Kidney diseases associated with anti-vascular endothelial growth factor (VEGF): an 8-year observational study at a single center

Similar Risk of Kidney Failure among Patients with Blinding Diseases Who Receive Ranibizumab, Aflibercept, and Bevacizumab: An Observational Health Data Sciences and Informatics Network Study

PURPOSE

To characterize the incidence of kidney failure associated with intravitreal anti-VEGF exposure; and compare the risk of kidney failure in patients treated with ranibizumab, aflibercept, or bevacizumab.

DESIGN

Retrospective cohort study across 12 databases in the Observational Health Data Sciences and Informatics (OHDSI) network.

SUBJECTS

Subjects aged ≥ 18 years with ≥ 3 monthly intravitreal anti-VEGF medications for a blinding disease (diabetic retinopathy, diabetic macular edema, exudative age-related macular degeneration, or retinal vein occlusion).

METHODS

The standardized incidence proportions and rates of kidney failure while on treatment with anti-VEGF were calculated. For each comparison (e.g., aflibercept versus ranibizumab), patients from each group were matched 1:1 using propensity scores. Cox proportional hazards models were used to estimate the risk of kidney failure while on treatment. A random effects meta-analysis was performed to combine each database's hazard ratio (HR) estimate into a single network-wide estimate.

MAIN OUTCOME MEASURES

Incidence of kidney failure while on anti-VEGF treatment, and time from cohort entry to kidney failure.

RESULTS

Of the 6.1 million patients with blinding diseases, 37 189 who received ranibizumab, 39 447 aflibercept, and 163 611 bevacizumab were included; the total treatment exposure time was 161 724 person-years. The average standardized incidence proportion of kidney failure was 678 per 100 000 persons (range, 0-2389), and incidence rate 742 per 100 000 person-years (range, 0-2661). The meta-analysis HR of kidney failure comparing aflibercept with ranibizumab was 1.01 (95% confidence interval [CI], 0.70-1.47; P = 0.45), ranibizumab with bevacizumab 0.95 (95% CI, 0.68-1.32; P = 0.62), and aflibercept with bevacizumab 0.95 (95% CI, 0.65-1.39; P = 0.60).

CONCLUSIONS

There was no substantially different relative risk of kidney failure between those who received ranibizumab, bevacizumab, or aflibercept. Practicing ophthalmologists and nephrologists should be aware of the risk of kidney failure among patients receiving intravitreal anti-VEGF medications and that there is little empirical evidence to preferentially choose among the specific intravitreal anti-VEGF agents.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Assessment of epidemiology and outcomes of adult patients with kidney-limited thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are usually associated with hematological features (RH-TMA). The epidemiology of TMA limited to kidneys (RL-TMA) is unclear Therefore, patients with TMA and native kidney biopsies were identified during 2009-2022 in 20 French hospitals and results evaluated. RL-TMA was present in 341/757 (45%) patients and associated with lower creatinine levels (median 184 vs 346 μmol/L) than RH-TMA. RL-TMA resulted from virtually all identified causes, more frequently from anti-VEGF treatment and hematological malignancies but less frequently from shigatoxin-associated hemolytic uremic syndrome (HUS), systemic sclerosis, gemcitabine and bacterial infection, and even less frequently when three or more causes/triggers were combined (RL-TMA: 5%; RH-TMA: 12%). RL-TMA was associated with significantly lower major cardiovascular events (10% vs 20%), kidney replacement therapy (23% vs 43%) and death (12% vs 20%) than RH-TMA during follow-up (median 28 months). Atypical HUS (aHUS) was found in 326 patients (RL-TMA: 43%, RH-TMA: 44%). Among the 69 patients with proven complement-mediated aHUS, eculizumab (anti-C5 therapy) was used in 43 (62%) (RL-TMA: 35%; RH-TMA: 71%). Among the 257 other patients with aHUS, including 51% with RL-TMA, eculizumab was used in 29 but with unclear effects of this treatment. Thus, RL-TMA represents a very high proportion of patients with TMA and results from virtually all known causes of TMA and includes 25% of patients with complement-mediated aHUS. Adverse outcomes of RL-TMA are lower compared to RH-TMA but remain significant. Anti-C5 therapy was rarely used in RL-TMA, even in proven complement-mediated aHUS, and its effects remain to be assessed.

Rationale for immune checkpoint inhibitors plus targeted therapy for advanced renal cell carcinoma

Renal cell carcinoma (RCC) is a frequent urological malignancy characterized by a high rate of metastasis and lethality. The treatment strategy for advanced RCC has moved through multiple iterations over the past three decades. Initially, cytokine treatment was the only systemic treatment option for patients with RCC. With the development of medicine, antiangiogenic agents targeting vascular endothelial growth factor and mammalian target of rapamycin and immunotherapy, immune checkpoint inhibitors (ICIs) have emerged and received several achievements in the therapeutics of advanced RCC. However, ICIs have still not brought completely satisfactory results due to drug resistance and undesirable side effects. For the past years, the interests form researchers have been attracted by the combination of ICIs and targeted therapy for advanced RCC and the angiogenesis and immunogenic tumor microenvironmental variations in RCC. Therefore, we emphasize the potential principle and the clinical progress of ICIs combined with targeted treatment of advanced RCC, and summarize the future direction.

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

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

Drug-induced glomerular diseases

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

Chronic thrombotic microangiopathy presenting as acute nephrotic syndrome in a patient with renal cancer receiving tyrosine kinase inhibitor therapy

Thrombotic microangiopathy (TMA) is a rare but serious side effect of tyrosine kinase inhibitor (TKI) therapy. Previous case reports of renal TMA have usually occurred in the first few months of TKI initiation with only very few cases occurring within 2-3 years. We report a case of a patient who was referred to the Nephrology service for nephrotic syndrome and worsening renal function after 8 years of sunitinib therapy for metastatic clear cell carcinoma of the kidney. Renal biopsy showed chronic TMA without another secondary aetiology identified. With discontinuation of sunitinib and pharmacological optimisation of his hypertension, his renal function and proteinuria both significantly improved. No relapse or recurrence of disease activity was noted after a year of follow-up. This case highlights the importance of remaining vigilant for the development of renal TMA even after an extended duration of TKI therapy.

Five years of safety profile of bevacizumab: an analysis of real-world pharmacovigilance and randomized clinical trials

OBJECTIVE

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor. It has a wide range of clinical applications in various cancers and retinal diseases. The drugs entered the Chinese market by a large margin in 2017, and the user population changed to some extent. This study reevaluated the safety of bevacizumab through an analysis of the World Pharmacovigilance database (Food and Drug Administration Open Vigil 2.1) in conjunction with a comprehensive meta-analysis of RCTs.

