Albuminuria, proteinuria Uzsoki utcai Kórház, Nephrologiai Osztály dr. Deák György Uzsoki utcai Kórház, Nephrologiai Osztály

Az albumin sorsa a nephronban 0 sec 40 sec 14 min 24 h Filtráció Kötődés a PTS kefeszegélyhez Endocytosis Megalin-cubilin receptorok Lysosomalis degradáció Transcytosis, reabsorpció Megalin is a 600-kDa transmembrane protein belonging to the LDL-receptor family Cubilin is a 460-kDa peripheral membrane protein, previously referred to as gp280, and identical to the intrinsic factor-vitamin B12 receptor known from the small intestine. V-ATP-ase, clathrin Albuminuria may be the consequence of decreased albumin re-uptake at tubular level. Endocytotic uptake of albumin by proximal tubular cells in culture is regulated by phosphatidyl inositide 3-kinase,42 an enzyme that in proximal tubule cell cultures is activated by insulin. This suggests that insulin might increase albumin endocytosis, possibly by stimulating interaction of clathrin-coated pits with the endosome compartment. The development of insulin resistance may therefore adversely effect tubular albumin uptake and lead to excretion of a larger fraction of the albumin that is filtered at the glomerulus. abolition of tubular reabsorption alone could result in up to 300 mg/24 h of albuminuria. Russo L. Kidney Int 2007;71:504.

glomeruláris filtrációs barrier 40 nm 60–100 nm

Glomeruláris filtrációs barrier Az endotheliális glycocalyx jelentősen akadályozza a proteinek filtrációját Glycoproteinek Collagen laminin HSPG Glycocalix: glycoproteins and heparan sulphate proteoglycans BM: it only makes a small direct contribution to the barrier to protein passage MAU: dysfunction of glom filtr barrier – damage to any tayer of it. Satchell S. Diabetologia (2008) 51:714–725

sejt membrán nephrin sejt membrán nephrin membrán pórus The glomerular filter viewed perpendicular to podocyte foot processes. Filtrate passes from within the glomerular capillary lumen (at bottom) through fenestrae between endothelial cells, across the glomerular basement membrane, and through the slit diaphragm between podocyte foot processes into the Bowman's space. Inset: slit diaphragm components are localized to lipid rafts. Podocin serves as a scaffolding molecule to localize nephrin and Neph1 to lipid rafts, which bring multiple proteins together in a small area of membrane to create a signaling platform. GBM, glomerular basement membrane. (B) Scanning electron micrograph of podocytes. Podocytes branch into progressively smaller primary, secondary, and tertiary foot processes, which interdigitate with tertiary foot processes from a neighboring podocyte. CB, podocyte cell body; P, primary foot process; S, secondary foot process; T, tertiary foot process. (C) The slit diaphragm model of Karnovsky and colleagues. Podocyte foot processes (left and right) with a central filament running in parallel. Perpendicular cross strands form a regular lattice, with rectangular pores between the strands. nephrin sejt membrán nephrin sejt membrán membrán pórus

Az albuminuria mechanizmusai Hemodinamikus Hyperfiltráció - Diabetes, hypertónia, inzulin rezisztencia, obezitás Nem-hemodinamikus Endothel glycocalyx dysruptio - Endothelial dysfunctio megelőzi az albuminuriát - Glycocalyx volumen korrelál az albuminuriával A slit diaphragma károsodása Csökkent tubuláris újrafelvétel - Az inzulin rezisztencia csökkenti az albumin endocytosisát - Tubulointerstitialis betegségek ROS Citokinek VGEF, IGF ET-1, ANG-II  NO insulin might increase albumin endocytosis, possibly by stimulating interaction of clathrin-coated pits with the endosome compartment. The development of insulin resistance may therefore adversely effect tubular albumin uptake and lead to excretion of a larger podocyte foot process effacement acute hyperinsulinemia increases the renal plasma flow and the glomerular hydrostatic pressure Insulin resistance, estimated by the glucose-clamp technique, is positively correlated with glomerular filtration fraction and is associated with glomerular hyperfiltration.47 insulin resistance -- SECONDARY hyperinsulinemia Hyperinsulinemia sustains salt- and volume-dependent hypertension by directly promoting sodium and water reabsorption at tubular level,57 by activating the sympathetic nervous system activity,58 and by inducing endothelial dysfunction - insulin-induced pre-glomerular vasodilation type 1 diabetic patients have decreased systemic glycocalyx volume, and this correlates with the presence of microalbuminuria

