Anti-PD-1 Immunotherapy May Induce Interstitial Nephritis With Increased Tubular Epithelial Expression of PD-L1

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.

Sex differences in mortality risk and U-shaped relationship with klotho levels: A long-term cohort study

BACKGROUNDS

It remains unclear whether there are sex differences in the correlation between klotho and mortality risk. The purpose of our study is to investigate the relationship between klotho levels and all-cause mortality, specifically examining potential sex disparities.

METHODS

The study utilized data from the National Health and Nutrition Examination Survey. The study employed the Cox proportional hazards model and Kaplan-Meier survival curves to conduct multivariate analyses investigating the associations between klotho and mortality. The impact of klotho level on mortality was assessed by a restricted cubic spline curve.

RESULTS

Our study included 13,748 participants. The hazard ratios (HR) for all-cause mortality were found to be higher in males compared to females. The risk of all-cause mortality decreased until the klotho level reached 959 pg/mL in all-cause mortality, then increased thereafter in females (P value for nonlinearity = 0.01, P overall = 0.02); no curved relationship was observed in males.

CONCLUSION

Klotho levels and mortality follow a U-shaped curve, with sex differences in the relationship. Males with higher klotho levels have a higher risk of all-cause death than females.

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.

Urinary soluble PD-1 as a biomarker of checkpoint inhibitor-induced acute tubulointerstitial nephritis

Background

Acute interstitial nephritis (AIN) related to immune checkpoint inhibitors (ICI-AIN) has a not completely understood pathophysiology. Our objectives were to analyze possible biomarkers for the differentiation between acute tubular necrosis (ATN) and AIN, especially in cancer patients, and to study the participation of the immune checkpoint pathway in ICI-AIN.

Methods

We performed an observational study. We recruited patients with incident diagnosis of ICI-AIN (n = 19). We measured soluble PD-1 (sPD-1), sPD-L1, and sPD-L2 in serum and urine at diagnosis and compared to it patients with non-ICI-related AIN (non-ICI-AIN) (n = 18) and ATN (n = 21). The findings were validated in an independent cohort from another institution (n = 30). Also, we performed PD-L1 and PD-L2 immunostaining of kidney biopsies from patients with ICI-AIN and compared to patients with non-ICI-AIN.

Results

Urinary sPD-1 (usPD-1) was higher in patients with AIN compared to ATN (P = .03). Patients with AIN also showed higher serum sPD-1 (ssPD-1) than patients with ATN (P = .021). In cancer patients, usPD-1 <129.3 pg/ml had a 71.43% sensitivity and 94.44% specificity to differentiate ATN from ICI-AIN, with a likelihood ratio of 12.86. In the external validation cohort, the same cutoff showed a sensitivity of 80%. In kidney biopsies, patients with ICI-AIN showed higher density of PD-L1 positive tubules than patients with non-ICI-AIN (P = .02). The proportion of patients having >2.64/mm2 PD-L2 positive tubules was higher among patients with ICI-AIN compared to non-ICI-AIN (P = .034). There was a positive correlation (P = .009, r = 0.72) between usPD-1 and the number of PD-L1 positive tubules.

Conclusions

UsPD-1 and ssPD-1 are higher in AIN than ATN. Moreover, there was a strong correlation between usPD-1 and renal tubular PD-L1 expression. Our findings suggest a role of usPD-1 as non-invasive biomarker to differentiate ICI-AIN from ATN, especially in cancer patients, which has been confirmed in an external validation cohort.

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.

Immunohistochemical Evaluation of Renal Biopsy with Anti-PD1 and p53 to Solve the Dilemma between Platinum- and Pembrolizumab-Induced AKI: Case Report and Review

Introduction: The combination therapy of platinum and pembrolizumab looks like a promising treatment in advanced non-small-cell lung cancer. However, both platinum-based chemotherapy and pembrolizumab can lead to AKI. AKI can occur due to acute tubular necrosis or interstitial nephritis. It is essential to identify the drug responsible for renal damage. For this purpose, we used new immunohistochemistry markers (p53 and anti-PD1 analysis). Case Description: A 77-year-old female patient with advanced non-small-cell lung cancer received the PD-1 inhibitor pembrolizumab and platinum-based chemotherapy carboplatin. The patient, after 60 days, experienced AKI. A kidney biopsy was performed, and two new immunohistochemical techniques for p53 (experimental markers of ATN from platinum) and anti-PDL1 (experimental markers of PD-1 inhibitors nephritis) were employed. Renal biopsies revealed severe tubular damage. No infiltration was detected, and the immunohistochemical assessment of PDL-1 was negative. The expression of p53 was positive. The renal biopsy suggested platinum-induced acute tubular necrosis. After discontinuing steroids and reducing carboplatin, the patient continued with pembrolizumab, and their renal function returned to normal within two months. Discussion: Combining checkpoint inhibitors and platinum-based therapies may result in AKI. The standard method of examining kidney tissue may not provide sufficient information about the effects of these drugs on the kidneys. To address this issue, we recommend incorporating an assessment of the analysis of the expression of PDL1 and p53. This personalized approach will help identify the best treatment option for the patient while ensuring the best possible cancer treatment plan.

Renal Immune-related Adverse Event of Pembrolizumab Masked by Pemetrexed

A Japanese woman in her 60s developed a kidney injury 9 weeks after treatment with pemetrexed, carboplatin, and pembrolizumab for stage IV lung adenocarcinoma. A renal biopsy showed chronic tubulointerstitial damage with minimal focal interstitial inflammation, consistent with pemetrexed-induced nephropathy; thus, pemetrexed was withdrawn. However, the kidney injury continued to worsen. A repeated biopsy showed severe acute tubulointerstitial nephritis, suggestive of a pembrolizumab-induced immune-related adverse event (irAE). The worsening after pemetrexed discontinuation suggested that the irAE had already begun, as the first biopsy showed focal inflammation. This case suggests thatcombining immune checkpoints and chemotherapy requires considering concurrent drug-induced nephrotoxicity.

