A D-vitamin receptor (VDR) aktiváció fontossága 4-es típusú

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1 A D-vitamin receptor (VDR) aktiváció fontossága 4-es típusú
CRS esetén: renális hatások Dr. Zakar Gábor orvos-igazgató B. Braun Avitum 9. Dialízis Központ, Székesfehérvár

2 Kardio-renális szindróma
és szelektív D-vitamin receptor aktiváció A D-vitamin receptor (VDR) aktiváció szerepe a kardiorenális szindrómában Renális hatások Zakar Gábor dr. Szent György Kórház I. Belgyógyászat – Nefrológia és B.Braun Avitum 9. Dialízisközpont, Székesfehérvár

3 Krónikus vesebetegség (KVB), D-vitamin hatás és a Ca-P anyagcsere
Csökkent D-vitamin receptor aktiváció * ↑RAAS aktiváció „renális hatásterület” Note to Facilitator: Discuss the relationship of VDR Activation to each of these markers in turn in the next 4 sections: SHPT [this one] 2. Proteinuria 3. Vascular inflammation, calcification. Also reduced vascular compliance (flexibility) 4. LVH Role of VDR activation in SHPT 1[Levin2007, 31b] 2[Andress2006, 37Figure 9] 3[Floege2008, 1Figure 1] References: Levin A, Bakris GL, Molitch M, et al. Prevalence of abnormal serum vitamin D, PTH, calcium, and phosphorus in patients with chronic kidney disease: results of the study to evaluate early kidney disease. Kidney Int. 2007;71(1):31-38. Andress DL. Vitamin D in chronic kidney disease: a systemic role for selective vitamin D receptor activation. Kidney Int. 2006;69(1):33-43. Floege J, Wheeler DC, Ireland E, et al. [F-PO1746] Serum PTH and Mortality Risk in a Large Cohort of European Hemodialysis (HD) Patients: 2-Year ARO Results Másodlagos hiperparatireózis (SHPT) Vaszkuláris kalcifikáció és gyulladás Balkalmra- hipertrófia Proteinuria ↑ * „csökken a D-vitamin hatás” Ronco C, et al. J Am Coll Cardiol 2008;52:1527–39

4 eGFR intervallumok (ml/min/1.73 m2)
A D-vitamin receptor (VDR) aktiváció már a vesebetegség korai szakában csökken Adapted from Levin2007, 34Figure 5 50 150 45 1,25D (pg/ml) 40 † 35 100 30 25D (ng/ml) 1,25D (pg/ml) 25D (ng/ml) 25 iPTH (pg/ml) 20 † 50 15 10 iPTH (pg/ml) 25D or 1,25D levels begin to decline in CKD patients in early Stage 2. 1[Levin2007, 34Figure 5] 1,25D decreases more steeply and in an earlier phase of CKD; therefore, VDR activation deficiency is an early feature of CKD that might not be reversed by giving exclusively 25D. 1[Levin2007, 34b] By late Stage 3 disease, when phosphate is elevated and calcium is low, there is a much higher incidence or prevalence of hyperparathyroidism. 1[Levin2007, 34b] By Stage 5, the majority of patients have secondary hyperparathyroidism (SHPT). 1[Levin2007, 35Figure 6] In uremic patients, 1,25D might be less active, ie, more hormone than in the general population might be needed for VDR activation (see also slide on MOA of VDR activators in chapter “Differences in VDR Activation Therapies”). References: 1. Levin A, Bakris GL, Molitch M, et al. Prevalence of abnormal serum vitamin D, PTH, calcium, and phosphorus in patients with chronic kidney disease: results of the study to evaluate early kidney disease. Kidney Int. 2007;71(1):31-38. 5 (n = 1814) ≥80 79–70 69–60 59–50 49–40 39–30 29–20 <20 n = 61 n = 117 n = 230 n = 396 n = 355 n = 358 n = 204 n = 93 *1,25D mérésével eGFR intervallumok (ml/min/1.73 m2) †p <0.001 Levin A, Bakris GL, Molitch M, et al. Kidney Int. 2007;71(1):31-38.

