Expression patterns of RelA and c-mip are associated with different glomerular diseases following anti-VEGF therapy

Lenvatinib rechallenge after failure of lenvatinib and sorafenib in metastatic thyroid cancer

The oral multikinase inhibitors sorafenib and lenvatinib are currently available as first-line treatment for patients with unresectable or metastatic thyroid cancer. However, treatment options for patients who are refractory to these multikinase inhibitors are limited. This study aimed to evaluate the safety and efficacy of rechallenged lenvatinib after failure of both lenvatinib and sorafenib in patients with metastatic thyroid cancer in the real-world clinical practice. We retrospectively reviewed the data of consecutive 16 patients with metastatic thyroid cancer who received lenvatinib as a rechallenge after failure of initial lenvatinib and sorafenib treatment at Shizuoka Cancer Center between 2016 and 2023. Of these, the initial lenvatinib was discontinued in 12 patients owing to progressive disease, in 3 patients owing to adverse events, and in 1 patient owing to both. The overall response rate was 6.7%, and disease control was achieved by rechallenge with lenvatinib in all patients with the target lesions. The median progression free survival after rechallenging with lenvatinib was 15.0 months. No new signs of toxicity were observed after rechallenging with lenvatinib. Our findings suggest that rechallenge with lenvatinib after failure of both lenvatinib and sorafenib showed manageable safety and modest efficacy in patients with metastatic thyroid cancer in clinical practice. The strategy of lenvatinib rechallenge may provide an alternative option for patients with no targetable driver genes or when selective kinase inhibitors are not indicated.

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.

Ocular and systemic vascular endothelial growth factor ligand inhibitor use and nephrotoxicity: an update

Tumor growth is intricately linked to the process of angiogenesis, with a key role played by vascular endothelial growth factor (VEGF) and its associated signaling pathways. Notably, these pathways also play a pivotal "housekeeping" role in renal physiology. Over the past decade, the utilization of VEGF signaling inhibitors has seen a substantial rise in the treatment of diverse solid organ tumors, diabetic retinopathy, age-related macular degeneration, and various ocular diseases. However, this increased use of such agents has led to a higher frequency of encountering renal adverse effects in clinical practice. This review comprehensively addresses the incidence, pathophysiological mechanisms, and current evidence concerning renal adverse events associated with systemic and intravitreal antiangiogenic therapies targeting VEGF-A and its receptors (VEGFR) and their associated signaling pathways. Additionally, we briefly explore strategies for mitigating potential risks linked to the use of these agents and effectively managing various renal adverse events, including but not limited to hypertension, proteinuria, renal dysfunction, and electrolyte imbalances.

Low serum concentrations of bevacizumab and nivolumab owing to excessive urinary loss in patients with proteinuria: a case series

PURPOSE

Proteinuria can cause interindividual variability in the pharmacokinetics of therapeutic antibodies and may affect therapeutic efficacy. Here, we measured the serum and urinary concentrations of bevacizumab (BV) and nivolumab (NIVO) in patients with proteinuria and reported a case series of these patients.

METHODS

Thirty-two cancer patients who received BV every 3 weeks or NIVO every 2 weeks between November 2020 and September 2021 at Kyoto University Hospital were enrolled in this study. The serum and urinary concentrations of BV and NIVO were measured using liquid chromatography-tandem mass spectrometry.

RESULTS

We divided the BV-treated patients and the NIVO-treated patients into two groups based on the urine protein-creatinine ratio (UPCR): UPCR 1 g/g or higher (BV, n = 9; NIVO, n = 3) and UPCR less than 1 g/g (BV, n = 14; NIVO, n = 6). Serum concentrations of the therapeutic antibodies adjusted by their doses were significantly lower in both BV- and NIVO-treated patients with UPCR 1 g/g or higher compared to those with less than 1 g/g. In patients with UPCR 1 g/g or higher, urinary concentrations of the therapeutic antibodies adjusted by their serum concentrations and urinary creatinine concentrations tended to increase.

CONCLUSION

This case-series study suggests a possibility of reduction in serum concentrations of BV and NIVO in patients with proteinuria by urinary excretion of these drugs.

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.

Pharmacology of Tyrosine Kinase Inhibitors: Implications for Patients with Kidney Diseases

Tyrosine kinase inhibitors (TKI) have introduced a significant advancement in cancer management. These compounds are administered orally, and their absorption holds a pivotal role in determining their variable efficacy. They exhibit extensive distribution within the body, binding strongly to both plasma and tissue proteins. Often reliant on efflux and influx transporters, TKI undergo primary metabolism by intestinal and hepatic cytochrome P450 enzymes, with nonkidney clearance being predominant. Owing to their limited therapeutic window, many TKI display considerable intraindividual and interindividual variability. This review offers a comprehensive analysis of the clinical pharmacokinetics of TKI, detailing their interactions with drug transporters and metabolic enzymes, while discussing potential clinical implications. The prevalence of kidney conditions, such as AKI and CKD, among patients with cancer is explored in their effect on TKI pharmacokinetics. Finally, the potential nephrotoxicity associated with TKI is also examined.

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.