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.

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.

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.

Serum sodium levels associate with recovery of kidney function in immune checkpoint inhibitor nephrotoxicity

Background

Immune checkpoint inhibitors (ICIs) are novel drugs targeting programmed cell death protein 1-ligand 1 (PD-L1) or its receptor (PD-1). Enhancing the immune system has also been associated with a wide range of immune-related adverse events (irAE). Among them, acute interstitial nephritis (AIN) is a rare but deleterious irAE in the kidney. However, determinants of recovery and long-term kidney function after ICI withdrawal and steroid therapy thereafter remain elusive. Therefore, we here aimed to identify parameters associated with recovery of kidney function in this previous established cohort of AIN in the context of ICI therapy.

Methods

We here monitored kidney function over a mean follow-up time of 812 days in comparison with clinical, histopathological and laboratory parameters associated with recovery of kidney function after AIN related to ICI nephrotoxicity.

Results

Abundance of intrarenal PD-L1/PD-1 did not correlate with recovery of kidney function. Furthermore, cumulative steroid dose that was initiated for treatment of AIN related to ICI nephrotoxicity was also not associated with improvement of kidney function. Finally, chronic lesions in the kidney including glomerular sclerosis and interstitial fibrosis/tubular atrophy (IF/TA) did not correlate with eGFR change during the follow-up time. However, we here identified that lower levels of serum sodium at time of kidney biopsy were the strongest independent predictor of renal recovery in ICI-related nephrotoxicity.

Conclusion

Because low serum sodium levels associated with better improvement of kidney function, these observations might contribute to novel approaches to enhance recovery after AIN related to ICI nephrotoxicity.

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.

Study protocol: a prospective single-center study for non-invasive biomonitoring of renal complications in cancer patients treated with immune checkpoint inhibitors

Background

The advent of immune checkpoint inhibitors (ICIs) has powerfully broadened the scope of treatment options for malignancies with an ongoing increase of indications, but immune-related adverse events (irAEs) represent a serious threat to treatment success. Agents directed against programmed cell death protein 1 (PD-1) or its ligand 1 (PD-L1) are known to cause renal complications with an incidence of 3%. In contrast, subclinical renal involvement is estimated to be much higher, up to 29%. We recently reported about urinary flow cytometry-based detection of urinary PD-L1-positive (PD-L1+) kidney cells correlating with tubular PD-L1-positivity that reflected susceptibility to develop ICI-related nephrotoxicity as an irAE attending ICI treatment. Therefore, we designed a study protocol to evaluate urinary detection of PD-L1+ kidney cells as a tool for non-invasive biomonitoring of renal complications in cancer patients treated with ICIs.

Methods

A prospective, controlled, non-interventional, longitudinal, single-center observational study will be conducted at the Department of Nephrology and Rheumatology of the University Medical Center Göttingen, Germany. We intend to enroll approximately 200 patients treated with immunotherapy from the Departments of Urology, Dermatology, and Hematology and Medical Oncology of the University Medical Center Göttingen, Germany. First, we will assess clinical, laboratory, histopathological, and urinary parameters in addition to urinary cell collection. Then, we will perform a correlative analysis between urinary flow cytometry of different PD-L1+ cell of renal origin with the onset of ICI-related nephrotoxicity.

Discussion

Because of growing ICI-treatment applicability with an expectable incidence of renal complications, providing cost-efficient and easily performable diagnostic tools for treatment-attendant and non-invasive biomonitoring becomes vital to improve both renal and overall survival rates in cancer patients receiving immunotherapy.

Trial registration

https://www.drks.de, DRKS-ID DRKS00030999.

Clinicopathological Features of Kidney Injury Related to Immune Checkpoint Inhibitors: A Systematic Review

(1) Background: Despite increasing recognition of immune checkpoint inhibitors (ICIs) and kidney immune-related adverse events (IRAEs), no large-sample studies have assessed the pathological characteristics and outcomes of biopsy-proven kidney IRAEs. (2) Methods: We comprehensively searched PubMed, Embase, Web of Science, and Cochrane for case reports, case series, and cohort studies for patients with biopsy-proven kidney IRAEs. All data were used to describe pathological characteristics and outcomes, and individual-level data from case reports and case series were pooled to analyze risk factors associated with different pathologies and prognoses. (3) Results: In total, 384 patients from 127 studies were enrolled. Most patients were treated with PD-1/PD-L1 inhibitors (76%), and 95% presented with acute kidney disease (AKD). Acute tubulointerstitial nephritis/acute interstitial nephritis (ATIN/AIN) was the most common pathologic type (72%). Most patients (89%) received steroid therapy, and 14% (42/292) required RRT. Among AKD patients, 17% (48/287) had no kidney recovery. Analyses of pooled individual-level data from 221 patients revealed that male sex, older age, and proton pump inhibitor (PPI) exposure were associated with ICI-associated ATIN/AIN. Patients with glomerular injury had an increased risk of tumor progression (OR 2.975; 95% CI, 1.176, 7.527; p = 0.021), and ATIN/AIN posed a decreased risk of death (OR 0.164; 95% CI, 0.057, 0.473; p = 0.001). (4) Conclusions: We provide the first systematic review of biopsy-proven ICI-kidney IRAEs of interest to clinicians. Oncologists and nephrologists should consider obtaining a kidney biopsy when clinically indicated.