5 A D-vitamin kezelés klasszikus indoka KVB 3-4 st. betegekben
iPTH - mikor mérjük? GFR 60 ml/min alatt meredeken nő a kóros i-PTH szintek aránya NKF – továbbképző anyag ábrája, Medscape 2009

6 NKF – továbbképző anyag ábrája, Medscape 2009
Se-P szintek és a filtrált foszfor ürített hányada (FE-P) KVB 3-4 st. betegekben A se-P csak néhány, előrehaladott KVB esetben emelkedett A FE-P viszont már a 60-as GFR körül fokozott. Mi a háttér ? NKF – továbbképző anyag ábrája, Medscape 2009

7 A ‘normál’ se-P háttere KVB 3-4 st. betegekben
i-PTH FGF-23 A csökkentett P-bevitel előírásával nem szabad a hiperfoszfatémiát megvárni ! A ‘normál’ se-P a fokozódó iPTH és FGF szekréció, (útján) csökkenő tubuláris P-reszorpció (növekvő FE-P) árán tartható fenn NKF – továbbképző anyag ábrája, Medscape 2009

8 + VDR aktiváció és a renin-angiotenzin (RA) tengely
A VDR aktiváció transzkripciós szinten gátolja ANGIOTENZINOGÉN RENIN + ANGOTENZIN I ACE-gátló Kimáz ANGIOTENZIN II VDR aktiváció és a renin-angiotenzin (RA) tengely ACEIs and ARBs cause the counter-regulatory increase in renin, which is likely deleterious. VDR activation directly inhibits renin at the transcription level. ARB feed-back hiperreninémia AT1 RECEPTOR ellenregulációs renin-szint növekedés Konstrikció Proliferáció ROS; gyulladás Fibrózis Aldoszteron Só és folyadék retenció Modosítás átvéve:: Giles TD. Blood Press Monit 2000;5(suppl 1):S3–S7

9 A transzkripciós hatás vázlata
Külső szignál Válasz- reakció szintetizált új fehérje-termék Az aktivált D-vitamin a DNS-könyvtár „kulcsa”

10 A VDR aktiváció a cAMP mediált renin-gén transzkripciót csökkenti
Klinikailag releváns dózisok esetén (hypercalcaemiát nem okozó ekvipotens PTH szuppresszív dózisok) a parikalcitol többféle hatást is gyakorol a reninre: A VDR aktiváció a CREB-CRE kötődést gátolja CBP/p300 PKA CBP/p300 Prorenin CREB/CREB VDR aktivátorok P VDR CREB/CREB D Pol II Pol II 0.01 0.001 0.1 1 10 0.00 0.02 0.04 0.06 0.08 Renin mRNS In vivo: egér vese -0.5 0.5 1.5 2.5 3.5 Dózis (s.c., µg/kg) Delta Ca (mg/dl) 4.5 CRE CRE PKA=protein kináz-A; CRE=cAMP response element; D=VDR aktivátor; Pol II=RNS polimeráz II A VDR aktivátorok egyforma erősséggel gátolják a renin szintézist: Data from Yuan, et al, suggests that VDR activation suppresses cAMP response element (CRE)-mediated transcriptional activity by blocking CREB binding to the CRE. The top left figure depicts a model of VDR activator-induced transrepression of renin gene expression. The cAMP-PKA pathway plays a key role in the stimulation of renin gene expression. This pathway activates CREB by phosphorylation, leading to recruitment of CBP/p300. In the presence of a VDR activator, liganded VDR interacts with CREB and blocks its binding to CRE, leading to reduction of renin gene transcription. -11 -10 -9 -8 -7 -6 0.00 0.02 0.04 0.06 0.08 Parikalcitol Kalcitriol Koncentráció [-log M] Renin/GAPDH arány As4.1 Yuan W et al. J Biol Chem 2007;282: Data on file, Abbott Laboratories