METHODS

Real-world pharmacovigilance data originating from case reports were mined using Open Vigil and coded at the preferred term (PT) level using the Standardized MedDRA Query. Proportional reporting ratios (PRR) and reporting odds ratios (ROR) were used to detect safety signals. Eligible items were screened by searching PubMed, Wanfang, and Web of Science, and data were extracted for systematic review and meta-analysis using RevMan 5.4 software.

RESULTS

Analysis of the drug pharmacovigilance database revealed that the most significant PRRs were limb decortication syndrome (PRR = 2926), stomal varices (PRR = 549), anastomotic (PRR = 457) and ureteral fistula (PRR = 406). Most safety signals at the PT level emerged as various types of injuries, toxicities, operational complications, systemic diseases, various reactions at the administration site, hematological and lymphatic disorders, and gastrointestinal disorders. Adverse reactions such as nasal septal perforation (PRR = 47.502), necrotizing fasciitis (PRR = 20.261), and hypertensive encephalopathy (PRR = 18.288) listed as rare in drug specifications should not be ignored with a high signal in the real world. A total of 8 randomized controlled trials (RCTs) were included in the meta-analysis, and the overall risk of adverse reactions following bevacizumab administration was relatively low, indicating a good safety profile (HR = 1.19, 95% CI:0.85 ~ 1.65, p = 0.32).

CONCLUSION

The frequent adverse reactions of bevacizumab occurring in the real world are consistent with the data provided in RCTs and drug specifications. However, adverse reactions such as nasal septum perforation, necrotizing fasciitis, hypertensive encephalopathy and so on, listed as rare in drug specifications, may have a high signal of correlation in the real world, which all requires active monitoring and timely adjustment of bevacizumab posology during its clinical use.

Renal Implications of Long-Term Systemic Bevacizumab for Recurrent Respiratory Papillomatosis

BACKGROUND

Bevacizumab is a vascular endothelial growth factor (VEGF) inhibitor that is used off-label for select cases of recurrent respiratory papillomatosis (RRP) that are severe, involve the distal airway or lung parenchyma, and refractory to other forms of adjuvant therapy. However, there is limited safety data for the use of bevacizumab in children and VEGF inhibitors are reported to have a range of adverse renal effects, including hypertension, proteinuria, and thrombotic microangiopathy (TMA).

CASE-DIAGNOSIS/TREATMENT

This report describes a case of severe juvenile-onset RRP that had an exceptionally high operative burden that was refractory to several adjuvant treatment strategies (including intralesional cidofovir and subcutaneous pegylated interferon). Bevacizumab treatment resulted in a dramatic and sustained improvement in disease control over a 5-year period. However, after 3 years of treatment, the patient developed hypertension and proteinuria and was found to have evidence of a glomerular TMA on kidney biopsy. These complications were successfully managed with a reduction in bevacizumab frequency and angiotensin-converting enzyme inhibitor initiation.

CONCLUSIONS

Clinicians caring for children treated with VEGF inhibitors should be aware of the potential renal complications and their management.

Immunoregulation mechanism of VEGF signaling pathway inhibitors and its efficacy on the kidney

Angiogenesis and immunosuppression are closely related pathophysiologic processes. Widely prescribed in malignant tumor and proliferative retinal lesions, VEGF signaling pathway inhibitors may cause hypertension and renal injury in some patients, presenting with proteinuria, nephrotic syndrome, renal failure and thrombotic microangiopathy. VEGF signaling pathway inhibitors block the action of both VEGF-A and VEGF-C. However, VEGF-A and VEGF-C produced by podocytes are vital to maintain the physiological function of glomerular endothelial cells and podocytes. There is still no effective treatment for kidney disease associated with VEGF signaling pathway inhibitors and some patients have progressive renal failure even after withdrawal of the drug. Recent studies reveal that blocking of VEGF-A and VEGF-C can activate CD4 +and CD8+ T cells, augment antigen-presenting function of dendritic cells, enhance cytotoxicity of macrophages and initiate complement cascade activation. VEGF and VEGFR are expressed in immune cells, which are involved in the immunosuppression and cross-talk among immune cells. This review summarizes the expression and function of VEGF-A and VEGF-C in the kidney. The current immunoregulation mechanisms of VEGF signaling pathway inhibitors are reviewed. Finally, combinate strategies are summarized to highlight the proposal for VEGF signaling pathway inhibitors.

Plasma exchange for treatment of a therapy-related thrombotic microangiopathy in a patient with advanced hepatocellular carcinoma-A case report

Key Clinical Message

Thrombotic microangiopathies are a side effect of anti-VEGF therapies, which are often limited to the kidneys but can also occur systemically and be life-threatening. Screening for increasing proteinuria is essential.

Abstract

We present the case of a 65-year-old male patient with a multifocal HCC, Barcelona clinic liver cancer (BCLC) classification B at the time of diagnosis. The HCC was treated with nine sessions of transarterial chemoembolization (TACE), and after a progress, the therapy was switched to a combination of atezolizumab and bevacizumab. Five months after therapy change, he presented with an acute kidney injury. The histopathology of the renal biopsy showed findings of a thrombotic microangiopathy (TMA), which we treated with 12 sessions of therapeutic plasma exchange in combination with steroids, resulting in a decreased TMA activity and later in a remission of the TMA. This case suggests the importance of monitoring the kidney function and proteinuria in patients under anti-vascular endothelial growth factor (VEGF) therapy and shows a rare differential diagnosis for a worsening of kidney function in these patients. Furthermore, it shows that therapeutic plasma exchange might be a valuable therapeutic option for patients with TMA due to anti-VEGF therapy.

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.

Focal Segmental Sclerosis Associated with the Novel Multi-tyrosine Kinase Inhibitor Ponatinib

Ponatinib is a novel multi-tyrosine kinase inhibitor (TKI) with potent inhibitory activity against refractory chronic myeloid leukemia (CML). Despite its high clinical efficacy, ponatinib induces various adverse events due to its multi-target characteristic. However, renal complications associated with ponatinib are rare. A 76-year-old woman had a history of chronic myeloid leukemia (CML) resistant to imatinib and nilotinib. Our patient developed proteinuria and renal function deterioration during treatment with ponatinib but not with imatinib or nilotinib. We herein report the first case of a patient with secondary focal segmental glomerulosclerosis (FSGS) with partial glomerular collapse induced by ponatinib treatment.

Renal Disorders with Oral Tyrosine Kinase Inhibitors in Metastatic Colorectal Cancer: An Analysis from the FDA Adverse Event Reporting System Database

BACKGROUND

this study assessed the nephrotoxicity of regorafenib (REG) and encorafenib (ENC) in metastatic colorectal cancer (mCRC) through an analysis of reports from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) database.