Az Angiotensin II hatásai Hemodinamikus  gl. kapilláris nyomás  gl. kapilláris permeabilitás Nem-hemodinamikus  NF B - citokinek  TGF, PDGF  ECM proteinek  PKC  proteinázok  eNOS  VCAM  makrofág / monocita infiltráció Vascular cell adhesion molecule Ly, mo- atheroma formation Érszűkítő, pro-inflammatorikus, pro-thrombotikus, pro-fibrotikus hatások

A (micro)albuminuria definíciói Időre gyűjtés (µg/min) Random alb/creat mg/mmol Dipstick 24 h albumin (mg) 24 h protein (mg) Normális – < 30 < 20 < 2,5 < 150 Micro-albuminuria – 30 - 300 20 - 200 2,5-25 < 500 Proteinuria + > 300 > 200 > 25 > 500 magas-norm. albuminuria Microalbuminuria is defined by a range of values within the continuum of urinary albumin excretion. Patients with microalbuminuria are negative for protein on usual dipstick testing and often have normal amounts of protein excreted on the 24-hour urine collections done for protein. However, these patients have abnormally elevated urinary albumin excretion at 20-200 µg/min or 30-300 mg/24 hours. Many patients with microalbuminuria go on to develop overt nephropathy, However, once a patient has overt proteinuria there is no reason to measure urinary albumin excretion, as a test for proteinuria is already positive. The goal is to identify nephropathy and MAU in the early stages, and to institute treatment before it is too late. 1. Parving H-H, et al. Renal protection in diabetes: an emerging role for calcium antagonists. J Hypertens 1996;14(suppl 4):S21-S25. Data from Heart Outcome Prevention Evaluation, Losartan Intervention For End point reduction in hypertension, and Framingham studies8,9,13 clearly suggest that only negligible amounts of albuminuria below approximately 2 mg/g of urinary creatinine (or an estimated excretion rate of 2 mg/day) should be considered as ‘normal’. This approximately corresponds to a urinary concentration of 1–2 mg/ml, which is below or close to the detection limit – 15 - 29 10 - 19 Klausen K. Circulation 2004;110;32, Ruggenenti P, Remuzzi G. KI, 2006;70:1214.

A MAU prediktorai a nem-diabeteses populációban Életkor Férfi nem Dohányzás Elhízás Inzulin rezisztencia Hyperlipidemia Hypertónia Natriuresis Glomeruláris hyperfiltráció Alacsony születési súly CRP correlates with MAU elevated vWF precedes MAU. Endothelial dysfunction precedes microalbuminuria.

Metabolikus szindróma, CKD és MAU NHANES III, N = 6217 Metabolikus szindróma Hypertónia Alacsony HDL Hypertrigliceridemia Hyperglycemia Abdominális elhízás CKD Chen and coworkers (looked for components of the metabolic sy in the NHANES population ) and grouped people according to the number of risk factors they had and looked for the prevalence of MAU and CKD. They found that the prevalence of albuminuria increases in parallel with increasing number of risk factors in a population Microalbuminuria Chen J. Ann Intern Med. 2004;140:167

A MAU prevalenciája Átlag populáció: 5 - 6 % (Ø DM, Ø HTN) Hypertoniás populáció: 15 - 40 % Diabeteses populáció: 20 - 40 % National Kidney Foundation guidelines recommend a front-end UAE screen in all patients who are at risk for renal disease, including those with diabetes, hypertension, family history of chronic kidney disease, age 60 yr, and racial and ethnic minorities

