Development and Validation of a Risk Model for Predicting Contrast-Associated Acute Kidney Injury in Patients With Cancer: Evaluation in Over 46,000 CT Examinations.

BACKGROUND. Patients with cancer undergo frequent CT examinations with iodinated contrast media and may be uniquely predisposed to contrast-associated acute kidney injury (CA-AKI). OBJECTIVE. The purpose of this study was to develop and validate a model for predicting the risk of CA-AKI after contrast-enhanced CT in patients with cancer. METHODS. This retrospective study included 25,184 adult patients (12,153 men, 13,031 women; mean age, 62.3 ± 13.7 [SD] years) with cancer who underwent 46,593 contrast-enhanced CT examinations between January 1, 2016, and June 20, 2020, at one of three academic medical centers. Information was recorded regarding demographics, malignancy type, medication use, baseline laboratory values, and comorbid conditions. CA-AKI was defined as a 0.3-mg/dL or greater increase in serum creatinine level from baseline within 48 hours after CT or a 1.5-fold or greater increase in the peak measurement within 14 days after CT. Multivariable models accounting for correlated data were used to identify risk factors for CA-AKI. A risk score for predicting CA-AKI was generated in a development set (n = 30,926) and tested in a validation set (n = 15,667). RESULTS. CA-AKI occurred after 5.8% (2682/46,593) of CT examinations. The final multivariable model for predicting CA-AKI included hematologic malignancy, diuretic use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, chronic kidney disease (CKD) stage 3a, CKD stage 3b, CKD stage 4 or 5, serum albumin level less than 3.0 g/dL, platelet count less than 150 × 103/µL, 1+ or greater proteinuria on baseline urinalysis, diabetes mellitus, heart failure, and contrast medium volume 100 mL or greater. A risk score (range, 0-53 points) was generated with these variables. The most points (13) were for CKD stage 4 or 5 and for albumin level less than 3 g/dL. The frequency of CA-AKI progressively increased in higher risk categories. For example, in the validation set, CA-AKI occurred after 2.2% of CT examinations in the lowest risk category (score ≤ 4) and after 32.7% of CT examinations in the highest risk category (score ≥ 30). The Hosmer-Lemeshow test result indicated that the risk score was a good fit (p = .40). CONCLUSION. A risk model in which readily available clinical data are used to predict the likelihood of CA-AKI after contrast-enhanced CT in patients with cancer was developed and validated. CLINICAL IMPACT. The model may help facilitate appropriate implementation of preventive measures in the care of patients at high risk of CA-AKI.

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.

Severe Neurological Toxicity of Immune Checkpoint Inhibitors: Growing Spectrum.

Expanding use of immune-checkpoint inhibitors (ICIs) underscores the importance of accurate diagnosis and timely management of neurological immune-related adverse events (irAE-N). We evaluate the real-world frequency, phenotypes, co-occurring immune-related adverse events (irAEs), and long-term outcomes of severe, grade III to V irAE-N at a tertiary care center over 6 years. We analyze how our experience supports published literature and professional society guidelines. We also discuss these data with regard to common clinical scenarios, such as combination therapy, ICI rechallenge and risk of relapse of irAE-N, and corticosteroid taper, which are not specifically addressed by current guidelines and/or have limited data. Recommendations for management and future irAE-N reporting are outlined. ANN NEUROL 2020;87:659-669.

Hyponatremia and other electrolyte abnormalities in patients receiving immune checkpoint inhibitors.

