[Show abstract][Hide abstract] ABSTRACT: Recent studies suggest a pathogenic role for glomerular haematuria among renal function. However, there is no data on the prevalence of haematuria from a large renal biopsy registry. We analysed the prevalence of gross (GH) and microscopic (mH) haematuria in 19,895 patients that underwent native renal biopsies from the Spanish Registry of Glomerulonephritis. Haematuria’s overall incidence was 63% (GH 8.6% and mH 55.1%), being more frequent in males (64.7% vs. 62.4%). GH was more prevalent in patients <18 years (21.3% vs. 7.7%). The commonest clinical presentation associated with GH was acute kidney injury (31.5%) and IgA Nephropathy (IgAN) (33.6%) was the most frequent histological finding. GH patients showed a significantly (p < 0.05) lower eGFR and proteinuria levels as compared with patients with mH and without haematuria. Moreover, mH was more prevalent in adults (56.3%). Nephrotic syndrome was the commonest clinical presentation in mH patients (32.2%) and IgAN (18.5%) the most frequent histological finding. In conclusion, haematuria, is a frequent urinalysis finding in patients underwent native renal biopsy. The most frequent histological finding in both GH and mH is IgAN. Whereas, GH is more frequent in young males with acute kidney injury, mH is commoner among adults with nephrotic syndrome.
[Show abstract][Hide abstract] ABSTRACT: CD163 is a membrane receptor expressed by macrophage lineage. Studies performed in atherosclerosis have shown that CD163 expression is increased at inflammatory sites, pointing at the presence of intraplaque hemorrhagic sites or asymptomatic plaques. Hence, imaging of CD163 expressing macrophages is an interesting strategy in order to detect atherosclerotic plaques. We have prepared a targeted probe based on gold-coated iron oxide nanoparticles vectorized with an anti-CD163 antibody for the specific detection of CD163 by MRI. Firstly, the specificity of the targeted probe was validated in vitro by incubation of the probe with CD163(+) or (−) macrophages. The probe was able to selectively detect CD163(+) macrophages both in human and murine cells. Subsequently, the targeted probe was injected in 16 weeks old apoE deficient mice developing atherosclerotic lesions and the pararenal abdominal aorta was imaged by MRI. The accumulation of probe in the site of interest increased over time and the signal intensity decreased significantly 48 hours after the injection. Hence, we have developed a highly sensitive targeted probe capable of detecting CD163-expressing macrophages that could provide useful information about the state of the atheromatous lesions.
Full-text · Article · Nov 2015 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: Rhabdomyolysis is a syndrome caused by injury to skeletal muscle that usually leads to acute kidney injury (AKI). Rhabdomyolysis has been linked to different conditions, including severe trauma and intense physical exercise. Myoglobin-induced renal toxicity plays a key role in rhabdomyolysis-associated kidney damage by increasing oxidative stress, inflammation, endothelial dysfunction, vasoconstriction, and apoptosis. New drugs that target the harmful effects of myoglobin have been recently developed, and some have been proven to be successful in animal models of acute renal failure secondary to rhabdomyolysis. This review aims to provide a comprehensive and updated overview of the pathological mechanisms of renal damage and describes new therapeutic approaches to this condition based on novel compounds that target key pathways involved in myoglobin-mediated kidney damage.
No preview · Article · Oct 2015 · Kidney and Blood Pressure Research
[Show abstract][Hide abstract] ABSTRACT: Haematuria has been traditionally considered as a benign hallmark of some glomerular diseases; however new studies show that haematuria may decrease renal function.
To determine the influence of haematuria on the rate of chronic kidney disease (CKD) progression in 71 proteinuric patients with advanced CKD (baseline eGFR <30 mL/min) during 12 months of follow-up.