A proteinuria veseelégtelenség progresszióját okozza A transzport szaturációja Toxikus sejtkárosodás Kemokinek Makrofág infiltráció PDGF ANGII, TGF-β, NF-κB Citokinek Fenotípus változás fibroblaszttá: epiteliális - mezenchimális tranzíció Apoptosis Fibrosis, tubular atrophy Podocyte-derived vascular endothelial growth factor (VEGF), a permeability and angiogenic factor whose expression is increased in diabetic kidney disease, is perhaps a major mediator of the increased protein filtration. Decreased podocyte number and/or density as a result of apoptosis or detachment, GBM thickening with altered matrix composition, and a reduction in nephrin protein in the slit diaphragm with podocyte foot process effacement, all comprise the principal features of diabetic podocytopathy that clinically manifests as albuminuria and proteinuria. Many of these events are mediated by angiotensin II whose local concentration is stimulated by high glucose, mechanical stretch, and proteinuria itself. Angiotensin II in turn stimulates podocyte-derived VEGF, suppresses nephrin expression, and induces TGF-beta1 leading to podocyte apoptosis and fostering the development of glomerulosclerosis. Proteinuria can then induce in tubular cells a genetic program leading to tubulointerstitial inflammation, fibrosis and tubular atrophy. Besides direct effects of albuminuria on tubular cells, pathophysiological changes in the ultrafiltration barrier lead to an increased tubular filtration of various growth factors (TGF-beta1, insulin-like growth factor I) that may further alter the function of tubular cells. Moreover, angiotensin II also stimulates uptake of ultrafiltered proteins into tubular cells and enhances the production of proinflammatory and profibrotic cytokines within the cells. Migration of macrophages and other inflammatory cells into the tubulointerstitium occurs. Increased synthesis and decreased turnover of extracellular matrix proteins in tubular cells and interstitial fibroblasts contribute to interstitial fibrosis. In addition, under locally high concentrations of angiotensin II and TGF-beta1, tubular cells may change their phenotype and become fibroblasts by a process called epithelial to mesenchymal transition (EMT) which contributes to interstitial fibrosis and tubular atrophy because of vanishing epithelia cells. An alternative explanation for the development of albuminuria in diabetic nephropathy that involves primarily an abnormality in tubular handling of ultrafiltered proteins has also been suggested, but these changes are not necessarily exclusive of the altered properties of glomerular ultrafiltration barrier.

Albuminuria és a vesebetegség progressziója irreverzibilis változások: Érzékenység Csökkent nephron szám Iniciáló faktorok Obesitás, Inzulin rezisztenia Diabetes mellitus, Hypertónia Progressziós faktorok Glykémiás kontroll, BP, proteinuria, dyslipidemia, Ca-PO4, anemia, dohányzás 300 mg/nap időleges hyperglycemia, hypertónia, protein terhelés GFR ( ml / min ) continuous relationship between UAE and risk. And like blood pressure,the concept of a threshold level to define normality is inconsistent with epidemiological data. Forman JP, Brenner BM. ‘Hypertension’ and ‘microalbuminuria’: the bell tolls for thee. Kidney Int 2006; 69: 22–28. subjects with progressive renal function deterioration, urinalysis invariably shows plasma proteins also different from albumin and clearance studies disclose the appearance of a shunt allowing for an unrestricted ultrafiltration of plasma macromolecules.84 At this stage, morphological evaluation of the kidney tissue identifies the appearance of diffuse glomerulosclerosis and tubulointerstitial infiltration,typical features of progressive nephropathies associated with proteinuria. structural changes do not correlate with MAU albuminuria proteinuria Progresszió, irreverzibilis változások: glom.scler., tub.int.inf. Funkcionális, potenciálisan reverzibilis változások, normális hisztológiai kép Idő Ruggenenti P, Remuzzi G. KI, 2006;70:1214.

