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.

Paraneoplastic Syndrome After Kidney Transplantation: Frequency, Risk Factors, Differences to Paraneoplastic Occurrence of Glomerulonephritis in the Native Kidney, and Implications on Long-Term Kidney Graft Function.

Posttransplant malignancies are an important complication of solid organ transplantation. Kidney transplant recipients are at particularly high risk of cancer development. The most relevant risk factors of carcinogenesis are the use of immunosuppressive agents and oncogenic viral infections. Additionally, immune dysregulation caused by these factors may predispose to various types of organ damage. Paraneoplastic glomerular diseases are one of the most interesting and understudied cancer manifestations. The appropriate diagnosis of paraneoplastic glomerular damage can be challenging in kidney transplant recipients, due to factors inherent to concomitant medication and common comorbidities. Recent advances in the field of molecular and clinical nephrology led to a significant improvement in our understanding of glomerular diseases and their more targeted treatment. On the other hand, introduction of novel anticancer drugs tremendously increased patients' survival, at the cost of kidney-related side effects. Our review aims to provide insights into diagnosis and treatment of paraneoplastic glomerular diseases, with a special attention to kidney transplant recipients.

Pitfalls of Current Diagnostic Criteria of Tumor Lysis Syndrome.

BACKGROUND: Tumor Lysis syndrome (TLS) is a well-recognized medical emergency in patients with cancer diagnosis. The diagnostic criteria of TLS have been revised many times since it was recognized, but still have many drawbacks limit diagnosis accuracy. SUMMARY: Autopsy studies in patients with perimortem diagnoses of TLS have shown that they may not have actually had TLS. Therefore, many cancer patients who are at risk for TLS, clinical and laboratory criteria may be fulfilled due to other causes of acute kidney injury. In this review, we aim to cast a spotlight on the shortcomings and pitfalls of the current diagnostic criteria for TLS, and propose a roadmap for developing a more rigorous criteria that improve on the diagnostic accuracy. KEY MESSAGES: Causes of AKI in patients with cancer other than TLS should be considered. Because current diagnostic criteria may miss those differential diagnosis, specific biomarkers that can tell when TLS is the underlying process is an important need, besides appropriate criteria that can jump over the pitfalls in the current criteria and enhance the recognition of TLS among other causes.

Membranous-like glomerulopathy with masked monotypic IgG deposits: A single center case series.

BACKGROUND: Membranous-like glomerulopathy with masked monoclonal IgG deposits (MGMID) is a newly recognized condition predominantly observed in young females, and its understanding in the pediatric population remains limited. MATERIALS AND METHODS: Four cases of MGMID are reported, including three pediatric patients. RESULTS: All patients were female, with ages ranging from 12 to 26 years. None of the patients had malignancies. They presented with kidney dysfunction, proteinuria, or hematuria. Kidney biopsies of all cases exhibited a membranous pattern of injury with monoclonal IgG-κ restriction, "unmasked" by pronase digestion. Pediatric cases were treated conservatively, while the adult case underwent immunosuppressive treatment. All patients had favorable outcomes, and none reached end stage kidney disease (ESKD). CONCLUSION: MGMID can affect both adult and pediatric patients. Further studies are needed to fully characterize its risk factors, optimal therapy, and outcomes.

Hypercalcemia of malignancy: Cancer treatment can be a cause as well.

While the incidence of hypercalcemia of malignancy (HCM) is on the decline, it still occurs in up to 30% of patients with cancer. Immune checkpoint inhibitor (ICI)-related hypercalcemia is becoming increasingly recognized. We describe a case of cemiplimab-induced hypercalcemia in a patient with metastatic squamous cell carcinoma of the earlobe and discuss a management algorithm for HCM. Timely diagnosis and management of HCM is critical for optimal care and the prevention of complications.

Renal involvement in genetic neurocutaneous syndromes.

