Inflammation In Kidney Disease Research Articles

PAR2-mediated cellular senescence promotes inflammation and fibrosis in aging and chronic kidney disease.

Cellular senescence contributes to inflammatory kidney disease via the secretion of inflammatory and profibrotic factors. Protease-activating receptor 2 (PAR2) is a key regulator of inflammation in kidney diseases. However, the relationship between PAR2 and cellular senescence in kidney disease has not yet been described. In this study, we found that PAR2-mediated metabolic changes in renal tubular epithelial cells induced cellular senescence and increased inflammatory responses. Using an aging and renal injury model, PAR2 expression was shown to be associated with cellular senescence. Under invitro conditions in NRK52E cells, PAR2 activation induces tubular epithelial cell senescence and senescent cells showed defective fatty acid oxidation (FAO). Cpt1α inhibition showed similar senescent phenotype in the cells, implicating the important role of defective FAO in senescence. Finally, we subjected mice lacking PAR2 to aging and renal injury. PAR2-deficient kidneys are protected from adenine- and cisplatin-induced renal fibrosis and injury, respectively, by reducing senescence and inflammation. Moreover, kidneys lacking PAR2 exhibited reduced numbers of senescent cells and inflammation during aging. These findings offer fresh insights into the mechanisms underlying renal senescence and indicate that targeting PAR2 or FAO may be a promising therapeutic approach for managing kidney injury.

Macrophage subpopulations in pediatric patients with lupus nephritis and other inflammatory diseases affecting the kidney

BackgroundMacrophages play an important role in the pathogenesis of lupus nephritis (LN), but less is known about macrophage subtypes in pediatric LN. Here we compared renal inflammation in LN with other inflammatory pediatric kidney diseases and assessed whether inflammation correlates with clinical parameters.MethodsUsing immunofluorescence microscopy, we analyzed renal biopsies from 20 pediatric patients with lupus nephritis (ISN/RPS classes II–V) and pediatric controls with other inflammatory kidney diseases for infiltration with M1-like (CD68 + /CD206 − , CD68 + /CD163 −), M2a-like (CD206 + /CD68 +), and M2c-like macrophages (CD163 + /CD68 +) as well as CD3 + T-cells, CD20 + B-cells, and MPO + neutrophilic granulocytes. In addition, the correlation of macrophage infiltration with clinical parameters at the time of renal biopsy, e.g., eGFR and serum urea, was investigated. Macrophage subpopulations were compared with data from a former study of adult LN patients.ResultsThe frequency of different macrophage subtypes in biopsies of pediatric LN was dependent on ISN/RPS class and showed the most pronounced M1-like macrophage infiltration in patients with LN class IV, whereas M2c-like macrophages were most abundant in class III and IV. Interestingly, on average, only half as many macrophages were found in renal biopsies of pediatric LN compared to adult patients with LN. The distribution of frequencies of macrophage subpopulations, however, was different for CD68 + CD206 + (M2a-like) but comparable for CD68 + CD163 − (M1-like) CD68 + CD163 + (M2c-like) cells in pediatric and adult patients. Compared to other inflammatory kidney diseases in children, fewer macrophages and other inflammatory cells were found in kidney biopsies of LN. Depending on the disease, the frequency of individual immune cell types varied, but we were unable to confirm disease-specific inflammatory signatures in our study due to the small number of pediatric cases. Worsened renal function, measured as elevated serum urea and decreased eGFR, correlated particularly strongly with the number of CD68 + /CD163 − M1-like macrophages and CD20 + B cells in pediatric inflammatory kidney disease.ConclusionAlthough M1-like macrophages play a greater role in pediatric LN patients than in adult LN patients, M2-like macrophages appear to be key players and are more abundant in other pediatric inflammatory kidney diseases compared to LN.

Association between dietary inflammatory index and chronic kidney disease in middle-aged and elderly populations.