BACKGROUND: Hyponatremia due to endocrinopathies such as adrenal insufficiency and hypothyroidism has been reported in patients receiving immune checkpoint inhibitors (ICIs). We determined the risk and predictors of hyponatremia and other electrolyte abnormalities in a 'real-world' sample of patients receiving ICIs to treat advanced malignancies. METHODS: This was a retrospective observational study of all patients who received ICIs from a single cancer center between 2011 and 2018. Patients were followed for 12 months after initiation of ICIs or until death. Common Terminology for Cancer Adverse Events version 5.0 criteria were used to grade the severity of hyponatremia and other electrolyte abnormalities. The predictors of severe (Grade 3 or 4) hyponatremia were determined using a multivariable logistic regression model. The etiology of Grade 3 or 4 hyponatremia was determined by chart review. RESULTS: A total of 2458 patients were included. Their average age was 64 years [standard deviation (SD) 13], 58% were male and 90% were white. In the first year after starting ICIs, 62% experienced hyponatremia (sodium <134 mEq/L) and 136 (6%) experienced severe hyponatremia (<124 mEq/L). Severe hyponatremia occurred on average 164 days (SD 100) after drug initiation. Only nine cases of severe hyponatremia were due to endocrinopathies (0.3% overall incidence). Risk factors for severe hyponatremia included ipilimumab (a cytotoxic T lymphocyte antigen-4 inhibitor) use, diuretic use and non-White race. Other severe electrolyte abnormalities were also commonly observed: severe hypokalemia (potassium <3.0 mEq/L) occurred in 6%, severe hyperkalemia (potassium ≥6.1 mEq/L) occurred in 0.6%, severe hypophosphatemia (phosphorus <2 mg/dL) occurred in 17% and severe hypocalcemia (corrected calcium <7.0 mg/dL) occurred in 0.2%. CONCLUSIONS: Hyponatremia is common in cancer patients receiving ICIs. However, endocrinopathies are an uncommon cause of severe hyponatremia.

Direct-acting antiviral therapy slows kidney function decline in patients with Hepatitis C virus infection and chronic kidney disease.

Hepatitis C virus (HCV) infection is common and can accelerate chronic kidney disease (CKD) progression. Direct-acting antiviral (DAA) therapies against hepatitis C have consistently shown rates of sustained viral remission. However, the effect on kidney function is unknown. In a retrospective observational cohort study of HCV-infected patients receiving DAA therapies from 2013 to 2017, the slopes of estimated glomerular filtration rate (eGFR) decline were compared in the three years before DAA therapy to the slope after therapy. Pre- and post-treatment albuminuria values were also compared. In all, 1,178 patients were included; mean age of 56, 64% male, 71% white, 21% were diabetic, and 42% with cirrhosis. In patients with eGFR less than 60ml/min per 1.73m2, the annual decline in eGFR in the three years prior to treatment was -5.98 ml/min per year (95% confidence interval -7.30 to -4.67) and improved to -1.32 ml/min per year (95% confidence interval -4.50 to 1.88) after DAA therapy. In patients with eGFR greater than 60ml/min per 1.73m2 the annual decline in eGFR in the three years prior to treatment was -1.43 ml/min per year (95% confidence interval -1.78 to -1.08) and after DAA therapy was -2.32 ml/min per year (95% confidence interval -3.36 to -1.03). Albuminuria improved significantly in patients without diabetes, but not in those with diabetes. Predictors of eGFR improvement included having CKD at baseline and being non-diabetic. Events of acute kidney injury were rare, occurring in 29 patients, and unrelated to antiviral therapy in 76% of cases. Thus, DAA therapy for HCVs infection may slow CKD progression.

Process of selecting and educating HCV-uninfected kidney waiting-list candidates for HCV-infected kidney transplantation.

Long waiting times for kidney transplant (KT) and the high risk of mortality on dialysis have prompted investigation into strategies to utilize hepatitis C virus (HCV)-infected organs to decrease discard rates of potentially viable kidneys. Due the opioid epidemic, the number of HCV-infected donors has increased significantly. With the development of direct-acting antiviral therapies for HCV infection, now more than 95% of patients who received treatment are cured. Experimental trials have used direct-acting antiviral therapy to treat HCV infection in HCV-uninfected transplant recipients of kidneys from HCV-viremic donors. To date, HCV has been eradicated in all cases. Though these strategies will potentially increase the donor pool of available kidneys, shorten waitlist times, and ultimately decrease mortality in patients waiting for KT, identifying the ideal candidates and educating them about a protocol to utilize direct-acting antiviral therapy to cure HCV after it is transmitted is essential. We present our approach to patient selection and education for a clinical trial in transplantation of HCV viremic kidneys into uninfected recipients.

Direct-acting antiviral therapy for hepatitis C virus infection in the kidney transplant recipient.