METHODS

descriptive and disproportional analyses were performed for all reports using ENC and REG as the primary suspect.

RESULTS

A total of 379 reports had at least one renal adverse drug reaction (ADR), and these ADRs were mainly related to REG (93.1%). Potential safety signals for REG included chromaturia (n = 44; ROR = 12.00, CI 95% = 8.92-16.16; IC = 2.36, IC025-IC075 = 2.06-2.66), hydronephrosis (10; 8.70, 4.67-16.19; 1.85, 1.23-2.47), nephrotic syndrome (7; 5.73, 2.73-12.03; 1.47, 0.73-2.21), renal impairment (53; 4.16, 3.17-5.45; 1.39, 1.12-1.66), dysuria (19; 3.06, 1.95-4.81; 1.06, 0.61-1.52), renal failure (38; 1.66, 1.20-2.28; 0.49, 0.17-0.81), and acute kidney injury (AKI) (43; 1.46, 1.08-1.97; 0.37, 0.07-0.67). For ENC, consistent disproportionalities were observed for AKI (n = 11; ROR = 3.79, CI 95% = 2.09-6.90; IC = 1.32, IC025-IC075 = 0.72-1.91) and dysuria (4; 6.50, 2.43-17.39; 1.86, 0.88-2.85).

CONCLUSIONS

these findings highlight some not extensively reported renal ADRs that require further investigations to better characterize the safety profiles of REG and ENC in patients with mCRC.

Pretreatment Proteinuria Predicts the Prognosis of Patients Receiving Systemic Therapy for Unresectable Hepatocellular Carcinoma

BACKGROUND

Proteinuria is a common adverse event in systemic therapy for hepatocellular carcinoma (HCC). However, whether the presence of pretreatment proteinuria affects the clinical course is still unclear.

METHOD

From 2011 to 2022, 321 patients with unresectable HCC who were treated with systemic therapy as first-line treatment were enrolled in this study. We retrospectively analyzed the presence of pretreatment proteinuria and the treatment course of systemic therapy.

RESULTS

In the cohort, 190 patients were tested for proteinuria qualitatively within 3 months before systemic therapy; 75 were treated with sorafenib, 72 were treated with lenvatinib, and 43 were treated with atezolizumab plus bevacizumab. Overall survival tended to be longer for patients treated with lenvatinib and significantly longer with atezolizumab plus bevacizumab in patients without pretreatment proteinuria but not for those treated with sorafenib. Further analysis was performed in 111 patients treated with lenvatinib or atezolizumab plus bevacizumab who had proteinuria measured quantitatively. Multivariate analysis including proteinuria, liver function, and HCC stage revealed that the severity of proteinuria was an independent predictor of prognosis.

CONCLUSION

Pretreatment proteinuria predicts a poorer prognosis in patients with unresectable HCC treated with lenvatinib or atezolizumab plus bevacizumab but not in those treated with sorafenib.

Onconephrology and Thrombotic Microangiopathy: Looking Beyond the Horizon

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

Renal Safety Profile of BCR-ABL Tyrosine Kinase Inhibitors in a Real-Life Setting: A Study Based on Vigibase®, the WHO Pharmacovigilance Database

Background: Alongside their BCR-ABL specificity, TKIs used in chronic myeloid leukemia also target other tyrosine kinases expressed in the kidney such as PDGFR, c-KIT, SRC, and VEGFR, which may result in specific renal adverse drug reaction (ADR). To evaluate the renal safety profile in real-life conditions, a case/non-case study was performed on VigiBase®, the WHO global safety database. Methods: From 7 November 2001 to 2 June 2021, all cases in which the involvement of imatinib, dasatinib, nilotinib, bosutinib, and ponatinib was suspected in the occurrence of renal ADR were extracted from VigiBase®. Disproportionality analyses were assessed using the reporting odds ratio. Results: A total of 1409 cases were included. Imatinib accounts for half of the reported cases. A signal of disproportionate reporting (SDR) of renal failure and fluid retention was found for the five TKIs. Only dasatinib and nilotinib were related to an SDR for nephrotic syndrome. Nilotinib and ponatinib were related to an SDR for renal artery stenosis, while dasatinib was related to an SDR for thrombotic microangiopathy. No SDR for tubulointerstitial nephritis was observed. Conclusion: This study identified a new safety signal, nephrotic syndrome, for nilotinib and highlights the importance of post-marketing safety surveillance.

Chemotherapy-Associated Thrombotic Microangiopathy

Thrombotic microangiopathy (TMA) is a syndrome of microangiopathic hemolytic anemia and thrombocytopenia with end-organ dysfunction. Although the advent of plasma exchange, immunosuppression, and complement inhibition has improved morbidity and mortality for primary TMAs, the management of secondary TMAs, particularly drug-induced TMA, remains less clear. TMA related to cancer drugs disrupts the antineoplastic treatment course, increasing the risk of cancer progression. Chemotherapeutic agents such as mitomycin-C, gemcitabine, and platinum-based drugs as well as targeted therapies such as antiangiogenesis agents and proteasome inhibitors have been implicated in oncotherapy-associated TMA. Among TMA subtypes, drug-induced TMA is less well-understood. Treatment generally involves withdrawal of the offending agent and supportive care targeting blood pressure and proteinuria reduction. Immunosuppression and therapeutic plasma exchange have not shown clear benefit. The terminal complement inhibitor, eculizumab, has shown promising results in some cases of chemotherapy-associated TMA including in re-exposure. However, the data are limited, and unlike in primary atypical hemolytic uremic syndrome, the role of complement in the pathogenesis of drug-induced TMA is unclear. Larger multicenter studies and unified definitions are needed to elucidate the extent of the problem and potential treatment strategies.

The need for kidney biopsy in the management of side effects of target and immunotherapy

Introduction

The introduction of innovative therapies, resulting from revisiting cancer as a disease of the immune system, has changed the scenario of complications. These new classes of drugs, such as targeted therapies and immune checkpoint inhibitors, assure substantial advantages in cancer therapy, despite some side effects affecting various organs, including the kidney. Histological evaluations of kidney disorders induced by targeted/immunotherapy are limited.

Method

In this study we examined the histological features of patients treated with new cancer agents who underwent a kidney biopsy for new onset kidney failure and/or urinary abnormalities.

