Incidence and Predictors of CKD and Estimated GFR Decline in Patients Receiving Immune Checkpoint Inhibitors

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 renal immune-related adverse events including acute kidney injury (AKI), most commonly manifesting as acute interstitial nephritis (AIN), though 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 clinicopathological 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 re-challenge 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.

[Nephroprotection: General principles and application to the patients with cancers - when nephroprotection is essential for oncological care plan]

Nephroprotection is a set of recommendations that aim to prevent the risks of acute and/or chronic renal failure and to limit the progression of renal failure towards an end stage. Nephroprotection is not limited to nephrology and applies to all patients at risk of renal failure. Cancer patients are particularly at risk of developing intrinsic and extrinsic renal failure, as well as the toxicity of specific treatments. However, they are poorly included in nephroprotection studies. Thus, current guidelines have not been adapted to these pathologies and oncology-specific comorbidities, such as malnutrition or prognosis, are often not taken into account. In this article, we review the established recommendations by transposing them to the cancer patient as a whole. In addition to the reminder of hygiene and dietary rules to control blood pressure and diabetes, we discuss the importance of therapeutic education, iatrogeny and treatment options to control renal failure in this context. The lack of clearly established data in cancer confirms the needs to strengthen links between oncologists, hematologists and nephrologists and reinforces the emergence of onco-nephrology as a new discipline.

Immune checkpoint inhibitors and their interaction with proton pump inhibitors-related interstitial nephritis

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and outcomes, leading to an expanding use in millions of patients worldwide. However, they can cause a spectrum of immune-related adverse events (irAEs). Essentially, any organs can be affected by irAEs, which have emerged as therapy-limiting side effects. In the kidneys, ICI-associated acute interstitial nephritis (ICI-AIN) leads to acute kidney injury (AKI) in 2%-5% of patients on ICI therapy. AKI associated with ICI therapy pathologically presents with AIN in nearly 90% of the cases, but the pathophysiology of ICI-AIN remains to be defined. The generation of autoreactive T cells in patients receiving AIN-inducible drugs, such as proton pump inhibitors (PPIs), is one of the leading theories, supported by a higher incidence of ICI-AIN in patients on these AIN-inducible drugs. In this review, we will discuss our understanding of the incidence, potential pathophysiological mechanisms, clinical presentations, risk factors, diagnosis, and management of PPI-related AIN and its interaction with ICI therapy.

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.

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.

Medication-Related Adverse Events and Discordancies in Cystatin C-Based vs Serum Creatinine-Based Estimated Glomerular Filtration Rate in Patients With Cancer

Importance

Serum creatinine-based estimated glomerular filtration rate (eGFRcr) may overestimate the glomerular filtration rate (GFR) in patients with cancer. Cystatin C-based eGFR (eGFRcys) is an alternative marker of GFR.

Objective

To determine whether the therapeutic drug levels and adverse events (AEs) associated with renally cleared medications were higher in patients with cancer whose eGFRcys was more than 30% lower than their eGFRcr.

Design, Setting, and Participants

This cohort study analyzed adult patients with cancer at 2 major academic cancer centers in Boston, Massachusetts. These patients had their creatinine and cystatin C measured on the same day between May 2010 and January 2022. The date of the first simultaneous eGFRcr and eGFRcys measurement was considered to be the baseline date.

Exposure

The primary exposure was eGFR discordance, defined as an eGFRcys that was more than 30% lower than the eGFRcr.

Main Outcomes and Measures

The primary outcome was risk of the following medication-related AEs within 90 days of the baseline date: (1) supratherapeutic vancomycin trough level greater than 30 μg/mL, (2) trimethoprim-sulfamethoxazole-related hyperkalemia (>5.5 mEq/L), (3) baclofen toxic effect, and (4) supratherapeutic digoxin level (>2.0 ng/mL). For the secondary outcome, a multivariable Cox proportional hazards regression model was used to compare 30-day survival of those with vs without eGFR discordance.

Results

A total of 1869 adult patients with cancer (mean [SD] age, 66 [14] years; 948 males [51%]) had simultaneous eGFRcys and eGFRcr measurement. There were 543 patients (29%) with an eGFRcys that was more than 30% lower than their eGFRcr. Patients with an eGFRcys that was more than 30% lower than their eGFRcr were more likely to experience medication-related AEs compared with patients with concordant eGFRs (defined as eGFRcys within 30% of eGFRcr), including vancomycin levels greater than 30 μg/mL (43 of 179 [24%] vs 7 of 77 [9%]; P = .01), trimethoprim-sulfamethoxazole-related hyperkalemia (29 of 129 [22%] vs 11 of 92 [12%]; P = .07), baclofen toxic effects (5 of 19 [26%] vs 0 of 11; P = .19), and supratherapeutic digoxin levels (7 of 24 [29%] vs 0 of 10; P = .08). The adjusted odds ratio for vancomycin levels more than 30 μg/mL was 2.59 (95% CI, 1.08-7.03; P = .04). Patients with an eGFRcys more than 30% lower than their eGFRcr had an increased 30-day mortality (adjusted hazard ratio, 1.98; 95% CI, 1.26-3.11; P = .003).