Depiction of immune heterogeneity of peripheral blood from patients with type II diabetic nephropathy based on mass cytometry

Diabetic nephropathy (DN) is the most prominent cause of chronic kidney disease and end-stage renal failure. However, the pathophysiology of DN, especially the risk factors for early onset remains elusive. Increasing evidence has revealed the role of the innate immune system in developing DN, but relatively little is known about early immunological change that proceeds from overt DN. Herein, this work aims to investigate the immune-driven pathogenesis of DN using mass cytometry (CyTOF). The peripheral blood mononuclear lymphocytes (PBMC) from 6 patients with early-stage nephropathy and 7 type II diabetes patients without nephropathy were employed in the CyTOF test. A panel that contains 38 lineage markers was designed to monitor immune protein levels in PBMC. The unsupervised clustering analysis was performed to profile the proportion of individual cells. t-Distributed Stochastic Neighbor Embedding (t-SNE) was used to visualize the differences in DN patients' immune phenotypes. Comprehensive immune profiling revealed substantial immune system alterations in the early onset of DN, including the significant decline of B cells and the marked increase of monocytes. The level of CXCR3 was dramatically reduced in the different immune cellular subsets. The CyTOF data classified the fine-grained differential immune cell subsets in the early stage of DN. Innovatively, we identified several significant changed T cells, B cell, and monocyte subgroups in the early-stage DN associated with several potential biomarkers for developing DN, such as CTLA-4, CXCR3, PD-1, CD39, CCR4, and HLA-DR. Correlation analysis further demonstrated the robust relationship between above immune cell biomarkers and clinical parameters in the DN patients. Therefore, we provided a convincible view of understanding the immune-driven early pathogenesis of DN. Our findings exhibited that patients with DN are more susceptible to immune system disorders. The classification of fine-grained immune cell subsets in this present research might provide novel targets for the immunotherapy of DN.

Divergent roles of PD-L1 in immune regulation during ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is a type of pathological injury that commonly arises in various diseases. Various forms of immune response are involved in the process of I/R injury. As a member of the B7 costimulatory molecule family, programmed death 1-ligand 1 (PD-L1) is an important target for immune regulation. Therefore, PD-L1 may be implicated in the regulation of I/R injury. This review briefly describes the immune response during I/R injury and how PD-L1 is involved in its regulation by focusing on findings from various I/R models. Despite the limited number of studies in this field of research, PD-L1 has shown sufficient potential as a clinical therapeutic target.

Immune checkpoint inhibitor related nephrotoxicity: Advances in clinicopathologic features, noninvasive approaches, and therapeutic strategy and rechallenge

Immune checkpoint inhibitors (ICIs) are used increasingly to treat more than 17 cancers and have shown promising therapeutic results. However, ICI use can result in a variety of immune-related adverse events (IRAEs) which can occur in any organ, including the kidneys. Acute kidney injury (AKI) is the most common nephrotoxicity, classically related to acute interstitial nephritis. Much more diverse patterns and presentations of ICI-related kidney injury can occur, and have implications for diagnostic and therapeutic management approaches. In this review, we summarize the recently approved ICIs for cancer, the incidence and risk factors for nephrotoxicity, our current understanding of the pathophysiological mechanisms and the key clinicopathological features of ICI-related AKI, and therapeutic strategies. We also explore important knowledge that require further investigation, such as the risks/benefits of ICI rechallenge in patients who recover from an episode of ICI-related AKI, and the application of liquid biopsy and microbiome to identify noninvasive biomarkers to diagnose and predict kidney injury and guide ICI therapy.

Immune Checkpoint Inhibitors’ Associated Renal Toxicity: A Series of 12 Cases

We present a series of twelve patients, bearing a wide range of solid malignancies, who received either PD-L1 or a combination of PD-L1 and CTLA-4 inhibitors. Following immunotherapy administration, they exhibited the clinical signs indicative of renal toxicity, including increased serum creatinine levels, proteinuria, nephrotic syndrome and/or hematuria. All patients underwent renal biopsy. Results: All cases demonstrated some degree of interstitial inflammation and tubular injury, while in five patients, glomerular alterations consistent with a specific glomerulopathy were also observed: secondary “lupus-like” membranous glomerulopathy in two cases and membranoproliferative glomerulonephritis, IgA glomerulonephritis and secondary AA amyloidosis in each of the remaining three patients. The two patients with “lupus-like” nephritis and the one with amyloidosis experienced nephrotic syndrome, while their creatinine was within normal range. In the remaining nine cases, deterioration of renal function was the main manifestation. Conclusion: Our findings harmonize with bibliographical data that identify tubulointerstitial nephritis as the most frequent histological lesion related to ICIs administration. The preferential involvement of tubulointerstitial tissue could be associated with the reported higher expression levels of PD-L1 on tubular epithelial cells, compared to glomeruli. On the other hand, glomerular involvement is probably a consequence of a systemic immune system reconstruction, induced by immune-checkpoints inhibition.

The role of kidney biopsy in immune checkpoint inhibitor nephrotoxicity

Immune checkpoint inhibitors, medications that boost host immune response to tumor cells, are now at the forefront of anti-cancer therapy. While efficacious in the treatment of patients with advanced cancer, immune checkpoint inhibitors can lead to serious autoimmune side effects involving any organ in the body. Immune checkpoint inhibitor nephrotoxicity is an increasingly recognized cause of acute kidney injury in patients with cancer. This review discusses the clinical and histopathologic diagnosis of immune checkpoint inhibitor nephrotoxicity, highlighting the need for more reliable non-invasive diagnostic testing. We focus on the controversy surrounding the role of kidney biopsy in diagnosis and management of suspected immune checkpoint inhibitor toxicity with inclination toward pursuing kidney biopsy in certain outlined circumstances. Finally, we briefly discuss treatment of immune checkpoint inhibitor nephrotoxicity and the decision to re-challenge immunotherapy in patients who experience these adverse events.