Results

The cohort included 30 adult patients. The most frequently administered therapies were immunotherapy (30%), targeted therapy (26.7%), immunotherapy plus targeted therapy (13.3%), immunotherapy plus chemotherapy (13.3%), targeted therapy plus chemotherapy (16.7%). The most common histological finding was tubular interstitial nephritis (30%) that was associated with acute tubular necrosis in 4 cases, and thrombotic microangiopathy (23.3%). After kidney biopsy, 16 of the 30 patients were treated according to the histological diagnosis. Fourteen patients were treated with steroids. One patient with membranous nephropathy was treated with a single dose of rituximab. A patient with severe thrombotic microangiopathy requiring dialysis received a treatment with eculizumab for 3 months. Overall some renal response was obtained in all patients treated with glucocorticoids, while complete kidney response was achieved in the patient treated with rituximab. Cancer treatment was resumed without change in 21 out of 30 patients.

Conclusion

Kidney biopsy is critical for the management of kidney toxicities and should be strongly encouraged for patients showing adverse kidney effects of novel cancer agents.

Do intravitreal anti-vascular endothelial growth factor agents lead to renal adverse events? A pharmacovigilance real-world study

Purpose

Intravitreal vascular endothelial growth factor (VEGF) blockade is essential in many macular edema diseases treatment. However, intravitreal VEGF treatment has been reported to lead to deteriorated proteinuria and renal function. This study aimed to explore the relationship between renal adverse events (AEs) and the intravitreal use of VEGF inhibitors.

Method

In the FDA's Adverse Event Reporting System (FAERS) database, we searched for renal AEs of patients receiving various anti-VEGF drugs. We performed statistics on renal AEs in patients treated with Aflibercept, Bevacizumab, Ranibizumab, and Brolucizumab (from January 2004 to September 2022) using disproportionate and Bayesian analysis. We also investigated the time to onset, fatality, and hospitalization rates of renal AEs.

Results

We identified 80 reports. Renal AEs were most frequently associated with Ranibizumab (46.25%) and Aflibercept (42.50%). However, the association between intravitreal anti-VEGFs and renal AEs was insignificant since the reporting odds ratio of Aflibercept, Bevacizumab, Ranibizumab, and Brolucizumab were 0.23 (0.16, 0.32), 0.24 (0.11, 0.49), 0.37 (0.27, 0.51) and 0.15 (0.04, 0.61), respectively. The median time to renal AEs onsets was 37.5 (interquartile range 11.0-107.3) days. The hospitalization and fatality rates in patients who developed renal AEs were 40.24 and 9.76%, respectively.

Conclusion

There are no clear signals for the risk of renal AEs following various intravitreal anti-VEGF drugs based on FARES data.

LDP alleviates TKI-induced proteinuria through reversing the expression of RelA in renal tissues

Tyrosine kinase inhibitors (TKIs), as an important tumor therapy, can induce severe proteinuria that significantly affects anti-tumor therapy. Existing therapies against proteinuria induced by other etiologies are currently ineffective for TKI-induced proteinuria. It has been shown that various types of proteinuria are related to podocyte damage caused by changes in the RelA signaling pathway. Our experiments confirmed that TKIs activate the renal RelA signaling pathway, and induce death of podocytes and destruction of the glomerular filtration barrier. Here we found that Liuwei Dihuang Pill (LDP) attenuated the inflammatory injury of podocytes through inhibiting activation of RelA, and subsequently relieved TKI-related proteinuria and prevented the progression of TMA and FSGS. Our finding indicated that LDP may be effective for the treatment of TKI-induced proteinuria, which is clinically significant.

Drug-induced thrombotic microangiopathy: An updated review of causative drugs, pathophysiology, and management

Drug-induced thrombotic microangiopathy (DITMA) represents 10%-13% of all thrombotic microangiopathy (TMA) cases and about 20%-30% of secondary TMAs, just behind pregnancy-related and infection-related forms. Although the list of drugs potentially involved as causative for TMA are rapidly increasing, the scientific literature on DITMA is quite scarce (mostly as individual case reports or little case series), leading to poor knowledge of pathophysiological mechanisms and clinical management. In this review, we focused on these critical aspects regarding DITMA. We provided an updated list of TMA-associated drugs that we selected from a scientific literature review, including only those drugs with a definite or probable causal association with TMA. The list of drugs is heterogeneous and could help physicians from several different areas to be familiar with DITMA. We describe the clinical features of DITMA, presenting the full spectrum of clinical manifestations, from systemic to kidney-limited forms. We also analyze the association between signs/symptoms (i.e., malignant hypertension, thrombocytopenia) and specific DITMA causative drugs (i.e., interferon, ticlopidine). We highlighted their multiple different pathophysiological mechanisms, being frequently classified as immune-mediated (idiosyncratic) and dose-related/toxic. In particular, to clarify the role of the complement system and genetic deregulation of the related genes, we conducted a revision of the scientific literature searching for DITMA cases who underwent renal biopsy and/or genetic analysis for complement genes. We identified a complement deposition in renal biopsies in half of the patients (37/66; 57%), with some drugs associated with major deposits (i.e., gemcitabine and ramucirumab), particularly in capillary vessels (24/27; 88%), and other with absent deposits (tyrosine kinase inhibitors and intraocular anti-VEGF). We also found out that, differently from other secondary TMAs (such as pregnancy-related-TMA and malignant hypertension TMA), complement genetic pathological mutations are rarely involved in DITMA (2/122, 1.6%). These data suggest a variable non-genetic complement hyperactivation in DITMA, which probably depends on the causative drug involved. Finally, based on recent literature data, we proposed a treatment approach for DITMA, highlighting the importance of drug withdrawal and the role of therapeutic plasma-exchange (TPE), rituximab, and anti-complementary therapy.

Glomerular Microangiopathy with Cellular Crescent-like Formation and Endotheliopathy Due to Ramucirumab Treatment for Metastatic Sigmoid Colon Cancer

We encountered a 77-year-old Japanese man who presented with nephrotic-range proteinuria 20 days after receiving ramucirumab treatment for metastatic sigmoid colon cancer. A kidney biopsy showed two characteristic histological findings. The first finding was podocyte injury with cellular crescent-like formation, although focal segmental glomerulosclerosis (FSGS) (collapsing variant) according to the Columbia classification may have been a more appropriate name for this injury, as hypertrophy and hyperplasia of epithelial cells, presumably resulting from podocyte injury, were seen between Bowman's capsule and the glomerular basement membrane (GBM); these changes appeared to be due to the collapse of the GBM rather than to GBM destruction with fibrinoid necrosis. The second finding was endotheliopathy characterized by prominent mesangial interposition via enlargement of the mesangial matrix with mesangiolysis. Proteinuria and renal dysfunction subsided after discontinuation of ramucirumab. Bevacizumab has been reported to induce glomerular microangiopathy with endothelial damage and swelling six months after treatment, but in this case, ramucirumab may have induced focal segmental glomerulosclerosis (FSGS) collapsing variant and glomerular microangiopathy with endotheliopathy via mesangial damage within 1 month. We believe that the damage to the glomerular podocyte and endothelial cells via mesangial damage secondary to ramucirumab in our patient was a different type of glomerular microangiopathy than the endothelial cell damage with enlargement of the subendothelial space caused by bevacizumab.

