Minimal change disease onset observed after bevacizumab administration

Effect of Intravitreal Anti-Endothelial Growth Factor Agents on Renal Function in Patients With Diabetes Mellitus

Introduction

Intravitreal administration of vascular endothelial growth factor inhibitors (anti-VEGF) is the treatment of choice in retinal pathology associated with type 2 diabetes mellitus (DM2). We aimed to analyze the effect of intravitreal anti-VEGF administration on renal function in patients with DM2.

Methods

This is a single-center retrospective and observational study of patients with DM2 with and without chronic kidney disease (CKD). We analyzed the evolution of renal function after anti-VEGF onset, compared with a control group.

Results

We included 45 patients (55.6% male) who received anti-VEGF therapy. Mean age was 74.4±11.5 (50-91) years. These were compared with 45 patients with similar characteristics. After 12 months, 76.3% had CKD with a mean reduction in estimated glomerular filtration rate (eGFR) of 19.4%. Nine patients (20%) had a >25% reduction in eGFR, and 3 patients (6.7%) had a >50% reduction in GFR. At 24 months, 80% of patients had CKD with a mean eGFR decrease of 28%. The mean eGFR slope of patients who had received anti-VEGF treatment was 10 ml/min/year compared to 1.5 ml/min/year in the control group (P < 0.05). After the first administration, 5 patients (17.2%) in the CKD group required renal replacement therapy during follow-up (mean time 22±12 months). Main risk factors for need of dialysis were age, presence of previous CKD, and baseline proteinuria.

Conclusion

Intravitreal anti-VEGF administration is a risk factor for CKD and rapid progression to end-stage kidney disease in patients with previous CKD. Knowing these drugs' implications is crucial to avoid CKD progression and opportunely limit their use in certain patients.

Onconephrology: mitigation of renal injury in chemotherapy administration

PURPOSE OF REVIEW

Onconephrology was first coined as a name for the intersection of cancer medicine and nephrology in the early 2010s. It was recognized then that beyond and understanding of kidney physiology, a new generation of nephrologists skilled in both molecular biology and precision medicine were needed to deal with the challenges of emerging cancer therapies. Stem cell transplants, biologic agents, adjuvants blocking basic cellular signaling pathways, immunotherapy were found to promote novel anticancer outcomes, but also to pose new risks to the kidneys. The field rapidly overlapped with emerging expertise in vascular glomerular disease, glomerular disease, and the same biologic agents now applied to auto immune systemic and kidney diseases.

RECENT FINDINGS

Many categories of chemotherapeutic agents have been discovered to have adverse renal side effects. In this review, we address classic chemotherapeutic nephrotoxicity and oncologic clinical situations leading to acute kidney injury. We also review the frontiers of nephrotoxicity reported with cell cycle inhibitors, diverse classes of tyrosine kinase inhibitors, immune checkpoint inhibitors, chimeric antigen receptor T-cell therapy, anticancer vaccines, and thrombotic microangiopathies triggered by malignancy and chemotherapy. The aim will be to focus on published strategies to mitigate nephrotoxicity.

SUMMARY

As onconephrology expands into its own field, it gives birth to new subdisciplines. An understanding that patient populations want the benefits of chemotherapy without the renal (and other) systemic toxicities is emerging. A need to develop a new class of molecular and genetic experts in onconephrology to mitigate nephrotoxicity from chemotherapy is apparent and urgent.

Long-Term Change in Renal Function After Intravitreal Anti-VEGF Treatment for Diabetic Macular Edema: A 2-Year Retrospective Cohort Study

INTRODUCTION

To investigate the longitudinal changes in renal function and associated factors after intravitreal anti-vascular endothelial growth factor (VEGF) administration in diabetic macular edema (DME).

METHODS

A total of 108 patients who had received intravitreal ranibizumab or aflibercept for DME and had follow-up visits for at least 2 years in one hospital were retrospectively enrolled. The estimated glomerular filtration rate (eGFR) at baseline and during the follow-up period and receipt of any renal replacement therapy were recorded. Linear regression and Cox regression models were used to evaluate factors associated with eGFR decline and renal replacement therapy.

RESULTS

After intravitreal anti-VEGF treatment, eGFR showed a mean decline of -10.4 ± 23.2% and -16.5 ± 26.4% at months 12 and 24, respectively. Patients in the eGFR > 120 mL/min and 15-30 mL/min groups had the greatest decline (-32.0 ± 20.6% and -37.4 ± 30.9%, respectively) while those in the 61-90 mL/min group had the smallest decline (-4.3 ± 19.7%) in eGFR after the 2-year treatment. One out of 52 patients (1.9%) receiving ranibizumab and five out of 56 patients (8.9%) receiving aflibercept started hemodialysis or peritoneal dialysis within the 2-year follow-up period (P = 0.21). Baseline eGFR correlated with renal replacement therapy after intravitreal anti-VEGF treatment (hazard ratio = 0.879 per increase of 1 in eGFR, P = 0.018).