GFR < 60 ml/min & MAU MAU N = 2966, Framingham offspring CV events- and total mortality, % MAU GFR > 60 ml/min normoalbuminuria 0 2 4 6 8 yr Levey A, Kidney Int, 2005;67:2089

Összmortalitás, CV mortalitás a GFR és albuminuria függvényében összmortalitás - ACR CV mortalitás - ACR összmortalitás - tesztcsík CV mortalitás - tesztcsík eGFR ml/perc Lancet 2010;375:2073 - 2081

összmortalitás kardiovaszkuláris mortalitás végállapotú veseelégtelenség akut veseelégtelenség vesefunkció romlás Summary of categorical meta-analysis (adjusted relative risk (RR)) for general population cohorts with albumin-to-creatinine ratio (ACR). Mortality is reported for general population cohorts assessing albuminuria as urine ACR. Kidney outcomes are reported for general population cohorts assessing albuminuria as either urine ACR or dipstick. Estimated glomerular filtration rate (eGFR) and albuminuria are expressed as categorical variables. All results are adjusted for covariates and compared with the reference cell (Ref). Each cell represents a pooled relative risk from a meta-analysis; bold numbers indicate statistical significance at P<0.05. Incidence rates per 1000 person-years for the reference cells are 7.0 for all-cause mortality, 4.5 for cardiovascular disease mortality, 0.04 for kidney failure, 0.98 for acute kidney injury (AKI), and 2.02 for kidney disease progression. Absolute risk can be computed by multiplying the relative risks in each cell by the incidence rate in the reference cell. Colors reflect the ranking of adjusted relative risk. The point estimates for each cell were ranked from 1 to 28 (the lowest RR having rank number 1, and the highest number 28). The categories with rank numbers 1–8 are green, rank numbers 9–14 are yellow, the rank numbers 15–21 are orange, and the rank numbers 22–28 are colored red. (For the outcome of kidney disease progression, two cells with RR <1.0 are also green, leaving fewer cells as orange.) Kidney International 80, 17-28 (July (1) 2011) 16

Prognózis a GFR & proteinuria alapján Albuminuria - Proteinuria mg/mmol Normoalbu-minuria ACR <3 Mikroalbu-minuria ACR 3-30 Proteinuria TPCR 45-350 Nephrotikus proteinuria TPCR >350 GFR stádi-um ml/ min/ 1.73m2 magas / normális >90 alacsony mérsékelt nagy igen nagy enyhén csökkent 60-89 mérsékelt VE 45-59 középsúlyos VE 30-44 súlyos veseelégt. 15-29 végstádiumú VE <15 A.S.Levey, J.Coresh: Lancet online Aug.15.2011 nyomán, módosítva 17 17

Albuminuria és mortalitás hypertóniában UAE ≥ 4,8 μg/min Cumulative mortality (%) UAE < 4,8 μg/min age-adjusted curves of cumulative mortality for a 60-year-old person based on 1734 hypertensive subjects évek Klausen K. Hypertension 2005;46;33

Az albuminuria új definíciója Időre gyűjtés (µg/min) Random alb/creat mg/mmol Dipstick 24 h albumin (mg) 24 h protein (mg) Normális – < 8 < 5 < 0,7 < 150 Microalbuminuria is defined by a range of values within the continuum of urinary albumin excretion. Patients with microalbuminuria are negative for protein on usual dipstick testing and often have normal amounts of protein excreted on the 24-hour urine collections done for protein. However, these patients have abnormally elevated urinary albumin excretion at 20-200 µg/min or 30-300 mg/24 hours. Many patients with microalbuminuria go on to develop overt nephropathy, However, once a patient has overt proteinuria there is no reason to measure urinary albumin excretion, as a test for proteinuria is already positive. The goal is to identify nephropathy and MAU in the early stages, and to institute treatment before it is too late. 1. Parving H-H, et al. Renal protection in diabetes: an emerging role for calcium antagonists. J Hypertens 1996;14(suppl 4):S21-S25. Data from Heart Outcome Prevention Evaluation, Losartan Intervention For End point reduction in hypertension, and Framingham studies8,9,13 clearly suggest that only negligible amounts of albuminuria below approximately 2 mg/g of urinary creatinine (or an estimated excretion rate of 2 mg/day) should be considered as ‘normal’. This approximately corresponds to a urinary concentration of 1–2 mg/ml, which is below or close to the detection limit MAU: Új definíció – 8 - 300 5 - 200 0,7 - 25 Klausen K. Circulation 2004;110;32, Ruggenenti P, Remuzzi G. KI, 2006;70:1214.