Hepatitis C virus infection (HCV) is a common comorbidity in patients who have undergone kidney transplantation and is associated with increased morbidity and mortality compared with recipients who do not have chronic HCV infection. Because interferon-α-based therapies can precipitate acute rejection, they are relatively contraindicated after kidney transplantation. Thus, the majority of kidney transplant recipients with HCV remain untreated. There are now all-oral, interferon-free direct-acting antiviral therapies for HCV infection that are extremely effective and well tolerated in the general population. Recent reports in the literature demonstrate that direct-acting antiviral therapies effectively cured HCV in 406 of 418 kidney transplant recipients (97%); the majority were treated with sofosbuvir-based regimens. Smaller numbers of kidney transplant recipients have been treated with paritaprevir-ritonavir, ombitasvir and dasabuvir, elbasvir-grazoprevir, or glecaprevir-pibrentasvir with excellent success. Direct-acting antiviral therapies were well tolerated and did not increase the rate of acute rejection. The latest advances include approval of regimens that can treat patients with advanced allograft dysfunction (eGFR < 30 ml/min per 1.73 m2) and "pan-genotypic" regimens that have activity against all 6 major genotypes of HCV. This review summarizes what is known about the epidemiology of HCV infection in kidney transplant recipients, and presents the landscape of direct-acting antiviral therapies and areas in need of further investigation.

Effect of the Opioid Crisis on the Donor Pool for Kidney Transplantation: An Analysis of National Kidney Deceased Donor Trends from 2010-2016.

BACKGROUND: The opioid crisis has led to a dramatic increase in the number of drug overdose deaths in the United States. Little is known about the effect of the opioid crisis on the kidney transplant donor pool, particularly on hepatitis C virus (HCV)-infected donors. METHODS: This is a retrospective analysis of the data from the Organ Procurement and Transplantation Network from 2010 to 2016. We determined the changes in characteristics of kidney transplant donors and evaluated which changes may be directly related to the opioid crisis. RESULTS: Between 2010 and 2016, we found a 26% increase in overall donors, including a 277% increase in the number of donors who died from drug overdose. Nineteen percent of donors who died of drug overdose had HCV infection. Donors who die from drug overdose and donors with HCV infection are younger, less likely to have diabetes or hypertension, and have favorable kidney donor profile index scores compared to average donors. Despite these favorable characteristics, HCV-infected donors appear to be notably underutilized, with substantially lower kidneys per donor being transplanted compared to HCV uninfected donors. CONCLUSION: The opioid crisis in the United States has substantially altered the kidney donor pool. Strategies to increase utilization of all potentially viable kidneys for transplant are needed, particularly in this era of new, highly effective, direct-acting antiviral therapy for HCV infection.

When and how can nephrologists treat hepatitis C virus infection in dialysis patients?

Hepatitis C virus (HCV) infection, a major cause of end-stage liver disease, is a common comorbidity in patients on dialysis and causes increased morbidity and mortality. Historically HCV has been extremely difficult to cure with interferon and ribavirin-based therapies, which are also associated with significant side effects, and few dialysis patients ever received HCV treatment. However, in the last 4 years, interferon-free direct-acting antiviral therapies have been approved, and several combinations have been studied in dialysis patients. A recently approved, pan-genotypic, direct-acting antiviral regimen, glecaprevir and pibrentasvir, may simplify prescribing. The simplicity of these new therapies, with few side effects, makes it possible for nephrologists to treat HCV infection in their patients on dialysis. We review the workflow and motivation behind nephrology-led management of HCV infection. We highlight the importance of identifying which patients need referral to a hepatologist or HCV specialist prior to treatment and which can be managed by their nephrologist. Nephrologist involvement would lead to improved access to treatment and ensure that appropriate patients are referred for HCV treatment. In this paper, we review the background of HCV infection, its effect on dialysis patients, and impact on kidney transplantation. In addition, we outline the therapy options for each genotype of HCV, and we discuss the benefits and barriers to nephrology-led HCV treatment.

Derivation and external validation of a simple risk score for predicting severe acute kidney injury after intravenous cisplatin: cohort study.