Management of hypertension in patients with cancer: challenges and considerations

The survival rates of many cancers have significantly improved due to recent advancements in cancer screening and therapeutics. Although better cancer outcomes are encouraging, additional health challenges have surfaced, the utmost of which is the burden imposed by various cardiovascular and renal toxicities of anticancer therapies. To improve the overall outcome of patients with cancer, it is essential to understand and manage these treatment-related adverse effects. The cardiovascular side effects of antineoplastic therapies are well-known and include left ventricular dysfunction, heart failure, myocardial ischaemia, QT prolongation, arrhythmia and hypertension. Among these, hypertension is the most common complication, prevalent in about 40% of all cancer patients, yet frequently overlooked and undertreated. This review explores the intricate connection between cancer and hypertension and provides distinct approaches to diagnosing, monitoring and managing hypertension in patients with cancer. We also outline the challenges and considerations that are relevant to the care of patients receiving anticancer drugs with prohypertensive potential.

Genome-Wide Association Analysis of Protein-Coding Variants in IgA Nephropathy

SIGNIFICANCE STATEMENT

Genome-wide association studies have identified nearly 20 IgA nephropathy susceptibility loci. However, most nonsynonymous coding variants, particularly ones that occur rarely or at a low frequency, have not been well investigated. The authors performed a chip-based association study of IgA nephropathy in 8529 patients with the disorder and 23,224 controls. They identified a rare variant in the gene encoding vascular endothelial growth factor A (VEGFA) that was significantly associated with a two-fold increased risk of IgA nephropathy, which was further confirmed by sequencing analysis. They also identified a novel common variant in PKD1L3 that was significantly associated with lower haptoglobin protein levels. This study, which was well-powered to detect low-frequency variants with moderate to large effect sizes, helps expand our understanding of the genetic basis of IgA nephropathy susceptibility.

BACKGROUND

Genome-wide association studies have identified nearly 20 susceptibility loci for IgA nephropathy. However, most nonsynonymous coding variants, particularly those occurring rarely or at a low frequency, have not been well investigated.

METHODS

We performed a three-stage exome chip-based association study of coding variants in 8529 patients with IgA nephropathy and 23,224 controls, all of Han Chinese ancestry. Sequencing analysis was conducted to investigate rare coding variants that were not covered by the exome chip. We used molecular dynamic simulation to characterize the effects of mutations of VEGFA on the protein's structure and function. We also explored the relationship between the identified variants and the risk of disease progression.

RESULTS

We discovered a novel rare nonsynonymous risk variant in VEGFA (odds ratio, 1.97; 95% confidence interval [95% CI], 1.61 to 2.41; P = 3.61×10 -11 ). Further sequencing of VEGFA revealed twice as many carriers of other rare variants in 2148 cases compared with 2732 controls. We also identified a common nonsynonymous risk variant in PKD1L3 (odds ratio, 1.16; 95% CI, 1.11 to 1.21; P = 1.43×10 -11 ), which was associated with lower haptoglobin protein levels. The rare VEGFA mutation could cause a conformational change and increase the binding affinity of VEGFA to its receptors. Furthermore, this variant was associated with the increased risk of kidney disease progression in IgA nephropathy (hazard ratio, 2.99; 95% CI, 1.09 to 8.21; P = 0.03).

CONCLUSIONS

Our study identified two novel risk variants for IgA nephropathy in VEGFA and PKD1L3 and helps expand our understanding of the genetic basis of IgA nephropathy susceptibility.

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

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

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

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

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.

State of the art in childhood nephrotic syndrome: concrete discoveries and unmet needs

Nephrotic syndrome (NS) is a clinical entity characterized by proteinuria, hypoalbuminemia, and peripheral edema. NS affects about 2-7 per 100,000 children aged below 18 years old yearly and is classified, based on the response to drugs, into steroid sensitive (SSNS), steroid dependent, (SDNS), multidrug dependent (MDNS), and multidrug resistant (MRNS). Forms of NS that are more difficult to treat are associated with a worse outcome with respect to renal function. In particular, MRNS commonly progresses to end stage renal failure requiring renal transplantation, with recurrence of the original disease in half of the cases. Histological presentations of NS may vary from minimal glomerular lesions (MCD) to focal segmental glomerulosclerosis (FSGS) and, of relevance, the histological patterns do not correlate with the response to treatments. Moreover, around half of MRNS cases are secondary to causative pathogenic variants in genes involved in maintaining the glomerular structure. The pathogenesis of NS is still poorly understood and therapeutic approaches are mostly based on clinical experience. Understanding of pathogenetic mechanisms of NS is one of the 'unmet needs' in nephrology and represents a significant challenge for the scientific community. The scope of the present review includes exploring relevant findings, identifying unmet needs, and reviewing therapeutic developments that characterize NS in the last decades. The main aim is to provide a basis for new perspectives and mechanistic studies in NS.

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

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

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.