A link between food-induced inflammation and common chronic diseases has been identified in studies. However, there was uncertainty about the influence of dietary inflammatory potential on the risk of chronic kidney disease (CKD) among middle-aged and older groups. Our research aimed to examine the connection between dietary inflammatory index (DII) to CKD in people aged 40 years and older. This study comprised ten cycles of the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Linear associations of DII with CKD, low-eGFR, and albuminuria were examined using multiple logistic regression, whereas non-linear associations were assessed by smoothed curve fitting. Besides, we conducted subgroup analyses and interaction tests. Of the 23,175 middle-aged and older individuals, a total of 5,847 suffered from CKD, making up 25.23% of all participants. After adjustment for all covariates, we found that increased DII scores were positive with an increased hazard of CKD (OR = 1.08, 95% CI: 1.05, 1.10, p < 0.0001), and the same was shown between DII and low-eGFR (OR = 1.16, 95% CI: 1.13, 1.19, p < 0.0001). After further converting DII into categorical variables, the above relationship still existed. These relations were consistent in different ages, genders, BMI, whether smoking, whether suffering from hypertension, and whether suffering from diabetes, with no significant stratification differences (all P for interaction >0.05). Surprisingly, we did not find a statistically significant correlation of DII to albuminuria after complete adjustment for covariates (OR = 1.02, 95% CI: 1.00, 1.05, p = 0.0742). Even when DII was considered as a categorical variable, this relation was still not statistically significant. Furthermore, we found an association in the shape of a U between DII and low-eGFR in the fully adjusted model, with a turning point at a DII of 1.6. Our findings indicated that middle-aged and older persons with greater levels of DII had a significantly higher risk of CKD.

State-of-the-art trends in the treatment of immune-mediated inflammatory kidney diseases: Translation of the fundamental science into clinical practice. A review

Immune-mediated kidney diseases like glomerulonephritis and tubulointerstitial nephritis are not the most common cause of chronic kidney disease in the population, however the difficulties in their management, as well as a more rapid deterioration of kidney function, compared to diabetes mellitus and hypertension, justify the importance of this problem for internal medicine. Due to the fundamental discoveries in pathology and to the introduction of various methods of laboratory and instrumental investigation in the second half of the XX century substantial progress was made in the diagnostic approaches and treatment of these conditions. State-of-the-art diagnostic approach requires complex evaluation of the clinical, laboratory and morphological data to identify the nosological form of the disease. The accumulation of knowledge in the field of diseases' pathogenesis led to the revision of the current classification of glomerulonephritis that should be based on the immunopathogenesis of these conditions. The following phenotypes were suggested: autoimmunity-related, autoinflammation-related, alloimmunity-related, infections-related, and monoclonal gammopathy-related. The assessment of disease activity and chronicity in the kidney tissue should be mandatory. Personalized selection of the optimal treatment modality on the basis of the diagnosis, severity, and individual features of the patient is currently possible. The leading trends include rational prescription of glucocorticoids (steroid-sparing regimens) and cytotoxic agents, e.g. cyclophosphamide, as well as the introduction of multitarget regimens that include biologic agents or small molecules selectively suppressing B-cells or various complement pathways. Another mandatory component of treatment on par with immune suppression is nephroprotective therapy, which currently comprises not only traditional renin-angiotensin-aldosterone antagonists, but also endothelin receptor antagonists and sodium-glucose cotransporter-2 inhibitors. Current guidelines emphasize the importance of the non-pharmacological interventions for the implementation of the nephroprotective strategy. Rational combination of the aforementioned approaches allows for the optimization of the management of patients with immune-mediated kidney diseases, although it requires high competencies and strict adherence to the principles of the evidence-based medicine from the healthcare providers.

Inflammatory Status and Chronic Kidney Disease in Cats: Old and New Inflammatory Markers—A Pilot Prospective Study

This prospective study aimed to evaluate inflammatory status in cats affected by chronic kidney disease (CKD) at IRIS stages 2–4, using serum amyloid A (SAA) and the erythrocyte sedimentation rate (ESR) as inflammatory markers. Thirty-two cats with CKD and ten clinically healthy cats (i.e., control group) were enrolled. The recording of signalment data, complete physical examinations, and abdominal ultrasonography were performed for each animal. Additionally, ESR levels, complete blood count, clinical chemistry (including SAA determination), serum protein electrophoresis, and complete urinalysis were executed. This study’s results showed that mean ESR and SAA concentrations in cats with CKD were statistically higher compared to those of the control group (p = 0.0005 and p = 0.007, respectively). The SAA concentration was significantly increased at IRIS stages 2, 3, and 4 compared to the control group. Meanwhile, the ESR was significantly higher in cats at IRIS stages 3 and 4 (p = 0.0003 and p = 0.0007, respectively), but not at IRIS stage 2, compared to the control group. These results provide evidence that feline CKD is associated with a systemic inflammatory status. Moreover, the rise in ESR appears to be more linked to advanced stages of the disease and could, therefore, correlate with the uremic condition.

The immunoregulatory roles of non-haematopoietic cells in the kidney.