CONCLUSIONS

In DME patients receiving intravitreal anti-VEGF treatment, a persistent decline in eGFR was observed during the 2-year treatment course. Patients with extremely high or low eGFR had greater eGFR decline, and those with poor baseline eGFR tended to require dialysis after intravitreal anti-VEGF treatment.

Risk of renal damage associated with intravitreal anti-VEGF therapy for diabetic macular edema in routine clinical practice

Purpose

Vascular endothelial growth factor inhibitors (anti-VEGF) have been shown to be effective in the treatment of diabetic macular edema. However, there is little information about the systemic effects of intraocular administration of anti-VEGF drugs in patients with coexistent diabetic nephropathy because it can produce adverse renal effects.

Methods

This retrospective cohort study analyzed the effect of intravitreal anti-VEGF drugs (bevacizumab, ranibizumab, or aflibercept) on eFGR and microalbuminuria (MicA) in patients with diabetic macular edema and nonproliferative retinopathy without chronic kidney disease (CKD).

Results

Sixty-six patients were included, 54.5% male and 45.5% female, with a mean age of 66.70 ± 11.6 years. The mean follow-up of patients with antiangiogenic treatment was 42.5 ± 28.07 months, and the mean number of injections was 10.91 ± 7.54. In 12.1% of the cases, there was a worsening of the glomerular filtration rate (eFGR) and a 19.7% worsening of the microalbuminuria (MicA). The number of injections was not related to the worsening of the eFGR (P = 0.74) or the MicA (P = 0.239). No relationship was found between the type of drug and the deterioration of the GFR (P = 0.689) or the MicA (P = 0.53).

Conclusions

Based on the results, there is a small proportion of patients with increase in MicA and the decrease in eFGR after anti-VEGF therapy, and these was no associated with the number of injection or the drug type. Ophthalmologists should be aware of renal damage in order to do a close monitoring of renal function and proteinuria after intravitreal administration of anti-VEGF mainly in hypertensive patients.

Nephrotic-range proteinuria and membranoproliferative glomerulonephritis-like pattern caused by interferon-β1b in a patient with multiple sclerosis

Interferon-beta (IFN-β) subtypes are widely used as immunomodulatory agents for relapsing-remitting multiple sclerosis (MS). Although generally well tolerated, a growing number of reports have recently shown association of long-term IFN-β therapy with several types of glomerulonephritis. Here, we present the case of a 42-year-old woman with MS who developed nephrotic-range proteinuria after taking IFN-β1b for nine years. Initially, due to the presence of histological features consistent with immunoglobulin A (IgA) nephropathy (granular IgA deposits in mesangial lesions), a tonsillectomy plus steroid pulse therapy was performed. However, proteinuria did not significantly decrease after these treatments. Therefore, a second renal biopsy was performed after three years, revealing a membranoproliferative glomerulonephritis-like pattern without immune complex. Further immunofluorescence analysis showed attenuated IgA staining. Consequently, IFN-β1b was replaced with dimethyl fumarate, resulting in complete remission, with proteinuria decreasing to the level of 0.2 g/day. Although it is a rare adverse effect, physicians should pay careful attention to the symptoms and findings of nephritis during the follow-up of patients under treatment with this agent.

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.

Membranoproliferative glomerulonephritis after intravitreal vascular growth factor inhibitor injections: A case report and review of the literature

Systemic administration of agents that inhibit vascular endothelial growth factor (VEGF) and therefore vascular proliferation is often used to treat various cancers. However, these agents are associated with a number of side effects, including proteinuria and renal injury. Intravitreal injection of anti-VEGF agents has become the cornerstone of macular disease treatment. Since these agents cross the blood-retina barrier and enter the circulation, systemic side effects have been reported. We report the novel case of a 57-year-old patient who presented with macular oedema secondary to central retinal vein occlusion, underwent three monthly loading-dose injections with the anti-VEGF agent ranibizumab, and 2 weeks after the second injection presented with biopsy-verified membranoproliferative glomerulonephritis. Twelve weeks after presenting with renal failure and 10 weeks after his last anti-VEGF injection, the patient demonstrated spontaneous recovery of his kidney function. The patient had a history that promoted renal fragility, including hypertension, liver transplantation 6 years earlier for alcohol-related cirrhosis and new-onset diabetes mellitus after transplant. Our literature review and case suggest that although adverse renal events after intravitreal anti-VEGF injections are very rare, ophthalmologists and nephrologists should be aware of this risk.

