Background: Acute kidney injury (AKI) has been observed in up to 20% of adult hospital admissions. Sepsis, diarrhea and heart failure, all causing reduced effective volume, are considered risk factors for AKI, especially among patients treated with medications that block the Renin-Angiotensin System (RAS), such as angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB). We aimed to determine the incidence of acute kidney injury (AKI) in emergency medical admissions in relation to the use and dosage of ACEi/ARB. Methods: A single-center observational study conducted in 577 consecutive medical admissions via the Emergency Room (ER) at a University General Hospital in Athens, Greece, between June and July 2018. Patients with incomplete medical records, discharged within 24 h, maintained on chronic renal replacement therapy, admitted to the Cardiology Department or the ICU were excluded. Thus, a total of 309 patients were finally included in this analysis. Results: We compared 86 (28%) patients who presented in the ER with AKI (AKIGroup) with 223 (72%) patients without AKI (non-AKI Group) at the time of admission. Patients in the AKI Group were more frequently male (58% vs. 46%, p = 0.06), with a higher frequency of diarrhea (16% vs. 6%, p = 0.006), edema (15% vs. 6%, p = 0.014) and lower systolic blood pressure (120 (107–135) vs. 126 (113–140), p = 0.007) at presentation, despite higher prevalence of hypertension (64% vs. 47%, p = 0.006). Overall, ACEi/ARB were more likely to have been prescribed in the AKI Group than in the non-AKI Group (49% vs. 28%, p = 0.001). Interestingly, AKI was more frequently observed in patients treated with the target or above target dosage of ACEi/ARB, but not in those receiving lower than the recommended dosage. Conclusion: The risk of AKI in emergency medical admissions is higher among users of ACEIs/ARB at target or above target dosages. Physicians should adjust RAS blockade according to estimated Glomerular Filtration Rate (eGFR) and advise their patients to withhold ACEi/ARB in cases of acute illness.

Stimulation of the antitumor activity of the immune system using immune checkpoint inhibitors (ICIs) has proven efficacy in the treatment of multiple types of cancer, inducing the speedily expanding approval of therapeutic indications for ICIs. The literature regarding the immune-related toxicities and nephrotoxicity of ICIs is limited. Herein, we present a patient with lung cancer treated with atezolizumab, an IgG1 monoclonal antibody aimed at the programmed death ligand 1 (PD-L1), who presented with vasculitic skin rash and rapidly deteriorating renal function, new onset of significant glomerular hematuria and proteinuria. The renal biopsy revealed acute necrotizing pauci-immune vasculitis, with fibrinoid necrosis. The patient received a course of high-dose glucocorticoids with recovery of renal function and skin lesions. Further immunosuppressive therapy was withheld, due to active malignancy in the lung, while oncology consultation recommended the continuation of treatment with atezolizumab, as the patient had shown substantial response.

Early diagnosis and initiation of appropriate immunosuppressive treatment remain the cornerstone of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis at the cost of significant toxicity. In this report, we present a case of a 69-year-old female who presented with advanced renal insufficiency and evidence of pulmonary hemorrhage and was MPO–ANCA-positive with a clinical phenotype of granulomatosis with polyangiitis. Organ involvement included rapidly progressive glomerulonephritis (GN), along with extrarenal manifestations (skin, upper and lower respiratory system involvement, and onset of saddle-nose deformity). Kidney biopsy established the diagnosis of pauci-immune crescentic, sclerotic GN. She received therapy with glucocorticoids and cyclophosphamide, mainly due to life-threatening extra-renal manifestations, such as pulmonary hemorrhage. She avoided vasculitis-related death but she developed severe therapy-related toxicity, resulting in the discontinuation of immunosuppressive therapy. Continuous re-evaluation of patients with ANCA-associated vasculitis in terms of response to immunosuppressive therapy and treatment-related toxicity is crucial for their management.