The deposition of immune complexes, activation of complement and infiltration of the kidney by cells of the adaptive and innate immune systems have long been considered responsible for the induction of kidney damage in autoimmune, alloimmune and other inflammatory kidney diseases. However, emerging findings have highlighted the contribution of resident immune cells and of immune molecules expressed by kidney-resident parenchymal cells to disease processes. Several types of kidney parenchymal cells seem to express a variety of immune molecules with a distinct topographic distribution, which may reflect the exposure of these cells to different pathogenic threats or microenvironments. A growing body of literature suggests that these cells can stimulate the infiltration of immune cells that provide protection against infections or contribute to inflammation - a process that is also regulated by draining kidney lymph nodes. Moreover, components of the immune system, such as autoantibodies, cytokines and immune cells, can influence the metabolic profile of kidney parenchymal cells in the kidney, highlighting the importance of crosstalk in pathogenic processes. The development of targeted nanomedicine approaches that modulate the immune response or control inflammation and damage directly within the kidney has the potential to eliminate the need for systemically acting drugs.

Abstract 16389: Inflammatory Chronic Kidney Disease is Associated With Incident Heart Failure: A Pooled Cohort Analysis

Introduction: High sensitivity C-reactive protein (hsCRP), a biomarker of inflammation, can risk stratify patients for cardiovascular disease including heart failure (HF). It is not well established if inflammation increases the risk of HF in patients with chronic kidney disease (CKD) and if hsCRP can be utilized to risk stratify patients with CKD for their risk of incident HF. Aims: We assessed the role of hsCRP in risk stratifying patients with CKD for incident HF. Methods: We studied participants of 3 major epidemiologic cohorts: Atherosclerosis Risk in Communities Study, Multi-Ethnic Study of Atherosclerosis, and Jackson Heart Study. High inflammation was classified as hsCRP &gt;3 mg/L and CKD was classified as estimated glomerular filtration rate &lt;60 mL/min/1.73m2. Participants were stratified into 3 groups: neither CKD nor high inflammation, CKD without high inflammation, or CKD with high inflammation. Cox hazards models adjusted for age, sex, race, body mass index, smoking, alcohol use, diabetes, hypertension, and coronary disease were utilized for analysis. Results: 8,692 participants with 460 incident HF events followed over a median 8.32 years were included in our analysis. Participants with CKD without high inflammation (HR = 1.45; 95% CI 1.14 to 1.85) and CKD with high inflammation (2.05; 1.61 to 2.61) were associated with an increased risk of incident HF compared with participants without CKD or high inflammation (referent, Figure). Furthermore, participants with CKD and a hsCRP &gt;3 mg/L had an increased risk of incident HF (1.41; 1.06 to 1.88) compared with participants with CKD but hsCRP ≤3 mg/L (referent). Conclusions: Patients with CKD and high levels of inflammation carry a 2-fold increased risk of incident HF. In patients with CKD, hsCRP levels &gt;3mg/L may be useful to risk stratify patients with increased risk of developing HF.

Features of pyelonephritis course in adolescent females with co-existing anаemic syndrome

Background. Anaemic syndrome of complex origin is not uncommon in urinary tract infection, particularly in dietary non-adherence, menstrual cycle disorders, or concomitant digestive diseases, recurrent respiratory infections, etc. However, there is currently insufficient epidemiological data on this comorbidity in the literature. This study aims to establish the features of pyelonephritis course in its combination with anaemic syndrome in children. Materials and methods. We analysed the medical records of 200 children aged 0 to 17 years with acute non-complicated pyelonephritis, complicated and recurrent urinary tract infections for 2012–2017. In the second stage of our work, we comprehensively examined 85 girls aged 11 to 17 who underwent inpatient treatment between 2018 and March 2023. Thirty children of the same age and gender made up the comparison group. A paediatric gastroenterologist, a paediatric gynaecologist and/or urologist examined all patients. Immunochemical method with electrochemiluminescence immunoassay was used to assess ferritin content; also, serum iron and total iron-binding capacity were measured. Results. Anaemic syndrome is common in most girls with urinary tract infections (58.8 % of сases). Among the causes, the follo­wing are distinguished: menstrual cycle disorders with abnormal uterine bleeding (50.0 %), chronic digestive disorders, in particular malabsorption syndrome of unknown origin (25.0 %), recurrent bronchopulmonary disorders (15.0 %), and unbalanced diet (10.0 %). The features of urinary tract infections and concomitant iron deficiency in children include fatigue (55.0 % in acute non-complicated pyelonephritis vs. 40.0 % in complicated urinary tract infections, р &lt; 0.05), dizziness (35.0 % in acute non-complica­ted pyelonephritis vs. 15.0 % in recurrent urinary tract infections, χ2 = 48.6532, р &lt; 0.05), and pallor (25.0 % in complicated urinary tract infections vs. 10 % in recurrent urinary tract infections, χ2 = 0.7168, р &gt; 0.05). The ferritin level was the highest in patients with complicated urinary tract infections (18.2 µg/mL). In patients with recurrent urinary tract infections, this indicator was the lo­west — 5.0 µg/mL. Conclusions. Retrospective analysis of medical records confirmed the presence of anaemia in 30.0 % of girls with inflammatory kidney diseases. During the physical examination, 58.8 % of female adolescents with urinary tract infections had signs of anaemic syndrome.

