therapy for the treatment of unresectable or advanced liver cancer.

METHOD

Related databases were searched from inception to December 2022 to identify randomized controlled studies and clinical trials that evaluated the combination of ICIs and anti-VEGF therapy for the treatment of unresectable liver cancer. The outcome index was extracted and analyzed by RevMan5.4.ResultsA total of 8 clinical trials were included. In terms of efficacy, the intervention group had longer OS and PFS for unresectable or advanced liver cancer than the control group. In terms of safety, (1) Adverse events of all grades showed that the combination treatment led to significantly higher risks of urinary system disorders, cardiovascular system disorder, blood system disorders and liver dysfunction than the control treatment. Compared with monotherapy, the combination treatment led to lower risks of gastrointestinal disorders. (2) Adverse events above grade 3 showed that, compared with the control treatment, the combination treatment led to significantly higher risks of urinary system disorders, blood systeam disorders, cardiovascular system disorders and liver dysfunction. Additionally, compared with monotherapy, the combination treatment led to significantly lower risks of gastrointestinal disorders.

CONCLUSIONS

ICIs combined with anti-VEGF therapy exerts significant clinical effects in patients with unresectable or advanced liver cancer, can prolong the survival of these patients and can improve their quality of life. However, clinical attention should be given to the occurrence of adverse reactions.

Proton pump inhibitors and adverse kidney outcomes during immune checkpoint blockade: time to sound the alarm?

Immune checkpoint inhibitors (ICIs) have significantly altered the treatment landscape for cancer in the last decade. However, their benefits are often offset by therapy-limiting immune-related adverse events (irAEs). Acute interstitial nephritis (AIN) is the most common renal irAE, but the exact mechanisms underlying its development are poorly understood. ICI-induced immune activation against drug-derived antigens, leading to an inflammatory response within the kidney interstitium, has been postulated, evidenced by current observations of a higher incidence of ICI-associated AIN in patients receiving AIN-inducing drugs such as proton pump inhibitors (PPIs). The role of PPIs in this specific context has garnered significant attention, given their ubiquitous use and sometimes misuse. In this issue of CKJ Miao et al. summarise and synthesize the best available evidence to clarify the interactions of PPIs with ICIs in the development of AIN and other adverse kidney outcomes. The sum of evidence provided appear to implicate PPIs in the development of clinically significant short- and long-term kidney-related adverse effects in patients on immune checkpoint blockade, although causality cannot be proven. In this editorial we discuss the key practical implications of these findings and emphasize the need for further quality studies to delineate the true relationship of ICIs and PPIs in the development of AIN.

Biopsy-proven acute tubulointerstitial nephritis in patients treated with immune checkpoint inhibitors: a pooled analysis of case reports

Introduction

Acute kidney injury (AKI) in cancer patients receiving immune checkpoint inhibitors (ICIs) may recognize multiple causes. Here, we reviewed cases of biopsy-proven acute tubulointerstitial nephritis (ATIN) to describe the clinical characteristics and outcomes of this condition.

Method

We conducted a pooled analysis of clinical cases of ICI-related biopsy-proven ATIN up to 1 May 2022. We collected data on clinical characteristics, AKI, biopsy findings, laboratory examinations, and renal outcomes.

Results

Eighty-five patients (61.4 ± 19 years, 56 male) were evaluated. Melanoma was the most prevalent diagnosis (51%), followed by non-small cell lung cancer (30%). ICI treatment consisted of PD-1, PDL-1 (nivolumab, pembrolizumab, atezolizumab), and CTLA-4 inhibitors (i) (ipilimumab) or combination PD-1i+CTLA4i. Renal toxicity developed after a median of four cycles of therapy. Fifty-one patients (65.5%) developed the most severe form of AKI- stage 3, including five patients requiring dialysis. All the 19 patients treated with dual ICI blockade developed AKI-stage 3, compared with 29 patients out of the 60 receiving a single agent (p<0.001). Most events were managed with corticosteroids associated with ICI withdrawal. In 15 patients ICI was restarted, but in six (40%) AKI recurred. Overall, 32 patients (40%) presented a complete renal recovery, which chance was inversely associated with dual ICI blockade (OR 0.15, 95CI 0.03-0.7, p=0.01).

Conclusion

ICI-related ATIN may develop late after the therapy initiation, presenting as severe AKI, particularly in patients with dual ICI blockade. Although this complication may be partially reversible, concerns remain about the renal function sequelae and the possibility of restarting ICI treatment.