Phakomatoses, otherwise known as neurocutaneous syndromes, are a heterogeneous group of rare genetic disorders that predominantly affect structures arising from the embryonic ectoderm, namely the skin, eye globe, retina, and central nervous system. In addition to the common neurocutaneous syndromes (neurofibromatosis, tuberous sclerosis complex, Sturge Weber syndrome, Von Hippel-Lindau syndrome), a large number of relatively uncommon phakomatoses have been described in the literature. Cardiovascular, pulmonary, and musculoskeletal systems involvement in these disorders have been reported. Data on kidney involvement is not well described. This review discusses renal involvement in neurocutaneous syndromes. This includes the association with renal masses (cyst, angiomyolipoma, benign or malignant tumor), known vasculopathy, glomerular or tubular disorders, urinary tract anomalies, hypertension, and chronic kidney disease.

AA amyloidosis associated with cancers.

Systemic AA amyloidosis is associated with systemic inflammatory processes such as autoimmune disorders or chronic infections. In addition, AA amyloidosis can develop in a localized or systemic form in patients with malignant neoplastic disorders, and usually involves kidneys impacting renal function. Among solid tumors, renal cell carcinoma (RCC) appears to be responsible for one-quarter to half of all cancers associated with amyloidosis. Among other solid cancers, various clinical presentations and pathological types of lung cancer and basal cell carcinoma skin were reported with AA amyloidosis more often than isolated case reports on other cancers with AA amyloidosis. Symptoms from kidney involvement rather than from the tumor per se were the presenting manifestations in cases of RCC associated with AA amyloidosis. Among hematological malignancies, clonal B cell/plasma cell dyscrasias such as monoclonal gammopathy and lymphoma were noted to be associated with AA amyloidosis. In addition, AA amyloidosis was reported in a substantial number of cases treated with immune checkpoint inhibitors such as pembrolizumab and nivolumab. The mechanism of association of cancer and AA amyloidosis seems to be mediated by the immune response exacerbated from the tumor and its microenvironment or immune therapy. The mainstay of treatment consists of therapy directed against the underlying malignancy or careful withdrawal of the offending agent. This review will discuss this rare but highly morbid clinical condition.

Kidney and urinary tract involvement in systemic mastocytosis.

Systemic mastocytosis (SM) is a disorder of excessive mast cell accumulation in tissues due to a somatic gain-of-function mutation, commonly in the KIT gene, which prevents apoptosis of mast cells. Whereas bone marrow, skin, lymph nodes, spleen and gastrointestinal tract are commonly involved, kidneys are rarely involved directly by SM. However, there are increasing reports of indirect kidney involvement in patients with SM. Novel anti-neoplastic agents to treat advanced forms of SM include non-specific tyrosine kinase inhibitors, which are reported to be associated with kidney dysfunction in some patients. SM is also associated with immune-mediated glomerulonephritis (GN) such as mesangioproliferative GN, membranous nephropathy and diffuse proliferative GN. Kidney injury, in the form of monoclonal deposition disease and primary light chain amyloidosis, is reported in SM associated with plasma cell dyscrasia. In this narrative review we discuss the various ways kidneys (and the urinary tract) are involved in patients with SM.

Frequency and characteristics of chemotherapy-associated thrombotic microangiopathy: Analysis from a large pharmacovigilance database.

We used the information component (IC), a disproportionate Bayesian analysis comparing the number of observed versus expected adverse drug reactions, to determine the potential association between anti-neoplastic agents and thrombotic microangiopathy (TMA). The IC025 indicates the lower end of 95% of IC, in which a value >0 suggests a disproportionality signal between the drug of interest and the adverse drug reaction. Carfilzomib had the highest IC025 for TMA among all studied chemotherapies followed by gemcitabine, mitomycin, bevacizumab, and bortezomib.

Simultaneous Heart-Kidney Transplant-Does Hospital Experience With Heart Transplant or Kidney Transplant Have a Greater Impact on Patient Outcomes?