Renal adverse reactions of tyrosine kinase inhibitors in the treatment of tumours: A Bayesian network meta-analysis

Objectives: Tumours remain a serious threat to human life. Following rapid progress in oncology research, tyrosine kinase inhibitors have been used to treat multiple tumour types. Given the great influence of kidneys on pharmacokinetics, renal toxicities associated with TKIs have attracted attention. However, the TKIs with the lowest risks of renal impairment are unclear. In this study, we conducted a Bayesian network meta-analysis to compare the incidence of renal impairment among different TKIs in patients with tumours. Methods and analysis: Six databases (PubMed, EMBASE, The Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang Data, and China Biomedical Literature Database) were electronically searched from inception to 1 November 2021 to identify randomized controlled trials on the incidence of renal impairment for different TKIs in patients with tumours. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Then, a pairwise meta-analysis was conducted using Stata version 13, and network meta-analysis within the Bayesian framework was conducted using R software version 3.5.3 with the package "gemtc 0.8-2" recalling JAGS (version 4.3.0). Results: Overall, 34 randomized controlled trials were included in this study. Although renal toxicity was common among patients receiving TKIs, the incidence and severity greatly differed among the drugs and studies. Elevated creatinine and protein levels were the most common nephrotoxic events, whereas haematuria was relatively rare. Among TKIs, nintedanib and ripretinib carried the lowest risks of renal impairment. Conclusion: TKIs displayed different profiles of renal toxicity because of their different targets and underlying mechanisms. Clinicians should be aware of the risks of renal impairment to select the optimal treatment and improve patient adherence to treatment. Systematic Review Registration: [www.crd.york.ac.uk/prospero/], identifier [CRD42022295853].

Nephrotic syndrome as a manifestation of thrombotic microangiopathy due to long-term use of sunitinib

Nephrotic syndrome in patients with cancer may be related to the primary malignancy or chemotherapeutic therapy. Solid organ cancers may cause membranous glomerulonephritis which is manifested by nephrotic syndrome; other less common histologic presentations include focal and segmental glomerulosclerosis and minimal change disease. In addition, chemotherapy agents may cause renal toxicity by affecting the small blood vessels, glomeruli, tubules, and interstitium. Tyrosine kinase inhibitors such as sunitinib may cause endothelial and podocyte damage leading to thrombotic microangiopathy affecting only the kidney and manifested by proteinuria and hypertension. We report a case of an elderly man with gastrointestinal stromal tumor (GIST) on treatment with sunitinib who had as a complication a thrombotic microangiopathy manifested with nephrotic syndrome and a hypertension of difficult control, which was finally controlled by stopping this drug but had a fatal outcome due to its malignancy.

A Linkage between Angiogenesis and Inflammation in Neovascular Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of visual impairment in the aging population with a limited understanding of its pathogenesis and the number of patients are all the time increasing. AMD is classified into two main forms: dry and neovascular AMD (nAMD). Dry AMD is the most prevalent form (80–90%) of AMD cases. Neovascular AMD (10–20% of AMD cases) is treated with monthly or more sparsely given intravitreal anti-vascular endothelial growth factor inhibitors, but unfortunately, not all patients respond to the current treatments. A clinical hallmark of nAMD is choroidal neovascularization. The progression of AMD is initially characterized by atrophic alterations in the retinal pigment epithelium, as well as the formation of lysosomal lipofuscin and extracellular drusen deposits. Cellular damage caused by chronic oxidative stress, protein aggregation and inflammatory processes may lead to advanced geographic atrophy and/or choroidal neovascularization and fibrosis. Currently, it is not fully known why different AMD phenotypes develop. In this review, we connect angiogenesis and inflammatory regulators in the development of nAMD and discuss therapy challenges and hopes.

Effectiveness and safety of sorafenib for renal cell, hepatocellular and thyroid carcinoma: pooled analysis in patients with renal impairment

PURPOSE

Sorafenib is an oral multikinase inhibitor with regulatory approval in advanced renal cell carcinoma (RCC), hepatocellular carcinoma (HCC) and refractory differentiated thyroid carcinoma (DTC). Vascular endothelial growth factor receptor (VEGFR) inhibitors like sorafenib may cause proteinuria. This study aimed to analyze the effectiveness and safety of sorafenib in RCC, HCC and DTC patients with chronic kidney disease (CKD).

METHODS

This retrospective study analyzed integrated data from prospective post-marketing surveillance studies for advanced RCC, HCC and DTC. Background factors considered to affect patients' prognosis were balanced by propensity score matching using eGFR cut-off values of 60 mL/min/1.73 m2.

RESULTS

In the combined matched population (N = 2430), sorafenib was equally effective in patients with lower and higher eGFR values. Sorafenib had an overall response rate (ORR: complete + partial responses) of 18.9% and a disease control rate (DCR: complete + partial responses + stable disease) of 67.0%. There were no significant differences between lower and higher eGFR groups for response rates. Renal function was maintained throughout the 12-month study period in the combined population and in each indication. Adverse events (AEs) and serious AEs were reported in 91.6% and 58.2% of propensity score-matched patients, and with no significant differences between lower and higher eGFR groups.

CONCLUSION

The effectiveness and safety of sorafenib were similar in patients with eGFR < 60 and ≥ 60 mL/min/1.73 m2 during the 12-month observation period, and without impairing renal function.

Pegylated Liposomal Doxorubicin and Kidney-Limited Thrombotic Microangiopathy in a Kidney Transplant Recipient: A Case Report

A 64-year-old man with Kaposi sarcoma in clinical remission after treatment with pegylated liposomal doxorubicin and a history of deceased-donor kidney transplantation 4 years prior presented with a slowly progressive increase in his serum creatinine level, well-controlled hypertension, stable subnephrotic-range proteinuria, and bland urinary sediment. An allograft kidney biopsy demonstrated thrombotic microangiopathy, without clinical or laboratory features of systemic involvement. Based on the timing of drug initiation preceding thrombotic microangiopathy, complete recovery after drug withdrawal, and the absence of other etiologies, it was concluded that pegylated liposomal doxorubicin was the likely cause of kidney-limited thrombotic microangiopathy. When pegylated liposomal doxorubicin was resumed, the patient developed hypertension and kidney allograft dysfunction. A new kidney biopsy was not performed because of the overall risk benefit. The case highlights the importance of recognizing novel etiologies of thrombotic microangiopathy in kidney transplant patients with malignancy. Although Kaposi sarcoma has not been linked to thrombotic microangiopathy, pegylated liposomal doxorubicin has been increasingly associated with drug-induced thrombotic microangiopathy. To our knowledge, this is the first case report that etiologically links pegylated liposomal doxorubicin to kidney-limited thrombotic microangiopathy in a kidney transplant patient.