Chapter 3: Management of kidney injury caused by cancer drug therapy, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

Cisplatin should be administered with diuretics and Magnesium supplementation under adequate hydration to avoid renal impairment. Patients should be evaluated for eGFR (estimated glomerular filtration rate) during the treatment with pemetrexed, as kidney injury has been reported. Pemetrexed should be administered with caution in patients with a CCr (creatinine clearance) < 45 mL/min. Mesna is used to prevent hemorrhagic cystitis in patients receiving ifosfamide. Febuxostat is effective in avoiding hyperuricemia induced by TLS (tumor lysis syndrome). Preventative rasburicase is recommended in high-risk cases of TLS. Thrombotic microangiopathy could be triggered by anticancer drugs and there is no evidence of efficacy of plasma exchange therapy. When proteinuria occurs during treatment with anti-angiogenic agents or multi-kinase inhibitors, dose reductions or interruptions based on grading should be considered. Grade 3 proteinuria and renal dysfunction require urgent intervention, including drug interruption or withdrawal, and referral to a nephrologist should be considered. The first-line drugs used for blood pressure elevation due to anti-angiogenic agents are ACE (angiotensin-converting enzyme) inhibitors and ARBs (angiotensin receptor blockers). The protein binding of drugs and their pharmacokinetics are considerably altered in patients with hypoalbuminemia. The clearance of rituximab is increased in patients with proteinuria, and the correlation with urinary IgG suggests similar pharmacokinetic changes when using other antibody drugs. AIN (acute interstitial nephritis) is the most common cause of ICI (immune checkpoint inhibitor)-related kidney injury that is often treated with steroids. The need for renal biopsy in patients with kidney injury that occurs during treatment with ICI remains controversial.

Chapter 1: Evaluation of kidney function in patients undergoing anticancer drug therapy, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

The prevalence of CKD may be higher in patients with cancer than in those without due to the addition of cancer-specific risk factors to those already present for CKD. In this review, we describe the evaluation of kidney function in patients undergoing anticancer drug therapy. When anticancer drug therapy is administered, kidney function is evaluated to (1) set the dose of renally excretable drugs, (2) detect kidney disease associated with the cancer and its treatment, and (3) obtain baseline values for long-term monitoring. Owing to some requirements for use in clinical practice, a GFR estimation method such as the Cockcroft-Gault, MDRD, CKD-EPI, and the Japanese Society of Nephrology's GFR estimation formula has been developed that is simple, inexpensive, and provides rapid results. However, an important clinical question is whether they can be used as a method of GFR evaluation in patients with cancer. When designing a drug dosing regimen in consideration of kidney function, it is important to make a comprehensive judgment, recognizing that there are limitations regardless of which estimation formula is used or if GFR is directly measured. Although CTCAEs are commonly used as criteria for evaluating kidney disease-related adverse events that occur during anticancer drug therapy, a specialized approach using KDIGO criteria or other criteria is required when nephrologists intervene in treatment. Each drug is associated with the different disorders related to the kidney. And various risk factors for kidney disease associated with each anticancer drug therapy.

Incidence, mortality, and risk factors of acute kidney injury after immune checkpoint inhibitors: Systematic review and meta-analysis of real-world evidence

BACKGROUND

To precisely quantify the incidence, mortality, and risk factors for acute kidney injury (AKI) following immune checkpoint inhibitor (ICI) treatment for cancer in real-world scenarios.

METHODS

Comprehensive searches were performed on PubMed, EMBASE and the Cochrane library. Real-world observational studies reporting incidence, mortality and/or factors for AKI in ICI-treated patients were eligible. Odds ratio (OR) with 95% CI for potential predictors and hazard ratio (HR) with 95% CI for mortality risk associated with AKI were calculated using the random-effect model.