Association between inflammatory bowel disease, nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease: A propensity score-matched analysis of US nationwide inpatient sample 2016-2018.

The incidence and prevalence of inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn's disease (CD), are increasing globally. We aimed to evaluate the potential association between IBD and nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease (CKD). Data of hospitalized adults ≥20 years of age were extracted from the U.S. National Inpatient Sample (NIS) during 2016-2018. Patients with UC, CD, or CKD were identified through the International Classification of Diseases, Tenth Revision (ICD-10) codes. Propensity score matching (PSM) analysis (1:1) was conducted to balance the characteristics between groups. Logistic regression analyses were performed to determine the relationships between UC or CD and kidney conditions. Three cohorts were included for analysis after PSM analysis. Cohorts 1, 2 and 3 contained 235 262 subjects (117 631 with CD or without IBD), 140 856 subjects (70 428 with UC or without IBD), and 139 098 subjects (69 549 with CD or UC), respectively. Multivariate analysis revealed that compared to non-IBD individuals, CD patients were significantly associated with greater odds for nephrolithiasis (adjusted odds ratio [aOR] 2.25, 95% confidence interval [CI] 2.08-2.43), tubulointerstitial nephritis (aOR 1.31, 95% CI 1.24-1.38), CKD at any stage (aOR 1.28, 95% CI 1.24-1.32), and moderate-to-severe CKD (aOR 1.22, 95% CI 1.17-1.26), while UC was associated with a higher rate of nephrolithiasis. Compared to UC, CD was associated with higher odds for all such kidney conditions. Patients with CD are more likely to have nephrolithiasis, tubulointerstitial nephritis, CKD at any stage, and moderate-to-severe CKD compared to non-IBD individuals.

Efficacy and Safety of Iptacopan in Patients With C3 Glomerulopathy

Complement 3 glomerulopathy (C3G) is a rare inflammatory kidney disease mediated by dysregulation of the alternative complement pathway. No targeted therapy exists for this aggressive glomerulonephritis. Efficacy, safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) (measured by complement biomarkers) of iptacopan were assessed in patients with C3G. In this phase 2, multicenter, open-label, single-arm, nonrandomized study, adults with biopsy-proven, native kidney C3G (native cohort) and kidney transplant recipients with C3G recurrence (recurrent kidney transplant [KT] cohort) received iptacopan twice daily (bid) for 84 days (days 1-21: 10-100 mg; days 22-84: 200 mg). The primary end point was the urine protein-to-creatinine ratio (UPCR; native cohort) and the change in the C3 deposit score of kidney biopsy (recurrent KT cohort). The complement pathway measures included Wieslab assay, soluble C5b9, and serum C3 levels. A total of 27 patients (16 native cohort and 11 recurrent KT cohort) were enrolled and all completed the study. In the native cohort, UPCR levels decreased by 45% from baseline to week 12 (P= 0.0003). In the recurrent KT cohort, the median C3 deposit score decreased by 2.50 (scale: 0-12) on day 84 versus baseline (P= 0.03). Serum C3 levels were normalized in most patients; complement hyperactivity observed pretreatment was reduced. Severe adverse events (AEs) included post-biopsy hematuria and hyperkalemia. No deaths occurred during the study. Iptacopan resulted in statistically significant and clinically important reductions in UPCR and normalization of serum C3 levels in the native cohort and reduced C3 deposit scores in the recurrent KT cohort with favorable safety and tolerability. (ClinicalTrials.gov identifier: NCT03832114).

Intravenous ferric carboxymaltose and ferric derisomaltose alter the intestinal microbiome in female iron-deficient anemic mice.

