Acute tubulointerstitial nephritis induced by checkpoint inhibitors versus classical acute tubulointerstitial nephritis: are they the same disease?

Immune checkpoint inhibitor-associated nephritis-treatment standard

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

Immune checkpoint inhibitors induce acute interstitial nephritis in mice with increased urinary MCP1 and PD-1 glomerular expression

INTRODUCTION

Immune checkpoint inhibitors (ICIs) induce acute interstitial nephritis (AIN) in 2-5% of patients, with a clearly higher incidence when they are combined with platinum derivatives. Unfortunately, suitable disease models and non-invasive biomarkers are lacking. To fill this gap in our understanding, we investigated the renal effects of cisplatin and anti-PD-L1 antibodies in mice, assessing PD-1 renal expression and cytokine levels in mice with AIN, and then we compared these findings with those in AIN-diagnosed cancer patients.

METHODS

Twenty C57BL6J mice received 200 µg of anti-PD-L1 antibody and 5 mg/kg cisplatin intraperitoneally and were compared with those receiving cisplatin (n = 6), anti-PD-L1 (n = 7), or saline (n = 6). After 7 days, the mice were euthanized. Serum and urinary concentrations of TNFα, CXCL10, IL-6, and MCP-1 were measured by Luminex. The kidney sections were stained to determine PD-1 tissue expression. Thirty-nine cancer patients with AKI were enrolled (AIN n = 33, acute tubular necrosis (ATN) n = 6), urine MCP-1 (uMCP-1) was measured, and kidney sections were stained to assess PD-1 expression.

RESULTS

Cisplatin and anti PD-L1 treatment led to 40% AIN development (p = 0.03) in mice, accompanied by elevated serum creatinine and uMCP1. AIN-diagnosed cancer patients also had higher uMCP1 levels than ATN-diagnosed patients, confirming our previous findings. Mice with AIN exhibited interstitial PD-1 staining and stronger glomerular PD-1 expression, especially with combination treatment. Conversely, human AIN patients only showed interstitial PD-1 positivity.

CONCLUSIONS

Only mice receiving cisplatin and anti-PDL1 concomitantly developed AIN, accompanied with a more severe kidney injury. AIN induced by this drug combination was linked to elevated uMCP1, consistently with human AIN, suggesting that uMCP1 can be potentially used as an AIN biomarker.

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.

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.

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.

Immune-Related Uncommon Adverse Events in Patients with Cancer Treated with Immunotherapy

Immunotherapy has dramatically changed the therapeutic landscape of oncology, and has become standard of care in multiple cancer types in front or late lines of therapy, with some longstanding responses and outstanding results. Notwithstanding, its use has brought a totally unique spectrum of adverse events, characterized by a myriad of diverse manifestations affecting nearly every organ and system of the body, including the endocrine, nervous, cardiac, respiratory and gastrointestinal systems. Uncommon adverse events, defined as those occurring in less than 1% of patients, comprise an even more heterogeneous group of diseases that are being seen more recurrently as the use of immune check-point inhibitors increases and indications spread in different tumor types and stages. Here, we comprehensively review some uncommon, but exceedingly important, immune-related adverse events, with special emphasis in the clinical approach and diagnostic workup, aiming to reunite the evidence published previously, allowing an increase in awareness and knowledge from all specialists implicated in the diagnosis, treatment, and care of cancer patients treated with immunotherapy.

Adverse Renal Effects of Anticancer Immunotherapy: A Review

Modern oncological therapy utilizes various types of immunotherapy. Immune checkpoint inhibitors (ICIs), chimeric antigen receptor T cells (CAR-T) therapy, cancer vaccines, tumor-targeting monoclonal antibodies (TT-mAbs), bispecific antibodies and cytokine therapy improve patients' outcomes. However, stimulation of the immune system, beneficial in terms of fighting against cancer, generates the risk of harm to other cells in a patient's body. Kidney damage belongs to the relatively rare adverse events (AEs). Best described, but still, superficially, are renal AEs in patients treated with ICIs. International guidelines issued by the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) cover the management of immune-related adverse events (irAEs) during ICI therapy. There are fewer data concerning real occurrence and possible presentations of renal adverse drug reactions of other immunotherapeutic methods. This implies the need for the collection of safety data during ongoing clinical trials and in the real-life world to characterize the hazard related to the use of new immunotherapies and management of irAEs.

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.

Risk factors associated with immune checkpoint inhibitor-induced acute kidney injury compared to other immune-related adverse events: a case-control study

Background

Immune checkpoint inhibitors (ICIs) foster anti-cancer immune responses. Their efficacy comes at the cost of immune-related adverse events (IRAEs). The latter affects various organs, including kidneys, mostly as acute tubulointerstitial nephritis, the pathophysiology of which remains unclear. We conducted a multicentre case–control study to compare the characteristics of patients with renal IRAEs (ICI-AKI) with those of patients diagnosed with other IRAEs.

Methods

We queried the French pharmacovigilance database for all adverse events involving ICIs. Reports were classified as ICI-AKI or extrarenal IRAE. For each ICI-AKI report, four reports of extrarenal IRAEs were randomly included (control group, 4:1 ratio). Variables showing an association with a P < 0.05 were included as covariates in a multivariate analysis.

Results

Therefore, 167 ICI-AKI reports were compared with 668 extrarenal IRAEs. At least one concomitant extrarenal IRAE was mentioned in 44.3% of ICI-AKI reports. Patients with ICI-AKI were significantly older than patients with extrarenal IRAEs (69.1 versus 64.6 years; P = 0.0135), and chronic kidney disease was significantly more prevalent (12.0% versus 3.3%; P = 0.0125). Patients with ICI-AKI were significantly more likely to be treated with fluindione [adjusted odds ratio (OR) 6.53, 95% confidence interval (95% CI) 2.21–19.31; P = 0.0007], a non-steroidal anti-inflammatory drug (NSAID, OR 3.18, 95% CI 1.07–9.4; P = 0.0368) or a proton-pump inhibitor (PPI, OR 2.18, 95% CI 1.42–3.34; P = 0.0004).

Conclusion

This study is limited by a lack of data, preventing confirmation of numerous reports therefore not included in the analysis. We are unable to draw definite pathophysiological conclusions from our data. Nonetheless, we suggest that ICIs may be a ‘second-hit’ that precipitates acute kidney injury caused by another concomitant drug (fluindione, NSAID or PPI).

Acute Tubulointerstitial Nephritis in Clinical Oncology: A Comprehensive Review

Acute kidney injury in patients who suffer a malignancy is a common complication. Due to its high prevalence and effective treatment, one of the most frequent causes that both oncologists and nephrologists must be aware of is acute tubulointerstitial nephritis (ATIN). ATIN is an immunomediated condition and the hallmark of the disease, with the presence of a tubulointerstitial inflammatory infiltrate in the renal parenchyma. This infiltrate is composed mainly of T lymphocytes that can be accompanied by macrophages, neutrophils, or eosinophils among other cells. One of the major causes is drug-related ATIN, and some antineoplastic treatments have been related to this condition. Worthy of note are the novel immunotherapy treatments aimed at enhancing natural immunity in order to defeat cancer cells. In the context of the immunosuppression status affecting ATIN patients, some pathogen antigens can trigger the development of the disease. Finally, hematological malignancies can also manifest in the kidney leading to ATIN, even at the debut of the disease. In this review, we aim to comprehensively examine differential diagnosis of ATIN in the setting of a neoplastic patient.