RESULTS

Eighteen articles comprising 12,111 patients receiving ICI were finally eligible. The pooled incidence was 16.0% (95% CI 11.2%-20.8%; n = 15) for AKI following ICI therapies overall and 3.5% (95% CI 2.1%-4.9%; n = 8) for ICI-induced AKI. Patients who developed AKI during ICI therapies had 51% increased risk of death compared with those without (HR 1.51, 95% CI 1.07-2.14). Regarding risk factors, statistically increased risk for AKI during ICI therapies was observed with preexisting chronic kidney diseases (OR 1.86, 1.25-2.78), diabetes (OR 1.26, 1.04-1.53), and concomitant extrarenal immune-related adverse events (OR 2.53, 1.79-3.56). Ipilimumab (OR 2.18, 1.43-3.32), combined ICI therapies (OR 1.80, 1.14-2.83) and concomitant use of proton pump inhibitors (OR 1.97, 1.56-2.49), renin-angiotensin system inhibitors (OR 1.50, 1.05-2.14), diuretics (OR 1.69, 1.27-2.26) also significantly predicted the incident AKI.

CONCLUSIONS

AKI episode is frequently observed during ICI exposure for cancer treatment, but ICI induced nephrotoxicity is only occasionally. Higher risk of AKI during ICI therapies was significantly associated with specific comorbidities, concomitant of certain drugs, ipilimumab and ICI combination therapies.

Immunological mechanisms underlying clinical phenotypes and noninvasive diagnosis of immune checkpoint inhibitor-induced kidney disease

Immune checkpoint inhibitors (ICIs) have become a mainstay of cancer therapy, with over 80 FDA-approved indications. Used in a variety of settings and in combination with each other and with traditional chemotherapies, the hyperactive immune response induced by ICIs can often lead to immune-related adverse events in bystander normal tissues such as the kidneys, lungs, and the heart. In the kidneys, this immune-related adverse event manifests as acute interstitial nephritis (ICI-AIN). In the era of widespread ICI use, it becomes vital to understand the clinical manifestations of ICI-AIN and the importance of prompt diagnosis and management of these complications. In this review, we delve into the clinical phenotypes of ICI-AIN and how they differ from traditional drug-induced AIN. We also detail what is known about the mechanistic underpinnings of ICI-AIN and the important diagnostic and therapeutic implications behind harnessing those mechanisms to further our understanding of these events and to formulate effective treatment plans to manage ICI-AIN.

Adverse renal effects of check-point inhibitors (ICI) in cancer patients: Recommendations of the Onco-nephrology Working Group of the Spanish Society of Nephrology

The most widely used approach in the immunotherapy treatment of cancer is the administration of monoclonal antibodies directed against regulatory molecules of immune control that inhibit the activation of T cells, the so-called check point inhibitors (ICI). ICI nephrotoxicity epidemiology and pathology; its diagnosis with or without kidney biopsy; the type and duration of treatment; the possibility of rechallenging after kidney damage; and its indication in patients with cancer and renal transplantation are certainly controversial. In the absence of definitive studies, this document is intended to specify some recommendations agreed by the group of Onconephrology experts of the Spanish Society of Nephrology in those areas related to ICI nephrotoxicity, in order to help decision-making in daily clinical practice in Onconephrology consultations.

Pembrolizumab-Induced Anti-GBM Glomerulonephritis: A Case Report

Immune checkpoint inhibitors are known to have a wide range of autoimmune toxicities, such as acute interstitial nephritis. Immunotherapy induced glomerulonephritis has been described, but anti-glomerular basement membrane disease (anti-GBM) is rarely reported. We present a case report of a 60-year-old woman with squamous cell carcinoma of the cervix who was treated with pembrolizumab, an anti-programmed cell death protein 1, and who developed severe acute kidney injury 4 months after therapy initiation. The immune workup showed a positive serum anti-GBM antibody (24 U/mL). The kidney biopsy showed crescentic glomerulonephritis with linear immunoglobulin G2 glomerular basement membrane staining, compatible with anti-GBM glomerulonephritis. The patient was treated with plasmapheresis, IV steroids, and cyclophosphamide, but she developed kidney failure, necessitating dialysis. Few case reports, such as the present case, provide a possible link between anti-GBM glomerulonephritis and immune checkpoint inhibitors, warranting early clinical suspicion and investigation in patients who are treated with these agents and subsequently develop acute kidney injury.

Case Report: Immune checkpoint inhibitor-induced multiorgan vasculitis successfully treated with rituximab

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer. ICIs have a unique side effect profile, generally caused by inflammatory tissue damage, with clinical features similar to autoimmune conditions. Acute kidney injury from ICIs has been well studied; incidence ranges from 1% to 5%, with higher incidence when combination ICI therapies are used. Although the overall reported incidence of ICI-associated glomerulonephritis is less than 1%, vasculitis is the most commonly reported ICI-related glomerulonephritis. Other biopsy findings include thrombotic microangiopathy, focal segmental glomerulosclerosis, minimal change disease, and IgA nephropathy with secondary amyloidosis. We report a case in which a woman previously treated with the PD-L1 inhibitor durvalumab for locally advanced non-small cell lung cancer with pre-existing antineutrophil cytoplasmic (anti-PR3) antibody who later developed multi-organ vasculitis after ICI exposure, which was successfully treated with rituximab, with continued cancer remission for 3 years.