The value of the multidisciplinary team in metastatic renal cell carcinoma: Paving the way for precision medicine in toxicities management

The new landscape of treatments for metastatic clear cell renal carcinoma (mRCC) is constantly expanding, but it is associated with the emergence of novel toxicities, adding to up to those observed in the tyrosine-kinase inhibitor (TKI) era. Indeed, the introduction of immune checkpoint inhibitors (ICIs) alone or in combination has been associated with the development of immune-related adverse events (irAEs) involving multiple-organ systems which, even if rarely, had led to fatal outcomes. Moreover, due to the relatively recent addition of ICIs to the previously available treatments, the potential additive adverse effects of these combinations are still unknown. A prompt recognition and management of these toxicities currently represents a fundamental issue in oncology, since it correlates with the outcome of cancer patients. Even if clinical guidelines provide indications for the management of irAEs, no specific protocol to evaluate the individual risk of developing an adverse event during therapy is currently available. A multidisciplinary approach addressing appropriate interventions aimed at reducing the risk of any insidious, severe, and/or dose-limiting toxicity might represent the most efficacious strategy to timely prevent and manage severe irAEs, allowing indirectly to improve both patients' cancer-specific survival and quality of life. In this review, we reported a five-case series of toxicity events that occurred at our center during treatment for mRCC followed by the remarks of physicians from different specialties, pinpointing the relevant role of an integrated and extended multidisciplinary team in a modern model of mRCC patient management.

Uncover diagnostic immunity/hypoxia/ferroptosis/epithelial mesenchymal transformation-related CCR5, CD86, CD8A, ITGAM, and PTPRC in kidney transplantation patients with allograft rejection

The aim of this study was to identify predictive immunity/hypoxia/ferroptosis/epithelial mesenchymal transformation (EMT)-related biomarkers, pathways and new drugs in allograft rejection in kidney transplant patients. First, gene expression data were downloaded followed by identification of differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA) and protein–protein interaction (PPI) analysis. Second, diagnostic model was construction based on key genes, followed by correlation analysis between immune/hypoxia/ferroptosis/EMT and key diagnostic genes. Finally, drug prediction of diagnostic key genes was carried out. Five diagnostic genes were further identified, including CCR5, CD86, CD8A, ITGAM, and PTPRC, which were positively correlated with allograft rejection after the kidney transplant. Highly infiltrated immune cells, highly expression of hypoxia-related genes and activated status of EMT were significantly positively correlated with five diagnostic genes. Interestingly, suppressors of ferroptosis (SOFs) and drivers of ferroptosis (DOFs) showed a complex regulatory relationship between ferroptosis and five diagnostic genes. CD86, CCR5, and ITGAM were respectively drug target of ABATACEPT, MARAVIROC, and CLARITHROMYCIN. PTPRC was drug target of both PREDNISONE and EPOETIN BETA. In conclusion, the study could be useful in understanding changes in the microenvironment within transplantation, which may promote or sustain the development of allograft rejection after kidney transplantation.

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.

Thrombotic Microangiopathy, Podocytopathy, and Damage to the Renal Tubules with Severe Proteinuria and Acute Renal Dysfunction Induced by Lenvatinib

Lenvatinib, a tyrosine kinase inhibitor (TKI), is a stronger inhibitor of vascular endothelial growth factor receptor, fibroblast growth factor receptors 1 to 4, and platelet-derived growth factor receptor (PDGFR) than other TKIs. We herein report a 77-year-old Japanese woman who received the minimum dose of lenvatinib for treatment of hepatocellular carcinoma. Within one month of starting treatment, she developed severe proteinuria, hypertension, and renal dysfunction. A kidney biopsy showed drug-induced thrombotic microangiopathy, podocytopathy, and polar vasculosis. We also observed damage to the renal tubules, where PDGFR is located. To our knowledge, this is the first report of lenvatinib-induced damage to the renal tubules.

Regorafenib-induced renal-limited thrombotic microangiopathy: a case report and review of literatures

Background

Regorafenib belongs to a sub-group of small-molecule multi-targeted tyrosine kinase inhibitors(TKIs). In various studies with respect to the side-effect of regorafenib, drug-associated proteinuria standardly qualified to be defined as nephrotic syndrome was rarely reported as well as the relation of regorafenib with the occurrence and development of thrombotic microangiopathy (TMA).

Case presentation

In this case report and literature review, we presented a 62-year-old patient receiving regorafenib for metastatic colon cancer, manifesting abundant proteinuria, in which TMA was also diagnosed through renal biopsy. As far as we were concerned, this was the first reported in terms of regorafenib-induced TMA confirmed by renal biopsy.

Conclusion

This case indicates that regorafenib, a kind of TKIs may result in TMA, which is a rare but life-threatening complication of cancer treatment drug. Insights from this case might help physicians diagnose rare forms of TMA and adjust treatment for patients in a timely manner.

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.

