Kidney Research and Clinical Practice最新文献

Background: The clinical significance and renal outcomes of C1q nephropathy (C1qN) are unclear; therefore, the implications of C1qN as a new pathological entity are uncertain. We compared the clinical characteristics of glomerulonephritis reclassified into cases that meet the definition of C1qN and glomerulonephritis not included in the definition of C1qN.

Methods: In total, 21,697 patients who underwent native kidney biopsy at 18 hospitals throughout Korea between 1979 and 2018 were retrospectively enrolled. A total of 77 patients were selected from the group that met the definition of C1qN after reclassification; however, six patients were excluded because of secondary systemic disease. Data on outcomes, incidences of end-stage renal disease (ESRD), and mortality were collected from the hospital records, the Korean Society of Nephrology's ESRD registry, and Statistics of Korea and were then unified based on Korean ethnicity. Characteristics of pathological findings classified into C1qN, without C1q stain, and with nondominant C1q stain that did not fulfill the criteria for C1qN were compared.

Results: No differences in clinicopathological findings and incidence of ESRD were evident (matched by age and sex) between glomerulonephritis cases reclassified into the group that met the definition of C1qN and those without C1q staining. Decreased proteinuria in patients with membranous nephropathies reclassified into the group that met the definition of C1qN was the only significant finding. Immunoglobulins showed higher intensity on immunofluorescence staining of the group that met the definition of C1qN. Additionally, C3 intensity was higher in reclassified immunoglobulin A nephropathy and membranous nephropathies.

Conclusion: Overall, reclassification into the group that met the definition of C1qN did not indicate a different clinicopathological identity. C1q activation and presumed classical complement pathway activation in kidney tissues in C1qN could not be confirmed. Hence, further studies are needed.

Background: Coronary artery calcification (CAC) is a surrogate of cardiovascular events in patients with chronic kidney disease (CKD). To establish the role of circulating osteoprotegerin (OPG) as a cardiovascular biomarker in patients with CKD, we investigated whether an increase in serum OPG levels is associated with the risk of CAC progression.

Methods: A total of 1,130 patients with CKD stage 1 to predialysis 5 were divided into quartiles according to serum OPG levels (Q1 to Q4). The coronary artery calcium score (CACS) was assessed at baseline and at the 4-year follow-up visit. CAC progression was defined as an increase in the CACS of more than 200 Agatston units over 4 years.

Results: Serum OPG levels were positively correlated with the CACS at baseline (R = 0.240, p < 0.001) and at the 4-year follow-up visit (R = 0.280, p < 0.001) as well as with changes in the CACS for 4 years (R = 0.270, p < 0.001) based on scatter plot analysis. Binary logistic regression analysis demonstrated that the risk of CAC progression was significantly increased in Q4 compared with Q1 (adjusted odds ratio, 3.706; 95% confidence interval, 1.154-11.902). Penalized spline curve analysis revealed a linear association between serum OPG levels and the risk of CAC progression.

Conclusion: An increase in circulating OPG levels was associated with the risk of CAC progression in patients with predialysis CKD.

Background: Denosumab has been reported to improve bone mineral density (BMD), but the clinical impact of denosumab on osteoporosis in kidney transplant recipients (KTRs) remains controversial.

Methods: We analyzed 98 KTRs who used denosumab from 2018 to 2023. We investigated the change in BMD, laboratory findings, complications of denosumab, fracture risk assessment tool (FRAX) score, acute rejection within 1 year, and graft failure.

Results: Mean T-scores at 1 year after denosumab were significantly increased compared to mean T-scores pre-denosumab at the femur neck and spine area, respectively (-2.68 ± 0.68 vs. -2.81 ± 0.68, p < 0.001; -2.78 ± 0.96 vs. -3.21 ± 1.00, p < 0.001). The levels of calcium and phosphorus significantly decreased and those of vitamin D significantly increased at 1 year after denosumab, but there were no significant differences in parathyroid hormone, allograft function, and tacrolimus trough level. There were no recurrent fractures among 12 KTRs with a history of fracture, but three de novo fractures happened. Cardiovascular events occurred in three patients. Denosumab-induced hypocalcemia developed in eight patients, but severe hypocalcemia was observed in only one patient. Acute kidney injury did not happen. Urinary tract infection (UTI) occurred in 17 patients. Arthralgia occurred in four patients. FRAX score was significantly decreased after denosumab. Acute rejection within 1 year after denosumab developed in three patients. There was no graft failure.

Conclusion: The use of denosumab in KTRs is effective and safe for the treatment of osteoporosis and prevention of fracture, but it should be carefully monitored for complications, especially UTI.