The incidence and risk factors for acute kidney injury in patients treated with immune checkpoint inhibitors

Recent observational studies reported acute kidney injury (AKI) events in over 10% of the patients treated with immune checkpoint inhibitors (ICIs). However, these studies included patients treated in high-resource settings and earlier lines. Therefore, we aimed to assess the AKI rates and predisposing factors in ICI-treated patients from a limited resource setting. We evaluated 252 patients with advanced cancer for this retrospective cohort study. AKI events were defined by Kidney Disease Improving Global Outcomes criteria. The median age was 59 years. The melanoma (18.3%), non-small cell lung cancer (14.7%) and renal cell carcinoma (22.6%) patients comprised over half of the cohort. During the follow-up, 45 patients (17.9%) had at least one AKI episode. In multivariable analyses, patients with chronic kidney disease (CKD) [odds ratio (OR), 3.385; 95% confidence interval (CI), 1.510-7.588; P  = 0.003], hypoalbuminemia (OR, 2.848; 95% CI, 1.225-6.621; P  = 0.015) or renin-angiotensin-aldosterone system (RAAS) inhibitor use (OR, 2.236; 95% CI, 1.017-4.919; P  = 0.045) had increased AKI risk. There was a trend towards increased AKI risk in patients with diabetes (OR, 2.042; 95% CI, 0.923-4.518; P  = 0.78) and regular proton pump inhibitors use (OR, 2.024; 95% CI, 0.947-4.327; P  = 0.069). In this study, we observed AKI development under ICIs in almost one in five patients with cancer. The increased AKI rates in CKD, hypoalbuminemia or RAAS inhibitor use pointed out a need for better onco-nephrology collaboration and efforts to improve the nutritional status of ICI-treated patients.

Kidney Adverse Events Associated with Immune Checkpoint Inhibitor Therapy: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

The blockade of immune regulatory sites, cytotoxic T-lymphocyte antigen 4, programmed cell death 1 (PD-1), and programmed cell death ligand 1 (PD-L1) with immune checkpoint inhibitors has revolutionized survival outcomes in patients with cancer. However, immune checkpoint inhibitors are associated with a range of immune-related adverse events. The aim of this network meta-analysis was to evaluate severe adverse kidney events in patients with oncological or hematological malignancy receiving monotherapy, dual therapy, or combined therapy treatment with immune checkpoint inhibitors when compared with either placebo or standard chemotherapy.

METHODS

Phase 3 randomized control trials reporting severe grade (3-5) adverse kidney events were identified across five electronic databases from inception to May 2022. This was supplemented with hand searching of medical journals and the National Clinical Trials registry. A Bayesian network meta-analysis was performed for AKI, hypertension, CKD, and the composite of all acute kidney adverse events. The results are reported as per the PRISMA guidelines.

RESULTS

Ninety-five randomized control trials reported severe grade adverse kidney events. The risk of developing severe AKI is higher among patients who received PD-1 plus chemotherapy (odds ratio [OR], 1.8; 95% credible interval [CrI], 1.4 to 2.5) and PD-L1 plus chemotherapy (OR, 1.8; 95% CrI, 1.2 to 2.7) compared with standard chemotherapy and placebo (94 studies, 63,357 participants). The risk of developing the composite of all severe acute kidney adverse events is higher among patients who received PD-1 plus chemotherapy (OR, 1.6; 95% CrI, 1.1 to 2.3) and PD-L1 plus chemotherapy (OR, 1.7; 95% CrI, 1.1 to 2.8) when compared with standard chemotherapy and placebo (95 studies, 63,973 participants).

CONCLUSIONS

The combined regimen of PD-1 plus chemotherapy and PD-L1 plus chemotherapy was associated with higher incidence of severe AKI and the composite of all severe acute kidney adverse events.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_07_10_CJN0000000000000160.mp3.

