The urine albumin-to-creatinine ratio is a reliable indicator for evaluating complications of chronic kidney disease and progression in IgA nephropathy in China

Multimodal Identification of Molecular Factors Linked to Severe Diabetic Foot Ulcers Using Artificial Intelligence

Diabetic foot ulcers (DFUs) are a severe complication of diabetes mellitus (DM), which often lead to hospitalization and non-traumatic amputations in the United States. Diabetes prevalence estimates in South Texas exceed the national estimate and the number of diagnosed cases is higher among Hispanic adults compared to their non-Hispanic white counterparts. San Antonio, a predominantly Hispanic city, reports significantly higher annual rates of diabetic amputations compared to Texas. The late identification of severe foot ulcers minimizes the likelihood of reducing amputation risk. The aim of this study was to identify molecular factors related to the severity of DFUs by leveraging a multimodal approach. We first utilized electronic health records (EHRs) from two large demographic groups, encompassing thousands of patients, to identify blood tests such as cholesterol, blood sugar, and specific protein tests that are significantly associated with severe DFUs. Next, we translated the protein components from these blood tests into their ribonucleic acid (RNA) counterparts and analyzed them using public bulk and single-cell RNA sequencing datasets. Using these data, we applied a machine learning pipeline to uncover cell-type-specific and molecular factors associated with varying degrees of DFU severity. Our results showed that several blood test results, such as the Albumin/Creatinine Ratio (ACR) and cholesterol and coagulation tissue factor levels, correlated with DFU severity across key demographic groups. These tests exhibited varying degrees of significance based on demographic differences. Using bulk RNA-Sequenced (RNA-Seq) data, we found that apolipoprotein E (APOE) protein, a component of lipoproteins that are responsible for cholesterol transport and metabolism, is linked to DFU severity. Furthermore, the single-cell RNA-Seq (scRNA-seq) analysis revealed a cluster of cells identified as keratinocytes that showed overexpression of APOE in severe DFU cases. Overall, this study demonstrates how integrating extensive EHRs data with single-cell transcriptomics can refine the search for molecular markers and identify cell-type-specific and molecular factors associated with DFU severity while considering key demographic differences.

Comparative effectiveness and safety for the treatments despite optimized renin-angiotensin system blockade among IgA nephropathy patients at high-risk of disease progression: A network meta-analysis of randomized controlled trials

OBJECTIVE

Approximately 20-40% of IgA nephropathy patients would develop end-stage renal disease, for whom safety concerns remained a major setback when using conventional pharmaceutical treatments. Evidence is lacking for optimal selection of effective and safe pharmaceuticals to slow the disease progression. To compare the effectiveness and safety profile of different treatments despite optimized RAS blockade for IgA nephropathy patients at high-risk of disease progression.

STUDY DESIGN

PubMed, ScienceDirect and Web of science databases published from 1990 to March 18th, 2023 without language restriction. Immunosuppressant and cortico-steroid treatments were considered as two independent regimens.

RESULTS

Fifteen trials with 1,983 participants were evaluated for the occurrence of five outcomes. For ESRD, dapagliflozin was superior to placebo (RR: 0.30; 95% CI 0.11, 0.80), immunosuppressant (RR:0.14; 95% CI 0.02,0.81) and RAS (RR:0.10; 95% CI 0.01,0.69). Glucocorticoid was superior to placebo (RR: 0.71; 95%CI 0.52,0.99). For clinical remission, immunosuppressant was superior to placebo (RR: 2.71; 95%CI 1.16, 6.31) and RAS monotherapy (RR: 2.87; 95%CI 1.60, 5.17). For 50% reduction in 24 h proteinuria or UPCR, immunosuppressant was superior to placebo (RR: 2.71; 95%CI 1.16, 6.31) and RAS monotherapy (RR: 2.40; 95%CI 1.04, 5.55). For SAE, dapagliflozin was superior to glucocorticoid (RR: 0.22; 95%CI 0.09, 0.54), whereas glucocorticoid was inferior to placebo (RR: 2.91; 95%CI 1.39, 6.07). Cluster ranking showed dapagliflozin appeared to have the lowest SAE risk and the best comparative therapeutic efficacy in preventing ESRD.