Conclusions and relevance

Results of this study suggest that among patients with cancer with simultaneous assessment of eGFRcys and eGFRcr, supratherapeutic drug levels and medication-related AEs occurred more commonly in those with an eGFRcys more than 30% lower than their eGFRcr. Future prospective studies are needed to improve and personalize GFR estimation and medication dosing in patients with cancer.

Immune-related adverse effects of checkpoint immunotherapy and implications for the treatment of patients with cancer and autoimmune diseases

During the past decade, there has been a revolution in cancer therapeutics by the emergence of antibody-based immunotherapies that modulate immune responses against tumors. These therapies have offered treatment options to patients who are no longer responding to classic anti-cancer therapies. By blocking inhibitory signals mediated by surface receptors that are naturally upregulated during activation of antigen-presenting cells (APC) and T cells, predominantly PD-1 and its ligand PD-L1, as well as CTLA-4, such blocking agents have revolutionized cancer treatment. However, breaking these inhibitory signals cannot be selectively targeted to the tumor microenvironment (TME). Since the physiologic role of these inhibitory receptors, known as immune checkpoints (IC) is to maintain peripheral tolerance by preventing the activation of autoreactive immune cells, IC inhibitors (ICI) induce multiple types of immune-related adverse effects (irAEs). These irAEs, together with the natural properties of ICs as gatekeepers of self-tolerance, have precluded the use of ICI in patients with pre-existing autoimmune diseases (ADs). However, currently accumulating data indicates that ICI might be safely administered to such patients. In this review, we discuss mechanisms of well established and newly recognized irAEs and evolving knowledge from the application of ICI therapies in patients with cancer and pre-existing ADs.

Cytokines and Immune Cell Phenotype in Acute Kidney Injury Associated With Immune Checkpoint Inhibitors

Introduction

Immune checkpoint inhibitors (ICIs) induce impressive antitumor responses but may lead to acute kidney injury (AKI) associated with ICI therapy (AKI-ICI). Biomarkers distinguishing AKI-ICI from AKI because of other causes (AKI-other) are currently lacking. Because ICIs block immunoregulatory pathways, we hypothesized that biomarkers related to immune cell dysregulation, including tumor necrosis factor alpha (TNF-α) and other markers of B and T cell activation in the systemic circulation and kidney tissue, may aid with the diagnosis of AKI-ICI.

Methods

This is a prospective study consisting of 24 participants who presented with AKI during ICI therapy, adjudicated to either have AKI-ICI (n = 14) or AKI-other (n = 10). We compared markers of kidney inflammation and injury (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1) as well as plasma and urine levels of T cell-associated cytokines (TNF-α, interferon-γ, interleukin (IL)-2, IL-4, IL-6, IL-8, IL-9, and IL-10) between groups. We also compared T-cell responses in the systemic circulation and in kidney tissue across groups, using mass cytometry systems.

Results

We observed increase in several specific immune cells, including CD4 memory, T helper cells, and dendritic cells in the kidney tissue, as well as in the urine cytokines IL-2, IL-10, and TNF-α, in patients who developed AKI-ICI compared to patients with AKI-other (P < 0.05 for all). The discriminatory ability of TNF-α on AKI cause was strong (area under the curve = 0.814, 95% confidence interval: 0.623-1.00. The CD4+ T cells with memory phenotype formed the dominant subset.

Conclusion

These results suggest that specific T-cell responses and their respective cytokines may be indicative of AKI associated with ICI therapy and may help to differentiate AKI-ICI from AKI-other. Urine TNF-α is a promising biomarker for AKI-ICI, which is most often caused by acute interstitial nephritis (AIN), and TNF-α pathway may serve as a potential target for therapeutic intervention.

Medication-related adverse events in patients with cancer and discrepancies in cystatin C- versus creatinine-based eGFR

Background

Creatinine-based estimated glomerular filtration rate (eGFRCRE) may overestimate kidney function in patients with cancer. Cystatin C-based eGFR (eGFRCYS) is an alternative marker of kidney function. We investigated whether patients with an eGFR discrepancy, defined as eGFRCYS >30% lower than the concurrent eGFRCRE, had an increased risk of adverse events resulting from renally-cleared medications.