Alport syndrome, characterized by renal failure, hearing loss, and ocular abnormalities due to collagen type IV gene mutations, exhibits distinctive ocular manifestations in the various ocular tissues including the cornea, lens, and retina. Ophthalmological examinations, providing noninvasive visibility of basement membrane anomalies caused by collagen type IV mutations, can have a role in Alport syndrome diagnostics. Lenticonus, macular fleck, and other abnormalities also can serve as indicators of inheritance patterns and predictors of severe mutations or early-onset renal failure. Recognizing these manifestations in advance enables timely surgical intervention, potentially improving long-term visual outcomes. This review highlights the ocular features in Alport syndrome and contributes to the understanding of the relationships among ocular abnormalities as well as the genotype-phenotype correlations in Alport syndrome. In these ways, hopefully, it will guide further research and help to inform the development of clinical strategies.

Background: Despite previous reports of auditory phenotypes in Alport syndrome (AS), there have been no studies specifically addressing audiological phenotypes in South Korea. Herein, we elaborated on the audiological characteristics associated with AS based on their genotypes.

Methods: We reviewed data from in-house AS patients between March 2014 and February 2023, excluding those without audiological documentation or genetic diagnoses. We retrieved medical history, hearing level, estimated glomerular filtration rate (eGFR), and genotypes from their medical records. The natural course of hearing loss and correlations between audiogram and eGFR were evaluated according to audio-gene profiles.

Results: Our study included 49 AS patients from 47 families, identifying 60 disease-causing variants, 45 of which were novel. All variants were classified as pathogenic or likely pathogenic based on ACMG-AMP guidelines. The auditory phenotypes of autosomal recessive AS (ARAS) and male X-linked AS (XLAS) patients demonstrated a progressive nature, with a down-sloping configuration. The ARAS with truncated variants exhibited an earlier onset of hearing loss than those with non-truncated variants. In male XLAS patients, the presence of truncated allele linked to more rapid hearing deterioration across all frequencies. In both ARAS and male XLAS patients, the presence of truncated allele was significantly associated with hearing severity and eGFR. Conversely, the majority of female XLAS and autosomal dominant AS maintained normal hearing levels without any correlation of eGFR, regardless of genotypes.

Conclusion: This study detailed the auditory phenotypes and the auditory-renal association of AS at a tertiary center in South Korea, providing valuable references that guide auditory testing and rehabilitation strategies.

Background: Although the relationship between fatty acids (FAs) and the risk of all-cause mortality has been long discussed, there is little evidence about the impact of each FA component on all-cause mortality by kidney function status.

Methods: We used data from the U.S. National Health and Nutrition Examination Survey 1999-2016. The intake of FAs was estimated as a percentage of total energy using a 1-day 24-hour dietary recall and divided by quartiles; the first quartile was regarded as a reference. We used a multivariate Cox proportional hazard model to identify the impact of FAs on all-cause mortality.

Results: Among 44,332 participants, during 129.0 ± 62.4 months of follow-up, there were 1,623 (6.2%), 3,109 (22.3%), and 2,202 deaths (53.1%) in the estimated glomerular filtration rate (eGFR) ≥90, 60-90, and <60 mL/min/1.73 m2 groups, respectively. Higher intake of SFAs significantly increased the risk of all-cause mortality in participants with eGFR 60-90 mL/min/1.73 m2 (adjusted hazard ratio, 1.20 in the 4th quartile). Likewise, higher intake of most PUFAs (octadecadienoic acid, octadecatrienoic acid, omega-6, and omega-3) significantly decreased the risk of all-cause mortality in participants with eGFR 60-90 mL/min/1.73 m2 . These effects of both SFAs and PUFAs were attenuated in participants with eGFR ≥90 and <60 mL/min/1.73 m2 .

Conclusion: The impact of dietary FAs on all-cause mortality was prominent in participants with eGFR 60-90 mL/min/1.73 m2 . More specified and targeted counseling for restricting SFAs and encouraging PUFAs needs to be considered, especially for participants with marginally decreased kidney function.

Background: Patients with chronic kidney disease (CKD) are at high risk for cardiovascular disease (CVD). We aimed to evaluate whether hemodialysis (HD) initiation is associated with CVD risk in patients with CKD.

Methods: This self-controlled case series, using data from a nationwide Korean health claims database, included patients with CKD who initiated HD between 2007 and 2019 and experienced CVD, including acute stroke or myocardial infarction (MI), between 2008 and 2020. The risk periods were categorized relative to HD initiation (-60 to -31, -30 to -11, -10 to -1, +1 to +10, +11 to +30, +31 to +60, and +61 to +150 days); the remaining period was set as baseline. The age-adjusted incidence rate ratio (IRR) of CVD in each risk period relative to the baseline was calculated.