[Angiogenesis inhibitors: mechanism of action and nephrotoxicity]

Tumoral angiogenesis is a key mechanism involved in the growth and spread of cancer cells. The development of angiogenesis inhibitors, particularly those targeting the Vascular Endothelial Growth Factor (VEGF) pathway, has improved the prognosis and survival of many cancer patients since they were approved in 2005 in France. Vascular Endothelial Growth Factor inhibitors have different mechanisms of action, targeting either the ligand (e.g. bevacizumab, anti-Vascular Endothelial Growth Factor monoclonal antibody; aflibercept, recombinant anti-Vascular Endothelial Growth Factor fusion protein), or its receptors such as tyrosine kinase inhibitors (e.g. sunitinib or sorafenib). These treatments can be combined with conventional chemotherapy, or other anti-cancer therapies, and are associated with variable tolerance depending on the patient's clinical condition and comorbidities. Additionally, angiogenesis inhibition may be associated with cardiovascular and/or kidney toxicity and therefore special monitoring is needed during the treatment duration. Development of hypertension and proteinuria are the commonest renal side effects; these are generally manageable and reversible when treatment is stopped. However, more severe toxicities have been reported such as acute kidney injury, glomerular and/or vascular insults such as thrombotic microangiopathy, and more rarely tubulointerstitial damage. The prescribing physician should be aware of these potentially serious. This article describes the mechanisms of action of antiangiogenic agents and their potential toxicities, with particular respect to the kidneys.

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.

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.

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.

The Syndromes of Thrombotic Microangiopathy: A Critical Appraisal on Complement Dysregulation

Thrombotic microangiopathy (TMA) is a rare and potentially life-threatening condition that can be caused by a heterogeneous group of diseases, often affecting the brain and kidneys. TMAs should be classified according to etiology to indicate targets for treatment. Complement dysregulation is an important cause of TMA that defines cases not related to coexisting conditions, that is, primary atypical hemolytic uremic syndrome (HUS). Ever since the approval of therapeutic complement inhibition, the approach of TMA has focused on the recognition of primary atypical HUS. Recent advances, however, demonstrated the pivotal role of complement dysregulation in specific subtypes of patients considered to have secondary atypical HUS. This is particularly the case in patients presenting with coexisting hypertensive emergency, pregnancy, and kidney transplantation, shifting the paradigm of disease. In contrast, complement dysregulation is uncommon in patients with other coexisting conditions, such as bacterial infection, drug use, cancer, and autoimmunity, among other disorders. In this review, we performed a critical appraisal on complement dysregulation and the use of therapeutic complement inhibition in TMAs associated with coexisting conditions and outline a pragmatic approach to diagnosis and treatment. For future studies, we advocate the term complement-mediated TMA as opposed to the traditional atypical HUS-type classification.

Evaluation of Proteinuria Using Urine Protein : Creatine Ratio in Treatment with Molecular Targeted Agents for Advanced Renal Cell Carcinoma

The usefulness of the urine protein : creatine ratio (UPCR) in management of molecular targeted therapy and immunotherapy has not been studied, although urine protein dipstick testing (uPr) is widely used in the clinical setting. The aim of this study was to investigate the usefulness of UPCR as compared to uPr in patients undergoing molecular targeted therapy for advanced renal cell carcinoma (RCC). A total of 25 patients (median age 68 years) with advanced RCC were included. Sunitinib, pazopanib, axitinib, sorefenib, everolimus, and nivolumab were administered to 15, 9, 16, 3, 7, and 13 patients, respectively, with duplication. Proteinuria was managed according to the grade determined by UPCR. Data at every treatment visit were retrospectively collected and uPr and UPCR were compared. The overall incidences of any grade of proteinuria associated with sunitinib, pazopanib, axitinib, sorafenib and everolimus were 86.7, 88.9, 93.8, 100, and 85.7%, respectively. There were discordances between the uPr-based grade and UPCR-based grade. UPCR did not meet the criteria of Grade 3 in 70.6, 100, 83.3, and 83.3% at visits in cases with uPr 3+ for sunitinib, pazopanib, sorafenib, and everolimus, respectively. In axitinib treatment, UPCR did not meet the criteria for withholding in 46.2% of the cases of uPr 2+ and more. Our study suggests that UPCR may be useful tool in management of adverse events associated with tyrosine kinase inhibitors, everolimus and can provide patients with optimal opportunities for receiving treatment.

CMIP interacts with WT1 and targets it on the proteasome degradation pathway

BACKGROUND

The Wilms tumor 1 suppressor gene, WT1, is expressed throughout life in podocytes and is essential for their function. Downregulation of WT1 has been reported in podocyte diseases but the underlying mechanisms remain unclear. Podocyte injury is the hallmark of idiopathic nephrotic syndrome (INS), the most frequent glomerular disease in children and young adults. An increase in the abundance of Cmaf-inducing protein (CMIP) has been found to alter podocyte function, but it is not known whether CMIP affects WT1 expression.

METHODS

Transcriptional and post-transcriptional regulation of WT1in the presence of CMIP was studied using transient transfection, mouse models, and siRNA handling.

RESULTS

We showed that overproduction of CMIP in the podocyte was consistently associated with a downregulation of WT1 according to two mechanisms. We found that CMIP prevented the NF-kB-mediated transcriptional activation of WT1. We demonstrated that CMIP interacts directly with WT1 through its leucine-rich repeat domain. Overexpression of CMIP in the M15 cell line induced a downregulation of WT1, which was prevented by lactacystin, a potent proteasome inhibitor. We showed that CMIP exhibits an E3 ligase activity and targets WT1 to proteasome degradation. Intravenous injection of Cmip-siRNA specifically prevented the repression of Wt1 in lipopolysaccharides-induced proteinuria in mice.