OBJECTIVE: To develop and externally validate a prediction model for severe cisplatin associated acute kidney injury (CP-AKI). DESIGN: Multicenter cohort study. SETTING: Six geographically diverse major academic cancer centers across the US. PARTICIPANTS: Adults (≥18 years) receiving their first dose of intravenous cisplatin, 2006-22. MAIN OUTCOME MEASURES: The primary outcome was CP-AKI, defined as a twofold or greater increase in serum creatinine or kidney replacement therapy within 14 days of a first dose of intravenous cisplatin. Independent predictors of CP-AKI were identified using a multivariable logistic regression model, which was developed in a derivation cohort and tested in an external validation cohort. For the primary model, continuous variables were examined using restricted cubic splines. A simple risk model was also generated by converting the odds ratios from the primary model into risk points. Finally, a multivariable Cox model was used to examine the association between severity of CP-AKI and 90 day survival. RESULTS: A total of 24 717 adults were included, with 11 766 in the derivation cohort (median age 59 (interquartile range (IQR) 50-67)) and 12 951 in the validation cohort (median age 60 (IQR 50-67)). The incidence of CP-AKI was 5.2% (608/11 766) in the derivation cohort and 3.3% (421/12 951) in the validation cohort. Each of the following factors were independently associated with CP-AKI in the derivation cohort: age, hypertension, diabetes mellitus, serum creatinine level, hemoglobin level, white blood cell count, platelet count, serum albumin level, serum magnesium level, and cisplatin dose. A simple risk score consisting of nine covariates was shown to predict a higher risk of CP-AKI in a monotonic fashion in both the derivation cohort and the validation cohort. Compared with patients in the lowest risk category, those in the highest risk category showed a 24.00-fold (95% confidence interval (CI) 13.49-fold to 42.78-fold) higher odds of CP-AKI in the derivation cohort and a 17.87-fold (10.56-fold to 29.60-fold) higher odds in the validation cohort. The primary model had a C statistic of 0.75 and showed better discrimination for CP-AKI than previously published models, the C statistics for which ranged from 0.60 to 0.68 (DeLong P<0.001 for each comparison). Greater severity of CP-AKI was monotonically associated with shorter 90 day survival (adjusted hazard ratio 4.63 (95% CI 3.56 to 6.02) for stage 3 CP-AKI versus no CP-AKI). CONCLUSION: This study found that a simple risk score based on readily available variables from patients receiving intravenous cisplatin could predict the risk of severe CP-AKI, the occurrence of which is strongly associated with death.

Evaluation of appendectomy as a potential risk factor for immune checkpoint inhibitor-associated enterocolitis.

Aims: The relationship between appendectomy and immune checkpoint inhibitor (ICI) enterocolitis was explored. Methods: Patients who began ICIs between July 2010 and September 2020 (n = 10,907) were included. The exposure group included patients with evidence of appendectomy prior to ICIs in operative notes (n = 380). The control group included patients with evidence of normal appendix in radiologic reports (n = 3602). ICI enterocolitis was defined as histopathologic evidence of colitis or enteritis attributed to ICIs. The association between appendectomy and ICI enterocolitis was characterized by multivariate logistic regression. Results: 248 patients (6.2%) developed ICI enterocolitis. The odds of ICI enterocolitis were similar among those with prior appendectomy and those without appendectomy (adjusted odds ratio: 0.82; 95% CI: 0.49-1.36; p = 0.449). Conclusion: No association was found between prior appendectomy and ICI enterocolitis.

Immune checkpoint inhibitors (ICIs) are a form of cancer treatment that 'unleash the brakes' on the body's immune system. One common and sometimes serious side effect of this type of drug is gut inflammation. Studies have shown that appendectomy, or surgical removal of the appendix, lowers the risk of inflammatory bowel disease, which is another cause of gut inflammation. This research assessed whether appendectomy reduces the risk of gut inflammation caused by ICIs. Patients on ICIs for cancer with and without prior appendectomy were identified. The rates of gut inflammation caused by ICIs between these two groups were compared and the rates of this side effect were similar. This suggests that appendectomy does not reduce the risk of gut inflammation caused by ICIs.

Immune-related adverse events and kidney function decline in patients with genitourinary cancers treated with immune checkpoint inhibitors.