Results: Of the 74,584 patients with CKD on incident HD, 12,875 patients with CVD (6,367 with ischemic stroke, 2,396 with hemorrhagic stroke, and 4,112 with MI) were included. Compared with the baseline period, the risk of CVD increased in the post-dialysis periods, decreasing with time since HD initiation; the adjusted IRR during the first 10 days after HD initiation was 2.95 (95% confidence interval, 2.44-3.56). Although the risks of ischemic stroke and MI decreased at 1 to 2 months after HD initiation, the hemorrhagic stroke risk was higher for 5 months.

Conclusion: After HD initiation, the CVD risk increases in patients with CKD. For CVD prevention, the CVD risk should be carefully evaluated in patients with CKD who require HD.

Kidney transplantation is recognized as an effective treatment for end-stage renal disease in Alport syndrome, demonstrating outcomes comparable to or even superior to those in other causes of renal failure. When considering living related donor kidney transplantation for Alport syndrome patients, it is crucial to consider genetic factors during the donor selection process. In addition to a comprehensive health check, genetic testing is strongly recommended for potential donors at risk of carrying mutations in COL4A3-COL4A5 before undergoing kidney transplantation. Individuals carrying these mutations face an inherent risk of kidney disease and due to the possibility of further deterioration in renal function after nephrectomy for transplantation, they are not suitable as priority donors. Posttransplant anti-glomerular basement membrane nephritis is rare but can lead to graft loss, especially in males with X-linked Alport syndrome.

Background: Acute kidney injury (AKI) may transition into acute kidney disease (AKD) or chronic kidney disease (CKD), leading to subacute and chronic deterioration, respectively. Despite extensive research on AKI, a significant gap exists in understanding the specific biomarkers and development of individualized treatments prior to progression to AKD and CKD.

Methods: As a consortium linking health medical records, biospecimens, and biosignals, eight Korean tertiary hospitals participated in the establishment of a retrospective and prospective cohort, each comprising approximately 1,500 patients with AKI receiving continuous kidney replacement therapy (CKRT). Other information included AKI-related information, CKRT prescriptions, and patient outcomes. Follow-up timeframes were set at baseline, 1 week, 3 months, and 1 year after the initiation of CKRT. Human biospecimens will be collected from the prospective cohort. An artificial intelligence model was developed using the retrospective cohort to predict the prognosis of AKD and its subsequent sequelae and to formulate patient-individualized treatments, with validation planned in a prospective cohort. Follow-up studies are scheduled to identify biomarkers related to outcomes using biospecimens. Finally, based on the results and literature review, decision-making on the prevention and management of diseases, as well as the development of treatment guidelines, are being planned.

Conclusion: This study will provide scientific evidence on clinical insights and appropriate management targets for AKI and AKD, which will form the basis for relevant treatment guidelines. Additionally, these findings may facilitate a more personalized approach to patient care, enabling clinicians to tailor treatments based on individual biomarker profiles and predictive models.

Background: There is no conclusive evidence regarding the survival benefits of automated peritoneal dialysis (APD) or the use of icodextrin. This study aimed to evaluate patient and technique survival among four groups divided based on peritoneal dialysis modality and icodextrin use over 1 year.

Methods: We specifically included patients who underwent a single peritoneal dialysis modality for at least 1 year during that period (n = 148). The participants were categorized into four groups for comparison: continuous ambulatory peritoneal dialysis (CAPD) without icodextrin (CAPD-ET, n = 39); CAPD with icodextrin (CAPD+ET, n = 35); APD without icodextrin (APD-ET, n = 40); and APD with icodextrin (APD+ET, n = 34).

Results: The CAPD+ET group had a higher patient survival rate than that of the APD-ET group and also had a higher technique survival trend than that of the APD-ET group, despite no statistical significance. In patients without diabetes mellitus (DM), the APD-ET group had a poorer patient survival trend than those of the APD+ET or CAPD+ET groups. In patients without DM, the APD+ET group had a higher technique survival than the APD-ET group. In addition, the APD+ET group showed a higher technique survival trend than did the CAPD-ET group, despite non-statistical significance. The edema index after 1 year of follow-up was higher in the APD-ET group than in the other groups.

Conclusion: The present study demonstrated that patients undergoing APD without icodextrin had poor patient and technique survival trends, which may be caused by poor volume control.