Az albuminuria jelentősége Az endothel dysfunctio jele Az inzulin rezisztencia jele A nephropathia jele DIAGNOSIS Albuminuria PROGNOSIS CV morbiditás, mortalitás, össz-mortalitás Veseelégtelenség

A MAU prevenciója T2DM-ban: BENEDICT N = 1204, F/U: 3,6 yr Ruggenenti P. N Engl J Med 2004;351:1941

A MAU regressziója normotóniás, T1DM-os, mikroalbuminuriás betegekben placebo vs ACE inhibitor RR Newman D. Health Technology Assessment 2005; Vol. 9

Az albuminuria redukciója párhuzamos a kardiovaszkuláris események redukciójával: RENAAL Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan Study ratio of urinary albumin (measured in milligrams per liter) to urinary creatinine (measured in grams per liter) from a first morning specimen of at least 300 (or a rate of urinary protein excretion of at least 0.5 g per day) and serum creatinine values between 1.3 and 3.0 mg per deciliter (115 and 265 μmol per liter), with a lower limit of 1.5 mg per deciliter (133 μmol per liter) for male patients weighing more than 60 kg. progression remission n=1513, Circulation 2004;110:921

A HOPE, LIFE, RENAAL, IDNT, és AASK vizsgálatok eredményei alapján az albuminuria csökkenése korrelált a végállapotú veseelégtelenség, kardiovaszkuláris események és a mortalitás rizikójának csökkenésével.

Mit lehet tenni, ha maximális adagú ACE gátló vagy ARB mellett a proteinuria 1g /nap feletti?! 1. ACE gátló ÉS ARB Szupramaximális adagú ACE gátló vagy ARB 2.

Kombinált ACE gátló és ARB kezelés hatása az albuminuriára - metaanalízis 1. vs ACEi 13 randomizált tanulmány, 425 beteg, Primer glomerulonephritis. Proteinuria 0,8-7,9 g/nap, Követési idő: 1,5 - 12 hó, GFR 37-110 ml/min vs ARB In both cases, a greater decrease in proteinuria between combination therapy and ACE inhibitor alone or ARB alone was observed when studies included subjects with greater baseline proteinuria. Combination therapy significantly decreased systolic and diastolic BP compared with ACE-inhibitor monotherapy and ARB monotherapy. no significant effect of combination therapy on GFR was found in comparison with either an ACE inhibitor (n 12 studies) orARB (n 8 studies; g/nap kombináció hatásosabb Catapano F, Am J Kidney Dis 2008;52:475.

kiindulási proteinuria g/nap Kombinált ACE gátló és ARB kezelés hatása az albuminuriára - metaanalízis 2. Δ proteinuria (kombináció - ACEi) kiindulási proteinuria g/nap

ACE gátló vagy ARB: albuminuria Δ proteinuria átlag arány ARB ACEi ARB hatásosabb ACEi hatásosabb Kunz R, Ann Intern Med. 2008;148:30

Supramaximális ARB adagolás Nem-diabeteses vesebetegség, proteinuria. n=78, Követés: 2 év, Telmisartan 80 mg/d vs 160 mg/d P< 0,01 P< 0,01 AJKD 2005;46:1074

A simvastatin javítja a slit-membrán fehérjék expresszióját T2DM-ban Alap 4 év simvastatin 4 év cholestiramin Tonolo G. Kidney Int 2006;70:177.