The mean rate of decline in eGFR was higher in patients with both haematuria and proteinuria (haemoproteinuria, HP, n=31) than in patients with proteinuria alone (P patients, n=40) (-3.8±8.9 vs 0.9±9.5 mL/min/1.73m2/year, p<0.05, respectively). The deleterious effect of haematuria on rate of decline in eGFR was observed in patients <65 years (-6.8±9.9 (HP) vs. 0.1±11.7 (P) mL/min/1.73m2/year, p<0.05), but not in patients >65 years (-1.2±6.8 (HP) vs. 1.5±7.7 (P) mL/min/1.73m2/year). Furthermore, the harmful effect of haematuria on eGFR slope was found patients with proteinuria >0.5 g/24 h (-5.8±6.4 (HP) vs. -1.37± 7.9 (P) mL/min/1.73m2/year, p<0.05), whereas no significant differences were found in patients with proteinuria < 0.5 g/24 h (-0.62±7.4 (HP) vs. 3.4±11.1 (P) mL/min/1.73m2/year). Multivariate analysis reported that presence of haematuria was significantly and independently associated with eGFR deterioration after adjusting for traditional risk factors, including age, serum phosphate, mean proteinuria and mean serum PTH (β=-4.316, p=0.025).
The presence of haematuria is closely associated with a faster decrease in renal function in advanced proteinuric CKD patients, especially in younger CKD patients with high proteinuria levels; therefore this high risk subgroup of patients would benefit of intensive medical surveillance and treatment.
[Show abstract][Hide abstract] ABSTRACT: Haematuria has long been considered to be a benign condition associated with glomerular diseases. However, new evidences suggest that haematuria has a pathogenic role in promoting kidney disease progression. An increased risk for end-stage renal disease has been reported in adolescents and young adults with persistent microscopic haematuria. A persistent impairment of renal function has been also reported following macroscopic haematuria-associated acute kidney injury in immunoglobulin A nephropathy. Haematuria-induced renal damage has been related to oxidant, cytotoxic and inflammatory effects induced by haemoglobin or haem released from red blood cells. The pathophysiological origin of haematuria may be due to a more fragile and easily ruptured glomerular filtration barrier, as reported in several glomerular diseases. In this review we describe a number of the key issues associated with the epidemiology and pathogenesis of haematuria-associated diseases, provide an update of recent knowledge on the role of haematuria on renal function outcome and discuss specific therapeutic approaches in this setting. 1. Glomerular haematuria is a common observation in a number of renal diseases that may lead to persistent renal injury. 2. Haematuria in children differs from that in adults in specific aspects, particularly in the frequency of glomerular diseases and renal disease outcome. 3. Regular follow-up of renal function in children with isolated microhaematuria may be recommended.
Full-text · Article · May 2015 · Pediatric Nephrology
[Show abstract][Hide abstract] ABSTRACT: Haematuria was known as a benign hallmark of some glomerular diseases, but over the last decade, new evidences pointed its negative implications on kidney disease progression. Cytotoxic effects of oxidative stress induced by hemoglobin, heme, or iron released from red blood cells may account for the tubular injury observed in human biopsy specimens. However, the precise mechanisms responsible for haematuria remain unclear. The presence of red blood cells (RBCs) with irregular contours and shape in the urine indicates RBCs egression from the glomerular capillary into the urinary space. Therefore glomerular haematuria may be a marker of glomerular filtration barrier dysfunction or damage. In this review we describe some key issues regarding epidemiology and pathogenesis of haematuric diseases as well as their renal morphological findings.
[Show abstract][Hide abstract] ABSTRACT: Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.
Full-text · Article · Jan 2015 · Vascular Health and Risk Management
[Show abstract][Hide abstract] ABSTRACT: Patients infected with the human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV.
The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII) and endothelial dysfunction (sVCAM-1 and ADMA) in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART) and 23 healthy subjects.
Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations.
HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART.
[Show abstract][Hide abstract] ABSTRACT: Intolerance to fava beans in subjects with glucose-6-phosphate-dehydrogenase deficiency (favism) may lead to severe hemolytic crises and decreased renal function. Renal biopsy findings exploring the molecular mechanisms of renal damage in favism have not been previously reported. We report a case of favism-associated acute kidney injury in which renal biopsy showed acute tubular necrosis and massive iron deposits in tubular cells. Interestingly, iron deposit areas were characterized by the presence of oxidative stress markers (NADPH-p22 phox and heme-oxigenase-1) and macrophages expressing the hemoglobin scavenger receptor CD163. In addition, iron deposits, NADPH-p22 phox, heme-oxigenase-1 and CD163 positive cells were observed in some glomeruli. These results identify both glomerular and tubular involvement in favism-associated acute kidney injury and suggest novel therapeutic targets to prevent or accelerate recovery from acute kidney injury.