BACKGROUND: In patients with genitourinary cancers, the effect of immune checkpoint inhibitors (ICIs) on kidney function is unknown. PATIENTS AND METHODS: This is a retrospective cohort study of patients with renal cell carcinoma (RCC) and urothelial carcinoma who received ICIs at two major cancer centers between 2012 and 2018. Cumulative incidence and Fine and Gray subdistribution hazard models were performed to determine predictors of the co-primary outcomes, (1) acute kidney injury (AKI) and (2) sustained estimated glomerular filtration rate (eGFR) loss, defined as a >20% decline in eGFR sustained ≥90 days. We also determined the association between immune-related adverse events (irAE) and adverse kidney outcomes among patients surviving ≥1 year. RESULTS: 637 patients were included; 320 (50%) patients had RCC and 317 (50%) patients had urothelial carcinoma. Half of the cohort had eGFR<60 mL/min/1.73 m2 at baseline. irAEs, AKI, and sustained eGFR loss were common, occurring in 33%, 25% and 16%, respectively. Compared to patients with urothelial carcinoma, patients with RCC were more likely to develop irAEs (aHR 1.61, 95% CI 1.20-2.18) and sustained eGFR loss (aHR 1.97, 95% CI 1.24-3.12), but not AKI (aHR 1.53, 95% CI 0.97-2.41). Among patients surviving ≥1 years, experiencing a non-renal irAE was associated with a significantly higher risk of sustained eGFR loss (aHR 1.71, 95% CI 1.14-2.57). CONCLUSION: AKI and sustained eGFR loss are common in patients with genitourinary cancers receiving ICIs. irAEs may be a novel risk factor for kidney function decline among patients receiving ICIs.

Diagnostic utility of CT for suspected immune checkpoint inhibitor enterocolitis.

BACKGROUND AND AIMS: Immune checkpoint inhibitor (ICI) enterocolitis is a common immune-related adverse event and can be fatal, especially when not diagnosed and treated promptly. The current gold standard for diagnosis is endoscopy with biopsy, but CT scan is a possible alternative. The primary objective of this study is to identify the diagnostic performance of CT in the evaluation of ICI enterocolitis. METHODS: With institutional review board approval, we conducted a retrospective cohort study of patients who received ICI therapy between 2015 and 2019 across a healthcare system. Patients were included if they underwent both abdominal CT and endoscopy with biopsy within 3 days. The radiological and pathological diagnoses, as well as clinical characteristics, were extracted from the electronic medical record. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CT for diagnosing ICI enterocolitis when compared with tissue diagnosis. RESULTS: Of the 4474 patients screened, 138 met inclusion criteria. Most common tumor types were melanoma (37%) and lung cancer (19%). Seventy-four per cent were treated with antiprogrammed cell death (PD-1)/PD-L1 therapy. Thirty-nine per cent had signs of enterocolitis on CT scan and 58% had biopsy-proven ICI enterocolitis. Sensitivity and specificity of CT were 50% and 74%, respectively. PPV was 73% and NPV was 52%. Of those with confirmed ICI enterocolitis, 70% had grade 3 or higher symptoms, 91% received steroids and 40% received infliximab. CONCLUSION: The performance of CT scan for diagnosis of ICI enterocolitis is moderate to poor and does not replace endoscopy with biopsy.

Preemptive Treatment With Elbasvir and Grazoprevir for Hepatitis C-Viremic Donor to Uninfected Recipient Kidney Transplantation.

INTRODUCTION: Long wait times for kidney transplants have prompted investigation into strategies to decrease the discarding of potentially viable organs. Recent reports suggest that kidneys from hepatitis C virus (HCV)-infected donors may be transplanted into HCV-naive donors followed by direct-acting antiviral therapy. METHODS: This was a pilot clinical trial to transplant kidneys from HCV-infected donors into HCV-naive recipients with preemptive use of elbasvir and grazoprevir for 12 weeks. The primary outcome was sustained virologic response 12 weeks after completion of therapy. Secondary outcomes were safety, quality of life, and early viral kinetics. RESULTS: A total of 33 patients were screened, and 8 underwent kidney transplantation from a HCV-viremic donors from August 2017 to March 2019. The median donor kidney donor profile index was 31% (range, 29%-65%), and patients who underwent transplantation waited a median of 6.5 months (range, 1-19 months). None had detectable HCV viremia beyond 2 weeks post-transplantation, and all achieved sustained virologic response 12 weeks after therapy (SVR12). There were no study-related severe adverse events. One patient experienced early graft loss due to venous thrombosis, whereas the remaining 7 patients had excellent allograft function at 6 months. CONCLUSION: Preemptive elbasvir and grazoprevir eliminated HCV infection in HCV-naive patients who received a kidney transplant from an HCV-infected donor.

Incidence and Clinical Features of Immune-Related Acute Kidney Injury in Patients Receiving Programmed Cell Death Ligand-1 Inhibitors.