High institutional transplant volume is associated with improved outcomes in isolated heart and kidney transplant. The aim of this study was to assess trends and outcomes of simultaneous heart-kidney transplant (SHKT) nationally, as well as the impact of institutional heart and kidney transplant volume on survival. All adult patients who underwent SHKT between 2005-2019 were identified using the United Network for Organ Sharing (UNOS) database. Annual institutional volumes in single organ transplant were determined. Univariate and multivariable analyses were conducted to assess the impact of demographics, comorbidities, and institutional transplant volumes on 1-year survival. 1564 SHKT were identified, increasing from 54 in 2005 to 221 in 2019. In centers performing SHKT, median annual heart transplant volume was 35.0 (IQR 24.0-56.0) and median annual kidney transplant volume was 166.0 (IQR 89.5-224.0). One-year survival was 88.4%. In multivariable analysis, increasing heart transplant volume, but not kidney transplant volume, was associated with improved 1-year survival. Increasing donor age, dialysis requirement, ischemic times, and bilirubin were also independently associated with reduced 1-year survival. Based on this data, high-volume heart transplant centers may be better equipped with managing SHKT patients than high-volume kidney transplant centers.

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.

Immune checkpoint inhibitor-associated hypercalcaemia.

Immune checkpoint inhibitors (CPIs) have recently become a cornerstone for the treatment of different advanced cancers. These drugs have the ability to reactivate the immune system against tumour cells but can also trigger a myriad of side effects, termed immune-related adverse events (irAEs). Although there are numerous reports of CPI-related endocrinopathies, hypercalcaemia as a suspected irAE is not well documented. The mechanisms of CPI hypercalcaemia are not clearly established. However, in our review, four distinct causes emerged: endocrine disease-related, sarcoid-like granuloma, humoral hypercalcaemia due to parathyroid-related hormone and hyperprogressive disease following CPI initiation. Prompt recognition of hypercalcaemia and the institution of therapy can be lifesaving, affording the opportunity to address the underlying aetiology. In this review we discuss the incidence, diagnosis and management of immune-related hypercalcaemia in oncological patients receiving CPI agents.

Outcomes of kidney transplantation in patients with myeloma and amyloidosis in the USA.

BACKGROUND: Recent improvement in treatment and patient survival has opened the eligibility of kidney transplantation to patients who developed end-stage kidney disease (ESKD) from plasma cell dyscrasias (PCDs). Data on clinical outcomes in this population are lacking. METHODS: We conducted a retrospective study of United Network for Organ Sharing/Organ Procurement and Transplantation Network dataset (2006-2018) to compare patient and graft outcomes of kidney transplant recipients with ESKD due to PCD versus other causes. RESULTS: Among 168 369 adult first kidney transplant recipients, 0.22-0.43% per year had PCD as the cause of ESKD. The PCD group had worse survival than the non-PCD group for both living and deceased donor types {adjusted hazard ratio [aHR] 2.24 [95% confidence interval (CI) 1.67-2.99] and aHR 1.40 [95% CI 1.08-1.83], respectively}. The PCD group had worse survival than the diabetes group, but only among living donors [aHR 1.87 (95% CI 1.37-2.53) versus aHR 1.16 (95% CI 0.89-1.2)]. Graft survival in patients with PCD were worse than non-PCD in both living and deceased donors [aHR 1.72 (95% CI 1.91-2.56) and aHR 1.30 (95% CI 1.03-1.66)]. Patient and graft survival were worse in amyloidosis but not statistically different in multiple myeloma compared with the non-PCD group. CONCLUSION: The study data are crucial when determining kidney transplant eligibility and when discussing transplant risks in patients with PCD.

Kidney transplantation in patients with multiple myeloma: narrative analysis and review of the last two decades.

There have been significant advances in the treatment of multiple myeloma in the last two decades. Approximately 25% of patients with newly diagnosed myeloma have some degree of kidney impairment. During the course of illness, nearly 50% of myeloma patients will develop kidney disease. Moreover, ∼10% of myeloma patients have advanced kidney disease requiring dialysis at presentation. Hemodialysis is associated with a significantly reduced overall survival (OS). In the setting of prolonged long-term OS due to the use of newer immunotherapeutic agents in the treatment of myeloma, patients with myeloma and advanced kidney disease may benefit from more aggressive management with kidney transplantation (KTx). Unfortunately, most data regarding outcomes of KTx in patients with myeloma come from single-center case series. With the advent of novel treatment choices, it remains unclear if outcomes of kidney transplant recipients with myeloma have improved in recent years. In this descriptive systematic review, we coalesced published patient data over the last 20 years to help inform clinicians and patients on expected hematologic and KTx outcomes in this complex population. We further discuss the future of KTx in patients with paraproteinemia.