CONCLUSIONS

These data suggest that CMIP is a repressor of WT1 and might be a critical player in the pathophysiology of some podocyte diseases. Because WT1 is required for podocyte integrity, CMIP could be considered a therapeutic target in podocyte diseases.

Association Between Renal Adverse Effects and Mortality in Patients With Hepatocellular Carcinoma Treated With Lenvatinib

BACKGROUND/AIM

Lenvatinib, a multitargeted tyrosine kinase inhibitor, was recently approved for hepatocellular carcinoma (HCC) treatment in Japan; however, the association between proteinuria following lenvatinib administration in HCC patients and early mortality is unknown. This study aimed to examine the association between nephrotic-range proteinuria (NRP) and mortality and evaluated the risk factors for NRP among Japanese HCC patients treated with lenvatinib.

PATIENTS AND METHODS

We retrospectively analyzed 45 consecutive patients receiving lenvatinib from 2018-2019. Primary outcome was overall survival. Cox proportional hazards regression was used to evaluate the association between NRP and overall survival. Logistic regression analyses were used to identify NRP risk factors after lenvatinib initiation.

RESULTS

The median age was 66 years, 56% were women, and 20% had pre-existing proteinuria. During a 1-year median follow-up, 24 died, and 5 developed NRP. Univariable logistic regression showed that pre-existing proteinuria was associated with higher NRP risk; however, the association was not significant after covariate adjustment. Following multivariable Cox analysis, NRP did not affect overall survival in advanced HCC patients receiving lenvatinib.

CONCLUSION

Urinalysis findings should be monitored regularly in patients receiving lenvatinib because NRP incidence was comparable to that of prior studies. Identifying the predictors of NRP after lenvatinib initiation warrants further investigation.

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.

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.

The Enigmatic Emerging Role of the C-Maf Inducing Protein in Cancer

The C-Maf-Inducing protein (CMIP) was first described as overexpressed in T cell subpopulations of idiopathic nephrotic syndrome (INS) patients. Later, it was found concomitantly upregulated in podocytes. CMIP expression has also been reported in several types of cancer, including blood malignancies and solid tumors, in many cases accompanied by nephrotic syndrome. In addition to these observations, the duality of CMIP overexpression in the kidney and INS lesions, has been extensively reported as one of the adverse effects of anticancer therapy based on anti-receptor tyrosine kinase drugs. As a consequence, a growing body of evidence points at CMIP as playing a role in cancer. This includes its reciprocal regulatory ties with NF-κB and WT1, and the more recent reports showing an involvement in regulatory circuits in cancer cells. The ensemble of the current information justifies to propose CMIP as an important piece of the puzzle of biological systems involved in cancer and other diseases and its potential as a target.

Hypertension and Prohypertensive Antineoplastic Therapies in Cancer Patients

The development of a wide range of novel antineoplastic therapies has improved the prognosis for patients with a wide range of malignancies, which has increased the number of cancer survivors substantially. Despite the oncological benefit, cancer survivors are exposed to short- and long-term adverse cardiovascular toxicities associated with anticancer therapies. Systemic hypertension, the most common comorbidity among cancer patients, is a major contributor to the increased risk for developing these adverse cardiovascular events. Cancer and hypertension have common risk factors, have overlapping pathophysiological mechanisms and hypertension may also be a risk factor for some tumor types. Many cancer therapies have prohypertensive effects. Although some of the mechanisms by which these antineoplastic agents lead to hypertension have been characterized, further preclinical and clinical studies are required to investigate the exact pathophysiology and the optimal management of hypertension associated with anticancer therapy. In this way, monitoring and management of hypertension before, during, and after cancer treatment can be improved to minimize cardiovascular risks. This is vital to optimize cardiovascular health in patients with cancer and survivors, and to ensure that advances in terms of cancer survivorship do not come at the expense of increased cardiovascular toxicities.

Nephrotoxicity of Anti-Angiogenic Therapies

The use of inhibitors of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling for the treatment of cancer has increased over the last decade. This signaling pathway plays a fundamental role in angiogenesis and also in kidney physiology. The emergence of anti-angiogenic therapies has led to adverse nephrotoxic effects, despite improving the outcomes of patients. In this review, we will present the different anti-angiogenic therapies targeting the VEGFR pathway in association with the incidence of renal manifestations during their use. In addition, we will discuss, in detail, the pathophysiological mechanisms of frequent renal diseases such as hypertension, proteinuria, renal dysfunction, and electrolyte disorders. Finally, we will outline the cellular damage described following these therapies.

