The Performance of Flash Replenishment Contrast-Enhanced Ultrasound for the Qualitative Assessment of Kidney Lesions in Patients with Chronic Kidney Disease.

We investigated the accuracy of CEUS for characterizing cystic and solid kidney lesions in patients with chronic kidney disease (CKD). Cystic lesions are assessed using Bosniak criteria for computed tomography (CT) and magnetic resonance imaging (MRI); however, in patients with moderate to severe kidney disease, CT and MRI contrast agents may be contraindicated. Contrast-enhanced ultrasound (CEUS) is a safe alternative for characterizing these lesions, but data on its performance among CKD patients are limited. We performed flash replenishment CEUS in 60 CKD patients (73 lesions). Final analysis included 53 patients (63 lesions). Four readers, blinded to true diagnosis, interpreted each lesion. Reader evaluations were compared to true lesion classifications. Performance metrics were calculated to assess malignant and benign diagnoses. Reader agreement was evaluated using Bowker's symmetry test. Combined reader sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing malignant lesions were 71%, 75%, 45%, and 90%, respectively. Sensitivity (81%) and specificity (83%) were highest in CKD IV/V patients when grouped by CKD stage. Combined reader sensitivity, specificity, PPV, and NPV for diagnosing benign lesions were 70%, 86%, 91%, and 61%, respectively. Again, in CKD IV/V patients, sensitivity (81%), specificity (95%), and PPV (98%) were highest. Inter-reader diagnostic agreement varied from 72% to 90%. In CKD patients, CEUS is a potential low-risk option for screening kidney lesions. CEUS may be particularly beneficial for CKD IV/V patients, where kidney preservation techniques are highly relevant.

Incidence and Prediction of Immune Checkpoint Inhibitor-related Nephrotoxicity.

Immune checkpoint inhibitors (ICIs) may cause immune-related adverse events that can affect any organ system, including the kidneys. Our study aimed to better characterize the incidence of and predictive factors for immune-related acute kidney injury (irAKI) and evaluate steroid responsiveness. An institutional database (Carolina Data Warehouse) was queried for patients who received ICIs and subsequently had substantial AKI, defined as a doubling of baseline creatinine. A retrospective chart review was performed to determine the cause of AKI. AKI events determined to be immune-related were further analyzed. A total of 1766 patients received an ICI between April 2014 and December 2018. A total of 123 (7%) patients had an AKI within 1 year of the administration of the first ICI dose. 14 (0.8% of all patients who received ICIs) of the AKI events were immune-related. History of an autoimmune disease (N=2, 14%, P=0.04) or history of other immune-related adverse events (irAEs) (N=8, 57%, P=0.01) was a significant predictor of irAKI. Of 14 irAKI patients, 9 received steroids with renal function improving to baseline in 5 patients, improving but not to baseline in 2, and 2 without improvement in renal function, including 1 becoming dialysis-dependent. Age, sex, urinalysis findings, and primary tumor site were not associated with irAKI. irAKI is relatively uncommon but likely under-recognized. Underlying autoimmune disease and history of nonrenal ICI-related irAEs are associated with irAKI. Early recognition and steroid administration are important for a positive outcome.