Thrombotic Microangiopathy Syndromes-Common Ground and Distinct Frontiers

Thrombotic microangiopathies (TMAs) have in common a terminal phenotype of microangiopathic hemolytic anemia with end-organ dysfunction. Thrombotic thrombocytopenic purpura results from von Willebrand factor multimerization, Shiga toxin-mediated hemolytic uremic syndrome causes toxin-induced endothelial dysfunction, while atypical hemolytic uremic syndrome results from complement system dysregulation. Drug-induced TMA, rheumatological disease-induced TMA, and renal-limited TMA exist in an intermediate space that represents secondary complement activation and may overlap with atypical hemolytic uremic syndrome clinically. The existence of TMA without microangiopathic hemolytic features, renal-limited TMA, represents an undiscovered syndrome that responds incompletely and inconsistently to complement blockade. Hematopoietic stem cell transplant-TMA represents another more resistant form of TMA with different therapeutic needs and clinical course. It has become apparent that TMA syndromes are an emerging field in nephrology, rheumatology, and hematology. Much work remains in genetics, molecular biology, and therapeutics to unravel the puzzle of the relationships and distinctions apparent between the different subclasses of TMA syndromes.

Identification of VEGF Signaling Inhibition-Induced Glomerular Injury in Rats through Site-Specific Urinary Biomarkers

Cancer therapies targeting the vascular endothelial growth factor (VEGF) signaling pathway can lead to renal damage by disrupting the glomerular ultrafiltration apparatus. The objective of the current study was to identify sensitive biomarkers for VEGF inhibition-induced glomerular changes in rats. Male Sprague-Dawley rats were administered an experimental VEGF receptor (VEGFR) inhibitor, ABT-123, for seven days to investigate the correlation of several biomarkers with microscopic and ultrastructural changes. Glomeruli obtained by laser capture microdissection were also subjected to gene expression analysis to investigate the underlying molecular events of VEGFR inhibition in glomerulus. ABT-123 induced characteristic glomerular ultrastructural changes in rats, including fusion of podocyte foot processes, the presence of subendothelial electron-dense deposits, and swelling and loss of fenestrations in glomerular endothelium. The subtle morphological changes cannot be detected with light microscopy or by changes in standard clinical chemistry and urinalysis. However, urinary albumin increased 44-fold as early as Day three. Urinary β2-microglobulin levels were also increased. Other urinary biomarkers that are typically associated with tubular injury were not significantly impacted. Such patterns in urinary biomarkers can provide valuable diagnostic insight to VEGF inhibition therapy-induced glomeruli injuries.

Nephrotic syndrome as a manifestation of thrombotic microangiopathy due to long-term use of sunitinib

Nephrotic syndrome in patients with cancer may be related to the primary malignancy or chemotherapeutic therapy. Solid organ cancers may cause membranous glomerulonephritis manifesting with nephrotic syndrome; other less common histologic presentations include focal and segmental glomerulosclerosis and minimal change disease. In addition, chemotherapy agents can cause renal toxicity by affecting the small blood vessels, glomeruli, tubules, and interstitium. Tyrosine kinase inhibitors such as sunitinib may cause endothelial and podocyte damage leading to renal limited thrombotic microangiopathy, manifested by proteinuria and hypertension. We report a case of an elderly man with gastrointestinal stromal tumor (GIST) on treatment with sunitinib who had as a complication of a thrombotic microangiopathy manifested with nephrotic syndrome and difficult-to-control hypertension, which was controlled by stopping this drug but with a fatal outcome due to its malignant neoplasm.

Acute kidney injury in cancer patients

OBJECTIVE

We want to know the causes of AKI in oncology patients, including disease-related complications and the nephrotoxicity of chemotherapy drugs, in order to provide more useful clinical information.

METHODS

In this review, an electronic search of the English language literature was performed in the database PubMed, with the results enriched by manual searches and citation mining, factors investigated in the selected articles included acute kidney injury, oncology, chemotherapy, anticancer drug, antitumor drug.

RESULTS

According to the searched articles, we summarized the causes (including pre-renal, intrinsic renal, and post-renal lesion) of AKI in cancer patients and the corresponding management measures. Among the pre-renal factors we mainly described hypercalcemia, hematopoietic cell transplantation, post-renal factors we mainly described hemorrhagic cystitis, and intrinsic renal factors we mainly described thrombotic microangiopathy, chemotherapeutics, tumor lysis syndrome, cast nephropathy, in which the emphasis was on chemotherapy drug associated AKI and its treatment.

CONCLUSIONS

AKI is not uncommon in cancer patients, and has diverse causes and negative outcomes. Both nephrologists and oncologists need to be aware of the unique reasons of AKI in this population and its optimal management.

Nephrotoxicity From Molecularly Targeted Chemotherapeutic Agents

The introduction of novel molecularly targeted therapies in the last 2 decades has significantly improved the patient survival compared to standard conventional chemotherapies. However, this improvement has been accompanied by a whole new spectrum of kidney adverse events. Although known as "targeted," many of these agents lack specificity and selectivity, and they have a tendency to inhibit multiple targets including those in the kidneys. Early detection and correct management of kidney toxicities is crucial to preserve kidney functions. The knowledge of these toxicities helps guide optimal and continued utilization of these potent therapies. The incidence, severity, and pattern of nephrotoxicity may vary depending on the respective target of the drug. Here, we review the mechanism of action, clinical findings of kidney adverse events, and their proposed management strategies.

Pediatric onco-nephrology: time to spread the word : Part I: early kidney involvement in children with malignancy

Onco-nephrology has been a growing field within the adult nephrology scope of practice. Even though pediatric nephrologists have been increasingly involved in the care of children with different forms of malignancy, there has not been an emphasis on developing special expertise in this area. The fast pace of discovery in this field, including the development of new therapy protocols with their own kidney side effects and the introduction of the CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy, has introduced new challenges for general pediatric nephrologists because of the unique effects of these treatments on the kidney. Moreover, with the improved outcomes in children receiving cancer therapy come an increased number of survivors at risk for chronic kidney disease related to both their cancer diagnosis and therapy. Therefore, it is time for pediatric onco-nephrology to take its spot on the expanding subspecialties map in pediatric nephrology.