Impact of Renal Function on the Prognosis of Patients Receiving Atezolizumab/Bevacizumab Combination Therapy and Lenvatinib Monotherapy for Unresectable Hepatocellular Carcinoma

INTRODUCTION

Several studies have reported kidney injury caused by immune checkpoint inhibitors, and proteinuria caused by vascular endothelial growth factor inhibitors for unresectable hepatocellular carcinoma (u-HCC). We investigated the relationship between renal function and prognosis in patients with u-HCC receiving atezolizumab and bevacizumab (AB) and lenvatinib (LEN) therapy.

METHODS

Fifty-one patients who received AB and 50 patients who received LEN therapy were included. We analyzed prognostic factors related to the overall survival (OS), and characteristics related to renal function.

RESULTS

In patients with AB therapy, OS was shorter in patients with baseline proteinuria of 1+ or higher, as assessed by urine dipstick test, compared to those with -/± (p = 0.024). There were many cases with two or more drugs with a high risk of renal dysfunction (p = 0.019) in patients with 1+ or higher. Furthermore, OS was shorter in the group with estimated glomerular filtration rate (eGFR) grade deterioration without urinary protein-creatinine ratio (UPCR) of 2 g/g·Cre or higher than in the other groups (p = 0.027). In the group where eGFR worsened without an increase in UPCR, there were many cases with a daily salt intake of 10 g or more (p = 0.027), three or more drugs with a high risk of renal dysfunction (p = 0.021), and a history of arteriosclerosis (p = 0.021). On the other hand, in patients with LEN therapy, OS tends to be shorter in patients with proteinuria of ± or higher, compared to those without (p = 0.074). There were many cases with a daily salt intake of 10 g or more in patients with ± or higher (p = 0.002).

CONCLUSION

In patients receiving AB and LEN therapy, baseline proteinuria was associated with OS. Renal function deterioration without proteinuria was associated with a poor prognosis in AB therapy. Excessive salt intake, preexisting atherosclerotic disease, and drug with a high risk of renal dysfunction were risk factors for renal deterioration.

Immunotherapy in oncology and the kidneys: a clinical review of the evaluation and management of kidney immune-related adverse events

Immune checkpoint inhibitors (ICI) are now widely used in the treatment of many cancers, and currently represent the standard of care for multiple malignancies. These agents enhance the T cell immune response to target cancer tissues, and have demonstrated considerable benefits for cancer outcomes. However, despite these improved outcomes, there are important kidney immune-related adverse events (iRAEs) associated with ICI. Acute tubulo-interstitial nephritis remains the most frequent kidney iRAE, however glomerular lesions and electrolytes disturbances are increasingly being recognized and reported. In this review, we summarize clinical features and identify risk factors for kidney iRAEs, and discuss the current understanding of pathophysiologic mechanisms. We highlight the evidence basis for guideline-recommended management of ICI-related kidney injury as well as gaps in current knowledge. We advocate for judicious use of kidney biopsy to identify ICI-associated kidney injury, and early use of corticosteroid treatment where appropriate. Selected patients may also be candidates for re-challenge with ICI therapy after a kidney iRAE, in view of current data on recurrent rates of kidney injury. Risk of benefits of re-challenge must be considered on an individual considering patient preferences and prognosis. Lastly, we review current knowledge of ICI use in the setting of patients with end-stage kidney disease, including kidney transplant recipients and those receiving dialysis, which suggest that these patients should not be summarily excluded from the potential benefits of these cancer therapies.

Immune Checkpoint Inhibitor-Associated Nephrotoxicity

CONTEXT

The clinical indications for immune checkpoint inhibitors (ICIs) are rapidly expanding. However, adverse events affecting multiple organs, including kidneys leading to ICI-associated acute kidney injury (AKI), remain a significant challenge with ICI therapy. Although AKI is considered a rare complication, it can be severe and result in treatment interruption or discontinuation of ICIs. Despite a generally favorable kidney prognosis, the possibility of re-challenging ICI therapy remains a subject of debate, particularly for patients who have exhausted other treatment options or experienced severe AKI. Subject of Review: In a recent review article, Sprangers et al. provide a comprehensive overview of the possible mechanisms and clinical manifestations of ICI-associated AKI [Nat Rev Nephrol. 2022;18(12):794-805]. The authors propose a practical strategy for diagnosing and managing suspected cases of ICI-associated AKI, which includes identifying a subset of eligible patients who may be re-exposed to ICIs following an episode of AKI. Second Opinion: The authors of the review article offer several recommendations on the diagnosis and treatment of ICI-associated nephrotoxicity. While we generally agree with the recommendations proposed by the authors, it is important to acknowledge that the available data primarily rely on small retrospective studies, as the authors have recognized. In addition, there are two key questions that need be carefully addressed in future studies: (1) the optimal dose and duration of corticosteroids and the use of alternative immunosuppressive agents in patients with ICI-associated nephrotoxicity and (2) a clear guideline for restarting ICI treatment in patients with AKI who have not fully recovered their kidney function.