Compartmentalization of Intrarenal Programmed Cell Death Protein 1-Ligand 1 and Its Receptor in Kidney Injury Related to Immune Checkpoint Inhibitor Nephrotoxicity

Background

Due to advances in cancer therapy, immune checkpoint inhibitors (ICIs) are new classes of drugs targeting programmed cell death protein 1-ligand 1 (PD-L1) or its receptor (PD-1) used in many cancer therapies. Acute interstitial nephritis (AIN) is a potential and deleterious immune-related adverse events (irAE) and the most common biopsy-proven diagnosis in ICI-related nephrotoxicity. AIN in patients receiving ICIs is was only seen in cases with tubular PD-L1 positivity, while PD-1 expression is limited to inflammatory cells and also observed in injured kidneys independent of ICI therapy. We have previously described that PD-L1 positivity can also be detected in glomerular and endothelial compartments. We here aimed to describe compartmentalization of renal PD-L1 expression specifically in injured kidneys with confirmed nephrotoxicity related to ICIs, its association with presence of PD-1, and clinical findings.

Methods

We included human kidney samples with AIN related to ICI therapy to describe PD-L1 and PD-1 expression localized to different renal compartments in association with clinical and laboratory parameters.

Results

We herein report compartmentalization of PD-L1 with tubular positivity in all cases, partially overlapping with glomerular and endothelial PD-L1 positivity. Furthermore, we provide evidence that tubular PD-L1 in ICI-related nephrotoxicity correlates with levels of C-reactive protein (CRP), while glomerular and endothelial PD-L1 positivity with lower serum levels of complement component C4. Interestingly, glomerular PD-L1 correlated with kidney function, while interstitial cell PD-1 positivity specifically with severity of kidney injury. Finally, we provide evidence for signaling pathways associated with intrarenal PD-L1/PD-1 expression.

Conclusion

Our findings implicate that that AIN related to ICI therapy requires presence of interstitial cells positive for PD-1, and that blocking PD-L1/PD-1 signaling may contribute to nephrotoxicity specifically related to these agents.

Pharmacological Treatments Available for Immune-Checkpoint-Inhibitor-Induced Colitis

Immune checkpoint inhibitor treatment has shown revolutionary therapeutic effects in various carcinomas. However, immune-related adverse events (irAE) following this treatment can sometimes lead to treatment discontinuation. One such frequently encountered adverse event is immune-related colitis (irAE colitis). Corticosteroids (CS) are the first-line treatment for irAE colitis, but we often encounter CS-refractory or -resistant cases. The application of multiple biologics has been proposed as a therapy to be administered after CS treatment; however, the efficacy and safety of biologics for patients with irAE colitis who do not respond to CS have not been established. This review summarizes the treatment regimens available for irAE colitis, focusing on the mechanism of action of corticosteroids, infliximab, vedolizumab, and other drugs.

Acute Kidney Injury Induced by Immune Checkpoint Inhibitors

BACKGROUND

Recent advances in immune therapy have focused on several agents that target tumor suppression; specifically, use of immune checkpoint inhibitors (ICIs), such as ipilimumab, pembrolizumab, and nivolumab, has become an important strategy in cancer therapy as they improve outcomes in malignant disease. However, the incidence of renal complications arising from the widespread use of ICIs may be underestimated.

SUMMARY

The most frequently reported renal condition caused by ICI use is acute interstitial nephritis, and for clinicians, the crucial question is how to effectively manage patients who develop renal side effects due to cancer treatment. Currently, treatment of kidney injury associated with ICIs adheres to clinical guidelines described in Kidney Disease Improving Global Outcomes, which entails drug withdrawal and glucocorticoids or combined immunosuppressant use based on disease stage; however, there is no consensus on renal biopsy.

KEY MESSAGES

Despite significant progress in prevention and treatment, the incidence and mortality of ICI-induced acute kidney injury (AKI) remain very high. This article will discuss the general clinical manifestations, mechanisms of toxicity, renal complications of ICI therapy, and related biomarkers of renal damage. It is envisaged that this information would help clinicians effectively manage AKI due to ICI therapy.

Brief Communication PD1-related Nephrotoxicity: Optimizing Its Clinical Management Through Histopathologic Features

Immune-related nephrotoxicity (ir-N) is a rare adverse event of immune-checkpoint(s) inhibitors (ICI) therapy and its clinical management is still debated. Among 501 consecutive ICI-treated patients at our Institution, 6 who developed an ir-N with clinical signs suggestive for an acute kidney injury underwent kidney biopsy. Histology showed an acute tubule-interstitial nephritis, simulating the scenario of acute T-cell-mediated kidney transplant rejection. Thus, the management of allograft kidney rejection routinely utilized at our clinic was implemented, leading to rapid renal function improvement. Histologic features supporting the definition of an immune-mediated acute kidney injury in ICI-treated patients may help optimizing the clinical management of ir-N.

Serum anti-CRP antibodies differentiate etiology and predict relapse in acute tubulointerstitial nephritis

INTRODUCTION

Acute tubulointerstitial nephritis (ATIN) is a common cause of acute kidney injury with various etiologies. It has been shown that autoimmune-related ATIN (AI-ATIN) has a higher recurrence rate and a greater likelihood of developing into chronic kidney disease compared with drug-induced ATIN, yet misdiagnosis at renal biopsy is not uncommon.

METHODS

Patients who were clinicopathologically diagnosed as ATIN from January 2006 to December 2015 in Peking University First Hospital were enrolled. Clinical, pathological and follow-up data were collected. Serum samples on the day of renal biopsy were collected and tested for anti-C-reactive protein (CRP) antibodies. CRP and its linear peptides were used as coating antigens to detect antibodies. Statistical analysis was used to assess the diagnostic value of the antibodies.