Background and Objectives: The genetic architecture of late-onset autosomal dominant polycystic kidney disease (ADPKD) remains incompletely defined. Pathogenic mutations in two genes that encode polycystin proteins, PKD1 and PKD2, prevail among these patients. Detection of PKD1 alterations by a sequencing method is challenging as this is a large gene with high GC content and multiple pseudogenes. Although next-generation sequencing (NGS) has become the cornerstone of molecular diagnosis, its limited availability in several settings and its limited sensitivity for structural variants may create a diagnostic blind spot, particularly for PKD2. Because PKD2-associated ADPKD follows a milder clinical course with delayed progression to end-stage renal disease (ESRD), its contribution to late-onset disease may be systematically underestimated. We hypothesized that a phenotype-driven strategy integrating copy number analysis would uncover clinically relevant PKD2 variants overlooked by DNA sequencing methods. Materials and Methods: Six well-characterized consecutive ADPKD patients that entered KRT (kidney replacement therapy) above 70 years old underwent targeted PKD2 analysis using bidirectional Sanger DNA sequencing of all coding exons and exon–intron boundaries, complemented by multiplex ligation-dependent probe amplification (MLPA) for copy number variant detection. Results: Pathogenic PKD2 variants were identified in 33% of the patients in this limited cohort. These included the recurrent nonsense variant p.Arg872Ter and a previously undescribed multi-exonic deletion encompassing exons 1–9 that was detectable exclusively by MLPA. Additionally a novel variant of unknown significance (VUS) (p.Leu273Gln) was detected. The high diagnostic yield in this phenotypically highly enriched cohort highlights the value of targeted structural variant analysis. Conclusions: Our findings identify structural PKD2 variation as an under-recognized cause of genetically unresolved late-onset ADPKD and demonstrate that phenotype-guided incorporation of copy number analysis can overcome limitations of NGS alone. A combined sequencing–MLPA approach may therefore provide a more complete and clinically informative molecular diagnosis, particularly in carefully selected patients with late-onset ADPKD.

Background/Objectives: Acute interstitial nephritis (AIN) is a cause of acute kidney injury (AKI) during immune checkpoint inhibitor (ICI) therapy, but biopsy-confirmed data are limited. We estimated institutional proportions of biopsy-confirmed AIN clinically attributed to ICI exposure (ICI-AIN) and characterized its presentation, pathology, treatment, and renal outcomes. Methods: We retrospectively reviewed native renal biopsies performed at Attikon University Hospital from February 2021 through December 2025. Cases were included when ICI exposure preceded AKI and the treating nephrology team documented clinicopathologic attribution to ICI exposure. Results: AIN was identified in 15 of 339 native renal biopsies; 12 cases were attributed to ICI exposure, representing 3.5% of native renal biopsies and 0.8% of 1472 unique ICI-treated patients. Median serum creatinine increased from 1.05 mg/dL at baseline to 3.50 mg/dL at biopsy assessment. During the AKI episode, 10 patients (83.3%) met Kidney Disease: Improving Global Outcomes (KDIGO) criteria for stage 3 AKI. All patients had pyuria, negative urine cultures, and subnephrotic proteinuria. Hematuria and peripheral eosinophilia occurred in four and two patients, respectively. All patients received corticosteroids, and none required kidney replacement therapy. Complete, partial, and absent recovery occurred in eight, two, and two patients, respectively; under the stricter baseline-relative definition, the corresponding numbers were five, five, and two. Conclusions: Biopsy-confirmed ICI-AIN was infrequently detected. Severe AKI was common, urinary findings were nonspecific, and residual renal dysfunction frequently persisted after corticosteroid treatment.

EULAR recommends kidney biopsy in systemic lupus erythematosus (SLE) patients with glomerular hematuria, whereas both ACR and KDIGO require the presence of proteinuria and/or impaired kidney function. We explored the value of hematuria for the diagnosis of new-onset lupus nephritis (LN). Cross-sectional study of SLE patients who underwent diagnostic kidney biopsy in two independent centers. Clinically significant LN was defined as ISN/RPS class III, IV, V, or mixed III/IV + V. Presentation patterns were categorized by glomerular hematuria, proteinuria, and impaired kidney function. Among patients with glomerular hematuria, regression models identified factors associated with clinically significant LN, and a nomogram was constructed. Of 227 biopsies, 181 (79.7%) showed clinically significant LN. Isolated glomerular hematuria was evident in 11 patients, of whom 9 revealed non-LN pathology; the two LN cases (class II and III) both demonstrated concurrent SLE serologic activity. Among patients with glomerular hematuria ( n = 137), independent factors associated with clinically significant LN included anti-dsDNA positivity (OR 12.00, 95% CI 3.36–51.40), higher non-renal SLEDAI score (OR 1.20 per point, 95% CI 1.02–1.46), higher proteinuria (OR 3.77 per 1 g/d, 95% CI 2.00–9.03), and younger age (OR 0.96 per year, 95% CI 0.91–1.00). The combined presence of these factors yielded a predicted probability of 97% (95% CI 90–99%) of clinically significant LN, whereas their absence was associated with a probability of only 6% (95% CI 1–23%). When considering the need for kidney biopsy in patients with lupus, hematuria should be evaluated in the context of overall disease activity; extra-renal and serologic activity substantially increase the likelihood of clinically significant LN.