Iron deficiency anemia (IDA) is a leading global health concern affecting approximately 30% of the population. Treatment for IDA consists of replenishment of iron stores, either by oral or intravenous (IV) supplementation. There is a complex bidirectional interplay between the gut microbiota, the host's iron status, and dietary iron availability. Dietary iron deficiency and supplementation can influence the gut microbiome; however, the effect of IV iron on the gut microbiome is unknown. We studied how commonly used IV iron preparations, ferric carboxymaltose (FCM) and ferric derisomaltose (FDI), affected the gut microbiome in female iron-deficient anemic mice. At the phylum level, vehicle-treated mice showed an expansion in Verrucomicrobia, mostly because of the increased abundance of Akkermansia muciniphila, along with contraction in Firmicutes, resulting in a lower Firmicutes/Bacteroidetes ratio (indicator of dysbiosis). Treatment with either FCM or FDI restored the microbiome such that Firmicutes and Bacteroidetes were the dominant phyla. Interestingly, the phyla Proteobacteria and several members of Bacteroidetes (e.g., Alistipes) were expanded in mice treated with FCM compared with those treated with FDI. In contrast, several Clostridia class members were expanded in mice treated with FDI compared with FCM (e.g., Dorea spp., Eubacterium). Our data demonstrate that IV iron increases gut microbiome diversity independently of the iron preparation used; however, differences exist between FCM and FDI treatments. In conclusion, replenishing iron stores with IV iron preparations in clinical conditions, such as inflammatory bowel disease or chronic kidney disease, could affect gut microbiome composition and consequently contribute to an altered disease outcome.

State-of-the-art paradigm of corticosteroid therapy for immune-mediated inflammatory kidney diseases

Since 1950's corticosteroids (CS) have remained the cornerstone of immunosuppressive therapy for immune-mediated kidney diseases. However multiple adverse events, associated with the prolonged CS therapy, became the basis for the development of novel treatment approaches. Current evidence supports the implementation of the steroid-sparing regimens for the treatment of different types of glomerulonephritis. Randomised controlled trial PEXIVAS demonstrated the efficacy and safety of early steroid tapering, starting from the second week of therapy, in patients with ANCA-associated vasculitis with kidney involvement. Several trials showed the efficacy of oral prednisolone 0.3-0.5 mg/kg/daily as a part of multitarget therapy for severe proliferative lupus nephritis. A combination of calcineurin inhibitors and low-dose CS are effective for remission induction in membranous nephropathy, as well as the steroid-free rituximab regimen for the patients with moderate risk of disease progression. Medium dose CS showed promising effect in patients with IgA-nephropathy. Long-term high dose CS remain the standard-of-care for the treatment of minimal change disease and focal segmental glomerulosclerosis, however patients with steroid-dependent and relapsing disease tacrolimus and rituximab can help to achieve steroid-sparing effect. The role of CS pulse-therapy is currently debated, nevertheless it remains a compulsory treatment in several conditions. Thus, overall trend is directed towards the minimization of the maximal doses of CS and/or treatment duration. However, to implement this approach morphological verification of the diagnosis and personalized assessment of the potential risk and benefit are required.

Abstract B031: Effect of macrophage inflammatory response and VHL mutation status on the development of clear cell renal carcinoma