Intravitreal vascular endothelial growth factors hypertension, proteinuria, and renal injury: a concise review

PURPOSE OF REVIEW

Nearly 20 years ago, vascular endothelial growth factor (VEGF)inhibitors (VEGFi) were adapted from systemic use from antiangiogenesis roles to intravitreal uses. Initially bevacizumab a murine immunoglobulin was injected 'off label' as a treatment for diabetic macular edema and age-related macular degeneration. Throughout the following decade aflibercept and finally ranibizumab were adapted and obtained Food and Drug Administration approval for intravitreal use. Initially systemic absorption was thought to be quite low after intravitreal injections and was quoted as being 200-fold lower than levels postulated to induce significant VEGF inhibition. Pharmacodynamic studies obtained in 2014 and again in 2017 revealed significant systemic absorption and detectable VEGF inhibition, this has since been confirmed in multiple subsequent studies.

RECENT FINDINGS

A few case reports of renal dysfunction and glomerular disease related to VEGFi were initially identified. Mixed findings on effects on blood pressure were noted in studies. More recently, 32 cases of de-novo glomerular disease and/or proteinuria exacerbation were identified. New studies have corroborated increased blood pressure, proteinuria exacerbation in patients with pre-existing nephrotic syndrome, and systemic VEGF depletion. Further, the most common lesion of systemic VEGFi nephrotoxicity, thrombotic microangiopathy, has recently been reported by our group.

SUMMARY

We will review the pharmacokinetic, translational, and epidemiological data that year upon year establish the finite-yet real risk of intravitreal VEGFi.

Review of intravitreal VEGF inhibitor toxicity and report of collapsing FSGS with TMA in a patient with age-related macular degeneration

Intravitreal vascular endothelial growth factor (VEGF) receptor blockade is used for a variety of retinal pathologies. These include age-related macular degeneration (AMD), diabetic macular edema (DME) and central retinal vein obstruction. Reports of absorption of intravitreal agents into systemic circulation have increased in number and confirmation of depletion of VEGF has been confirmed. Increasingly there are studies and case reports showing worsening hypertension, proteinuria, renal dysfunction and glomerular disease. The pathognomonic findings of systemic VEGF blockade, thrombotic microangiopathies (TMAs), are also being increasingly reported. One lesion that occurs in conjunction with TMAs that has been described is collapsing focal segmental glomerulosclerosis (cFSGS). cFSGS has been postulated to occur due to TMA-induced chronic glomerular hypoxia. In this updated review we discuss the mechanistic, pharmacological, epidemiological and clinical evidence of intravitreal VEGF toxicity. We review cases of biopsy-proven toxicity presented by our group and other investigators. We also present the third reported case of cFSGS in the setting of intravitreal VEGF blockade with a chronic TMA component that was crucially found on biopsy. This patient is a 74-year-old nondiabetic male receiving aflibercept for AMD. Of the two prior cases of cFSGS in the setting of VEGF blockade, one had AMD and the other had DME. This case solidifies the finding of cFSGS and its association with chronic TMA as a lesion that may be frequently encountered in patients receiving intravitreal VEGF inhibitors.

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.

Hepatocellular carcinoma in patients with renal dysfunction: Pathophysiology, prognosis, and treatment challenges

The population of patients with hepatocellular carcinoma (HCC) overlaps to a high degree with those for chronic kidney disease (CKD) and end-stage renal disease (ESRD). The degrees of renal dysfunction vary, from the various stages of CKD to dialysis-dependent ESRD, which often affects the prognosis and treatment choice of patients with HCC. In addition, renal dysfunction makes treatment more difficult and may negatively affect treatment outcomes. This study summarized the possible causes of the high comorbidity of HCC and renal dysfunction. The possible mechanisms of CKD causing HCC involve uremia itself, long-term dialysis status, immunosuppressive agents for postrenal transplant status, and miscellaneous factors such as hormone alterations and dysbiosis. The possible mechanisms of HCC affecting renal function include direct tumor invasion and hepatorenal syndrome. Finally, we categorized the risk factors that could lead to both HCC and CKD into four categories: Environmental toxins, viral hepatitis, metabolic syndrome, and vasoactive factors. Both CKD and ESRD have been reported to negatively affect HCC prognosis, but more research is warranted to confirm this. Furthermore, ESRD status itself ought not to prevent patients receiving aggressive treatments. This study then adopted the well-known Barcelona Clinic Liver Cancer guidelines as a framework to discuss the indicators for each stage of HCC treatment, treatment-related adverse renal effects, and concerns that are specific to patients with pre-existing renal dysfunction when undergoing aggressive treatments against CKD and ESRD. Such aggressive treatments include liver resection, simultaneous liver kidney transplantation, radiofrequency ablation, and transarterial chemoembolization. Finally, focusing on patients unable to receive active treatment, this study compiled information on the latest systemic pharmacological therapies, including targeted and immunotherapeutic drugs. Based on available clinical studies and Food and Drug Administration labels, this study details the drug indications, side effects, and dose adjustments for patients with renal dysfunction. It also provides a comprehensive review of information on HCC patients with renal dysfunction from disease onset to treatment.