CONCLUSIONS

The current findings highlighted dapagliflozin was a promising pharmaceutical treatment alternative to achieve optimal outcomes for IgA nephropathy patients at high risk of disease progression.

REGISTRATION

PROSPERO CRD42022374418.

Relationship of serum copper and zinc with kidney function and urinary albumin to creatinine ratio: Cross-sectional data from the NHANES 2011-2016

BACKGROUND & OBJECTIVE

Chronic kidney disease (CKD) is a common condition in worldwide with underlying causes. The role of trace elements such as copper and zinc in CKD is uncertain. We aimed to examine the relationship of serum copper and zinc with kidney function status and explore its possible effect modifiers in the general population.

METHODS

Data from 5353 National Health and Nutrition Examination Survey (NHANES) participants from 2011 to 2016 were analyzed for the role of trace elements in the age range 18 to 80 years. The kidney outcomes were reduced estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 and increased urinary albumin-to-creatinine ratio (ACR) ≥ 30 mg/g.

RESULTS

Findings showed a significant positive association between serum copper and urinary ACR (OR = 1.04, 95% CI = 1.00-1.07). Serum copper levels of 18.0 μmol/L (median) or higher (reference level <18.0 μmol/L) were significantly associated with increased urinary ACR (OR = 1.67, 95% CI = 1.21-2.31) after adjusting for confounding factors. In contrast, there was a significant inverse association between serum zinc and reduced eGFR (OR = 0.89,95% CI = 0.81-0.99). Where serum zinc level was greater than 12.3 μmol/L (median), the prevalence of reduced eGFR was lower (OR = 0.65, 95% CI = 0.16-0.60). In addition, a stratified analysis based on various risk factors found that in those individuals with serum albumin greater than 43 g/L or systolic blood pressure greater than 120 mmHg, positive correlations between serum copper and risk of increased urinary ACR was more significant.

CONCLUSIONS

Our findings suggest that the reference levels of serum copper and zinc levels in healthy individuals may be different from current understanding. If further studies substantiate the same, the results will be a useful guide for designing future clinical trials and nutritional guidelines.

New Possibilities in Quantitative Assessment of Albuminuria in Patients with Atrial Fibrillation and Chronic Kidney Disease

Aim. To evaluate the relationship between albumin to creatinine ratio (ACR) in a single and 24-hours urine spots and chronic kidney disease (CKD) progression pace in patients with atrial fibrillation, CKD and diabetes mellitus.

Material and methods. 60 patients with atrial fibrillation (AF) and CKD were enrolled, study duration was 15 months. The patients were divided into two groups depending on the presence of DM. Total number of ACR tests was 170, dynamics of CKD progression was estimated with CKD-EPI formula for first visit and 15th month’s follow-up.

Results. The median score of CHA2DS2VASс scale was 4 [3;5]. The risk of hemorrhagic complications in both groups was low (median score 1 [1;1]. There is a strong statistically significant correlation between ACR in a single and 24-hours urine spots (p<0.001). No significant changes in kidney function within 15 months were found (GFR 53 [46;59] ml/min/1.73 m2 vs 50.5 [45.63] ml/min/1.73 m2 for patients with diabetes mellitus [DM] [p=0.94] and GFR 52.5 [46.58] ml/min/1.73 m2 vs 50 [44.58] ml/min/1.73 m2 for patients without DM [p=0.711]). When comparing the renal function of patients with and without DM after 15 months statistically significant differences were also not found (p = 0.510).

Conclusion. In respect that assessment of single sample ACR is much more practical and reliable, this method might replace traditional 24-hours urine assessment in future. However, due to the small sample size and the presence of wide discrepancies in individual cases, which can be associated with preanalytical errors in urine collection, large randomized clinical trials are needed to confirm the obtained data.

