ANCA-associated glomerulonephritis (ANCA-GN) is a leading cause of pauci-immune crescentic GN. Recent evidence indicates that complement activation, marked by C3 deposition in glomeruli, may contribute to more severe renal injury and influence renal outcomes. We aim to evaluate the clinical, histopathological, and prognostic implications of C3 deposition in ANCA-GN. We retrospectively analyzed 195 patients with biopsy-proven ANCA-GN from the Turkish Society of Nephrology Glomerular Diseases registry from 2002 to 2022. Patients were classified as C3-positive or C3-negative according to kidney biopsy immunofluorescence findings. Clinical characteristics, histopathologic lesion profiles, and follow-up outcomes (remission, relapse, and survival) were compared between the two groups. Of 195 patients, 54 (27.7%) had C3 deposition. The C3-negative group was more likely to exhibit PR3-ANCA positivity, whereas the C3-positive group was strongly associated with the presence of MPO-ANCAs (22.2% vs. 77.8%; p = 0.001). Compared with C3-negative patients, C3-positive patients had higher levels of proteinuria (2026 mg/day vs. 1790 mg/day; p = 0.049) and lower HDL levels (30 mg/dL vs. 37 mg/dL; p = 0.009). Fibrocellular crescents were more common in C3-positive patients than in C3-negative patients (p < 0.001). Immune complex deposits, including IgG (26.4% vs. 3.5%; p < 0.001), IgA (14.8% vs. 0.7%; p < 0.001), IgM (25.0% vs. 3.5%; p < 0.001), and C1q (13.7% vs. 0.8%; p < 0.001) were significantly greater in the C3-positive group. However, no significant difference was detected in overall survival (85.8% for C3-negative patients vs. 88.9% for C3-positive patients; p = 0.249). Similarly, the remission (62.1% vs. 59.4%; p = 0.786) and relapse rates (14.8% vs. 11.1%; p = 0.532) did not differ between the groups. In ANCA-GN, glomerular C3 deposition is associated with an MPO-ANCA serotype, greater proteinuria, and more severe renal histology (including immune-complex deposition and more fibrocellular crescents), indicating more pronounced complement activation and tissue injury. However, C3 deposition did not predict worse patient or renal survival in our cohort. Not applicable.

Although acute kidney injury (AKI) is common among patients with coronavirus disease 2019 (COVID-19), there are only limited data on its occurrence at intensive care unit (ICU) admission. Assessing the factors associated with AKI is essential for early diagnosis and intervention. This study aims to compare the clinical and laboratory characteristics and survival outcomes of COVİD-19 patients with and without AKI at ICU admission and determine the factors associated with AKI. In this study, patients with SARS-CoV-2 infection were categorized based on the presence (AKI group) or absence (non-AKI group) of AKI. Clinical and laboratory data and outcomes were analyzed retrospectively. Of the 712 patients included in this study, 198 were assigned to the AKI group and 514 were assigned to the non-AKI group. Patients with AKI had more comorbidities and higher disease severity; higher rates of invasive mechanical ventilation, vasopressor therapy, and mortality; and longer hospital stays (p < 0.05). Our multivariate analysis identified advanced age, a high Acute Physiology and Chronic Health Evaluation II score, a high neutrophil-to-lymphocyte ratio, a low albumin level, and the presence of comorbidities as independent factors associated with AKI. In patients with COVID-19, AKI observed at ICU admission is associated with advanced age and increased disease severity. The early diagnosis and monitoring of patients may improve clinical outcomes.

Background and Objectives: Sarcopenia is highly prevalent among older adults with chronic kidney disease (CKD) and is associated with adverse clinical outcomes. The finger-ring (Yubi-wakka) test is a simple anthropometric screening tool based on calf circumference; however, its performance in older adults with CKD remains unclear. This study aimed to investigate the association of the finger-ring test with low muscle mass, sarcopenia, and comprehensive geriatric assessment parameters and to evaluate its diagnostic performance for identifying low muscle mass in older adults with CKD. Materials and Methods: This cross-sectional study included 115 patients aged ≥65 years with CKD who were evaluated in geriatric and nephrology inpatient services. After excluding two participants with missing finger-ring measurements, 113 individuals were analyzed. Muscle mass was assessed using bioelectrical impedance analysis and low muscle mass was defined according to EWGSOP2-based Turkish cut-off values. Demographic characteristics, anthropometric measurements, laboratory findings, and comprehensive geriatric assessment parameters were recorded. Correlation analyses, logistic regression models, receiver operating characteristic (ROC) analyses, and likelihood-ratio tests were performed. Results: Among 113 participants, 62 were classified as finger-ring positive (FR = 0) and 51 as finger-ring negative (FR = 1). Low muscle mass was significantly more frequent in the FR = 0 group than in the FR = 1 group (51.6% vs. 24.0%, p = 0.005). Finger-ring test results showed strong correlations with calf circumference (rho = 0.689, p < 0.001) and body mass index (BMI) (rho = 0.631, p < 0.001), whereas the correlation with muscle mass was modest (rho = 0.250, p = 0.008). For detecting low muscle mass, the finger-ring test demonstrated an area under the curve (AUC) of 0.643 (95% CI 0.554–0.732), sensitivity of 72.7%, specificity of 55.9%, positive predictive value of 51.6%, and negative predictive value of 76.0%. In multivariable analyses, BMI remained the strongest independent determinant of finger-ring test results, whereas the association with muscle mass lost statistical significance after BMI adjustment. Adding age and sex significantly improved discrimination, while the contribution of nutritional status was limited. Conclusions: The finger-ring test is associated with low muscle mass in older adults with CKD; however, its diagnostic performance is modest and appears to be substantially influenced by body size and calf circumference. Therefore, the finger-ring test should be considered a simple adjunctive screening tool rather than a stand-alone method for identifying low muscle mass in this population.

Fibrinolytic Activity in Patients with Newly Diagnosed Multiple Myeloma - Acta Haematologica Oncologica Turcica