Clinical features of acute kidney injury in patients receiving dabrafenib and trametinib.

BACKGROUND: Our objective was to characterize the incidence, risk factors and clinical features of acute kidney injury (AKI) in patients receiving dabrafenib and trametinib. METHODS: We performed a retrospective cohort study examining the kidney outcomes of patients in a large healthcare system who received dabrafenib/trametinib between 2010 and 2019. The primary outcome was AKI, defined as a 1.5-fold increase in serum creatinine from baseline within a 12-month study period. AKI severity and etiology was determined for each case by chart review. Logistic regression was used to evaluate baseline predictors of AKI. RESULTS: A total of 199 patients who received dabrafenib in our healthcare system from 2010 to 2019 were included in the analysis. Forty-two patients (21%) experienced AKI within 12 months; 10 patients (5% of the total cohort, 24% of AKI patients) experienced AKI occurring during a dabrafenib/trametinib-induced febrile syndrome characterized by fever, chills, gastrointestinal symptoms and elevated liver enzymes. Preexisting liver disease was the only significant predictor of AKI in the cohort. One patient had biopsy-proven granulomatous acute interstitial nephritis that resolved with corticosteroids. CONCLUSIONS: Oncologists and nephrologists should be aware that AKI is common after dabrafenib/trametinib and a substantial number of cases occur in the setting of treatment-induced pyrexia.

Use of TIMP-2 and IGFBP-7 for prediction of postoperative acute kidney injury after cardiac surgery.

BACKGROUND: The following cell cycle arrest urinary biomarkers, tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP-7), have been used for early detection of acute kidney injury (AKI) in critically ill patients. The purpose of this study is to validate the use of these urinary biomarkers in patients undergoing open heart surgery. MATERIALS AND METHODS: In a single-center prospective observational study, urine samples were collected in 108 consecutive patients who underwent open heart surgery immediately after separation from cardiopulmonary bypass and on postoperative day 1, and were sent for the biomarker [TIMP-2]*[IGFBP7] analysis. Acute kidney injury was defined based on KDIGO criteria, and levels of [TIMP-2]*[IGFBP7] were analyzed for the ability to predict AKI. RESULTS: Of the 108 patients, 19 (17.6%) patients developed postoperative AKI within 48 hours of surgery. At the threshold of > 0.3 (ng/mL)2/1,000, post-cardiopulmonary bypass [TIMP-2]*[IGFBP-7] had a sensitivity of 13% and specificity of 82% for predicting postoperative AKI. Postoperative day-1 [TIMP-2]*[IGFBP-7] had a sensitivity of 47% and a specificity of 59% for predicting postoperative AKI. There were no differences in [TIMP-2]*[IGFBP-7] values at either timepoint between patients who developed postoperative AKI as compared to those who did not. CONCLUSION: Urinary [TIMP-2]*[IGFBP7] was not predictive of the risk of AKI after cardiac surgery in this single-center study population.

Kidney toxicity of the BRAF-kinase inhibitor vemurafenib is driven by off-target ferrochelatase inhibition.