Abstract Kidney[A1] cancer is a serious health care issue problem around the worldworldwide. It is symptomless asymptomatic in the early stage and is refractory to most [A2] of the cancer treatment modalities. The most prevalent form of the kidney cancer, renal cell carcinoma of the clear-cell type (ccRCC), is mainly caused by loss-of-function of the von Hippel-Lindau tumor suppressor gene (VHL). VHL protein is an E3 ubiquitin ligase and. iIts most prominentmain degradation target is the alpha subunit of the hypoxia-inducible factor (HIF). However, the etiology of ccRCC formation development remains unclear. Recent animal model studies in our laboratory have indicatedWe recently observed that tissue inflammation and fibrosis are the early events in ccRCC development is tissue inflammation and fibrosis. This interesting result provides important supports for the concept notion that chronic inflammation is can induce tumorigenesisic and. It is also consistent with the epidemiological evidence linking inflammatory kidney disease and kidney cancer. In the current present study, we explored the mechanistic detailsm by which changes within the VHL mutant cells orchestrateeffect[A3] a systemic inflammatory response[A4], and found that the metabolic abnormalities caused by VHL gene mutation lead to unresolved chronic endoplasmic reticular stress (ER stress), which in turn induces activation of JNK and NFκB, two major components of pro-inflammatory signaling pathways components[A5]. On the other hand, our previous study also demonstrated that LCN2[A6] sensitizes the inflammatory response of VHL mutant HK-2 cells in vhl mutant condition and the chemotactic abilityies of macrophage RAW 264.7 cells. [A7] However, the wider implication of this tumorigenic process [A8] that of RAW 264.7 cells is stillremains unclear and then warrants further investigationswill be discussed. Accumulating evidence indicated that Lon protease (Lon) is a multifunctional protein that mediatesinvolved in protein quality control and oxidative stress responses in mitochondria. However, the molecular mechanisms underlying the effects of Lon on the progression of ccRCC progression and inflammatory response inof the vhl VHL mutant condition cells remain largely unknown. Therefore, in this study, we aimed to elucidate the inflammatory effect role of inflammatory RAW 264.7 macrophages on the development of ccRCC development inusing cultured vhl VHL mutant renal tubular cells and RAW264.7 cells. Moreover, d Decoding how the action involved signaling pathways drive or suppress signals cellular and inflammatory responses or preventing it is a major research challenge. Once elucidated, it will for future research and will require the definition ofprovide the rationale for drug design and application on anti-ccRCC formation therapeutic strategies based onvia targeting macrophages infiltration. Citation Format: Chan-Yen Kuo. Effect of macrophage inflammatory response and VHL mutation status on the development of clear cell renal carcinoma [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr B031.

Coelenterazine Indicators for the Specific Imaging of Human and Bovine Serum Albumins

Albumin assays in serum are important for the prognostic assessment of many life-threatening diseases, such as heart failure, liver disease, malnutrition, inflammatory bowel disease, infections, and kidney disease. In this study, synthetic coelenterazine (CTZ) indicators are developed to quantitatively illuminate human and bovine serum albumins (HSA and BSA) with high specificity. Their functional groups were chemically modified to specifically emit luminescence with HSA and BSA. The CTZ indicators were characterized by assaying the most abundant serum proteins and found that the CTZ indicators S6 and S6h were highly specific to HSA and BSA, respectively. Their colors were dramatically converted from blue, peaked at 480 nm, to yellowish green, peaked at 535 nm, according to the HSA–BSA mixing ratios, wherein the origins and mixing levels of the albumins can be easily determined by their colors and peak positions. The kinetic properties of HSA and BSA were investigated in detail, confirming that the serum albumins catalyze the CTZ indicators, which act as pseudo-luciferases. The catalytic reactions were efficiently inhibited by specific inhibitors, blocking the drug-binding sites I and II of HSA and BSA. Finally, the utility of the CTZ indicators was demonstrated through a quantitative imaging of the real fetal bovine serum (FBS). This study is the first example to show that the CTZ indicators specify HSA and BSA with different colors. This study contributes to the expansion of the toolbox of optical indicators, which efficiently assays serum proteins in physiological samples. Considering that these CTZ indicators immediately report quantitative optical signals with high specificity, they provide solutions to conventional technical hurdles on point-of-care assays of serum albumins.

#4476 PRIMARY GLOMERULAR DISEASES AND LONG-TERM RISKS OF CKD PROGRESSION, CARDIOVASCULAR EVENTS AND DEATH: A SWEDISH NATIONWIDE COHORT STUDY