Patients and Methods

We conducted a cohort study of adult patients with cancer who had serum creatinine and cystatin C measured on the same day between May 2010 and January 2022 at two academic cancer centers in Boston, MA. The primary outcome was the incidence of each of the following medication-related adverse events: 1) supratherapeutic vancomycin levels (>30μg/mL); 2) trimethoprim-sulfamethoxazole-related hyperkalemia (>5.5mEq/L); 3) baclofen-induced neurotoxicity; and 4) supratherapeutic digoxin levels (>2.0ng/mL).

Results

1988 patients with cancer had simultaneous eGFRCYS and eGFRCRE. The mean age was 66 years (SD±14), 965 (49%) were female, and 1555 (78%) were non-Hispanic white. eGFR discrepancy occurred in 579 patients (29%). Patients with eGFR discrepancy were more likely to experience medication-related adverse events compared to those without eGFR discrepancy: vancomycin levels >30μg/mL (24% vs. 10%, p=0.004), trimethoprim- sulfamethoxazole-related hyperkalemia (24% vs. 12%, p=0.013), baclofen-induced neurotoxicity (25% vs. 0%, p=0.13), and supratherapeutic digoxin levels (38% vs. 0%, p=0.03). The adjusted OR for vancomycin levels >30μg/mL was 2.30 (95% CI 1.05 - 5.51, p = 0.047).

Conclusion

Among patients with cancer with simultaneous assessment of eGFRCYS and eGFRCRE, medication-related adverse events occur more commonly in those with eGFR discrepancy. These findings underscore the importance of accurate assessment of kidney function and appropriate dosing of renally-cleared medications in patients with cancer.

Diagnosis and management of immune checkpoint inhibitor-associated acute kidney injury

Since their introduction into clinical practice a decade ago, immune checkpoint inhibitors (ICIs) have had an overwhelming impact on cancer treatment. Use of these agents in oncology continues to grow; however, the increased use of these agents has been associated with a parallel increase in ICI-associated immune-related adverse events, which can affect virtually any organ, including the kidneys. ICI-associated acute kidney injury (ICI-AKI) occurs in 2-5% of patients treated with ICIs. Its occurrence can have important consequences, including the temporary or permanent discontinuation of ICIs or other concomitant anticancer therapies and the need for prolonged treatment with corticosteroids. Various mechanisms have been proposed to underlie the development of ICI-AKI, including loss of tolerance to self-antigens, reactivation of drug-specific effector T cells, and the production of kidney-specific autoantibodies. ICI-AKI most commonly manifests as acute tubulo-interstitial nephritis on kidney biopsy and generally shows a favourable response to early initiation of corticosteroids, with complete or partial remission achieved in most patients. The evaluation of patients with suspected ICI-AKI requires careful diagnostic work-up and kidney biopsy for patients with moderate-to-severe ICI-AKI to ensure accurate diagnosis and inform appropriate treatment.

Immune checkpoint inhibitors and kidney disease

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICIs) have changed the landscape of cancer treatment. However, use of ICIs can be limited by inflammatory toxicities referred to as immune-related adverse events (irAEs). ICI-associated acute kidney injury (ICI-associated AKI) affects 3-5% of ICI users.

RECENT FINDINGS

With the rapidly growing indication of ICI, knowledge of ICI-associated kidney toxicity has also expanded from case series to large multicentre cohort studies. In this review, we discuss the clinical features, risk factors, clinicopathological correlations and prognosis of ICI-associated AKI from the most recent rigorously conducted retrospective cohort studies. We also discuss recent advances in diagnostic biomarker investigation, treatment and the unique challenge faced in the kidney transplant population.

SUMMARY

With more comprehensive understanding of the clinical features and risk factors, ICI-associated AKI is commonly diagnosed clinically, especially given the inherent challenges performing a kidney biopsy in the cancer population; however, this highlights the urgent need for improved noninvasive diagnostic biomarkers to aid diagnosis and prognosis. Prospective studies are needed to better define the optimal treatment of ICI-associated AKI and to minimize the risk of graft loss in patients with kidney transplant who require ICIs.

