Circulating inflammation-related factors are correlated with systemic redox status in IgA nephropathy; a case-control study

The nuclear factor kappa B signaling pathway is a master regulator of renal fibrosis

Renal fibrosis is increasingly recognized as a global public health problem. Acute kidney injury (AKI) and chronic kidney disease (CKD) both result in renal fibrosis. Oxidative stress and inflammation play central roles in progressive renal fibrosis. Oxidative stress and inflammation are closely linked and form a vicious cycle in which oxidative stress induces inflammation through various molecular mechanisms. Ample evidence has indicated that a hyperactive nuclear factor kappa B (NF-ƙB) signaling pathway plays a pivotal role in renal fibrosis. Hyperactive NF-ƙB causes the activation and recruitment of immune cells. Inflammation, in turn, triggers oxidative stress through the production of reactive oxygen species and nitrogen species by activating leukocytes and resident cells. These events mediate organ injury through apoptosis, necrosis, and fibrosis. Therefore, developing a strategy to target the NF-ƙB signaling pathway is important for the effective treatment of renal fibrosis. This Review summarizes the effect of the NF-ƙB signaling pathway on renal fibrosis in the context of AKI and CKD (immunoglobulin A nephropathy, membranous nephropathy, diabetic nephropathy, hypertensive nephropathy, and kidney transplantation). Therapies targeting the NF-ƙB signaling pathway, including natural products, are also discussed. In addition, NF-ƙB-dependent non-coding RNAs are involved in renal inflammation and fibrosis and are crucial targets in the development of effective treatments for kidney disease. This Review provides a clear pathophysiological rationale and specific concept-driven therapeutic strategy for the treatment of renal fibrosis by targeting the NF-ƙB signaling pathway.

Effects and mechanisms of Chinese herbal medicine on IgA nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN), is the main cause of end-stage renal disease, that causes serious physical and psychological burden to patients worldwide. Some traditional treatment measures, such as blocking the renin-angiotensin-aldosterone system, controlling blood pressure, and following a low-protein diet, may not achieve satisfactory results. Therefore, more effective and safe therapies for IgAN are urgently needed.

PURPOSE

The aim of this review is to summarize the clinical efficacy of Chinese herbal medicines (CHMs) and their active ingredients in the treatment and management of IgAN based on the results of clinical trials, systematic reviews, and meta-analyses, to fully understand the advantages and perspectives of CHMs in the treatment of IgAN.

STUDY DESIGN AND METHODS

For this review, the following electronic databases were consulted: PubMed, ResearchGate, Science Direct, Web of Science, Chinese National Knowledge Infrastructure and Wanfang Data, "IgA nephropathy," "traditional Chinese medicine," "Chinese herbal medicine," "herb," "mechanism," "Meta-analysis," "systematic review," "RCT" and their combinations were the keywords to search the relevant literature. Data were collected from 1990 to 2022.

RESULTS

This review found that the active ingredients of CHMs commonly act on multiple signaling pathways in the clinical treatment of IgAN, mainly with antioxidant, anti-inflammatory and anti-fibrosis effects, and regulation of autophagy.

CONCLUSION

Compared with the single-target therapy of modern medicine, CHMs can regulate the corresponding pathways from the aspects of anti-inflammation, anti-oxidation, anti-fibrosis and autophagy to play a multi-target treatment of IgAN through syndrome differentiation and treatment, which has good clinical efficacy and can be used as the first choice or alternative therapy for IgAN treatment. This review provides evidence and research direction for a comprehensive clinical understanding of the protective effect of Chinese herbal medicine on IgAN.

Association between geriatric nutritional risk index and pathological phenotypes of IgA nephropathy

Background

IgA nephropathy (IgAN) is an immune disease related to oxidative stress and inflammation. It is the most common type of glomerulonephritis in the world and is the cause of chronic kidney disease and end-stage renal disease (ESRD). The Geriatric Nutritional Risk Index (GNRI) is a practical and uncomplicated method to assess the risk of morbidity and mortality, but its ability to assess IgAN is still unclear. Here, we evaluated the association between the GNRI and clinical and histologic findings of IgAN.