Abstract Background and Aims Although glomerular diseases are the third most frequent cause of end-stage kidney disease worldwide (after diabetes and hypertension), little is known about their long-term risks and complications. Method Using data from the Swedish Renal Registry (SRR-CKD) 2005-2021, we compared clinical outcomes between patients with the four most frequent primary glomerular diseases (IgA nephropathy [IgAN], focal segmental glomerulosclerosis [FSGS], minimal change disease [MCD] and membranous nephropathy [MN]) and patients with CKD attributed to non-inflammatory etiologies (i.e. without systemic auto-immune, inflammatory, infectious, hematologic malignancy, genetic disease, or polycystic kidney disease). Poisson models were used to estimate adjusted incidence rate ratios (IRR) of all-cause and cause-specific hospitalizations (cardiovascular-, acute kidney injury-, thromboembolism- and infection-related). Cox proportional hazards models were used to estimate adjusted hazard ratios (HR) of kidney replacement therapy (KRT), major adverse cardiovascular events (MACE) and death. Results We identified 2967 patients with primary glomerular disease (71% men, age 57 years, eGFR 28 mL/min/1.73 m2, uACR 63 mg/mmol) and 40026 patients with a non-inflammatory CKD (64% men, age 74 years, eGFR 22 mL/min/1.73 m2, uACR 20 mg/mmol). As compared to non-inflammatory CKD, patients with primary glomerular diseases were younger, had a lower prevalence of cardiovascular disease, higher eGFR but higher albuminuria. Over median follow-up of 6.3 [3.3;9.9] years, there were median 3.0 [1.0;7.0] hospitalizations per patient, 9890 (23%) KRT, 11708 (27%) MACE, and 21091 (49%) deaths. As compared to non-inflammatory CKD, patients with primary glomerular disease had a lower risk of all-cause (IRR 0.77 [0.75;0.79]), and all cause-specific hospitalizations, MACE (HR 0.56 [0.50;0.63]) and death (HR 0.57 [0.52;0.62], but a similar risk of KRT (HR 1.02 [0.95;1.10]) or AKI (HR 0.84 [0.70;1.02]) (Figure 1). Within primary glomerular diseases and as compared to IgAN, patients with FSGS had a higher risk of death (HR 1.29 [1.03;1.60]) and MACE (HR 1.49 [1.12;1.97]), and patients with MN and MCD had a lower risk of KRT. Conclusion In this nationwide analysis of patients with advanced CKD undergoing nephrologist-care, those with primary glomerular disease have an observed lower risk of adverse clinical events compared to non-inflammatory CKD diseases. However, their risks of AKI or KRT are similar, emphasizing the need of adequate treatment strategies in this population. We speculate that the long-term continuous exposure to comorbidities like diabetes and hypertension in patients with non-inflammatory CKD might explain these differences. Within single primary glomerular disease etiologies, FSGS is associated with the highest risk of cardiovascular and fatal complications. The study received grant support from CSL Vifor.

The role of uric acid in the development of infl ammation in kidney disease

Asymptomatic hyperuricemia is frequently seen in patients with kidney disease. A significant number of epidemiological studies suggest that elevated uric acid levels play a causal role in the development and progression of kidney disease. But whether hyperuricemia is simply the result of reduced renal excretion of uric acid or contributes to the progression of renal disease remains controversial. Over the past two decades, numerous experimental studies have expanded the knowledge of the biological effects of uric acid beyond its role in the development of gout. In particular, uric acid induces activation of the immune system and affects not only renal tissue cells but also endothelial cells. All this has led to the presentation of uric acid as a potential and modifying risk factor for kidney disease. This review examines the effects of uric acid on the immune system and further on renal tissue during inflammation.

Fate mapping reveals compartment-specific clonal expansion of mononuclear phagocytes during kidney disease

Fate mapping reveals compartment-specific clonal expansion of mononuclear phagocytes during kidney disease

Study on the effect of periodontitis on renal tissue in atherosclerotic mice

Periodontitis is immune inflammatory disease, atherosclerosis (AS) and chronic kidney disease (CKD) are two common systemic diseases. Periodontitis promotes AS and CKD, and CKD interacts with AS. The objective of this animal study was to evaluate the changes of kidney when periodontitis and atherosclerosis exist separately and the degenerative effects of periodontitis on the kidney in atherosclerotic mice. A total of 40 male Apoe-/- mice were randomly divided into four groups: control (NC), periodontitis (PD), AS and AS with PD (AS + PD). AS was induced by high-fat diet feeding, and PD was induced by injection of Porphyromonas gingivalis-Lipopolysaccharide (P.g-LPS) (endotoxin suspension) into the buccal side of mouse maxillary molars. The right maxilla of mice was scanned with micro-CT to evaluate alveolar bone loss; aortic tissue was stained with HE and Oil-Red O to evaluate arterial plaque formation; serum was collected to detect the changes of blood lipids and serum renal function parameters (blood urea nitrogen [BUN], serum creatinine [Scr]); renal histopathological changes were evaluated by HE staining (glomerular and tubular damage scores), PAS staining (glomerular Mesangial matrix index) and Masson staining (percentage of renal fibrosis area); qRT-PCR and ELISA were used to evaluate the expression of renal inflammatory cytokines (tumor necrosis factor-α, Interleukin-1β, neutrophil surface marker Ly6G). The amount of alveolar bone loss: PD group was significantly higher than NC group (p < .05); AS + PD group was higher than PD group, the difference was not statistically significant. Atherosclerotic plaque formation and serum lipid changes: AS group were significantly worse than NC group (p < .05), and AS + PD group were worse than AS group. The results of the corresponding qualitative and quantitative analyses of kidney tissue in experimental animals gradually deteriorated in the NC group, PD group, AS group and AS + PD group and worsened sequentially. Renal function parameters: the content of BUN in AS group was higher than that in PD group, the difference was not statistically significant; Scr in AS group was significantly higher than that in PD group (p < .05); the contents of BUN and Scr in AS + PD group were higher than those in AS group, the difference was not statistically significant. Glomerular and tubular damage scores: AS group were higher than PD group, the difference was not statistically significant; AS + PD group were significantly higher than AS group (p < .001). The ratio of glomerular mesangial matrix to glomerular area and the percentage of renal fibrosis area: AS group were significantly higher than PD group (p < .001), and AS + PD group were significantly higher than AS group (p < .001). Expression of inflammatory cytokines: AS group was higher than PD group, the difference was not statistically significant; AS + PD group was significantly higher than AS group (p < .05). Both PD and AS can aggravate the inflammatory stress of kidney tissue and cause the damage of kidney tissue, and the inflammatory increase and damage effect of AS is stronger; PD can promote kidney damage of atherosclerotic mice by aggravating the renal inflammation in atherosclerotic mice; renal function parameters were not completely synchronized with the changes of renal inflammation and histopathology in each group of mice; PD can promote AS, periodontal inflammation in mice with AS is more severe, and the special changes of blood lipids in mice with AS are closely related to the above results.