Predictive and prognostic value of magnesium serum level in FOLFIRI plus cetuximab or bevacizumab treated patients with stage IV colorectal cancer: results from the FIRE-3 (AIO KRK-0306) study

Magnesium wasting is a frequent side effect of epidermal growth factor receptor (EGFR)-antibody treatment as magnesium-absorption mechanisms are dependent on EGFR signaling. EGFR-inhibition results in decreased renal reabsorption. There is evidence that hypomagnesemia during cetuximab treatment correlates with response. The prognostic role of hypomagnesemia during bevacizumab treatment has not been studied yet. Here, we evaluate the prognostic value of hypomagnesemia in patients with metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab as first-line therapy. A total of 391 of 752 patients of the firstline irinotecan study population had magnesium levels measured at baseline and for the first three cycles (6 weeks) of treatment. Of those, 240 had Rat Sarkoma wildtype tumors. Overall hypomagnesemia was more common in the cetuximab compared to the bevacizumab arm (80 vs. 43%, P < 0.005). During therapy, magnesium showed a time-dependent decrease to 80% of baseline in the cetuximab and to 89% in the bevacizumab arm. Whereas magnesium continued to decrease over time in the cetuximab-treated patients, it remained stable in the bevacizumab-treated. Overall response rate (ORR) was associated with higher magnesium at week 6 (20.9 vs. 79.1%, P = 0.041). Bevacizumab-treated patients with magnesium levels below the median value at week 6 had a significantly longer progression-free survival (PFS; 11.7 vs. 9.9 months, P = 0.034; hazard ratio 0.73) and a trend towards longer overall survival (OS) (29.6 vs. 23.2 months, P = 0.089; hazard ratio 0.77). Hypomagnesemia at predefined time points and magnesium nadir had no significant effect on ORR, OS and PFS in the cetuximab arm. Our data show different magnesium kinetics in patients with metastatic colorectal cancer treated with cetuximab or bevacizumab. For patients treated with cetuximab, hypomagnesemia did not have an impact on response and survival. Hypomagnesemia might have a prognostic value in bevacizumab treatment.

Worsening of renal function and uncontrolled hypertension from intravitreal bevacizumab injections

Vascular endothelial growth factor (VEGF) inhibitors are used in the treatment of various cancers as well as diabetic retinopathy. The systemic use of these drugs has been associated with adverse effects such as worsening hypertension, proteinuria, and renal function. There have been some reported cases of worsening hypertension, thrombotic microangiopathy, or glomerular disease after intravitreal injections of bevacizumab, aflibercept, and ranibizumab. We present a case of a patient who was taking intravitreal bevacizumab injections for diabetic retinopathy and was hospitalized with worsening renal function, high blood pressure, and nephrotic-range proteinuria in the setting of tight glycemic control.

Angiogenesis Inhibitors as Anti-Cancer Therapy Following Renal Transplantation: A Case Report and Review of the Literature

Solid organ transplant recipients on long-term immunosuppressive medication are at increased risk of developing malignancy, and treatment of advanced cancers with angiogenesis inhibitors in this context has not been widely studied. We present a case of recurrent high-grade serous ovarian carcinoma treated with paclitaxel and bevacizumab in the context of prior renal transplantation where the patient responded well to treatment with controlled toxicities, discussing the potential for increased rates of adverse events and drug interactions in this select population.

The Challenging Management of Cancer: An Immunonephrologist's Perspective

INTRODUCTION

Onconephrology is an emerging medical subspecialization that focuses on the numberless interrelations between cancer and kidney diseases. Tumor cells evade immune surveillance through activation of immune checkpoint pathways that suppress antitumor immune responses. By blocking checkpoints, new anticancer agents disrupt immune homeostasis but potentially induce immune-mediated diseases. Nephrologists and nephroimmunologists should be able to treat the nephrotoxic sequelae of cancer therapy and ensure continuation of the life-saving treatment.

METHODS

Thirty-seven renal biopsies have been carried out over 42 months in oncologic patients, that is, 5.2% of the total native renal biopsies were carried out in the same period. The commonest diagnoses (>6 cases) were interstitial tubular nephritis, membranous glomerulopathy, IgA nephropathy, vasculitis, and focal and segmental glomerulosclerosis.

