Manohar, Sandhya

ABSTRACT Peptide receptor radionuclide therapy (PRRT) has transformed the management of neuroendocrine tumors and other malignancies by enabling targeted radiation delivery while minimizing systemic toxicity. However, incidental renal radiation exposure presents a significant risk of radiation nephropathy, and this risk varies based on the unique characteristics of the radionuclide and its decay phenomenon as well as the peptide being utilized. This review explores the historical development of PRRT, the physics of radionuclide therapy as necessary for a practicing nephrologist, and key mechanisms of radiation-related kidney injury. We detail renal handling of radionuclides, dose thresholds and pathological features of PRRT-induced nephropathy. Furthermore, we discuss both current and prospective strategies to reduce renal toxicity—such as amino acid infusions, receptor saturation, cleavable linkers and emerging protective agents. Special considerations for PRRT in patients with chronic kidney disease and those on dialysis are highlighted. As PRRT applications expand, multidisciplinary collaboration is essential to optimize renal safety.

Key Points This study demonstrates that peritoneal dialysis is a safe and feasible option for patients with autosomal dominant polycystic kidney disease, even with high cystic organ volumes. Larger organ volumes, including height-adjusted cumulative kidney and liver volume, were not associated with increased peritoneal dialysis–related complications. Background Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent genetic kidney disorder and the fourth leading cause of kidney failure. Peritoneal dialysis (PD), preferred for its home-based convenience and cost-effectiveness, is often underutilized in ADPKD because of concerns over enlarged kidneys and heightened risk of complications. Methods This retrospective cohort study used data from the Mayo Clinic Polycystic Kidney Disease Database to evaluate individuals with ADPKD undergoing PD. We analyzed demographics, clinical parameters, and PD-related parameters. Complications were correlated with kidney and liver volumes derived from pre-kidney failure imaging. Results A total of 155 individuals with ADPKD on PD were included, of whom 45.1% were male. The mean age at PD initiation was 54.3±12.8 years, and the mean body mass index was 28.0±7.0 kg/m 2 . The median duration of PD was 24.3 months (interquartile range [IQR], 10.7–43.1), with 21.9% transitioning to hemodialysis. The most common complications were abdominal hernias (30.3%) and peritonitis (23.9%), with a peritonitis rate of 0.11 episodes per patient-year. Imaging analyses performed on a subset of 50 patients showed a median height-adjusted total kidney liver volume of 2731.9 ml/m (IQR, 2102.5–3131.1) and a median height-adjusted total kidney volume of 1303.5 ml/m (IQR, 733.1–1829.4). Kaplan–Meier analysis demonstrated no differences in complications rates on the basis of height-adjusted total kidney liver volume or height-adjusted total kidney volume (above versus below median values) or body mass index categories. Multivariate Cox regression analysis revealed that higher height-adjusted cumulative organ volume was associated with a lower risk of PD-related complications (hazard ratio=0.56, P = 0.026). Conclusions PD is a safe and feasible treatment option for patients with ADPKD, with no increased risk of PD-related complications associated with larger height-adjusted cumulative organ volumes. Infectious complication rates in this cohort were within International Society of Peritoneal Dialysis guideline thresholds, further supporting the safety of PD in this population.

Significance Statement Kidney toxicity from use of immune checkpoint inhibitors is being recognized as an increasingly frequent complication of treatment. However, existing data on immune checkpoint inhibitor–associated AKI have been limited to small, mostly single-center studies. In this multicenter study of 138 patients with immune checkpoint inhibitor–associated AKI and 276 controls, the authors characterize the clinical features of this complication and identify risk factors associated with its development, clinicopathologic features, and determinants of kidney recovery after an episode. Failure to achieve kidney recovery was associated with worse overall survival, and a minority (23%) of patients who were retreated with immune checkpoint inhibitors had a recurrence of AKI. The study provides insights into immune checkpoint inhibitor–associated AKI, although further study is needed to inform the care of affected patients. Background Despite increasing recognition of the importance of immune checkpoint inhibitor–associated AKI, data on this complication of immunotherapy are sparse. Methods We conducted a multicenter study of 138 patients with immune checkpoint inhibitor–associated AKI, defined as a ≥2-fold increase in serum creatinine or new dialysis requirement directly attributed to an immune checkpoint inhibitor. We also collected data on 276 control patients who received these drugs but did not develop AKI. Results Lower baseline eGFR, proton pump inhibitor use, and combination immune checkpoint inhibitor therapy were each independently associated with an increased risk of immune checkpoint inhibitor–associated AKI. Median (interquartile range) time from immune checkpoint inhibitor initiation to AKI was 14 (6–37) weeks. Most patients had subnephrotic proteinuria, and approximately half had pyuria. Extrarenal immune-related adverse events occurred in 43% of patients; 69% were concurrently receiving a potential tubulointerstitial nephritis–causing medication. Tubulointerstitial nephritis was the dominant lesion in 93% of the 60 patients biopsied. Most patients (86%) were treated with steroids. Complete, partial, or no kidney recovery occurred in 40%, 45%, and 15% of patients, respectively. Concomitant extrarenal immune-related adverse events were associated with worse renal prognosis, whereas concomitant tubulointerstitial nephritis–causing medications and treatment with steroids were each associated with improved renal prognosis. Failure to achieve kidney recovery after immune checkpoint inhibitor–associated AKI was independently associated with higher mortality. Immune checkpoint inhibitor rechallenge occurred in 22% of patients, of whom 23% developed recurrent associated AKI. Conclusions This multicenter study identifies insights into the risk factors, clinical features, histopathologic findings, and renal and overall outcomes in patients with immune checkpoint inhibitor–associated AKI.