The Link Between Conventional and Novel Anti-Cancer Therapeutics with Thrombotic Microangiopathy

BACKGROUND

Kidney disease associated with cancer and anti-cancer therapies has been increasingly recognized in the field of onco-nephrology. In particular, drug-induced nephrotoxicity has important implications since most chemotherapeutic agents have a nephrotoxic potential. Also, standard creatinine clearance methods used for the measurement of kidney function have been questioned in cancer patients due to factors like low muscle mass and poor nutritional status. Overestimations of the glomerular filtration rate, not only can increase the nephrotoxic potential of different agents, but also further limit the use of first-line therapies.

OBJECTIVE

This review covers specifically the drug-induced thrombotic microangiopathy and its two pathophysiologic mechanisms which include immune or idiosyncratic reactions, and non-immune or dose-dependent ones.

CONCLUSION

As novel cancer therapies are developed, it is paramount to pursue a better understanding of conventional and novel chemotherapeutic agents and their role in kidney disease.

Nephrotoxicity of cancer therapeutic drugs: Focusing on novel agents

Kidney injury caused by anticancer agents is a common problem that can interfere with and affect the dose intensity of anticancer therapy, thus restricting patient survival. Recent advances in targeted and immunotherapeutic agents have transformed the landscape of medical oncology, and these agents have been widely employed in clinical practice. While typically associated with favorable toxicity profiles, several novel anticancer drugs present distinctive nephrotoxicities. It remains urgent to closely monitor renal injuries associated with these agents, and medical practitioners should be familiar with general principles for managing nephrotoxicity associated with novel cancer drugs. This review provides an in-depth investigation of the literature and guidelines regarding the prevalence, clinical presentations, mechanisms, and management of nephrotoxicity for each drug.

Endothelial Endothelin Receptor A Expression Is Associated With Podocyte Injury and Oxidative Stress in Patients With Focal Segmental Glomerulosclerosis

INTRODUCTION

The podocyte is thought to be the mainly affected cell type in focal segmental glomerulosclerosis (FSGS). However, recent studies have also indicated a role for glomerular endothelial cells and podocyte-endothelial crosstalk in FSGS development. An experimental model for podocyte injury showed that increased endothelin-1 (ET-1) signaling between podocytes and endothelial cells induces endothelial oxidative stress and subsequent podocyte loss. In the current study, we investigated endothelial endothelin receptor A (ETAR) expression in patients with FSGS and its association with podocyte injury and glomerular oxidative stress.

METHODS

We selected 39 biopsy samples of patients with FSGS and 8 healthy control subjects, and stained them for ETAR, nephrin and 8-oxo-guanine, a DNA lesion caused by oxidative damage. Glomeruli with ETAR-positive endothelium and with nephrin loss were scored, and the 8-oxo-guanine-positive glomerular area was measured.

RESULTS

The mean percentage of glomeruli with ETAR-positive endothelial cells in patients with FSGS was higher compared to that in healthy control subjects (52% vs. 7%; P < 0.001). The presence of glomerular ETAR-positive endothelium was strongly associated with nephrin loss both on the biopsy level (rho = 0.47; P < 0.01), as on the level of individual glomeruli (odds ratio = 2.0; P < 0.001). Moreover, glomeruli with ETAR-positive endothelium showed more 8-oxo-guanine-positive staining (1.9% vs. 2.4%; P = 0.037). Finally, 8-oxo-guanine positivity in glomeruli was associated with increased levels of proteinuria.

CONCLUSION

Taking together our findings, we show that ETAR is increased in glomerular endothelial cells of patients with FSGS and associated with podocyte damage and glomerular oxidative stress. These findings support the hypothesis that ET-1 signaling in glomerular endothelial cells contributes to disease development in patients with FSGS.

VEGF-VEGFR2 inhibitor-associated hyaline occlusive glomerular microangiopathy: a Japanese single-center experience

BACKGROUND

Inhibitors of vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) signaling, such as bevacizumab (Bmab), are used for the treatment of various advanced cancers. However, these inhibitors induce renal thrombotic microangiopathy (TMA). Recently, two European cohort studies showed a distinctive histopathological pseudothrombotic pattern different from TMA in Bmab-treated patients.

METHODS

We analyzed 9 renal biopsies from proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors in our Japanese cohort. Clinical and laboratory features were also assessed in these patients.

RESULTS

All 9 patients had moderate to heavy proteinuria with normal or slightly elevated serum creatinine levels. On light microscopy, a patchy pattern of hemispherical/spherical lesions along glomerular capillary walls was a characteristic finding. On immunofluorescence microscopy, staining for immunoglobulins (IgM dominant) at varying intensities was observed mainly along glomerular capillary walls. Especially, hemispherical/spherical positive staining for immunoglobulins was a characteristic pattern. Immunohistochemical studies showed positive staining for immunoglobulins and negative staining for CD61-positive platelets in capillary hemispherical/spherical lesions and positive VEGF staining in podocytes. On electron microscopy, variably electron-dense material in dilated glomerular capillaries and partial effacement of podocyte foot processes were observed. After the withdrawal of VEGF-VEGFR2 inhibitors, proteinuria improved without any specific treatment in 8 patients.

CONCLUSIONS

Histopathological findings in our patients treated with VEGF-VEGFR2 inhibitors were consistent with those observed in the recently described new form of Bmab-associated hyaline occlusive glomerular microangiopathy. This form should be considered in proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors. Discontinuing VEGF-VEGFR2 inhibitors may lead to improvement of glomerular microangiopathy induced by these drugs.

Renal toxicity of targeted therapies for renal cell carcinoma in patients with normal and impaired kidney function

The introduction of novel targeted therapies during the last 2 decades has led to a significant improvement in patients' clinical outcomes with renal cell carcinoma. However, this improvement came at the price of a whole new spectrum of adverse events, including renal toxicity. Systemic treatment of patients with kidney neoplasms who often present with impairment of kidney function, even prior to treatment, poses an increasing diagnostic and therapeutic challenge for clinicians. Common lifestyle-related comorbidities, i.e., hypertension and diabetes, may contribute to further impairment of kidney function. The lack of official guidelines and the exclusion of patients with reduced kidney function from the clinical trials of recently approved drugs complicate the issue even further. Early detection and correct management of renal toxic effects are crucial to preserve kidney function and ensure the optimal administration of life-prolonging therapies. This review presents detailed information on the renal toxicities of three groups of drugs commonly used in renal cell carcinoma treatment: tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and immune checkpoint inhibitors. We outline the incidence and underlying mechanisms of renal adverse effects with a focus on patients on renal replacement therapy, as well as present suggestions for their management.