CASE PRESENTATION

Three example cases, including focusing on key questions which could involve the nephrologists are reported in detail. They include a cancer-related Goodpasture Syndrome, the peculiar toxic effects of pemetrexed on tubular cells, and the intriguing relationship between bevacizumab and cryoglobulinemic glomerulonephritis.

CONCLUSION

As shown by these 3 example cases, nephrologists need to be open-minded with regard to kidney biopsy in order to get a timely diagnosis. Nephrologists also need to improve their knowledge of cancer biology and therapy in order to prevent kidney problems, manage therapy-related immune-mediated disorders, and improve patient life expectancy.

Worsening proteinuria and renal function after intravitreal vascular endothelial growth factor blockade for diabetic proliferative retinopathy

Systemic vascular endothelial growth factor (VEGF) inhibitions can induce worsening hypertension, proteinuria and glomerular diseases of various types. These agents can also be used to treat ophthalmic diseases like proliferative diabetic retinopathy, diabetic macular edema, central retinal vein occlusion and age-related macular degeneration. Recently, pharmacokinetic studies confirmed that these agents are absorbed at levels that result in biologically significant suppression of intravascular VEGF levels. There have now been 23 other cases published that describe renal sequela of intravitreal VEGF blockade, and they unsurprisingly mirror known systemic toxicities of VEGF inhibitors. We present three cases where stable levels of proteinuria and chronic kidney disease worsened after initiation of these agents. Two of our three patients were biopsied. The first patient's biopsy showed diabetic nephropathy and focal and segmental glomerulosclerosis (FSGS) with collapsing features and acute interstitial nephritis (AIN). The second patient's biopsy showed AIN in a background of diabetic glomerulosclerosis. This is the second patient seen by our group, whose biopsy revealed segmental glomerulosclerosis with collapsing features in the setting of intravitreal VEGF blockade. Though FSGS with collapsing features and AIN are not the typical lesions seen with systemic VEGF blockade, they have been reported as rare case reports previously. In addition to reviewing known elements of intravitreal VEGF toxicity, the cases presented encompass renal pathology data supporting that intravitreal VEGF blockade can result in deleterious systemic and renal pathological disorders.

Thrombotic Microangiopathy and Acute Kidney Injury Induced After Intravitreal Injection of Vascular Endothelial Growth Factor Inhibitors VEGF Blockade-Related TMA After Intravitreal Use

Vascular endothelial growth factor (VEGF) inhibition can cause worsening hypertension, proteinuria, chronic kidney injury, and glomerular disease. Thrombotic microangiopathy (TMA) and other nephrotic disorders have been reported with systemic VEGF blockade. These same agents are given intravitreally for age-related macular degeneration (AMD) and diabetic retinopathy (DR), albeit at lower doses than those given for systemic indications. Systemic absorption of anti-VEGF agents when given intravitreally has been shown consistently along with evidence of significant intravascular VEGF suppression. While worsening hypertension has only been seen in some large-scale studies, case reports show worsening proteinuria and diverse glomerular diseases. These include TMA-associated lesions like focal and segmental glomerulosclerosis with collapsing features (cFSGS). In this paper, we report three cases of TMA likely associated with the use of intravitreal anti-VEGF therapy. These patients developed the signature lesion of VEGF blockade in a 6 to 11 month time frame after starting intravitreal VEGF inhibitors. The literature is reviewed showing similar cases. Intravitreal VEGF blockade may cause these adverse events in a hitherto unidentified subgroup of patients. Well-controlled prospective observational trials are needed to determine the event rate and identify which subgroups of patients are at increased risk. A registry for patients who develop worsening hypertension, proteinuria exacerbation, and glomerular diseases from intravitreal VEGF blockade is proposed.

Nephrotoxicity of anti-angiogenesis drugs

Neoangiogenesis is a basic factor for most physiological as well as pathological processes i.e. tumor metastases. The most important is vascular endothelium growth factor (VEGF) and its receptors (VEGFR1/2) in angiogenesis processes. Nowadays antiangiogenic agents (which inhibit VEGF like bevacizumab neither VEGFR2 like ramucirumab) are widely used in very different chemotherapeutic regimens in clinical oncology. The signalling pathway VEGF-VEGFR plays a crucial role in supporting of adequate kidney function. Appearance of antiangiogenic drugs led to adverse nephrotoxic effects: arterial hypertension, proteinuria, rarely nephrotic syndrome, and kidney dysfunction. Various hystological variants of nephropathy are described, however, in most cases, signs of thrombotic microangiopathy of the renal vessels are noted. This literature review discusses mechanisms, clinical and morphological aspects of nephropathy associated with antiangiogenic drugs.