Drug-Induced Podocytopathies: Report of Four Cases and Review of the Literature

Kidney injury due to medications is a well-known clinical entity. Although drug-induced tubulointerstitial disease is commonly encountered, there are few reports in the literature associated with glomerular injury due to medications. The recognition of this type of kidney injury is crucial, as rapid discontinuation of the offending agent is critical to maximizing the likelihood of quick and effective renal function recovery. In this article, we present four cases that presented with nephrotic syndrome and were diagnosed with biopsy-proven podocytopathies, associated with exposure to a certain medication. All of them experienced complete resolution of nephrotic syndrome within days or weeks after discontinuation of the offending drug. We also present the data, which were found in a Medline search from the year 1963 until the present, regarding cases with podocytopathies associated with penicillamine, tamoxifen and the combination of pembrolizumab-axitinib, including only adult cases from the English literature. The Medline search revealed nineteen cases of penicillamine-induced minimal-change disease (MCD), one case of tamoxifen-induced MCD, and none associated with pembrolizumab-axitinib therapy. We also searched for the largest studies and meta-analyses regarding drug-induced podocytopathies after a Medline search from 1967 to the present of the English literature.

Pembrolizumab induced-C3 glomerulonephritis and RBC cast nephropathy: a case report

BACKGROUND

Immune checkpoint inhibitors (ICIs) are increasingly being used in the treatment of several cancers. Pembrolizumab is an anti-programmed cell death-1 (anti-PD-1) monoclonal antibody that is approved for the treatment of metastatic non-small cell lung cancer (NSCLC). Pembrolizumab-associated renal toxicity is relatively rare, even in pembrolizumab-associated glomerulonephritis. In this study, we report a rare case of pembrolizumab-induced C3 glomerulonephritis (C3GN) and RBC cast nephropathy.

CASE PRESENTATION

A 68-year-old man with NSCLC was receiving treatment with pembrolizumab. After 19 cycles of pembrolizumab therapy, he presented with gross hematuria, severe lower-limb edema and oliguria. Laboratory tests revealed hypoalbuminemia, increased serum creatinine and low serum C3 level. Renal biopsy revealed a typical membranoproliferative glomerulonephritis accompanied by remarkable RBC casts in tubular cavities and tubulointerstitial infiltration of CD8-positive lymphocytes. Based on C3-only immunofluorescence deposit on glomeruli, a diagnosis of C3GN was made. Pembrolizumab was considered the cause of C3GN. Pembrolizumab was discontinued immediately, and 60 mg/day of prednisone was initiated. One dose of cyclophosphamide (400 mg, IV) was also administered. Upon treatment, his symptoms improved rapidly and serum creatinine decreased a lot. However, the patient became dialysis dependent eventually.

CONCLUSION

This is the first case of C3GN with RBC cast nephropathy caused by ICIs. This rare case caused by the prolonged use of pembrolizumab further strengthens the relationship between ICIs and C3GN. Thus, periodic evaluation of urine and renal function is recommended in patients receiving pembrolizumab and other ICIs.

Onconephrology and Thrombotic Microangiopathy: Looking Beyond the Horizon

Thrombotic microangiopathies (TMAs) represent a complex interaction of endothelial and podocyte biology, nephron physiology, complement genetics, and oncologic therapies with host immunology. The complexity of various factors, such as molecular causes, genetic expressions, and immune system mimicking, along with incomplete penetrance, make it difficult to find a straightforward solution. As a result, there may be variations in diagnosis, study, and treatment approaches, and achieving a consensus can be challenging. Here, we review the molecular biology, pharmacology, immunology, molecular genetics, and pathology of the various TMA syndromes in the setting of cancer. Controversies in etiology, nomenclature, and points requiring further clinical, translational, and bench research are discussed. Complement-mediated TMAs, chemotherapy drug-mediated TMAs, TMAs in monoclonal gammopathy, and other TMAs central to onconephrology practice are reviewed in detail. In addition, established and emerging therapies within the US Food and Drug Administration pipeline subsequently are discussed. Finally, a comprehensive review of critical areas of onconephrology clinical practice is presented as practical value to the clinical practitioner and seeds of investigation to be sown among the community of atypical hemolytic uremic syndrome researchers.