Thrombotic microangiopathy in oncology - a review

Thrombotic microangiopathy is a syndrome triggered by a wide spectrum of situations, some of which are specific to the Oncology setting. It is characterized by a Coombs-negative microangiopathic haemolytic anemia, thrombocytopenia and organ injury, with characteristic pathological features, resulting from platelet microvascular occlusion.

TMA is rare and its cancer-related subset even more so. TMA triggered by drugs is the most common within this group, including classic chemotherapy and the latest targeted therapies. The neoplastic disease itself and hematopoietic stem-cell transplantation could also be potential triggers.

Evidence-based medical guidance in the management of cancer-related TMA is scarce and the previous knowledge about primary TMA is valuable to understand the disease mechanisms and the potential treatments.

Given the wide spectrum of potential causes for TMA in cancer patients, the aim of this review is to gather the vast information available. For each entity, pathophysiology, clinical features, therapeutic approaches and prognosis will be covered.

Abnormal Crosstalk between Endothelial Cells and Podocytes Mediates Tyrosine Kinase Inhibitor (TKI)-Induced Nephrotoxicity

Vascular endothelial growth factor A (VEGFA) and its receptor VEGFR2 are the main targets of antiangiogenic therapies, and proteinuria is one of the common adverse events associated with the inhibition of the VEGFA/VEGFR2 pathway. The proteinuric kidney damage induced by VEGFR2 tyrosine kinase inhibitors (TKIs) is characterized by podocyte foot process effacement. TKI therapy promotes the formation of abnormal endothelial‒podocyte crosstalk, which plays a key role in TKI-induced podocyte injury and proteinuric nephropathy. This review article summarizes the underlying mechanism by which the abnormal endothelial‒podocyte crosstalk mediates podocyte injury and discusses the possible molecules and signal pathways involved in abnormal endothelial‒podocyte crosstalk. What is more, we highlight the molecules involved in podocyte injury and determine the essential roles of Rac1 and Cdc42; this provides evidence for exploring the abnormal endothelial‒podocyte crosstalk in TKI-induced nephrotoxicity.

Toceranib phosphate-associated nephrotic syndrome in a dog: a case report

Background

Nephrotic syndrome (NS) is rare in dogs and is characterized by concurrent clinical findings of proteinuria, hyperlipidemia, hypoalbuminemia, and edema. NS has been reported in humans receiving tyrosine kinase inhibitors (TKI) and in dogs receiving masitinib. This is the first report of NS in a dog receiving toceranib phosphate.

Case presentation

An 8-year-old, female, spayed Labrador retriever was diagnosed with a 10 cm mast cell tumor on the left lateral abdomen. After completion of a 12-week vinblastine and prednisone protocol, she began treatment with toceranib phosphate (2.6 mg/kg by mouth, every other day). Proteinuria was documented prior to starting toceranib. On day 426 after diagnosis (day 328 of toceranib phosphate treatment), the dog was evaluated for diarrhea, lethargy and anorexia. On physical examination, dependent edema was noted on the ventral chest and abdomen, and sterile neutrophilic inflammation was aspirated from a 2.3 cm splenic nodule. The following laboratory values were reported: albumin < 1.5 g/dL; cholesterol 378 mg/dl and urine protein to creatinine ratio of 3.79. The patient was diagnosed with NS, and treatment with toceranib phosphate was discontinued. Low-dose aspirin was started in addition to an increased dosage of enalapril (0.47 mg/kg q12hr). No other therapy was instituted. The dog improved clinically, and laboratory values returned to near normal over the 8-week follow-up. She was euthanized 1399 days after discontinuing toceranib phosphate with progressive disease.

Conclusions

Nephrotic syndrome is a potential adverse event associated with the drug toceranib phosphate which may be reversible with discontinuation of treatment. Careful monitoring of urine protein, serum biochemistry, blood pressure and patient weight is advisable during treatment with toceranib phosphate.

Thrombotic Microangiopathy Associated with Pazopanib in a Kidney Transplant Recipient

Thrombotic microangiopathy (TMA) is characterised by abnormalities in the walls of arterioles and capillaries, precipitated by hereditary or acquired characteristics, and culminating in microvascular thrombosis because of dysregulated complement activity. A number of drugs can precipitate TMA, including vascular endothelial growth factor (VEGF) inhibitors, because of their effects on endothelial repair. Pazopanib is a VEGF inhibitor used for the treatment of renal cell carcinoma (RCC); it is uncommonly associated with TMA. A 52-year-old male, 5 years post his second kidney transplant secondary to immunoglobulin (Ig) A nephropathy, presented with hypertension, fluid overload, and worsening graft function (peak creatinine 275 µmol/L, baseline 130–160 µmol/L) and nephrotic range proteinuria 2 months after commencing pazopanib for metastatic RCC. His maintenance immunosuppression included ciclosporin, mycophenolate, and prednisolone. Haematological parameters were unremarkable. Allograft biopsy demonstrated glomerular and arteriolar changes consistent with chronic active TMA, with overlying features of borderline cellular rejection. He was treated with intravenous methylprednisolone 250 mg for 3 days and commenced on irbesartan 75 mg daily. Drug-induced TMA from pazopanib was suspected, particularly given the documented association with other tyrosine kinase inhibitors (TKIs). In consultation with his medical oncologist, pazopanib was ceased, and an alternate TKI cabozantinib was commenced. Serum creatinine remained <200 µmol/L 3 months after admission. This is the first reported biopsy-proven case of TMA attributed to pazopanib in a kidney transplant recipient. With increasing clinical indications for and availability of TKIs, clinicians need to be aware of their association with TMA events in kidney transplant recipients, who are already susceptible to TMA due to abnormal vasculature, infectious triggers, ischaemia-reperfusion injury, and use of calcineurin inhibitor.

Clinical significance of measuring ADAMTS-13, its inhibitor and von Willebrand factor in obstetric and gynecological practice

ADAMTS-13 is a crucial metalloproteinase involved in liberating fragments of von Willebrand factor (vWF) into the plasma as well as regulating its activity by cleaving "ultra-large" multimers into smaller and less active counterparts. Many pathological conditions, including those emerged during pregnancy are characterized by increased level of vWF and decreased ADAMTS-13 activity. In this regard, it is necessary to monitor the levels of vWF and ADAMTS-13 activity to prevent thrombotic thrombocytopenic purpura (Moschcowitz disease) as one of the most severe forms of thrombotic microangiopathy.