Bevacizumab-associated glomerular microangiopathy that occurred after postoperative chemotherapy for ovarian cancer

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor (VEGF) that is used to treat patients with various cancers. However, it is known to be associated with adverse events, such as hypertension and proteinuria. The histology of bevacizumab-induced nephropathy is known as thrombotic microangiopathy or minimal change nephrotic syndrome. Recently, however, the terms "bevacizumab-associated glomerular microangiopathy" and "anti-VEGF therapy-induced glomerular microangiopathy" have been proposed. We present a case of a 68-year-old woman who was administered postoperative chemotherapy (carboplatin, paclitaxel, and bevacizumab) for stage IV ovarian cancer. Proteinuria and hypertension appeared after three courses; however, six courses were completed. Then, gemcitabine and carboplatin were administered for recurrence of her cancer. She was diagnosed with nephrotic syndrome after eight courses. Renal biopsy showed accumulation of periodic acid-Schiff (PAS)-positive substances in the capillary walls and para-mesangial areas. Double contouring of basement membranes was also observed. Immunofluorescence microscopy revealed positive staining for IgG, IgA, IgM, C3, C4, and C1q. Immunosuppressive therapy was administered, but was ineffective. Further examination by electron microscopy and immunostaining led to a diagnosis of bevacizumab-associated glomerular microangiopathy.

Intravitreal bevacizumab-induced exacerbation of proteinuria in diabetic nephropathy, and amelioration by switching to ranibizumab

Certain diabetic and hypertensive patients started on intravitreal vascular endothelial growth factor inhibition for diabetic retinopathy may experience worsening of hypertension and proteinuria. The etiology of this is the newly recognized absorption of intravitreally injected vascular endothelial growth factor inhibitors, and the susceptibility of patients with pre-existing renal disease to exacerbations depends on the degree of systemic absorption. There are eighteen reported cases of worsening hypertension, woresening proteinuria, worsening renal function, thrombotic microangiopathy, and glomerular disease noted after initiation of intravitreal vascular endothelial growth factor blockade. This nineteenth case demonstrates worsening hypertension and proteinuria with the start of bevacizumab. Both blood pressure and proteinuria parameters showed overall improvement with switching to the less absorbed and lower potency agent ranibizumab. There was a slight rise in serum creatinine after bevacizumab therapy, which stabilized at a new baseline, and the serum creatinine remained stable on ranibizumab. There were no other nephrotoxic exposures that explained the mild rise in serum creatinine. Because of improvement in renal function and proteinuria, a renal biopsy was deferred for the time. This case re-demonstrates the risk of worsening proteinuria with vascular endothelial growth factor inhibitors when given intravitreally in some patients. The demonstration of improvement in blood pressure and proteinuria with the use of lower potency agents like ranibizumab is novel and an important concept confirming observations from pharmacokinetic studies. The switch to ranibizumab offers a therapeutic option when proteinuria worsens with intravitreal vascular endothelial growth factor blockade, and the patient requires ongoing intravitreal therapy for treatment of diabetic retinopathy.

Everolimus worsening chronic proteinuria in patient with diabetic nephropathy post liver transplantation

Mammalian target of rapamycin (mTOR) inhibitors are used in renal sparing protocols and transplant immunosuppression in patients with solid organ and stem cell transplants. They cause various side effects, including proteinuria, which is mediated by blockade of the vascular endothelial growth factor receptor pathway. There have been various reports of mTOR inhibitors causing proteinuria or worsening proteinuria form preexisting renal glomerulo-pathies. We report a 73-year old male with diabetic glomerulosclerosis, acute liver failure due to Budd-Chiari syndrome, chronic low platelets, and worsening proteinuria from 0.46 g protein/g creatinine to 2.2 g protein/g creatinine. Workup revealed no thrombotic microangiopathy through skin biopsy, and a renal biopsy confirmed only clinically suspected diabetic and hypertensive glomerulosclerosis and possible calcineurin inhibitors. On discontinuation of everolimus urine protein decreased back to 0.6 g/g creatinine. We review the mechanism of mTOR-induced proteinuria and how this may affect diabetic nephropathy secondarily. We also consider the clinical implications of this in transplant patients receiving these agents.

Progression of diabetic nephropathy after successful pancreas transplantation alone: a case report

Pancreas transplantation is the only method that can nearly cure insulin-dependent diabetes mellitus. However, the effect of pancreas transplantation on patients with diabetic nephropathy has recently been considered controversial. In this report, we present a case of abrupt aggravation of proteinuria after successful pancreas transplantation alone without evidence of calcineurin inhibitor (CNI) toxicity. A 22-year-old female patient with type I diabetes mellitus underwent pancreas transplantation alone. The patient already had retinopathy and mild proteinuria, which in this case, may mean diabetic nephropathy. Her glucose levels were managed within the normal range after successful pancreas transplantation. However, the amount of proteinuria fluctuated. Kidney needle biopsy was performed owing to severe elevation of proteinuria, 2 years after the transplantation. Electron microscopy revealed diabetic glomerulosclerosis without evidence of CNI toxicity. This case indicates that diabetic nephropathy can be aggravated after pancreas transplantation, despite well-managed glucose levels and absence of CNI toxicity.