Urine Neutrophil Gelatinase Associated Lipocalin as a Predictor of Vesicoureteral Reflux and Renal Parenchymal Damage: A Systematic Review

Background: Vesicoureteral reflux (VUR) is the most common congenital urinary tract abnormality in children. Renal parenchymal damage is the most devastating complication of severe undiagnosed VUR. Different diagnostic biomarkers have been introduced as alternatives for radiologic evaluation in these patients. This review article aimed to increase the knowledge about the role of urine neutrophil gelatinase-associated lipocalin (uNGAL) in children affected by primary VUR and renal parenchymal damage. Methods: A systematic review of PubMed, Scopus, Web of Science, ProQuest, and Ovid was conducted in September 2022 to retrieve studies that investigated the correlation between uNGAL or uNGAL/Cr excretion and primary VUR in male/female patients younger than 18 years of age. Patients with secondary VUR, age older than 18 years, infectious or inflammatory disorders, obstructive uropathies, and acute or chronic kidney diseases were excluded. Two reviewers independently screened the titles and abstracts of the search results and then assessed the full texts selected from the pertinent studies. Results: Eighteen research articles with a total sample of 699 patients were found to measure uNGAL in VUR or renal scarring. UNGAL or uNGAL/Cr had increased excretion in the majority of children with primary VUR or RPD, with a positive or no correlation to the severity of VUR. Conclusions: Several studies addressed uNGAL and uNGAL/Cr as putative biomarkers for the prediction of VUR or reflux-associated RPD.

The von Hippel-Lindau Tumor Suppressor Gene Mutations Modulate Lipocalin-2 Expression in Ferroptotic-Inflammatory Pathways.

A previous study of an animal model with tumor suppressor gene von Hippel-Lindau (VHL) conditional knockdown suggested that tissue inflammation and fibrosis play important roles in the development of clear-cell renal cell carcinoma (ccRCC), which is consistent with the epidemiological evidence linking inflammatory kidney disease and renal cancer. Ferroptosis and inflammation have been linked in a recent study, but the exact mechanism remains unclear. This study is aimed at investigating the mechanism of lipocalin-2- (LCN-2-) mediated ferroptosis and inflammation in vhl-mutated HK-2 cells and mouse primary proximal tubule cells (mRTCs) and the polarization of macrophage RAW 264.7 cells. Based on the levels of lipid reactive oxygen species (ROS) and the expression of glutathione peroxidase 4 (GPX4) in HK-2 cells, we observed that a VHL mutation increased ROS production and depressed GPX4 expression, whereas LCN-2 knockdown reversed these effects. Accordingly, VHL appears to affect ferroptosis in an LCN-2-dependent manner. We also revealed that LCN-2 sensitizes HK-2 cells to inflammation and macrophage RAW 264.7 cells to M1-like polarization. This study provides novel insights into the potential therapeutic target and strategy for attenuating the progression of ccRCC by revealing the role of VHL in regulating chronic inflammation within the LCN-2-ferroptosis pathway.