RESULTS

Altogether 146 patients were enrolled. The receiver operating characteristic-area under the curve of the anti-CRP antibody for the identification of late-onset AI-ATIN was 0.750 (95% confidence interval 0.641-0.860, P < 0.001) and the positivity was associated with ATIN relapse (adjusted hazard ratio = 4.321, 95% confidence interval 2.402-7.775, P < 0.001). Antibodies detected by CRP linear peptide 6 (PT6) were superior with regard to differentiating patients with AI-ATIN, while antibodies detected by peptide 17 (PT17) could predict ATIN relapse. Antibodies detected by these two peptides were positively correlated with the severity of tubular dysfunction and pathological injury.

CONCLUSIONS

Serum anti-CRP antibody could be used to differentiate late-onset AI-ATIN and predict relapse of ATIN at the time of renal biopsy. The CRP linear peptides PT6 and PT17 could be used as coating antigens to detect anti-CRP antibodies, which may provide more information for the clinical assessment of ATIN.

Soluble PD-L1 Concentration Is Proportional to the Expression of PD-L1 in Tissue and Is Associated with a Poor Prognosis in Esophageal Squamous Cell Carcinoma

INTRODUCTION

We determined the soluble programmed cell death-1 ligand-1 (sPD-L1) concentration in patients with esophageal squamous cell carcinoma (ESCC), and confirmed the PD-L1 expression in resected specimens.

METHODS

Blood samples were collected from 73 patients with histologically proven ESCC. The serum levels of sPD-L1 were measured using an enzyme-linked immunosorbent assay. The correlations between the sPD-L1 concentration and the expression of PD-L1 in tumor specimens and tumor depth, lymph node metastasis, disease stage, and various laboratory data were assessed.

RESULTS

sPD-L1 levels in patients with high PD-L1 expression levels in tumor tissue were significantly higher than in patients with low PD-L1 expression levels (p = 0.042). The OS of the sPD-L1-high group was significantly worse than that of the low group (p = 0.028). Similarly, patients in whom a tissue specimen was PD-L1-positive group showed significantly poorer OS.

CONCLUSION

The sPD-L1 concentration was correlated with the PD-L1 expression in tissues. Patients with PD-L1-positive tissue specimens showed significantly higher sPD-L1 levels in comparison to PD-L1-negative cases. Furthermore, patients with high sPD-L1 expression levels had a significantly worse prognosis than those with low sPD-L1 expression levels, and patients with a PD-L1-positive tissue specimen had a significantly worse prognosis than patients in whom the tissue specimen showed a low PD-L1 expression level.

Current trends of anti-cancer molecular targeted therapies: a narrative review focusing on renal complications and their histological features

Among the recent advancements in cancer treatment, the emergence of novel drugs targeting a specific molecule has considerably modulated the therapeutic strategies. Despite the efficacy, the associated renal complications distinct from conventional chemotherapeutic drugs have been reported. Targeted therapy drugs include monoclonal antibodies and small molecule agents. Bevacizumab is one of the monoclonal antibodies that targets vascular endothelial growth factor (VEGF) and blocks tumor angiogenesis. This anti-angiogenic effect causes endothelial injury, resulting in "thrombotic microangiopathy-like lesion" confined to the glomerulus. Segmental hyalinosis of the glomerular tuft is also observed. The small molecular agents, including tyrosine kinase inhibitors (TKIs), such as pazopanib, can cause endothelial injury and podocytopathy through blocking VEGF receptors and their downstream signaling. Minimal change nephrotic syndrome and focal segmental glomerulosclerosis are associated with TKIs-induced renal complications. Immune checkpoint inhibitors (ICIs), such as PD-1, CTLA-4 and PD-L1, are a novel form of immunotherapy against cancer, which modulates immune checkpoints. Owing to its unique function, ICIs cause inflammatory side effects referred to as immune-related adverse events (irAEs). irAEs in the kidney commonly include acute tubulointerstitial nephritis and tubulitis, occasionally accompanied by granuloma formation. The occurrence of vasculitis, thrombotic microangiopathy, and glomerulonephritis is also reported. Renal toxicity associated with other molecular drugs such as protease inhibitors and mammalian target of rapamycin inhibitors has also been documented. In this article, we review the clinico-histopathological aspects of renal complications associated with molecular targeted therapies, focusing on anti-VEGF agents and immune checkpoint inhibitors from the pathologists' viewpoint.

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.

Immunotherapy-Related Acute Kidney Injury

Nephrotoxicity associated with immunotherapy is increasingly being encountered in clinical practice. Drugs that augment the immune system to eradicate cancer are revolutionary in the field of oncology. Older generation immunotherapies such as high-dose interleukin and interferon-alpha are now being replaced with more effective immune checkpoint inhibitors and chimeric antigen receptor T-cell therapies, which have shown promising results in numerous clinical trials. Unfortunately, these treatments come with a unique baggage of adverse effects including nephrotoxicity. This onconephrology review summarizes the immunotherapies currently in use and their kidney-related toxicities, pathophysiology, and their management.

Kidney injury associated with antitumor therapy: focus on the adverse events of modern immuno-oncological drugs

Immune checkpoint inhibitors (ICIs), including cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and programmed death protein 1 (PD-1) or its ligand (PD-L1), are a new generation of immuno-oncological drugs that to date have demonstrated efficacy in a number of malignancies. The mechanism of ICT inhibitors action consist in the potentiation of the immune response by eliminating the tumor cells inhibitory effect on the T-lymphocytes activation. However, excessive immune system activation can cause the development of a special class of immune-related adverse events (irAEs) involved a wide variety of organs and systems, including the kidneys. Despite the fact that immuno-mediated kidney injury caused by ICI therapy develops quite rarely, it can be serious and determine the patient's prognosis, which necessitates early diagnosis and timely start of treatment. In this regard, awareness of the manifestations of ICI-associated renal irAEs is particularly relevant not only for oncologists and for nephrologists, but for doctors of other specialties. In this review, we elucidated the main variants of immuno-mediated kidney injury caused by ICI therapy, discussed possible predictors and mechanisms of their development, and considers the general principles of diagnosis and management of patients according to the severity of irAEs.