Chronic Kidney Disease and Cancer: Inter-Relationships and Mechanisms

Chronic kidney disease (CKD) has been recognized as an increasingly serious public health problem globally over the decades. Accumulating evidence has shown that the incidence rate of cancer was relatively higher in CKD patients than that in general population, which, mechanistically, may be related to chronic inflammation, accumulation of carcinogenic compounds, oxidative stress, impairment of DNA repair, excessive parathyroid hormone and changes in intestinal microbiota, etc. And in patients with cancer, regardless of tumor types or anticancer treatment, it has been indicated that the morbidity and incidence rate of concomitant CKD was also increased, suggesting a complex inter-relationship between CKD and cancer and arousing increasing attention from both nephrologists and oncologists. This narrative review focused on the correlation between CKD and cancer, and underlying molecular mechanisms, which might provide an overview of novel interdisciplinary research interests and the potential challenges related to the screening and treatment of CKD and cancer. A better understanding of this field might be of help for both nephrologists and oncologists in the clinical practice.

Renal Function Outcomes in Metastatic Non-Small-Cell Lung Carcinoma Patients Treated with Chemotherapy or Immune Checkpoint Inhibitors: An Unexpected Scenario

Immune checkpoint inhibitors (ICIs) and platinum-based chemotherapy (CT) are effective therapeutic agents for the palliative treatment of metastatic non-small-cell lung cancer (NSCLC); the aim of our study was to investigate the acute and chronic renal toxicities in this setting. We collected data on 292 patients who received cisplatin (35%), carboplatin-based regimens (25%), or ICI monotherapy (40%). The primary and secondary outcomes were compared to the acute kidney injury (AKI) rate and the mean estimated GFR (eGFR) decay between groups, respectively, over a mean follow-up duration of 15 weeks. We observed 26 AKI events (8.9%), mostly stage I AKI (80.7%); 15% were stage II AKI, 3.8% were stage III, and none required renal replacement therapy or ICU admission. The AKI rates were 10.9%, 6.8%, and 8.9% for the cisplatin, carboplatin, and ICI groups, respectively, and no significant differences were observed between the groups (p = 0.3). A global mean eGFR decay of 2.2 mL/min was observed, while for the cisplatin, carboplatin, and ICI groups, the eGFR decay values were 2.3 mL/min, 1.1 mL/min, and 3.5 mL/min, respectively. No significant differences were observed between the groups. Cisplatin/carboplatin-based CT and ICIs resulted in a similar incidence of AKI and eGFR decay, suggesting the safety of their cautious use, even in CKD patients.

OUP accepted manuscript

Cancer is the second leading cause of death in people with chronic kidney disease (CKD) after cardiovascular disease. The incidence of CKD in patients with cancer is higher than in the non-cancer population. Across various populations, CKD is associated with an elevated risk of cancer incidence and cancer death compared with people without CKD, although the risks are cancer site-specific. Higher risk of cancer is detectable in mild CKD [estimated glomerular filtration rate (eGFR) 60-89 mL/min/1.73 m2], although this risk is more obvious if sensitive markers of kidney disease are used, such as cystatin C. Independent of eGFR, albuminuria is associated with increased risk of site-specific cancer incidence and death. Here, we explore the potential mechanisms for the increased risk of cancer observed in CKD, including patient factors (shared risks such as cardiometabolic disease, obesity, smoking, diet, lifestyle and environment), disease (genetic, inflammatory and infective) and treatment factors. In particular, we discuss the ways in which renal adverse events associated with conventional chemotherapies and newer systemic anti-cancer therapies (including targeted and immunotherapies) may contribute to worse cancer outcomes in people with CKD. Finally, we review the potential benefits of acknowledging increased risk of cancer in risk prediction tools used for the management of CKD.

Immune Checkpoint Inhibitors and Kidney Toxicity: Advances in Diagnosis and Management

Immune checkpoint inhibitors are now approved for more than 50 indications, and increasing numbers of patients with advanced cancer are receiving immunotherapy. Immune-related adverse events that result from checkpoint inhibitors can affect any organ system. The most common kidney side effect is acute kidney injury, typically caused by acute interstitial nephritis. This review covers the most recent advances in immune checkpoint inhibitor-induced acute kidney injury. The review focuses on the differences between checkpoint inhibitor classes in causing acute kidney injury and differentiating immune checkpoint inhibitor-induced kidney damage from other causes of acute kidney injury. We describe the appropriate use of a kidney biopsy in the diagnosis of acute kidney injury and highlight the need for identification of noninvasive diagnostic and predictive biomarkers of immune checkpoint inhibitor-induced acute kidney injury. In the treatment section, approaches to corticosteroid use and the risks and benefits of rechallenging patients who experience acute kidney injury are debated. We also clarify the long-term adverse effects of immune checkpoint inhibitors on kidney function and the risk of chronic kidney disease in cancer survivors.