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.

Positron emission tomography as an adjuvant diagnostic test in the evaluation of checkpoint inhibitor-associated acute interstitial nephritis.

BACKGROUND: Acute interstitial nephritis is an immune-related adverse event that can occur in patients receiving immune checkpoint inhibitor therapy. Differentiating checkpoint inhibitor-associated acute interstitial nephritis from other causes of acute kidney injury in patients with cancer is challenging and can lead to diagnostic delays and/or unwarranted immunosuppression. In this case report, we assess the use of 18F-flourodeoxyglucose positron-emission tomography imaging as an alternative diagnostic modality in the evaluation of potential acute interstitial nephritis. CASE PRESENTATION: A 55-year-old woman with metastatic vulvar melanoma underwent treatment with two cycles of ipilimumab plus nivolumab, followed by seven cycles of nivolumab combined with radiation therapy. During her treatment, she developed non-oliguric acute kidney injury to a creatinine of 4.5 mg/dL from a baseline of 0.5 mg/dL. A clinical diagnosis of acute interstitial nephritis was made, and steroids were initiated, with rapid improvement of her acute kidney injury. Retrospectively, four positron-emission tomography scans obtained for cancer staging purposes were reviewed. We found a markedly increased 18F-flourodeoxyglucose uptake in the renal cortex at the time acute interstitial nephritis was diagnosed compared to baseline. In three cases of acute kidney injury due to alternative causes there was no increase in 18F-flourodeoxyglucose uptake from baseline. CONCLUSIONS: To our knowledge, this is the first report describing increased 18F-flourodeoxyglucose uptake in the renal cortex in a patient with checkpoint inhibitor-associated acute interstitial nephritis. Our findings suggest that 18F-flourodeoxyglucose positron-emission tomography may be a valuable test for diagnosing immune-mediated nephritis, particularly in patients where timely kidney biopsy is not feasible.

Laboratory Tests and X-ray Imaging in a Surgical Intensive Care Unit: Checking the Checklist.

CONTEXT: Patients in the surgical intensive care unit (ICU) frequently undergo laboratory and imaging testing. These tests can lead to iatrogenic anemia and radiation exposure. Many of these tests may be unnecessary for the management of a patient's illness in the surgical ICU, and their ordering may be a reflex rather than in response to a clinical question. Checklists have been used in critical care to identify and address patient care strategies. OBJECTIVE: To examine whether adding a "diagnostic testing" section to a daily checklist used for patient rounds in a surgical ICU would decrease the amount of laboratory tests and chest x-ray imaging ordered. METHODS: An additional section was added to an established ICU daily checklist, which included the following 2 questions: "Is a [chest x-ray] needed for clinical management tomorrow?" and "What laboratory tests are medically necessary for tomorrow?" Comparison was made between 3-month preintervention (control group) and intervention (intervention group) periods. Medical records of hospitalized patients during the preintervention and intervention periods were compared to determine differences in the number of tests ordered per day during each period. RESULTS: A total of 307 adult patients at a single institution were included in the analysis: 155 in the control group and 152 in the intervention group. The patients in each group were similar in terms of sex, age, Sequential Organ Failure scores, Charlson Comorbidity Index scores, elective admission status, surgical procedures, number of days of mechanical ventilation, ICU length of stay, and in-hospital death. No statistical reductions in laboratory tests or chest x-ray imaging ordered per day from the preintervention to intervention period were found. CONCLUSION: The addition of the diagnostic testing section to the daily checklist did not result in a reduction of the amount of tests ordered per day. Further research on test appropriateness and the possible addition of a clinician decision-making tool could be studied in the future to assist with reduction of tests ordered in the surgical ICU.