No preview · Article · Mar 2014 · Clinical nephrology
[Show abstract][Hide abstract] ABSTRACT: Klotho is a renal protein with anti-aging properties that is downregulated in conditions related to kidney injury. Hyperlipidemia accelerates the progression of renal damage, but the mechanisms of the deleterious effects of hyperlipidemia remain unclear.
We evaluated whether hyperlipidemia modulates Klotho expression in kidneys from C57BL/6 and hyperlipidemic apolipoprotein E knockout (ApoE KO) mice fed with a normal chow diet (ND) or a Western-type high cholesterol-fat diet (HC) for 5 to 10 weeks, respectively.
In ApoE KO mice, the HC diet increased serum and renal cholesterol levels, kidney injury severity, kidney macrophage infiltration and inflammatory chemokine expression. A significant reduction in Klotho mRNA and protein expression was observed in kidneys from hypercholesteromic ApoE KO mice fed a HC diet as compared with controls, both at 5 and 10 weeks. In order to study the mechanism involved in Klotho down-regulation, murine tubular epithelial cells were treated with ox-LDL. Oxidized-LDL were effectively uptaken by tubular cells and decreased both Klotho mRNA and protein expression in a time- and dose-dependent manner in these cells. Finally, NF-κB and ERK inhibitors prevented ox-LDL-induced Klotho downregulation.
Our results suggest that hyperlipidemia-associated kidney injury decreases renal expression of Klotho. Therefore, Klotho could be a key element explaining the relationship between hyperlipidemia and aging with renal disease.
[Show abstract][Hide abstract] ABSTRACT: Evidence is emerging for the inflammatory nature of many ageing-associated diseases, including atherosclerosis, vascular calcification, diabetes and chronic kidney disease (CKD), among others. Ageing itself results in chronic low-grade inflammation that promotes end-organ damage. Inflammatory organ damage, in turn, may contribute to inflammation. Recent research has identified the kidney-secreted hormone Klotho as a central player at the ageinginflammation interface. Thus, systemic or local renal inflammation decreases kidney Klotho expression. Klotho down-regulation may be induced by specific cytokines such as tumour necrosis factor- or TWEAK through the canonical activation of the inflammatory transcription factor nuclear factor kappa B (NFB) and, specifically RelA. In addition, inflammatory cytokines lead to the epigenetic inactivation of Klotho transcription. Klotho itself has antioxidant and anti-inflammatory properties and the canonical NFB component RelA is one of its targets. Klotho is a key regulator of phosphate balance and a role of phosphate in ageing has been shown. However, the potential relationship between phosphate and inflammation requires further clarification. A correct understanding of these interactions may lead to the design of novel therapeutic approaches to CKD and CKD-related inflammatory and ageing features as well as to inflammation/ageing in general.
No preview · Article · Dec 2012 · Nephrology Dialysis Transplantation
[Show abstract][Hide abstract] ABSTRACT: Background:
Macroscopic hematuria (MH) may cause acute kidney injury (AKI) in IgA nephropathy. Up to 25% of patients with MH-associated AKI do not recover baseline renal function. Our objective was to identify subjects at high risk for an adverse renal function.
We examined macrophages, oxidative stress markers (NADPH-p22 and HO-1) and the hemoglobin scavenger receptor (CD163) in renal biopsy specimens from 33 MH-AKI patients with complete recovery (CR, n = 17) or incomplete recovery (IR, n = 16) of renal function after 6.72 (range 0.5-21.5) years of follow-up.
CD163-expressing macrophages, HO-1 and NADPH-p22 expression were located in areas surrounding tubules with iron deposits and filled with erythrocyte casts. CD163-positive macrophages score and HO-1- and p22-positive staining correlated positively with percentage of tubules with erythrocyte casts and tubular necrosis. Macrophage infiltration, CD163-positive macrophage score, NADPH-p22- and HO-1-positive staining areas were significantly greater in IR patients when compared with CR patients. The CD163-positive macrophage score and oxidative stress markers (p22 and HO-1) were negatively correlated with renal function outcome, as determined by estimated glomerular filtration rate (eGFR) and proteinuria, at the end of the follow-up period. In multivariate analysis, the CD163-positive macrophage score remained significantly associated with final eGFR and proteinuria after adjustment by age, gender, duration of MH, initial eGFR and proteinuria.