BACKGROUND: Programmed cell death receptor ligand 1 (PD-L1) inhibitors are immune checkpoint inhibitors (ICIs) with a side effect profile that may differ from other classes of ICIs such as those directed against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 receptor (PD-1). Being the more recently approved class of checkpoint inhibitors, there are no studies investigating the frequency, etiology and predictors of acute kidney injury (AKI) in patients receiving PD-L1 inhibitors. METHODS: This was a retrospective cohort study of patients who received PD-L1 inhibitors during 2017 to 2018 in our healthcare system. AKI was defined by a ≥1.5-fold rise in serum creatinine from baseline. The etiology of all cases of sustained AKI (lasting >48 hours) and clinical course were determined by review of electronic health records. RESULTS: The final analysis included 599 patients. Within 12 months of ICI initiation, 104 patients (17%) experienced AKI, and 36 (6%) experienced sustained AKI; however, only 5 (<1%) experienced suspected PD-L1-related AKI. The PD-L1-related AKI occurred a median of 99 days after starting therapy. All patients concurrently received another medication known to cause acute interstitial nephritis (proton pump inhibitors, nonsteroidal anti-inflammatory drugs, or antibiotics) at the time of the suspected PDL1-related AKI. CONCLUSION: Although AKI is common in patients receiving PD-L1 therapy, the incidence of suspected PD-L1-related AKI is low (<1%) and may be less common when compared to other classes of ICIs. This cohort provides further validation that other drugs associated with acute interstitial nephritis may be involved in the pathogenesis of ICI-related AKI.

Varied phenotypes and management of immune checkpoint inhibitor-associated neuropathies.

OBJECTIVE: To describe the spectrum, clinical course, and management of neuropathies associated with immune checkpoint inhibitors (ICIs). METHODS: Patients with ICI-related neuropathy (irNeuropathy) were identified and their clinical characteristics compared to neuropathy attributed to cytotoxic agents. RESULTS: We identified 19 patients with irNeuropathies. ICIs included anti-programmed death-1 (PD1), 9; anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), 2; and combination of anti-CTLA4 and anti-PD1, 8. Median number of ICI doses prior to neuropathy onset was 4. Rate of neuropathies following ICI therapy was 0.7%. Underlying malignancies included melanoma (n = 15), lung adenocarcinoma (n = 3), and cholangiocarcinoma (n = 1). Neuropathy phenotypes were cranial neuropathies with or without meningitis (n = 7), nonlength-dependent polyradiculoneuropathies with and without cranial nerve involvement (n = 6), small-fiber/autonomic neuropathy (n = 2), ANCA-associated mononeuritis multiplex (n = 1), sensory neuronopathy (n = 1), length-dependent sensorimotor axonal polyneuropathy (n = 1), and neuralgic amyotrophy (n = 1). Immune-related adverse events involving other organ systems were common (58%). Corticosteroid use for management of neuropathy was associated with improvement in median modified Rankin Scale score (1 vs 0, p = 0.001) and Inflammatory Neuropathy Cause and Treatment Disability score (2 vs 0.5, p = 0.012) (Class IV). Significantly higher proportion of irNeuropathies had acute or subacute and nonlength-dependent presentations (p < 0.001) and rate of hospitalization for irNeuropathy was also higher (p = 0.002) compared to toxic neuropathy from chemotherapy. CONCLUSION: Neuropathy is a rare complication of ICIs that often responds to immunosuppression. Recognition of its wide phenotypic spectrum and distinct clinical characteristics and prompt management with corticosteroids may lead to favorable outcomes.

The Incidence, Causes, and Risk Factors of Acute Kidney Injury in Patients Receiving Immune Checkpoint Inhibitors.