Methods

In a cross-sectional study, we included 348 biopsy-verified IgAN patients. The Oxford classification was used to analyze the pathological characteristics of the included patients. Based on previous studies, the participants were divided into two groups using a cutoff value of 92. Differences in clinicopathological indices between the two groups were compared. The correlation between the GNRI and the indicators was evaluated by using a bivariate correlation analysis. A binary logistic regression analysis was conducted to determine the factors associated with the crescent lesions in IgAN.

Results

In this study, 138 out of 348 patients (39.7%) had low GNRI scores (GNRI < 92). Patients in the low GNRI group tended to have a significantly lower body mass index; lower hemoglobin, serum albumin, serum IgG, and serum C3 levels; and higher 24-h proteinuria. The proportions of females, Oxford M1 and Oxford C1/2 were higher in the low GNRI group. The GNRI was positively correlated with body mass index (r = 0.57, P < 0.001), hemoglobin (r = 0.35, P < 0.001), serum albumin (r = 0.83, P < 0.001), serum IgG (r = 0.32, P < 0.001), and serum C3 (r = 0.26, P < 0.001) and negatively correlated with 24-h proteinuria (r = -0.36, P < 0.001) and the proportion of crescents (r = -0.24, P < 0.001). The GNRI scores and serum IgG levels were considered independent factors influencing the crescent lesions in IgAN.

Conclusions

The GNRI can reflect the severity of clinical and histologic phenotypes in IgAN patients. Lower GNRI and serum IgG levels may suggest an increased risk of crescent lesions and are potential markers for disease monitoring in IgAN.

A Rare Case of Superior Vena Cava Syndrome in a Patient With Rheumatoid Arthritis and IgA Nephropathy

Superior vena cava syndrome (SVCS) is a vascular condition resulting from an impaired venous return to the right atrium. The majority of SVCS cases are caused by mass effect in which extrinsic compression of the vessel leads to obstruction of blood flow. In less common cases of SVCS, thrombus formation and luminal narrowing can result in poor return through the SVC. Inflammatory causes of SVCS are even rarer and poorly documented. IgA nephropathy and rheumatoid arthritis (RA) are two autoimmune diseases with the potential to cause vasculitis, thus increasing the likelihood of intraluminal vessel occlusion. We report a rare case of SVCS in a 65-year-old female with a past medical history significant for atrial fibrillation, IgA nephropathy, chronic kidney disease stage IIIA, and RA who presented with headache, dizziness, and neck pain and swelling extending down the left upper extremity for three days. Inflammatory SVCS is uncommon and cases of SVCS secondary to RA and IgA nephropathy are underreported in the literature thus far. Our hope in presenting this case is to encourage a greater degree of suspicion for vascular complications, such as SVCS, in patients with autoimmune and inflammatory conditions.

Association of redox and inflammation-related biomarkers with prognosis in IgA nephropathy: A prospective observational study

BACKGROUND

IgA nephropathy (IGAN) has a variable prognosis. Risk stratification tools are usually based on clinical parameters combined with histologic Oxford-MEST-C score. Circulating redox- and inflammation-related biomarkers may be related to histological changes in IGAN. Therefore, we studied the performance of these biomarkers in predicting the rate of GFR-loss in IGAN.

METHODS

This was an observational prospective study. Fifty-seven stable patients with IGAN were examined at baseline and after a mean observational time of 5.9 ± 1.1 years. The main outcome measure was eGFR-loss per year with predefined groups, stable (<1.5 ml/min/1,73 m²/year, intermediate (between 1.5 and 2.5), and progressive (>2.5).

RESULTS

Fifteen patients were in the progressive, 11 in the intermediate, and 31 in the stable groups. Positive relationships were detected between eGFR-loss per year and baseline nitrate, oxidized free cysteine, parathyroid hormone, APRIL, TNFR1, CD30, chitinase 3, and LIF-5. The progressive group had elevated concentrations of these markers plus AOPP and osteopontin. Through ROC analysis, it was observed that AOPP, oxidized free cysteine, TNFR1, osteopontin, and LIF-5 had the best ability to identify progressive vs. non-progressive diseases. The combination of urinary albumin/creatinine ratio with AOPP and TNFR1 significantly improved the ability to identify progressive eGFR decline with ROC AUC 95% (adjusted 85%).