Monitoring Immune Responses in IgA Nephropathy: Biomarkers to Guide Management

IgA nephropathy (IgAN) is the commonest biopsy-reported primary glomerulonephritis worldwide. It has an incidence which peaks among young adults, and 30 to 40% of patients' progress to end stage kidney disease within twenty years of diagnosis. Ten-year kidney survival rates have been reported to be as low as 35% in some parts of the world. The successful management of IgAN is limited by an incomplete understanding of the pathophysiology of IgAN and a poor understanding of how pathophysiology may vary both from patient to patient and between patient groups, particularly across races. This is compounded by a lack of rigorously designed and delivered clinical trials in IgAN. This is slowly changing, with a number of Phase 2 and 3 clinical trials of novel therapies targeting a number of different putative pathogenic pathways in IgAN due to report in the next 5 years. From our current, albeit limited, understanding of the pathophysiology of IgAN it is unlikely a single therapy will be effective in all patients with IgAN. The successful management of IgAN in the future is, therefore, likely to be reliant on targeted therapies, carefully selected based on an individualized understanding of a patient's risk of progression and underlying pathophysiology. The potential role of biomarkers to facilitate personalization of prognostication and treatment of IgAN is immense. Here we review the progress made over the past decade in identifying and validating new biomarkers, with a particular focus on those that reflect immunological responses in IgAN.

Spot urine protein/creatinine ratio as a reliable estimate of 24-hour proteinuria in patients with immunoglobulin A nephropathy, but not membranous nephropathy

BACKGROUND

Proteinuria is known to be associated with both kidney function deterioration and cardiovascular diseases. While proteinuria estimation from 24-h urine samples has traditionally been considered as the standard method for assessment of the degree of urinary protein excretion, sample collection is associated with several technical problems such as inaccurate collection and the potential spread of drug-resistant pathogens. Therefore, the spot urine protein/creatinine ratio (PCR) assessment is currently recommended as an alternative. While the utility of PCR has been validated, studies on the association between spot urine PCR and 24-h proteinuria (24HP) in patients with chronic glomerular nephritis (CGN) and nephrotic syndrome (NS) are limited. This study aimed to evaluate whether an estimated result from a spot urine PCR could sufficiently approximate the daily urine protein excretion amount from a 24-h urine sample in patients with immunoglobulin A nephropathy (IgAN), minimal change disease (MCD), and membranous nephropathy- nephrotic syndrome (MN-NS).

METHODS

The study participants included 161 patients with IgAN, MCD, or MGN-NS at the Jikei University Kashiwa Hospital and Kanagawa Prefecture Shiomidai Hospital. The correlation between spot urine PCR and a 24-h urine protein was investigated using linear regression analysis with Spearman's correlation (r) coefficient and intraclass correlation coefficient (ICC).

RESULTS

While high correlation coefficients (r = 0.86, P < 0.001) and substantial agreement (ICC: 0.806, P < 0.001) were observed in patients with IgAN, similar correlations were not observed in patients with MCD or MN-NS. In the patients with MCD, r was 0.53 (P < 0.001), which signified a slight correlation, and in the patients with MN-NS, r was 0.289 (P = 0.17), which was not statistically significant.

CONCLUSIONS

This study revealed that spot urine PCR is a reliable estimate of 24HP value in patients with IgAN. In contrast, there is a considerable difference between the daily urine protein excretion amount based on a 24-h urine sample and that which is calculated from spot urine PCR in patients with NS.