Minimal change disease concurrent with acute interstitial nephritis after long-term use of sorafenib in a patient with renal cell carcinoma

Sorafenib is one of the multi-targeted tyrosine kinase inhibitors (TKI), mainly used for treating advanced renal cell carcinoma. Accumulated evidence indicates a minority of patients develop nephrotic syndrome (NS) as a high-grade nephrotoxic injury; however, evidence of NS after long-term use of sorafenib remains unclear. A 64-year-old man developed NS following 2-year use of sorafenib and his NS persisted even after sorafenib use was discontinued. Renal biopsy disclosed minimal change disease (MCD) concurrent with acute tubulointerstitial nephritis, indicating secondary MCD with which sorafenib may be involved. To prevent permanent renal insufficiency, we administered glucocorticoid and succeeded in achieving complete remission from NS. Nephrotoxic injuries could occur at any time with variable onset after sorafenib. Renal biopsy should be pursued in the case of NS associated with TKI therapy. To facilitate recovery of renal dysfunction, administration of prednisolone should be considered, particularly when NS does not disappear after cessation of TKIs.

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.

Angiotensin-converting enzyme inhibitors have adverse effects in anti-angiogenesis therapy for hepatocellular carcinoma

At present, anti-angiogenic drugs (AADs) are widely used in the systemic treatment of hepatocellular carcinoma (HCC) or other types of cancer, and have achieved good anti-cancer effect, whereas treatment-related proteinuria can affect the routine use of AADs, which in turn abates the overall efficacy. Currently, most clinicians prescribe angiotensin-converting enzyme inhibitors (ACEIs) to alleviate proteinuria according to diabetic nephropathy guidelines or expert recommendations. However, the efficacy of ACEIs in reducing AAD-related proteinuria and its effect on the anticancer effect of AADs is unknown. Our clinical data showed that some HCC patients experienced tumor progression by ACEIs administration for the treatment of proteinuria caused by AADs. Here, we confirmed that in different tumor-bearing mouse models, ACEIs did not delay the appearance of proteinuria or alleviate proteinuria caused by AADs but compromised the anticancer efficacy of AADs. This effect is unrelated to the change in the VEGF signaling pathway. Our data showed that the combination of ACEIs and AADs flared the production of kidney-derived erythropoietin (EPO). In turn, EPO compromises the anti-angiogenic effects of AADs and decreases antitumor activity. In conclusion, for the treatment of proteinuria caused by AADs, ACEIs have no efficacy while also promoting AADs resistance. This finding is of great significance to guide clinical standardized management of side effects of anti-angiogenic therapy for cancer patients.

Improvement of lenvatinib-induced nephrotic syndrome after adaptation to sorafenib in thyroid cancer: A case report

BACKGROUND

Target therapy is licensed by United States Food and Drug Administration on certain cancers. Both sorafenib and lenvatinib are tyrosine kinase inhibitor and indicated on radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC). Lenvatinib is more effective in cancers' control than sorafenib, but causes more nephrotoxicity than sorafenib does. This case is the second published case about the serial adaptions from lenvatinib to sorafenib for improving the proteinuria and, meanwhile, achieving the therapeutic goal.

CASE SUMMARY

A 56-year-old man suffered from bilateral edematous lower extremities after 1-mo prescription of lenvatinib of 20 mg/d for RAI-refractory DTC. Aside from this symptom, he also developed hypertension. His laboratory showed grade-3 proteinuria (estimated 24-h urine protein: 9993 mg), hypoalbuminemia and hypercholesterolemia. Anti-vascular endothelial growth factor (VEGF) therapy-induced nephrotic syndrome was impressed. After reduced dosage of lenvatinib of 10 mg/d and related symptomatic drugs, limited improvement was observed in both adverse effects and caner control. Under this condition, we substituted sorafenib of 400 mg/d for lenvatinib of 10 mg/d. After a 5-mo prescription, not only hypertension and peripheral edema were greatly improved, but also proteinuria was improved from grade three to grade one (estimated 24-h urine protein: 962 mg). At the same time the cancer control was achieved, judged from computed tomography and laboratory evidence [thyroglobulin (Tg) before prescription of sorafenib: 354.7 ng/mL; Tg after prescription of sorafenib: 108.9 ng/mL].

CONCLUSION

Adaption from lenvatinib to sorafenib is a feasible method to improve the anti-VEGF therapy-induced nephrotic syndrome and achieve the therapeutic goal at the same time.

Nephrotoxicity Associated with Novel Anticancer Agents (Aflibercept, Dasatinib, Nivolumab): Case Series and Nephrological Considerations

Cancer patients have an incidence of about 60% kidney disease development and are at elevated risk of acute renal damage. Kidney disease in these patients is frequently associated with nephrotoxicity from the ongoing oncological treatment. New anticancer therapeutic strategies, such as targeted therapies and immunotherapies, offer substantial benefits in the treatment of many neoplasms. However, their use is associated with significant nephrotoxicity, which qualitatively differs from that seen with traditional cytotoxic chemotherapy, while the underlying mechanisms are complex and still to be clearly defined. Nephrologists need to be knowledgeable about the array of such renal toxicities for effective collaboration with the oncologist in the prevention and management of kidney involvement. Renal adverse effects may range from asymptomatic proteinuria to renal failure, and their prompt identification and timely treatment is essential for optimal and safe care of the patient. In this article, after presenting clinical cases we discuss the differing renal toxicity of three novel anticancer agents (aflibercept, dasatinib, and nivolumab) and possible measures to counter it.