BACKGROUND AND OBJECTIVES: Immune checkpoint inhibitor use in oncology is increasing rapidly. We sought to determine the frequency, severity, cause, and predictors of AKI in a real-world population receiving checkpoint inhibitors. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We included all patients who received checkpoint inhibitor therapy from May 2011 to December 2016 at Massachusetts General Hospital. Baseline serum creatinine, averaged 6 months before checkpoint inhibitor start date, was compared with all subsequent creatinine values within 12 months of starting therapy. AKI was defined by Kidney Disease: Improving Global Outcomes criteria for fold changes in creatinine from baseline. Sustained AKI events lasted at least 3 days and was our primary outcome. The cause of sustained AKI was determined by chart review. Cumulative incidence and subdistribution hazard models were used to assess the relationship between baseline demographics, comorbidities, and medications, and sustained AKI and potential checkpoint inhibitor-related AKI. RESULTS: We included 1016 patients in the analysis. Average age was 63 (SD 13) years, 61% were men, and 91% were white. Mean baseline creatinine was 0.9 mg/dl (SD 0.4 mg/dl), and 169 (17%) had CKD (eGFR<60 ml/min per 1.73 m2) at baseline. A total of 169 patients (17%) experienced AKI, defined by an increase in creatinine at least 1.5 times the baseline within 12 months; 82 patients (8%) experienced sustained AKI and 30 patients (3%) had potential checkpoint inhibitor-related AKI. The first episode of sustained AKI occurred, on average, 106 days (SD 85) after checkpoint inhibitor initiation. Sixteen (2%) patients experienced stage 3 sustained AKI and four patients required dialysis. Proton pump inhibitor use at baseline was associated with sustained AKI. CONCLUSIONS: AKI is common in patients receiving checkpoint inhibitor therapy. The causes of sustained AKI in this population are heterogenous and merit thorough evaluation. The role of PPI and other nephritis-inducing drugs in the development of sustained AKI needs to be better defined.

Transplantation of hepatitis C virus infected kidneys into hepatitis C virus uninfected recipients.

Long wait times for kidney transplant and the high risk of mortality on dialysis have prompted investigation into strategies to increase organ allocation and decrease discard rates of potentially viable kidneys. Organs from hepatitis C virus (HCV) antibody positive donors are often rejected; nearly 500 HCV-infected kidneys are discarded annually in the United States. Due the opioid epidemic, the number of HCV-infected donors has increased because of a rise in both new HCV infections and drug-related deaths. In the past 5 years, HCV has been transformed into a curable illness with direct-acting antiviral therapies (DAAs) that are effective in >95% of patients treated and are extremely well tolerated. Recent data has shown several direct-acting antiviral combinations are safe and effective after kidney transplant, and can achieve the same high cure rate seen in the general population and without increasing the rate of acute rejection. Because of this, strategies to decrease discard of HCV-infected organs have been devised. Two recent studies have transplanted HCV-uninfected dialysis patients with kidneys from donors actively infected with HCV; recipients were treated with DAA in the peri-transplant period. More research is needed to determine the safety and efficacy of this approach, but it has the potential to dramatically increase the donor pool of available kidneys, shorten waitlist times and ultimately decreases mortality in patients waiting for kidney transplant.

Effect of Sofosbuvir-Based Hepatitis C Virus Therapy on Kidney Function in Patients with CKD.

BACKGROUND AND OBJECTIVES: Hepatitis C virus infection is common in patients with CKD and leads to accelerated progression to ESRD. Sofosbuvir is a potent direct-acting antiviral therapy against hepatitis C virus; however, there are concerns about its safety in patients with CKD. The objective of our study was to determine the safety and efficacy of sofosbuvir in patients with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We studied a retrospective observational cohort of patients with CKD defined by eGFR<60 ml/min per 1.73 m2, ≥30 mg albuminuria per 1 g creatinine, or ≥200 mg proteinuria per 1 g creatinine who received sofosbuvir-based therapy in a large health care system. Regression models were constructed to predict likelihood of sustained virologic response, detect adverse events, and examine changes in eGFR from baseline to follow-up. RESULTS: Ninety-eight patients with CKD (42% stage 1 or 2 CKD and 58% stage 3 CKD) were included. Mean age was 62 years old, 78% were men, and 65% were white. Additionally, 49% of patients had diabetes, 38% of patients had cirrhosis, and 33% of patients had prior solid organ transplant. Overall sustained virologic response was 81% and varied by regimen used and viral genotype. Average baseline eGFR was equivalent to average on-treatment eGFR, but seven patients experienced a rise in creatinine ≥1.5 times baseline while taking sofosbuvir; all but one recovered. In patients with eGFR<60 ml/min per 1.73 m2 at baseline (stage 3 CKD), regression models showed that hepatitis C cure was associated with a 9.3 (95% confidence interval, 0.44 to 18) ml/min per 1.73 m2 improvement in eGFR during the 6-month post-treatment follow-up period. Adverse events were common (81%), but serious adverse events (17%) and treatment discontinuations (8%) were uncommon. CONCLUSIONS: Sofosbuvir-based direct-acting antiviral therapy is safe and effective in a cohort of patients with CKD infected with hepatitis C.