Nivolumab-associated glomerular endothelial injury in a patient with gastric cancer

A 68-year-old male with gastric cancer was treated with tegafur/gimeracil/oteracil and oxaliplatin for 6 months. Thereafter, he was treated with paclitaxel and ramucirumab for 3 months. However, neither regimen had much effect. Thus, he was treated with nivolumab for 2 months, but he developed proteinuria, microhematuria, and an acute kidney injury. A kidney biopsy revealed occasional swollen endothelial cells and proliferating mesangial cells. Few abnormal findings were seen in the tubules or interstitial tissue. Immunofluorescent staining showed segmental immunoglobulin A and complement component 3 deposition, in the mesangial area. Electron microscopy showed a small amount of electron-dense deposits in the paramesangial area and swollen endothelial cells. Mesangial interposition, the loss of endothelial cell fenestration, and subendothelial edema were also observed. Furthermore, foot process effacement and villous transformation of epithelial cells were noted. After the discontinuation of nivolumab, the patient's renal function gradually improved, and his proteinuria disappeared. Nivolumab treatment was restarted at that time because of cancer progression; however, it was ineffective. No occult blood was detected from 7 months after the administration of the last dose of nivolumab. This is a unique case, in which a kidney biopsy revealed evidence of nivolumab-associated glomerular endothelial injury.

PD-1 immunobiology in glomerulonephritis and renal cell carcinoma

BACKGROUND

Programmed cell death protein (PD)-1 receptors and ligands on immune cells and kidney parenchymal cells help maintain immunological homeostasis in the kidney. Dysregulated PD-1:PD-L1 binding interactions occur during the pathogenesis of glomerulopathies and renal cell carcinoma (RCC). The regulation of these molecules in the kidney is important to PD-1/PD-L1 immunotherapies that treat RCC and may induce glomerulopathies as an adverse event.

METHODS

The expression and function of PD-1 molecules on immune and kidney parenchymal cells were reviewed in the healthy kidney, PD-1 immunotherapy-induced nephrotoxicity, glomerulopathies and RCC.

RESULTS

PD-1 and/or its ligands are expressed on kidney macrophages, dendritic cells, lymphocytes, and renal proximal tubule epithelial cells. Vitamin D3, glutathione and AMP-activated protein kinase (AMPK) regulate hypoxic cell signals involved in the expression and function of PD-1 molecules. These pathways are altered in kidney disease and are linked to the production of vascular endothelial growth factor, erythropoietin, adiponectin, interleukin (IL)-18, IL-23, and chemokines that bind CXCR3, CXCR4, and/or CXCR7. These factors are differentially produced in glomerulonephritis and RCC and may be important biomarkers in patients that receive PD-1 therapies and/or develop glomerulonephritis as an adverse event CONCLUSION: By comparing the functions of the PD-1 axis in glomerulopathies and RCC, we identified similar chemokines involved in the recruitment of immune cells and distinct mediators in T cell differentiation. The expression and function of PD-1 and PD-1 ligands in diseased tissue and particularly on double-negative T cells and parenchymal kidney cells needs continued exploration. The possible regulation of the PD-1 axis by vitamin D3, glutathione and/or AMPK cell signals may be important to kidney disease and the PD-1 immunotherapeutic response.

Variable Expression of Programmed Cell Death Protein 1-Ligand 1 in Kidneys Independent of Immune Checkpoint Inhibition

Context

Due to recent advantages in cancer therapy, immune checkpoint inhibitors (ICIs) are new classes of drugs targeting programmed cell death protein 1 (PD-1) or its ligand programmed cell death protein 1-ligand 1 (PD-L1) used in many cancer therapies. Acute interstitial nephritis (AIN) is a potential and deleterious immune-related adverse events (irAE) in the kidney observed in patients receiving ICIs and the most common biopsy-proven diagnosis in patients who develop acute kidney injury (AKI). Based on previous reports, AIN in patients receiving ICIs is associated with tubular positivity for PD-L1, implicating that PD-L1 positivity reflects susceptibility to develop renal complications with these agents. It remains unclear if PD-L1 positivity is acquired specifically during ICI therapy or expressed independently in the kidney.

Methods

PD-L1 was analyzed in experimental mouse models of ischemia-reperfusion injury (IRI), folic acid-induced nephropathy (FAN), unilateral ureteral obstruction (UUO), and nephrotoxic serum nephritis (NTN) by immunostaining, SDS-PAGE, and subsequent immunoblotting. In addition, we included a total number of 87 human kidney samples (six renal biopsies with AIN related to ICI therapy, 13 nephrectomy control kidneys, and 68 ICI-naïve renal biopsies with various underlying kidney diseases to describe PD-L1 expression.

Results

We here report distinct PD-L1 expression in renal compartments in multiple murine models of kidney injury and human cases with various underlying kidney diseases, including ICI-related AIN and renal pathologies independent of ICI therapy. PD-L1 is frequently expressed in various renal pathologies independent of ICI therapy and could potentially be a pre-requisit for susceptibility to develop AKI and deleterious immune-related AIN. In addition, we provide evidence that tubular PD-L1 positivity in the kidney is associated with detection of urinary PD-L1⁺ tubular epithelial cells.

Conclusion

Our study implicates that PD-L1 is frequently expressed in various renal pathologies independent of ICI therapy and could potentially be a pre-requisit for susceptibility to develop AKI and deleterious immune-related AIN. Because non-invasive detection of PD-L1⁺ cells in corresponding urine samples correlates with intrarenal PD-L1 positivity, it is attractive to speculate that further non-invasive detection of PD-L1⁺ cells may identify patients at risk for ICI-related AIN.

