Kidney360最新文献

Background: Renal involvement in primary Sjögren's syndrome (SS) is uncommon but clinically consequential. Prior studies have been limited by small samples and incomplete biopsy data. We evaluated a large biopsy-confirmed cohort to characterize clinicopathologic features of SS with renal involvement and identify predictors of renal recovery and long-term outcomes.

Methods: We retrospectively identified adults with SS and kidney biopsy at Mayo Clinic (2012-2025). Clinical, laboratory, and histologic data were extracted. Predictors of complete renal recovery within 6 months, defined as serum creatinine (sCr) returning to within 25% of baseline or <1.4 mg/dL if baseline was unknown, were evaluated using logistic regression. Cox regression assessed long-term risk of a composite endpoint: newly developed or progressive chronic kidney disease (CKD), end-stage kidney disease, or all-cause mortality.

Results: Fifty-six patients were included (median age 57 years; 91% female). Extraglandular manifestations occurred in 76%, and baseline CKD in 65%. Median sCr at baseline and biopsy were 1.3 and 1.6 mg/dL, respectively. Anti-Ro/SSA was positive in 80%. Low C3 occurred in 14% and low C4 in 25%. Tubulointerstitial nephritis was the predominant lesion (71%). Moderate/severe interstitial fibrosis/tubular atrophy and arteriosclerosis were present in 36% and 41%, respectively. Immunosuppressive therapy was applied in 84%.Complete recovery occurred in 67%. Over a median 3.9 years (IQR 1.4-7.2), 43% reached the composite endpoint. Baseline sCr ≥2mg/dL, 24-hour proteinuria ≥1g, and presence of segmental glomerulosclerosis were associated with lower odds of recovery (OR=0.16, 0.13 and 0.11, P=0.02, 0.001 and 0.008, respectively) and higher long-term risk (HR=4.51, 2.92 and 3.52, P=0.002, 0.01 and 0.02, respectively). Moderate/severe arteriosclerosis also increased long-term risk (HR=2.56, P=0.03).

Conclusions: In biopsy-confirmed SS-related renal involvement, the severity of kidney dysfunction and the extent of chronic glomerular and vascular injury strongly predict renal prognosis. Early detection and targeted management of high-risk features may improve long-term renal outcomes.

Background: Conventional angiography remains the standard diagnostic modality for arteriovenous (AV) access dysfunction in hemodialysis patients, but its geometric accuracy is limited. Intravascular ultrasound (IVUS) offers superior lesion detection, yet its absolute measurement accuracy remains uncertain. Using three-dimensional (3D) printed vascular conduits as reference standards, we assessed the accuracy of IVUS versus angiography, hypothesizing that complex conduit geometry, quantified by Gaussian curvature, would exacerbate angiographic error.

Methods: Clinically relevant AV access geometries were modeled with computer-aided design (CAD) and fabricated using 3D printing. Lumen diameters were measured by contrast angiography and IVUS and compared with CAD dimensions. Conduit geometry was characterized using finite element-based Gaussian curvature mapping. Paired Student's t-test, Tukey-Kramer correction for multiple testing, and linear mixed-effect modeling were performed to examine the influence of clustering of lesions within conduits.

Results: IVUS demonstrated significantly lower measurement error compared with angiography, especially in stenotic segments with >50% luminal narrowing, which persisted even after correction for multiple comparisons (P < 0.05). These high-grade stenoses frequently coincided with regions of especially high positive or negative Gaussian curvature, reflecting complex conduit geometry. In such regions, angiography consistently underestimated lumen diameter, with error magnitude increasing in curved or tortuous lesions. IVUS measurements closely approximated CAD measurements, retaining accuracy even in severe stenoses. For mild stenoses (<50%) and aneurysmal dilatations, both modalities performed comparably.

Conclusions: Geometric complexity directly contributes to modality-specific error. Angiography systematically underestimates lumen dimensions in complex, stenotic regions, while IVUS detects them with higher fidelity and preserves accuracy. These findings establish IVUS as the more reliable modality for evaluating AV access dysfunction and support its integration into routine practice in guiding intervention for AV access stenosis.

Measured glomerular filtration rate (mGFR) remains the reference standard for precise assessment of kidney function when estimated approaches are insufficient. This second part of a two-part series reviews exogenous filtration markers used to obtain mGFR, including inulin, iothalamate, iohexol, and radionuclide-based tracers, with emphasis on their physiologic handling, analytic methods, accuracy, and clinical applicability. The review further examines emerging fluorescent and near-infrared tracers coupled with transcutaneous monitoring technologies that enable rapid or continuous assessment of GFR. Together, these approaches illustrate the evolution of mGFR measurement toward methods that are more practical, scalable, and responsive to dynamic changes in kidney function, while maintaining analytical accuracy.

Background: Current treatment of autosomal dominant polycystic kidney disease (ADPKD) is mainly focused on inhibiting cystogenesis through arginine vasopressin suppression and there have been interests in achieving similar vasopressin suppression by reduction of osmolality with increased water intake. However, the causal relationship between serum osmolality and kidney outcome remained unclear in ADPKD patients. We aim to evaluate the relationship of serum osmolality and its effect on kidney outcome in ADPKD patients.