Evaluation of long-term intravitreal anti-vascular endothelial growth factor injections on renal function in patients with and without diabetic kidney disease

Background

Administering anti-vascular endothelial growth factor (anti-VEGF) by intraocular injection has been shown to have a safe systemic profile. Nevertheless, incidents of acute kidney injury following anti-VEGF injection have been reported. We assessed the long-term effect of multiple intravitreal anti-VEGF injections on measures of renal function in patients with diabetes including rate of change of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (ACR).

Methods

A retrospective review of patients receiving diabetic macular oedema (DMO) treatment was undertaken. Serum creatinine, ACR, number of intravitreal anti-VEGF injections and clinical characteristics were collected from electronic healthcare records (EHR). A co-efficient of eGFR and ACR change with time was calculated over a mean duration of 2.6 years. Regression modelling was used to assess variation in the number of anti-VEGF injections and change in eGFR and ACR.

Results

The EHR of 85 patients with DMO (59% male, 78% type 2 diabetes mellitus [T2DM]) were reviewed. On average, 26.8 intravitreal anti-VEGF injections were given per patient over a mean duration of 31 months. No association between increasing number of anti-VEGF injections and rate of eGFR decline (beta = 0.04, 95% confidence intervals [CI]: − 0.02, 0.09; p = 0.22) or ACR change over time (beta = 0.02, CI: − 0.19, 0.23; p = 0.86) was detected, following adjustment for hypertension, cerebrovascular disease, T2DM, and medications taken.

Conclusion

Our data suggests regular long-term intravitreal VEGF inhibition does not significantly alter the rate of change in eGFR and/or ACR with increasing number of treatment injections.

Bevacizumab-associated glomerular microangiopathy

Bevacizumab is a humanized monoclonal IgG1 antibody, which neutralizes vascular endothelial growth factor and is used for treating multiple cancer types. As a known and frequent adverse event, this therapy can lead to renal damage including proteinuria and nephrotic syndrome. In a retrospective approach, we analyzed 17 renal biopsies from patients receiving bevacizumab treatment. We observed a distinctive histopathological pseudothrombotic pattern different from the previously reported thrombotic microangiopathy. Since this pattern includes some features similar to acute and chronic thrombotic microangiopathy, focal segmental glomerulosclerosis and cryoglobulinemic membranoproliferative glomerulonephritis, biopsies with these diagnoses were included for comparison. Clinical, laboratory, light microscopic, immunohistochemical (including a proximity ligation assay), proteomic and electron microscopic features were assessed. Nephrotic syndrome was present in 15 of the 17 bevacizumab-treated patients. All 17 displayed a patchy pattern of variably PAS-positive hyaline pseudothrombi occluding markedly dilated glomerular capillaries in their biopsies. Mass spectrometry-based proteome analysis revealed a special protein pattern demonstrating some features of thrombotic microangiopathy and some of cryoglobulinemic glomerulonephritis, including a strong accumulation of IgG in the pseudothrombi. Proximity ligation assay did not show interaction of IgG with C1q, arguing for accumulation without classic pathway complement activation. In contrast to thrombi in thrombotic microangiopathy cases, the hyaline pseudothrombi did not contain clusters of CD61-positive platelets. Electron microscopy of bevacizumab cases did not show fibrin polymers or extensive loss of podocyte foot processes. Even though cases of bevacizumab-associated microangiopathy share some features with thrombotic microangiopathy, its overall histopathological pattern is quite different from acute or chronic thrombotic microangiopathy cases. We conclude that bevacizumab therapy can lead to a unique hyaline occlusive glomerular microangiopathy, likely arising from endothelial leakage followed by subendothelial accumulation of serum proteins. It can be diagnosed by light microscopy and is an important differential diagnosis in cancer patients with nephrotic syndrome.

Nephrotoxicity induced by intravitreal vascular endothelial growth factor inhibitors: emerging evidence

Vascular endothelial growth factor (VEGF) inhibitors have emerged as powerful tools to treat malignant neoplasms and ocular diseases by virtue of their ability to inhibit angiogenesis. Recent data indicate that intravitreal injections of VEGF inhibitors can lead to significant systemic absorption as well as a measurable reduction of plasma VEGF activity. There is increasing evidence showing that vitreal absorption of these drugs is associated with cases of accelerated hypertension, worsening proteinuria, glomerular disease, thrombotic microangiopathy, and possible chronic renal function decline. In this review, the 3 most commonly used anti-VEGF agents-bevacizumab, ranibizumab, and aflibercept-are discussed, highlighting their intravitreal absorption and associated effects on the kidney as a target organ system. We provide clinical suggestions for clinicians to both better manage patients receiving anti-VEGF agents intravitreally and detect any putative systemic renal effects of these agents. While acknowledging the risks of aberrant retinal angiogenesis, it is important for clinicians to be aware of the potential for adverse renal risks with use of these agents.