By decreasing the production of farnesylated and geranylgeranylated proteins, statins reduce the activation of the transcription factor nuclear factor kappa-B, which plays an important role in regulating genes encoding proinflammatory cytokines and adhesion molecules statins seem to have a direct effect on cellular components of inflammation, insofar as they inhibit the expression of major histocompatibility complex class II on endothelial cells and monocytes, resulting in inhibition of T-cell Activation The phosphatidylinositol-3 kinase-Akt (PI3K/Akt) pathway leads to phosphorylation and thus activation of endothelial NO synthase (eNOS), resulting in increased NO production. Statins seem to increase eNOS activity via post-translational activation of the PI3K/Akt pathway Endothelial progenitos cells can transdifferentiate into myocardial and vascular cells and thus contribute significantly to neoangiogenesis, endothelial repair, and possibly myocardial remodeling (40). Statins increase the number of circulating EPCs Elevated cholesterol levels have been associated with overexpression of angiotensin II type 1 receptor (54). Treatment with statins, in turn, has been shown to decrease levels of these receptors, resulting in both decreased angiotensin II-mediated vasoconstriction and enhanced response to angiotensin receptor blocker drugs. Rho proteins are small GTPases that regulate cytoskeleton organization and cell adhesion, thus contributing to cell migration and endothelial permeability statins have been shown to inhibit vascular endothelial growth factor-induced upregulation of angiotensin converting enzyme inability of ezetimibe, in comparison with atorvastatin alone or in combination with ezetimibe, to improve endothelial vasodilator function in the forearm circulation of patients with coronary artery disease (CAD), despite its LDL-cholesterol lowering effect In hypercholesterolemic patients with angiographically-documented coronary artery disease, simvastatin significantly improved the percent flow-mediated dilator response to hyperemia, whereas the response to nitroglycerin was not significantly modified (Koh et al 2003). In the same patients, it significantly lowered the plasma levels of TNF-α, CRP, fibrinogen and ICAM-1 they increase the stability of the plaque whose rupture leads to thrombosis by exposing blood to the highly thrombogenic contents of its lipid core (Liao 2002). Rather than reducing lipid levels (which reduces plaque size and modifies the physiochemical compositions of the lipid core) (Koh 2000; Takemoto et al 2001), statins exert their beneficial effects by decreasing the infiltration and activity of macrophages and T-lymphocytes within the plaque, and inhibiting proteolytic enzymes such as matrix metalloproteinases (MMP), which are thought to be responsible for the plaque rupture induced by the thinning, ulceration and fissuring of the fibrous cap

A simvastatin megőrzi a vesefunkciót és csökkenti az albuminuriát T2DM-ban N = 86, MAU, HT ACE, BB, thiazide + simvastatin vs cholestiramin F/U: 4 év On the contrary - PREVEND IT: Conclusions—In microalbuminuric subjects, treatment with fosinopril had a significant effect on urinary albumin excretion. In addition, fosinopril treatment was associated with a trend in reducing cardiovascular events. Treatment with pravastatin did not result in a significant reduction in urinary albumin excretion or cardiovascular events. Tonolo G. Kidney Int 2006;70:177.

A lipid szintek változása statin és cholestiramin mellett Tonolo G. Kidney Int 2006;70:177.

J Am Soc Nephrol 17: 2006–2016, 2006.

Pentoxifillin hatása a proteinuriára és vesefunkcióra TNFα sejtproliferáció gyulladás matrix akkumuláció S-L Lin, Am J Kidney Dis 2008;52:464

Pentoxifillin diabeteses nephropathiában: metaanalízis 10 randomizált tanulmány, 476 diabeteses beteg Albuminuria > 30 mg/ nap vagy GFR < 60 ml/min Albuminuria p<0,01 pentoxifillin vs placebo pentoxifillin vs ACEi mg/nap

Multifaktoriális terápiás intervenció Életmód - Dohányzás elhagyása - Normális testtömegindex elérése (BMI < 25 kg/m2) - Sófogyasztás csökkentése (24 h urine Na < 80 mmol) Vérnyomás - Cél: < 130/80 Hgmm < 125/75 Hgmm ha > 1g/nap proteinuria - ACE gátló vagy Angiotensin Receptor Blokkoló (diuretikummal, CCB-val, értágítóbéta blokkolóval kombinálva) - ACEi ÉS ARB kombináció ha a proteinuria > 1g/nap (vagy supramaximális ACEi vagy ARB) Statinok - LDL cél < 2,6 mmol/l, nagyon magas rizikó: < 1,8 mmol/l Szoros glikémiás kontroll - HBA1c cél < 6,5 % - Izulin rezisztencia csökkentők Aspirin Nebivolol Rationale for new therapeutic option: very low LDL-C goal <1.8mmol/L 􀂃􀂃 Since the ATP III guidelines were published, however, the results of HPS and PROVE IT have suggested that additional benefit is provided with further reductions in LDL-C below 2.6mmol/L. 􀂃􀂃 Therefore, a new therapeutic option—an LDL-C goal of <1.8mmol/L—has been introduced