MicroRNA profiling in kidney in pigs fed ochratoxin A contaminated diet

OTA is a toxic metabolite produced by fungus belonging to Aspergillus and Penicillium genera. Kidney is the main target of this toxin; OTA is considered as one of the etiological factors at the origin of the human Balkan endemic nephropathy. microRNA are short non-coding transcrips (18-22 nucleotides in length) regulating key cellular processes. Various miRNAs have been established to play important roles in development of renal carcinoma and urothelial cancer. The objective of this study is to analyse the miRNA profiling in the kidney of piglets experimentally intoxicated with feed contaminated with OTA. Fifteen piglets (five pigs/group) were randomly distributed into 3 groups, fed normal diet (Group 1: control), or diets contaminated with OTA in two concentrations: 50 μg OTA/kg feed (Group 2: 50 μg OTA/kg feed) or 200 μg OTA/kg feed (Group 3: 200 μg OTA/kg feed) for 28 days. At the end of the experiment blood samples were taken for serological analyses. Animals from control group and 200 μg OTA/kg feed were sacrificed and kidney samples were taken for histological and molecular analyses. As resulted from molecular profiling study there are 8 miRNA differentially expressed in OTA kidney vs control kidney, in which five miRNA were overexpressed in the kidney of OTA intoxicated animals: miR-497 (FC = 6.34), miR-133a-3p (FC = 5.75), miR-423-3p (FC = 5.48), miR-34a (FC = 1.68), miR-542-3p (1.65) while three miRNA were downregulated: miR-421-3p (FC = -3.96); miR-490 (FC = -3.87); miR-9840-3p (FC = -2.13). The altered miRNAs as effect of OTA are strongly connected to the engine of cancer, disturbing nodal points in different pathways, as TP53 signalling. This proof-of-concept study proves the actual utility of miRNAs as biomarkers of mycotoxin exposure, including OTA.

Acute kidney injury in the patient with cancer

Dramatic advances in the care of patients with cancer have led to significant improvement in outcomes and survival. However, renal manifestations of the underlying cancer as well as the effects of anti-neoplastic therapies leave patients with significant morbidity and chronic kidney disease risks. The most common renal manifestations associated with cancer include acute kidney injury (AKI) in the setting of multiple myeloma, tumor lysis syndrome, post-hematopoietic stem cell therapy, and AKI associated with chemotherapy. Knowledge of specific risk factors, modification of risk and careful attention to rapid AKI diagnosis are critical for improving outcomes.

Podocyte Injury in Lupus Nephritis

Systemic lupus erythematosus (SLE) is characterized by a broad spectrum of renal lesions. In lupus glomerulonephritis, histological classifications are based on immune-complex (IC) deposits and hypercellularity lesions (mesangial and/or endocapillary) in the glomeruli. However, there is compelling evidence to suggest that glomerular epithelial cells, and podocytes in particular, are also involved in glomerular injury in patients with SLE. Podocytes now appear to be not only subject to collateral damage due to glomerular capillary lesions secondary to IC and inflammatory processes, but they are also a potential direct target in lupus nephritis. Improvements in our understanding of podocyte injury could improve the classification of lupus glomerulonephritis. Indeed, podocyte injury may be prominent in two major presentations: lupus podocytopathy and glomerular crescent formation, in which glomerular parietal epithelial cells play also a key role. We review here the contribution of podocyte impairment to different presentations of lupus nephritis, focusing on the podocyte signaling pathways involved in these lesions.

CMIP is a negative regulator of T cell signaling

Upon their interaction with cognate antigen, T cells integrate different extracellular and intracellular signals involving basal and induced protein–protein interactions, as well as the binding of proteins to lipids, which can lead to either cell activation or inhibition. Here, we show that the selective T cell expression of CMIP, a new adapter protein, by targeted transgenesis drives T cells toward a naïve phenotype. We found that CMIP inhibits activation of the Src kinases Fyn and Lck after CD3/CD28 costimulation and the subsequent localization of Fyn and Lck to LRs. Video microscopy analysis showed that CMIP blocks the recruitment of LAT and the lipid raft marker cholera toxin B at the site of TCR engagement. Proteomic analysis identified several protein clusters differentially modulated by CMIP and, notably, Cofilin-1, which is inactivated in CMIP-expressing T cells. Moreover, transgenic T cells exhibited the downregulation of GM3 synthase, a key enzyme involved in the biosynthesis of gangliosides. These results suggest that CMIP negatively impacts proximal signaling and cytoskeletal rearrangement and defines a new mechanism for the negative regulation of T cells that could be a therapeutic target.