Increased macrophage infiltration, CD163 expression and oxidative stress are significant prognostic factors for an IR of renal function in patients with MH-associated AKI. These molecular pathways may be involved in the renal response to injury and could be useful to improve diagnosis and therapeutics.
No preview · Article · Oct 2012 · Nephron Clinical Practice
[Show abstract][Hide abstract] ABSTRACT: Introduction:
Proteinuria is a common finding in glomerular diseases that contributes to the progression of chronic kidney injury. Tubular cells reabsorb the excess of albumin and other plasma proteins from the tubular lumen, triggering several pathophysiologic responses, such as overexpression of fibrogenic mediators and inflammatory chemokines. Chemokines are implicated both in the recruitment of inflammatory infiltrate and in a number of physiological and pathological processes related to protein overload.
In recent years, the specific chemokines and their receptors and the intracellular signaling pathways involved in proteinuria-induced renal damage have been identified. This review provides an overview of the role of chemokines and their receptors in proteinuria-related renal disease and summarizes novel therapeutic approaches to restrain the progression of renal damage.
Inhibition of chemokine-induced biological activities is a promising therapeutic strategy in proteinuric disorders. Neutralizing antibodies and small organic molecules targeting chemokines and chemokine receptors have been proven to prevent inflammation and renal damage in experimental models of protein overload. Some of these compounds are currently being tested in human clinical trials.
No preview · Article · Aug 2012 · Expert Opinion on Therapeutic Targets
[Show abstract][Hide abstract] ABSTRACT: Oxidative stress is involved in the chronic pathological vascular remodelling of both abdominal aortic aneurysm and occlusive atherosclerosis. Red blood cells (RBCs), leukocytes and platelets present in both, aneurysmal intraluminal thrombus and intraplaque haemorraghes, could be involved in the redox imbalance inside diseased arterial tissues. RBCs haemolysis may release the pro-oxidant haemoglobin (Hb), which transfers heme to tissue and low-density lipoproteins. Heme-iron potentiates molecular, cell and tissue toxicity mediated by leukocytes and other sources of reactive oxygen species (ROS). Polymorphonuclear neutrophils release myeloperoxidase and, along with activated platelets, produce superoxide mediated by NADPH oxidase, causing oxidative damage. In response to this pro-oxidant milieu, several antioxidant molecules of plasma or cell origin can prevent ROS production. Free Hb binds to haptoglobin (Hp) and once Hp-Hb complex is endocytosed by CD163, liberated heme is converted into less toxic compounds by heme oxygenase-1. Iron homeostasis is mainly regulated by transferrin, which transports ferric ions to other cells. Transferrin-bound iron is internalised via endocytosis mediated by transferrin receptor. Once inside the cell, iron is mainly stored by ferritin. Other non hemo-iron related antioxidant enzymes (e.g. superoxide dismutase, catalase, thioredoxin and peroxiredoxin) are also involved in redox modulation in vascular remodelling. Oxidative stress is a main determinant of chronic pathological remodelling of the arterial wall, partially linked to the presence of RBCs, leukocytes, platelets and oxidised fibrin within tissue and to the imbalance between pro-/anti-oxidant molecules. Understanding the complex mechanisms underlying redox imbalance could help to define novel potential targets to decrease atherothrombotic risk.