Correlation of the severity of chronic kidney disease with serum inflammation, osteoporosis and vitamin D deficiency

Correlation of the severity of chronic kidney disease (CKD) with serum inflammation, osteoporosis and vitamin D deficiency was investigated. A total of 78 patients suffering from CKD who presented to the Union Hospital from December 2015 to December 2017 were selected randomly and divided into three groups based on the severity of the disease. Comparisons of interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), indicators of osteoporosis [serum phosphate, serum calcium and bone mineral density (BMD)], content of 25(OH)D, serum sodium, serum potassium and BUN were conducted among groups. The correlation of in vivo creatinine (Cr) with C-reactive protein (CRP), TNF-α, BMD and vitamin D deficiency were analyzed. With the aggravation of illness, IL-6, CRP, TNF-α, serum phosphate, serum sodium, serum potassium and blood urea nitrogen (BUN) were increased gradually, while serum calcium, BMD and vitamin D were decreased significantly (P<0.05). The content of Cr in patients suffering from osteoporosis was significantly higher than that in normal group (P<0.05). The Cr of patients in the group with abnormal CRP was significantly higher than that with normal CRP (P<0.05). Analysis showed that there is positive correlation between Cr and CRP (r=0.6961, P<0.001), as well as between Cr and TNF-α (r=0.8969, P<0.001); and negative correlation between Cr and BMD (r=0.5472, P<0.001), and between Cr and 25(OH)D (r=0.4733, P<0.001). The severity of CKD is correlated with serum inflammation, osteoporosis and vitamin D deficiency. The higher the severity of the illness, the worse the condition of osteoporosis will be.

Curvature facilitates podocyte culture in a biomimetic platform

Most kidney diseases begin with abnormalities in glomerular podocytes, motivating the need for podocyte models to study pathophysiological mechanisms and new treatment options. However, podocytes cultured in vitro face a limited ability to maintain appreciable extents of differentiation hallmarks, raising concerns over the relevance of study results. Many key properties such as nephrin expression and morphology reach plateaus that are far from the in vivo levels. Here, we demonstrate that a biomimetic topography, consisting of microhemispheres arrayed over the cell culture substrate, promotes podocyte differentiation in vitro. We define new methods for fabricating microscale curvature on various substrates, including a thin porous membrane. By growing podocytes on our topographic substrates, we found that these biophysical cues augmented nephrin gene expression, supported full-size nephrin protein expression, encouraged structural arrangement of F-actin and nephrin within the cell, and promoted process formation and even interdigitation compared to the flat substrates. Furthermore, the topography facilitated nephrin localization on curved structures while nuclei lay in the valleys between them. The improved differentiation was also evidenced by tracking barrier function to albumin over time using our custom topomembranes. Overall, our work presents accessible methods for incorporating microcurvature on various common substrates, and demonstrates the importance of biophysical stimulation in supporting higher-fidelity podocyte cultivation in vitro.

Diagnostic and prognostic value of galectin-3, serum creatinine, and cystatin C in chronic kidney diseases

OBJECTIVES

This study was undertaken to determine the diagnostic and prognostic values of galectin-3 (Gal-3) in patients with chronic kidney disease (CKD).

METHODS

Patients with CKD (n=150) were enrolled as the CKD group, which was divided into six groups according to glomerular filtration rates (GFR) indexes. At the same time, 50 healthy adults were chosen for the control group (NC). Measured data included the levels of serum Gal-3, serum creatinine (SCr), β₂ -microglobulin (β₂ -MG), 24-hour urinary protein, cystatin C (CysC), serum albumin (Alb) and other related indicators.

RESULTS

There was no significant difference between CKD and NC group in age, gender and the level of Alb. CKD group had lower estimated glomerular filtration rate (eGFR) but higher Gal-3, CysC, SCr, β₂ MG and 24-hour urinary protein excretion than control group (P<.001). Moreover, the receiver operating characteristic (ROC) analysis of Gal-3, CysC and SCr revealed that the corresponding areas under the curve (AUC) were 0.89, 0.83 and 0.85, respectively, and the AUC value of joint ROC curve of Gal-3, CysC and SCr was 0.96. In addition, the 6-year kidney survival rates of low Gal-3 group and high Gal-3 group were 47.3% and 22.8% respectively (HR=2.65; P<.01).

CONCLUSIONS

Our study verified Gal-3, CysC and SCr were negatively related to eGFR. Besides, it is suggested that Gal-3 can be used as an indicating factor in the diagnosis of CKD; the joint analysis of Gal-3, CysC and SCr for CKD may distinctly improve diagnostic accuracy.