A multitude of disease and therapy related factors drive the frequent development of kidney disorders in cancer patients. Along with chemotherapy, the newer targeted therapeutics can also cause kidney dysfunction through on and off-target mechanisms. Interestingly, among the small molecule inhibitors approved for the treatment of cancers that harbor BRAF-kinase activating mutations, vemurafenib can trigger tubular damage and acute kidney injury. BRAF is a proto-oncogene involved in cell growth. To investigate the underlying mechanisms, we developed cell culture and mouse models of vemurafenib kidney toxicity. At clinically relevant concentrations vemurafenib induces cell-death in transformed and primary mouse and human kidney tubular epithelial cells. In mice, two weeks of daily vemurafenib treatment causes moderate acute kidney injury with histopathological characteristics of kidney tubular epithelial cells injury. Importantly, kidney tubular epithelial cell-specific BRAF gene deletion did not influence kidney function under normal conditions or alter the severity of vemurafenib-associated kidney impairment. Instead, we found that inhibition of ferrochelatase, an enzyme involved in heme biosynthesis contributes to vemurafenib kidney toxicity. Ferrochelatase overexpression protected kidney tubular epithelial cells and conversely ferrochelatase knockdown increased the sensitivity to vemurafenib-induced kidney toxicity. Thus, our studies suggest that vemurafenib-associated kidney tubular epithelial cell dysfunction and kidney toxicity is BRAF-independent and caused, in part, by off-target ferrochelatase inhibition.

Acute kidney injury in pediatric patients hospitalized with acute COVID-19 and multisystem inflammatory syndrome in children associated with COVID-19.

This study describes the incidence, associated clinical characteristics and outcomes of acute kidney injury in a pediatric cohort with COVID-19 and Multisystem Inflammatory Syndrome in Children (MIS-C). We performed a retrospective study of patients 18 years of age and under admitted to four New York hospitals in the Northwell Health System interned during the height of the COVID-19 pandemic, between March 9 and August 13, 2020. Acute kidney injury was defined and staged according to Kidney Disease: Improving Global Outcomes criteria. The cohort included 152 patients; 97 acute-COVID-19 and 55 with MIS-C associated with COVID-19. Acute kidney injury occurred in 8 with acute-COVID-19 and in 10 with MIS-C. Acute kidney injury, in unadjusted models, was associated with a lower serum albumin level (odds ratio 0.17; 95% confidence interval 0.07, 0.39) and higher white blood cell counts (odds ratio 1.11; 95% confidence interval 1.04, 1.2). Patients with MIS-C and acute kidney injury had significantly greater rates of systolic dysfunction, compared to those without (80% vs 49%). In unadjusted models, patients with acute kidney injury had 8.4 days longer hospitalizations compared to patients without acute kidney injury (95% confidence interval, 4.4-6.7). Acute kidney injury in acute-COVID-19 and MIS-C may be related to inflammation and/or dehydration. Further research in larger pediatric cohorts is needed to better characterize risk factors for acute kidney injury in acute-COVID-19 and with MIS-C consequent to COVID-19.

A multi-center study on safety and efficacy of immune checkpoint inhibitors in cancer patients with kidney transplant.

Immune checkpoint inhibitors (ICIs) are widely used for various malignancies. However, their safety and efficacy in patients with a kidney transplant have not been defined. To delineate this, we conducted a multicenter retrospective study of 69 patients with a kidney transplant receiving ICIs between January 2010 and May 2020. For safety, we assessed the incidence, timing, and risk factors of acute graft rejection. For efficacy, objective response rate and overall survival were assessed in cutaneous squamous cell carcinoma and melanoma, the most common cancers in our cohort, and compared with stage-matched 23 patients with squamous cell carcinoma and 14 with melanoma with a kidney transplant not receiving ICIs. Following ICI treatment, 29 out of 69 (42%) patients developed acute rejection, 19 of whom lost their allograft, compared with an acute rejection rate of 5.4% in the non-ICI cohort. Median time from ICI initiation to rejection was 24 days. Factors associated with a lower risk of rejection were mTOR inhibitor use (odds ratio 0.26; 95% confidence interval, 0.09-0.72) and triple-agent immunosuppression (0.67, 0.48-0.92). The objective response ratio was 36.4% and 40% in the squamous cell carcinoma and melanoma subgroups, respectively. In the squamous cell carcinoma subgroup, overall survival was significantly longer in patients treated with ICIs (median overall survival 19.8 months vs. 10.6 months), whereas in the melanoma subgroup, overall survival did not differ between groups. Thus, ICIs were associated with a high risk of rejection in patients with kidney transplants but may lead to improved cancer outcomes. Prospective studies are needed to determine optimal immunosuppression strategies to improve patient outcomes.