Full-text · Article · Jul 2012 · Thrombosis and Haemostasis
[Show abstract][Hide abstract] ABSTRACT: Haematuria is a frequent manifestation of glomerular disease. However, nephrologists devote more attention to the monitoring
and therapeutic targeting of another key manifestation of glomerular injury, proteinuria. Recent reports have propelled haematuria
to the forefront of clinical nephrology. Thus, glomerular macroscopic haematuria is associated with the development of acute
kidney injury (AKI) with predominant tubular cell damage and there is increasing evidence for the negative impact of glomerular
haematuria-associated AKI on long-term renal function outcome both in the context of IgA nephropathy and in anticoagulated
patients. In addition, an epidemiological association between isolated microscopic haematuria in young adults and long-term
incidence of end-stage renal disease has been described. Finally, a clearer understanding of how haematuria may cause tubular
injury is emerging through detailed histological assessment of human biopsies and experimental models of haemoglobin-mediated
Preview · Article · Jan 2012 · Nephrology Dialysis Transplantation
[Show abstract][Hide abstract] ABSTRACT: Hematuria is a common finding in various glomerular diseases. This article reviews the clinical data on glomerular hematuria and kidney injury, as well as the pathophysiology of hematuria-associated renal damage. Although glomerular hematuria has been considered a clinical manifestation of glomerular diseases without real consequences on renal function and long-term prognosis, many studies performed have shown a relationship between macroscopic glomerular hematuria and AKI and have suggested that macroscopic hematuria-associated AKI is related to adverse long-term outcomes. Thus, up to 25% of patients with macroscopic hematuria-associated AKI do not recover baseline renal function. Oral anticoagulation has been associated with glomerular macrohematuria-related kidney injury. Several pathophysiologic mechanisms may account for the tubular injury found on renal biopsy specimens. Mechanical obstruction by red blood cell casts was thought to play a role. More recent evidence points to cytotoxic effects of oxidative stress induced by hemoglobin, heme, or iron released from red blood cells. These mechanisms of injury may be shared with hemoglobinuria or myoglobinuria-induced AKI. Heme oxygenase catalyzes the conversion of heme to biliverdin and is protective in animal models of heme toxicity. CD163, the recently identified scavenger receptor for extracellular hemoglobin, promotes the activation of anti-inflammatory pathways, opening the gates for novel therapeutic approaches.
Preview · Article · Nov 2011 · Clinical Journal of the American Society of Nephrology
[Show abstract][Hide abstract] ABSTRACT: Decreased renal function has been observed in diseases with intravascular haemolysis, including paroxysmal nocturnal haemoglobinuria (PNH). However, the mechanisms via which haemoglobin enhances renal damage in this pathology are not fully known. We report a case of acute renal failure associated to PNH and extensive haemosiderin deposits in tubular cells. Renal biopsy also revealed a strong immunostaining of CD163 (a haemoglobin scavenger receptor expressed in macrophages) and oxidative stress markers (NADPH-p22 phox and haeme oxigenase-1) in areas with deposits of iron. This fact provides evidence for a pathogenic role for free haemoglobin in tubulointerstitial renal injury in human PNH disease.
[Show abstract][Hide abstract] ABSTRACT: CD163 is a macrophage receptor for haemoglobin-haptoglobin (Hb-Hp) complexes, responsible for the clearance of haemoglobin. We hypothesized that production of soluble CD163 (sCD163) may be due to proleolytic shedding of membrane CD163 by neutrophil elastase, reported to be increased in culprit atherosclerotic plaques. We analysed the relationship between CD163 solubilization and elastase in vitro, in macrophage culture, ex vivo in human atherosclerotic plaque samples, and in vivo, in plasma of patients with coronary artery disease.
Neutrophil elastase was shown to enhance CD163 shedding and to decrease the uptake of Hb-Hp complexes by cultured macrophages. In addition, cultured carotid endarterectomy samples showing features of intraplaque haemorrhage released more sCD163 and elastase/α1-antitrypsin (α1-AT) complexes than non-haemorrhagic plaques (n= 44). Plasma levels of sCD163 and neutrophil elastase (complexed with α1-AT) were measured in patients with an acute coronary syndrome (ACS, n= 42), stable angina pectoris (SAP, n= 28), or normal coronary angiograms without subclinical atherosclerosis (n= 21). Acute coronary syndrome patients had higher sCD163 and elastase/α1-AT complexes plasma concentrations than subjects without coronary atherosclerosis. Circulating sCD163 and elastase/α1-AT complexes were positively correlated in patients with ACS (r = 0.56, P< 0.0002) and SAP (r = 0.62, P< 0.0005).
Our results suggest that neutrophil elastase promotes CD163 shedding, resulting in a decreased clearance of Hb by macrophages, which may favour plaque destabilization. This may be reflected by increased plasma levels of sCD163 and elastase/α1-AT complexes which are positively correlated in patients with coronary artery disease.
Full-text · Article · May 2011 · European Heart Journal