Acute interstitial nephritis and PR3-ANCA following reintroduction of pembrolizumab: a case report

Renal toxicity from immune checkpoint inhibitors (ICIs) is an increasingly recognized cause of acute kidney injury among patients with cancer. ICI-associated acute kidney injuries typically present as acute interstitial nephritis and the timing of onset is highly variable. Herein, we present a case of a patient with relapsed metastatic melanoma previously treated with pembrolizumab who developed grade 3 immune-related renal toxicity after reintroduction of the same ICI, secondary to acute interstitial nephritis with accompanying high PR3-antineutrophil cytoplasmic antibody titer. The patient improved after steroid treatment and discontinuation of pembrolizumab. This case highlights the importance of not excluding ICI-related nephrotoxicity as a possible cause of renal failure, including in those who previously tolerated ICI treatment, since it is a treatable entity.

Onconephrology: The intersections between the kidney and cancer

Onconephrology is a new subspecialty of nephrology that recognizes the important intersections of kidney disease with cancer. This intersection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, paraneoplastic glomerulonephritis, and the interactions of chronic kidney disease with cancer. Data clearly demonstrate that, when patients with cancer develop acute or chronic kidney disease, outcomes are inferior, and the promise of curative therapeutic regimens is lessened. This highlights the imperative for collaborative care between oncologists and nephrologists in recognizing and treating kidney disease in patients with cancer. In response to this need, specific training programs in onconephrology as well as dedicated onconephrology clinics have appeared. This comprehensive review covers many of the critical topics in onconephrology, with a focus on acute kidney injury, chronic kidney disease, drug-induced nephrotoxicity, kidney disease in stem cell transplantation, and electrolyte disorders in patients with cancer.

Interstitial nephritis with pembrolizumab: A case report and review

Introduction

Pembrolizumab is a monoclonal antibody approved for adult patients with advanced non–small-cell lung cancer (NSCLC). Although immune related adverse events are considered to be well tolerated, complications may occur and discontinuation of the treatment could be required.

Case report

A 62-year old patient diagnosed with advanced non-small cell lung cancer experienced a decline in the renal function after seven cycles with pembrolizumab. Management & outcome: After ruling out other common causes of interstitial nephritis, pembrolizumab was attributed as a cause of interstitial nephritis. At first, toxicity was managed with corticosteroids and closely monitoring the patient, but finally pembrolizumab had to be discontinued due to the kidney function did not recover.

Discussion

Renal and urinary disorders were reported in <3% of patients treated with pembrolizumab, being interstitial nephritis the most reported toxicity. The kidney damage can be a complication to consider in patients receiving pembrolizumab. Early identification of an increase in serum creatinine levels may help with prevention by establishing an effective treatment, although it may not mean a total recovery of kidney function.

Immune Checkpoint Inhibitors and Immune-Related Adverse Renal Events

Renal toxicities have been increasingly recognized as complications of the immune checkpoint inhibitors (ICIs). Recent studies have outlined the incidence and potential risk factors for nephrotoxicity. For clinicians, the key question is how to manage patients who develop these adverse renal effects. This is of paramount importance to providers as ICI use for cancer therapy becomes more widespread and nephrotoxicity increasingly develops. As clinicians encounter ICI-associated nephrotoxicity, an appropriate approach to management is required to facilitate the best outcomes in patients with cancer. Importantly, ICI rechallenge in patients who developed ICI-related acute kidney injury (AKI) is unclear and represents a conundrum for providers. Clinicians struggle with the "if, when, and how to" questions related to ICI rechallenge in this subset of patients. In addition, ICI use in the transplant population raises concerns for promoting acute rejection when treating cancer in these patients. We herein review current information on these various topics.

Programmed cell death-1 (PD-1) and programmed death-ligand 1 (PD-L1) expression in PD-1 inhibitor-associated colitis and its mimics

AIMS

Immune checkpoint inhibitors (ICIs) have revolutionised the treatment of advanced malignancies by boosting immune-mediated destruction of neoplastic cells, but are associated with side effects stemming from generalised immune system activation against normal tissues. Checkpoint ligand expression in non-tumoral cells of tissues affected by immune-related adverse effects has been described in ICI-associated hypophysitis, myocarditis, and acute interstitial nephritis. We aimed to investigate the tissue expression of the immune checkpoint receptor programmed cell death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), in PD-1 inhibitor-associated colitis (PD1i colitis).

METHODS AND RESULTS

PD-1 and PD-L1 immunohistochemical expression levels were analysed in 15 cases of PD1i colitis and potential mimics-infectious colitis and inflammatory bowel disease (IBD). Increased epithelial expression of PD-L1 was observed in PD1i colitis as compared with normal colon and infectious colitis, but the expression level was lower than that in IBD. Conversely, PD-1 expression in inflammatory cells was higher in infectious colitis, intermediate in IBD, and minimal or absent in normal colon and in patients receiving PD-1 inhibitors.

CONCLUSIONS

Although our results do not justify the use of PD-L1 as a discriminatory marker of PD1i colitis against other entities within the differential diagnosis, they support the concept that PD1i colitis and IBD have similar pathogenetic mechanisms. They also highlight the fact that PD-L1 epithelial overexpression is a commonly used mechanism of the gastrointestinal tract mucosa to protect itself from inflammatory-mediated damage resulting from different aetiologies, which probably underpins the high incidence of gastrointestinal immune-related adverse effects in patients receiving ICI therapies, in whom this mechanism is disrupted.

Nivolumab-induced IgA nephropathy in a patient with advanced gastric cancer: A case report

INTRODUCTION

Immune checkpoint inhibitors including nivolumab, an antibody against programmed death-1, have been increasingly introduced in various cancer treatment regimens, and are reported to be associated with immune-related adverse events. Nivolumab-induced renal injury is generally caused by acute interstitial nephritis and is managed by drug discontinuation and steroid therapy. Although this agent can infrequently induce glomerulonephritis, the pathogenesis and therapeutic strategy remain undetermined.