CONCLUSIONS

We found prognostic biomarkers related to the rate of eGFR-loss in IGAN. These biomarkers may help identify patients at risk of progressive disease. AOPP, oxidized free cysteine, TNFR1, and osteopontin are promising prognostic biomarkers in IGAN, however, further validation studies are needed.

Targeting Enrichment and Correlation Studies of Glutathione and Homocysteine in IgAVN Patient Urine Based on a Core-Shell Zr-Based Metal-Organic Framework

Aminothiols are closely related to chronic kidney disease, but little is known regarding levels of related aminothiols in the urine of immunoglobulin A vasculitis with nephritis (IgAVN) patients. Herein, a well-defined core-shell Zr-based metal-organic framework (Zr-MOF) composite SiO₂@50Benz-Cys was constructed as a mercury ion affinity material via a solvent-assisted ligand exchange strategy for the selective extraction and enrichment of low-concentration aminothiols in IgAVN patient urine. SiO₂@50Benz-Cys was competent to enrich the total glutathione (GSH) and total homocysteine (Hcy) in virtue of the excellent affinity after chelation with mercury ions. The extraction efficiencies were closely related to the pH, dithiothreitol amount, and the dose of functional Zr-MOF. Coupled with HPLC-MS/MS in optimized conditions, GSH and Hcy were determined with low detection limits of 0.5 and 1 nmol L^-1, respectively. The recoveries of GSH and Hcy for the urine sample at three spiked levels were in the range of 85.3-105% and 79.5-103%, which showed good precision and accuracy. Benefiting from the matrix interference elimination in the process of extraction, the simultaneous detection of aminothiols in the urine of the healthy group and immunoglobulin A vasculitis (IgAV) and IgAVN patients was successfully carried out, suggesting that the Zr-MOF and the robust method together provided a potential application in the analysis of urinary biomolecules. The analysis of variance (ANOVA) showed that the levels of GSH and Hcy had significant differences between the patients and the control. This work is very valuable as it provides a better understanding of concentration alterations of GSH and Hcy in urine involved with IgAVN for clinical research.

Lower serum bilirubin is associated with poor renal outcome in IgA nephropathy patients

Aims: IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis worldwide. We conducted this study to explore the relationship between serum bilirubin and renal outcome of patients with IgAN. Methods: A total of 1492 biopsy proven IgAN patients were recruited and divided into two groups according to their median serum bilirubin concentration: the low bilirubin group (serum bilirubin≤9.7umol/L, n=753) and high bilirubin group (serum bilirubin>9.7umol/L, n=739). Basic clinical characteristics were assessed at the time of renal biopsy and the relationships between serum bilirubin and the combined endpoints were analyzed. The combined endpoints were defined as a 50% decline in estimate glomerular filtration rate (e-GFR), end-stage kidney disease (ESKD), renal transplantation and/or death. In addition, propensity score matching (PSM) was then performed to improve balance and simulate randomization between patients in different groups. Kaplan-Meier survival analysis was applied to explore the role of serum bilirubin in the progression of IgAN. Three clinicopathological models of multivariate Cox regression analysis were established to evaluate the association of serum bilirubin and renal prognosis of IgAN. Results: During median 5-year follow-up period, significant differences were shown in Kaplan-Meier analysis. In the unmatched group, 189 (12.7%) patients progressed to the renal combined endpoints. Among this, 122 in 753 patients (16.2%) were in low bilirubin group and 67 in 739 patients (9.1%) were in high bilirubin group (p<0.001). After PSM, there were 134 (11.8%) patients reached the combined endpoints, which included 77 in 566 patients (14.6%) in low bilirubin group and 57 in 566 patients (10.1%) in high bilirubin group (p=0.039). The results of three models (including demographics, pathological, clinical indicators and serum bilirubin) demonstrated that a lower basic serum bilirubin level was significantly associated with a higher risk of reaching combined endpoints in IgAN patients both in unmatched and matched cohort. Conclusion: Serum bilirubin level may be negatively associated with the progression of IgAN.