Bioinformatics Analysis of the Core Genes Related to Lupus Nephritis Through a Network and Pathway-Based Approach

In this study, we explored the genes genetically associated with lupus nephritis (LN), and their function by bioinformatics analysis. We collected genes potentially associated with LN from National Center for Biotechnology Information Center (NCBI-Gene) and Online Mendelian Inheritance in Man (OMIM) databases. The major bioinformatics analysis linked with genes was then revealed by weighted gene co-expression network analysis (WGCNA), crosstalk analysis, functional analysis, and Pivot algorithm. Two hundred twenty-three LN-related genes were obtained by intersecting NCBI-Gene and OMIM databases. Two thousand five hundred sixty-eight LN-related proteins and 23 modules were excavated by String protein interaction network and WGCNA co-expression analysis, respectively. Pivot algorithm included no coding RNA, transcription factor and drug indicated the high-count correlation-associated modules related to cancer, kidney pathophysiological changes, and kidney injury, respectively. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis based on 23 modules revealed LN-related genes mainly involved in immune response. Moreover, 19 genes that came from intersection of LN, arthritis, pleurisy, and myocarditis have close relationship with immune diseases and immune processes. Our results from this research may have important implications for understanding the genes underlying LN. Also, the framework proposed in this work can be used to research pathological molecular network and genes related to LN.

NFκB and Kidney Injury

The global burden of chronic kidney disease will increase during the next century. As NFκB, first described more than 30 years ago, plays a major role in immune and non-immune-mediated diseases and in inflammatory and metabolic disorders, this review article summarizes current knowledge on the role of NFκB in in vivo kidney injury and describes the new and so far not completely understood crosstalk between canonical and non-canonical NFκB pathways in T-lymphocyte activation in renal disease.

Protease-activated receptor 2 protects against VEGF inhibitor-induced glomerular endothelial and podocyte injury

Vascular endothelial growth factor (VEGF) inhibitors cause glomerular injury. We have recently shown that activation of protease-activated receptor 2 (PAR2) by factor Xa exacerbated diabetic kidney disease. However, the role of PAR2 in glomerular injury induced by VEGF blockade is not known. Herein, we investigated the effect of the lack of PAR2 on VEGF inhibitor-induced glomerular injury. Although administering an anti-VEGF antibody by itself did not show renal phenotype in wild type mice, its administration to mice lacking endothelial nitric oxide synthase (eNOS) caused glomerular injury. Different from what we expected, administration of an anti-VEGF antibody in mice lacking PAR2 and eNOS exacerbated albuminuria and reduced the expression levels of CD31, pro-angiogenic VEGF, and angiogenesis-related chemokines in their kidneys. Podocyte injury was also evident in this model of mice lacking PAR2. Our results suggest that PAR2 is protective against VEGF inhibitor-induced glomerular endothelial and podocyte injury.

Therapeutic Inhibition of VEGF Signaling and Associated Nephrotoxicities

Inhibition of vascular endothelial growth factor A (VEGFA)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling is a common therapeutic strategy in oncology, with new drugs continuously in development. In this review, we consider the experimental and clinical evidence behind the diverse nephrotoxicities associated with the inhibition of this pathway. We also review the renal effects of VEGF inhibition's mediation of key downstream signaling pathways, specifically MAPK/ERK1/2, endothelial nitric oxide synthase, and mammalian target of rapamycin (mTOR). Direct VEGFA inhibition via antibody binding or VEGF trap (a soluble decoy receptor) is associated with renal-specific thrombotic microangiopathy (TMA). Reports also indicate that tyrosine kinase inhibition of the VEGF receptors is preferentially associated with glomerulopathies such as minimal change disease and FSGS. Inhibition of the downstream pathway RAF/MAPK/ERK has largely been associated with tubulointerstitial injury. Inhibition of mTOR is most commonly associated with albuminuria and podocyte injury, but has also been linked to renal-specific TMA. In all, we review the experimentally validated mechanisms by which VEGFA-VEGFR2 inhibitors contribute to nephrotoxicity, as well as the wide range of clinical manifestations that have been reported with their use. We also highlight potential avenues for future research to elucidate mechanisms for minimizing nephrotoxicity while maintaining therapeutic efficacy.

Expression of CMIP in podocytes is restricted to specific classes of lupus nephritis

Lupus glomerulopathies are classified into various histological patterns, which probably result from different pathophysiological origins. Podocyte injury can be demonstrated in lupus nephritis but its clinical relevance is far little appreciated and is often masked by proliferative lesions and inflammatory cell infiltrations. Two patterns of podocyte lesions may be considered, either occurring in the context of renal inflammation or reflecting podocyte dysfunction in non-proliferative and non-inflammatory glomerulopathies. This distinction remains elusive since no reliable biomarker discriminates between both entities. CMIP was recently found induced in some glomerular disease but its expression in different lupus nephritis classes has not been investigated. Twenty-four adult patients with lupus nephritis, including non-proliferative (n = 11) and proliferative (n = 13) glomerulopathies were analyzed. Clinical, biological and immunological data were compared with immunomorphological findings. We analyzed by quantitative and qualitative methods the expression of CMIP in different histological classes. We found CMIP abundance selectively increased in podocytes in class II and class V glomerulopathies, while in proliferative forms (class III and class IV), CMIP was rarely detected. CMIP was not expressed in cellular crescents, endothelial cells or mesangial cells. CMIP colocalized with some subsets of B and T cells within glomerular or interstitial mononuclear cell infiltrates but never with macrophages. Hematuria is rarely present in lupus glomerulopathies expressing CMIP. There was no correlation between classical immunological markers and CMIP expression. Thus, CMIP induction in lupus nephritis seems restricted to non-proliferative glomerulopathies and may define a specific pattern of podocyte injury.