Development of Focal Segmental Glomerulosclerosis and Thrombotic Microangiopathy in a Liver Transplant Patient on Sorafenib for Hepatocellular Carcinoma: A Case Report

Transplant patients are at risk for hemodynamic injury and glomerular diseases such as focal segmental glomerulosclerosis (FSGS) and thrombotic microangiopathy (TMA). Calcineurin inhibitors (CNI) can cause various patterns of acute kidney injury (AKI) in transplant patients and their effects must be differentiated from kidney injury due to other agents. Transplant populations are also at risk for atypical infections and malignancies. These conditions and the agents that are used to treat them can then induce their own set of glomerular diseases. We report a patient with hepatitis C who had received an orthotopic liver transplant and then developed recurrent hepatocellular carcinoma, which was treated with the oral tyrosine kinase inhibitor (TKI) sorafenib. In a manner temporally related to the initiation of the TKI, progressive AKI and high-grade rising proteinuria were noted. A biopsy disclosed FSGS and concomitant TMA. Despite the discontinuation of the TKI and high-dose steroid treatment, the patient developed end-stage renal disease and was initiated on hemodialysis. After determining the TKI as the probable culprit, as opposed to CNIs, the patient successfully received a living related renal transplant. CNIs are used to maintain renal and hepatic allografts without the development of hematuria, significant proteinuria, or significant impairment of renal function. It is noted that the pathologic phenotype observed in this case is only the second reported case of concomitant TMA and FSGS in a sorafenib-treated patient.

Three patients with injection of intravitreal vascular endothelial growth factor inhibitors and subsequent exacerbation of chronic proteinuria and hypertension

Vascular endothelial growth factor (VEGF) receptor inhibition is a commonly used tool to prevent vascular proliferation in tumors and retinal diseases. The antiangiogenic effects of these drugs have made them potent adjunct therapies when given systemically for malignancies. They are also useful tools to ameliorate diminishing eyesight in retinopathy. Hypertension and proteinuria have been observed in systemic VEGF inhibitor therapy, with rarer presentations involving nephrotic-range proteinuria due to glomerulopathies. Pharmacokinetic studies have shown detectable blood levels of anti-VEGF inhibitors up to 30 days postintravitreal injection. Animal studies have also demonstrated binding of VEGF inhibitors in simian glomeruli 1 week after a single intravitreal injection. We report three patients who received intravitreal bevacizumab and/or aflibercept with worsening hypertension, proteinuria and renal injury. Data regarding emerging evidence of VEGF inhibitor nephrotoxicity after intravitreal injections are also presented. The clinical data and the existing literature are reviewed to support the hypothesis that intravitreal anti-VEGF agents may be unrecognized nephrotoxins. These agents are given to vulnerable patients with diabetes, hypertension and preexisting nephropathy and proteinuria. This case series is reported to spur further study of the systemic effects of intravitreal VEGF inhibitors.

Biological agents in gastrointestinal cancers: adverse effects and their management

Biological therapy comprises agents that by virtue of their unique mechanisms of action, are able to specifically incite a response against or target malignant cells. They differ from conventional chemotherapy with regard to mechanisms of action, indications and side effect profile. Biologic agents have revolutionized therapy for a number of malignancies. In the setting of gastrointestinal (GI) malignancies, agents targeting vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (Her2/Neu) and epidermal growth factor receptor (EGFR) have proven to be invaluable additions to chemotherapy. However, these agents bring with them a set of side effects attributable to their unique mechanisms of action. The anti VEGF agents-bevacizumab, aflibercept and ramucirumab, can result in renal and vascular complications such as hypertension, arterial thrombotic events (ATE), proteinuria and GI perforations. The anti EGFR agents classically cause dermatological toxicities, in addition to hypomagnesemia, which can be dose limiting for patients. Trastuzumab, a monoclonal antibody that targets Her2/Neu, is known to cause cardiotoxicity, especially when used with anthracyclines. Use of immunotherapy agents such as nivolumab is associated with the development immune related adverse events (irAEs). The use of these agents is expected to increase over the next few years and it is crucial that patients and practitioners are aware of their adverse effects and current management strategies. This review highlights the adverse events associated with the use of biologic and immunologic therapies in GI cancers, their incidence and current management strategies.