PATIENT CONCERNS

A 78-year-old man was diagnosed with advanced gastric cancer with portal thrombosis. First- and second-line chemotherapies were ineffective; thus, nivolumab monotherapy was initiated. Although it effectively prevented tumor growth, proteinuria and microhematuria appeared 2 months later. Despite drug discontinuation, serum creatinine progressively increased from 0.72 to 1.45 mg/dL. Renal biopsy revealed mesangial IgA and C3 deposition in immunofluorescence analysis and mesangial proliferation with crescent formation in light microscopy.

DIAGNOSIS

The patient was diagnosed with IgA nephropathy. Based on the temporal relationship between the nivolumab therapy and abnormal urinalysis, IgA nephropathy was considered to have been induced by nivolumab.

INTERVENTIONS

A moderate dose (0.6 mg/kg/day) of prednisolone was orally administrated, with tapering biweekly.

OUTCOMES

Steroid therapy stabilized his serum creatinine levels and markedly reduced proteinuria. However, bacterial pneumonia substantially impaired his performance status; thus, nivolumab could not be restarted despite tumor regrowth.

LESSONS

IgA nephropathy should be recognized as an uncommon renal adverse event during nivolumab therapy. After drug discontinuation, nivolumab-induced IgA nephropathy is likely to respond to moderate doses of steroid therapy with early tapering. However, more evidence is needed to determine whether nivolumab can be safely restarted during or after steroid therapy.

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

Background

The incidence of acute tubulointerstitial nephritis (ATIN) related to drugs has dramatically increased over recent years. A new subtype of ATIN, apparently different from classical drug-related ATIN, has emerged that has been related to the administration of immune checkpoint inhibitors (ICIs). We investigated these differences between ICI-related ATIN (ICI ATIN) and non-ICI-related ATIN in terms of clinical features, response to treatment with steroids and the evolution of kidney function.

Methods

A total of 47 patients diagnosed with ATIN from two centres were recruited. Of these, 13 patients presented with ATIN during ICI treatment and 34 were diagnosed with ATIN attributed to other drugs. The main demographic, clinical and analytical variables such as gender, age and current medication were recorded. The type of malignancy, oncological treatment, ICI dose and presence of extrarenal immune-related adverse events were also reviewed. Renal biopsy diagnosis, time to drug withdrawal and ATIN-specific treatment, as well as laboratory data during follow-up, were also studied.

Results

Patients diagnosed with ICI ATIN presented with lower creatinine (ICI ATIN 3.8 ± 1.03  versus classical ATIN 5.98 ± 4.15 mg/dL, P = 0.007) at diagnosis and higher urinary leucocyte counts (ICI ATIN 263.2 ± 418.04 versus classical ATIN 133.55 ± 284.62, P = 0.048) compared with patients with non-ICI-related ATIN. Time from initiation of the culprit drug to ATIN diagnosis was longer in patients with ICI ATIN than in those with classical ATIN (197.07 ± 184.99 versus 114.4 ± 352.16 days, P = 0.006). In addition, during follow-up, the slope of decreasing creatinine over time was lower for ICI ATIN compared with non-ICI-related ATIN.

Conclusions

In this study, we analysed differences between ICI ATIN and classical ATIN. We found that patients with ICI ATIN presented with a larger latency period after culprit drug initiation, milder acute kidney injury and slower creatinine amelioration compared with those with classical ATIN. These results may, in part, be ascribed to potential differences in the pathological mechanisms involved in ATIN development, suggesting that ICI and classical ATIN may be different diseases with similar renal histologies.

The role of programed death-ligand 1 in renal diseases

Programed death-ligand 1 (PD-L1, B7-H1, CD274) is a coinhibitory molecule that plays a vital role in the pathogenesis of both neoplastic and nonneoplastic diseases. However, the role of PD-L1 in primary and secondary renal diseases remains to be clarified. Previous studies have shown that both intracellular and intercellular PD-L1 participate in renal diseases via complex mechanisms. PD-L1 plays a dual role in lupus nephritis and has a protective effect in renal ischemia reperfusion injury and nephrotoxic nephritis but not in proliferative immune complex glomerulonephritis. PD-L1 supplementation, anti-PD-L1 antibodies, and D-peptide antagonists have promising application prospects in the treatment of renal diseases. In this review, we summarize the available data published on PD-L1 in renal diseases for the first time.

Acute fatal myocarditis after a single dose of anti-PD-1 immunotherapy, autopsy findings: a case report

Nivolumab (PD-1 inhibitor) and Ipilimumab (CTLA-34 inhibitor) are both commonly used immune checkpoint inhibitor therapies for various cancers. Various adverse events are associated with these therapies, including hepatitis, nephritis, dermatitis, and myocarditis. It is believed these adverse events occur in part because modified cellular receptors lead to enhanced CD4 and CD8 lymphoproliferation. These events usually occur after several months and rounds of treatment. Here we present a case of an 81-year-old male with recurrent renal cell carcinoma (RCC) who experienced myocarditis after only a single dose of combination therapy with Nivolumab and Ipilimumab. He presented with elevated troponins and a third-degree heart block; three days after admission he died. Histologic examination revealed a predominance of CD3 T cells (CD4 > CD8) and CD68 macrophages, with occasional CD20 B cells. C4d staining was negative in the interstitial capillaries, suggesting that antibody-mediated injury of endothelial cells did not play a significant role in the pathogenesis of this myocarditis. Additional studies ruled out an infectious etiology. Immune checkpoint inhibitors are increasingly more common, and it is important clinicians are aware patients can present with myocarditis early in the course of treatment.