Immune Checkpoint Inhibitor-Associated AKI: Debates in Diagnosis, Management, and Rechallenge

Immune checkpoint inhibitors (ICIs) are now established treatments for advanced cancer and their use is now ubiquitous. The high upside of ICIs is tempered by their toxicity profile affecting almost every organ, including the kidneys. Although acute interstitial nephritis is the major kidney-related adverse effect of checkpoint inhibitors, other manifestations such as electrolyte abnormalities and renal tubular acidosis have been described. With increasing awareness and recognition of these events, the focus has shifted to non-invasive identification of ICI-acute interstitial nephritis, with sophisticated approaches involving biomarkers and immunologic signatures being studied. Although the management of immune-related adverse events with corticosteroids is straightforward, there now are more data to help guide immunosuppressive regimens, ICI rechallenge, and delineate risk and efficacy in special populations such as individuals on dialysis or those who have received a transplant.

Revisiting the role of acute kidney injury in patients on immune checkpoint inhibitors: a good prognosis renal event with a significant impact on survival

In the last decade, immune checkpoint inhibitors (ICI) have become a cornerstone in the treatment of a wide range of malignancies. It is well established that ICI are associated with multiple immune-related adverse events, a spectrum of autoimmune toxicities, that can also affect the kidney. In this issue of Clinical Kidney Journal, Kanbay et al. report the first meta-analysis and systematic review evaluating the impact of ICI-related acute kidney injury (ICI-AKI) on long-term kidney and patient outcomes (including mortality). The authors report a high incidence of ICI-AKI (mostly mild AKI episodes) with high rates of recovery resulting in a good kidney outcomes. However, the occurrence of ICI-AKI has a significant impact on mortality in ICI-treated patients probably related to temporary or definitive cessation of ICI. Additional studies are needed to establish the safety of ICI re-challenging in patients with ICI-AKI, and to determine the optimal treatment strategy for them.

The Onco-Nephrology Field: The Role of Personalized Chemotherapy to Prevent Kidney Damage

In recent years, the onco-nephrology field has acquired a relevant role in internal medicine due to the growing number of cases of renal dysfunction that have been observed in cancer patients. This clinical complication can be induced by the tumor itself (for example, due to obstructive phenomena affecting the excretory tract or by neoplastic dissemination) or by chemotherapy, as it is potentially nephrotoxic. Kidney damage can manifest as acute kidney injury or represent a worsening of pre-existing chronic kidney disease. In cancer patients, physicians should try to set preventive strategies to safeguard the renal function, avoiding the concomitant use of nephrotoxic drugs, personalizing the dose of chemotherapy according to the glomerular filtration rate (GFR) and using an appropriate hydration therapy in combination with nephroprotective compounds. To prevent renal dysfunction, a new possible tool useful in the field of onco-nephrology would be the development of a personalized algorithm for the patient based on body composition parameters, gender, nutritional status, GFR and genetic polymorphisms.

Cancer immunotherapy with immune checkpoint inhibitors (ICIs): potential, mechanisms of resistance, and strategies for reinvigorating T cell responsiveness when resistance is acquired

Cancer is still the leading cause of death globally. The approval of the therapeutic use of monoclonal antibodies against immune checkpoint molecules, notably those that target the proteins PD-1 and PD-L1, has changed the landscape of cancer treatment. In particular, first-line PD-1/PD-L1 inhibitor drugs are increasingly common for the treatment of metastatic cancer, significantly prolonging patient survival. Despite the benefits brought by immune checkpoint inhibitors (ICIs)-based therapy, the majority of patients had their diseases worsen following a promising initial response. To increase the effectiveness of ICIs and advance our understanding of the mechanisms causing cancer resistance, it is crucial to find new, effective, and tolerable combination treatments. In this article, we addressed the potential of ICIs for the treatment of solid tumors and offer some insight into the molecular pathways behind therapeutic resistance to ICIs. We also discuss cutting-edge therapeutic methods for reactivating T-cell responsiveness after resistance has been established.