Methods: Three hundred and eleven tolvaptan treatment-naïve ADPKD patients were recruited prospectively from the CysticHK cohort, a territory-wide ADPKD registry across twelve tertiary hospitals in Hong Kong. Beside clinical data, serial measurement of serum and urinary osmolality were obtained every six months over five years. All participants were treated according to the standard of clinical care. The primary outcome was the 40% decline from baseline eGFR.

Results: Patients with a high serum osmolality have a worse kidney outcome, as shown by the Kaplan-Meier plots (log-rank p=<0.001) and the Cox regression model that showed a 5.91 times higher risk of reaching 40% eGFR decline compared to the top with bottom quartiles of osmolality (p=0.018). In contrast, there is an inverse relationship for urine osmolality. A ROC analysis to assess the predictive efficacy of osmolality for identifying those at high risk of kidney decline also showed a good performance for serum osmolality (AUC 0.81, 95%CI, 0.73-0.89; p<0.001). The urinary osmolality did not show a clinical meaningful predictive efficacy (AUC 0.35, 95%CI 0.28-0.43; p=0.003).

Conclusions: Serum osmolality may be a possible surrogate marker for the clinical monitoring of ADPKD patients, especially when access to copeptin level is limited; and high serum osmolality conveys possible detrimental effect on the kidney outcomes.

Background: Percutaneous kidney biopsy remains the gold standard for evaluation of AKI, given that clinicians' pre-biopsy clinical impression of AKI, based on history, exam, and non-invasive testing may not lead to a unifying diagnosis. In this study, we evaluated the concordance of pre-biopsy clinical diagnosis with post-biopsy final diagnosis among patients with clinical AKI.

Methods: We leveraged data collected prospectively through the Novel Approaches in the Investigation of Kidney Disease (NAIKiD) Study between 2020 and 2023, in which adult patients admitted to the Johns Hopkins Hospital and scheduled for clinical kidney biopsies consented to provide biosamples paired with data collection. Up to 3 pre-biopsy clinical diagnoses were recorded for each patient, along with up to 3 post-biopsy diagnoses, adjudicated by a study nephrologist post-biopsy. We investigated the concordance of pre- and post-biopsy diagnoses among patients with suspected acute interstitial nephritis (AIN) or acute tubular injury (ATI).

Results: Among 164 total participants, 29 patients had a suspected clinical diagnosis of AIN and 47 had a suspected clinical diagnosis of ATI pre-biopsy. Among the participants with suspected AIN, only 7 (24%) had AIN confirmed on biopsy. Of the 22 biopsies without AIN present, alternative diagnoses noted on histology included focal segmental glomerulosclerosis (FSGS), ATI, and various glomerular diseases. Out of 47 participants with suspected ATI, ATI was confirmed on biopsy in 27 (57%) participants. In the 20 biopsies without ATI present, alternative histological findings also included glomerular diseases, diabetic nephropathy, and FSGS predominantly.

Conclusions: Patients with suspected ATI or AIN who undergo percutaneous kidney biopsy are often found to have alternative, significant findings present on histology. Among patients without relative or absolute contraindications, kidney biopsy remains an essential part of clinical evaluation, while future research should focus on the development of non-invasive approaches for kidney disease diagnosis.

Background: Aberrant mucosal immune responses are underlying causes of Immunoglobulin A nephropathy (IgAN), the most prevalent type of chronic glomerulonephritis. However, the role of T cells in IgAN pathogenesis remains elusive. To address this knowledge gap, we profiled the T-cell receptor (TCR) repertoire in the tonsils of patients with IgAN.

Methods: This study included 27 and 20 patients with biopsy-confirmed IgAN and recurrent tonsillitis (RT), respectively, who underwent tonsillectomy. The TCR repertoire was determined by high-throughput sequencing coupled with unbiased adaptor ligation polymerase chain reaction (PCR). Furthermore, the usage of variable and joining regions in TCRα (TRA) and β (TRB) genes in each group was assessed. TRA clonotypes shared among the patients were characterized by complementary determining region 3 (CDR3) lengths, types of mucosal-associated invariant T (MAIT) cells, hydrophobicity, and their relationships with tonsillar galactose-deficient IgA1 (Gd-IgA1) and tonsillar IgA-binding indices of tonsillar bacteria.

Results: The TRA repertoire exhibited significantly lower similarity in patients with IgAN than did in RT cases (P < 0.001). Sharing TRA clonotypes among patients with IgAN was significantly sparser than that among RT cases. The relative abundance of shared TRA clonotypes with shorter CDR3 lengths was significantly increased in patients with IgAN (P_adj = 0.041), which was characterized by low MAIT match scores. Significant negative correlations were observed between the MAIT scores and hydrophobicity for these TRA clonotypes in patients with IgAN. The relative abundances of these clonotypes significantly and positively correlated with the IgA binding indices of the phylum Bacteroidetes (P_adj = 0.008) in both groups and tonsillar Gd-IgA1 levels in patients with IgAN (P = 0.035).

Conclusions: The results in this study suggest aberrant T-cell subsets involvement in tonsillar immunity in patients with IgAN.