11 A parikalcitol gátolja az obstruktív NP okozta gyulladást
UUO egerek napi 0,3 μg/ttkg sc. parikalcitol kezelése 7 vagy 14 napon át (n=5 állat / csoport) RANTES TNF-α MCP-1 10 12 * * * * 8 * 10 Áltag ± SEM relatív mRNS szintek (indukció mértéke) Áltag ± SEM relatív mRNS szintek (indukció mértéke) 8 † 6 * 6 † † 4 4 † † † † 2 2 † Imitált Vivőanyag 0,3 μg 0,1 μg Imitált Vivőanyag 0,3 μg 0,1 μg UUO UUO The effect of paricalcitol on renal inflammation was investigated in a mouse model of obstructive nephropathy. Paricalcitol inhibited RANTES/CC-chemokine ligand 5 (CCL5) and TNF-α but not MCP-1/ CCL2 mRNA expression in obstructive nephropathy. Renal mRNA levels of RANTES, TNF-α, and MCP-1 in Sham and unilateral ureteral obstruction (UUO) mice treated with vehicle, or paricalcitol 0.3 μg/kg or 0.1 μg/kg. Relative mRNA levels at 7 days and 14 days after UUO were calculated and expressed as fold induction over sham controls (value=1.0) after normalization with β-actin. 7 napos parikalcitol kezelés 14 napos parikalcitol kezelés *p<0,01 vs. imitált kontrollok; †p<0,01 vs. vivőanyag kontrollok RANTES proinflammatoricus cytokin, az ureter obstrukciónak kitett vesében a gyulladásos sejtes reakció kialakulásáért felelős A TNF-α az infiltráló sejtek által termelt gyulladásos cytokin A parikalcitol mindkét citokin expresszióját gátolta Tan X et al. J Am Soc Nephrol 2008;19:

12 VDR hatás az obstruktív NP egér-modelljében
csökkent a TGF-β receptor (TβR-1) és az alfa-SMA kontraktilis protein expressziója Imitált UUO UUO + parikalcitol TβR-1 TGF-β1 This slide shows representative micrographs showing the expression and localization of TβR-1 (C through E) and TGF-β1 (F through H) proteins by immunohistochemical staining, as well as immunofluorescence staining demonstrating that paricalcitol abolished TGF-β1–-induced α-SMA and fibronectin expression and assembly. TGF-β1 signaling is known to play a crucial role in renal fibrogenesis and mediates several key fibrotic processes, including epithelial to mesenchymal transition (EMT). This pre-clinical study shows that paricalcitol could influence TGF-β1 and its receptor (TβR-1) expression in obstructive nephropathy. Kidney tissues immunostained with anti-TβR-1 antibody indicated significant induction of renal TβR-1 in the obstructed kidney over the sham controls (D vs C). However, paricalcitol significantly inhibited TβR-1 induction that was caused by ureteral obstruction (E). In addition, TGF-β1 was markedly induced in the obstructed kidney, as reported previously; paricalcitol also abrogated TGF-β1 expression that was induced by ureteral obstruction. Of note, both TGF-β1 and TβR-1 were localized predominantly in the tubular epithelia, suggesting that tubular epithelial cells are the primary targets of this potent profibrotic cytokine under pathologic conditions. Similarly, paricalcitol also inhibits the expression of α-SMA in obstructed kidney in a dose dependent manner. α-SMA is a contractile protein that indicates myofibroblasts transformation. Paricalcitol also completely restored VDR abundance in the obstructed kidney in a dose dependent manner. In summary, compared with vehicle controls, paricalcitol significantly attenuated renal interstitial fibrosis in mouse kidney after ureteral obstruction, indicating potential kidney protective benefit. α-SMA Csökkent az obstrukció okozta intersticiális fibrózis UUO = egyoldali ureter obstrukció; TβR-I, TGF-β I. típusú receptor; α-SMA, α-simaizom aktin Tan X et al. J Am Soc Nephrol 2006;17:

13 A szelektív VDR aktivátor parikalcitol az NF-ĸB modulációjával gátolja a vesegyulladást
A parikalcitol gátolja az NF-κB-t (egy génexpressziót szabályozó faktor), amely így gátolja a RANTES (proinflammatoricus kemokin) indukcióját A parikalcitol ezt a hatást úgy fejti ki, hogy elősegíti a VDR és az NF-κB közötti kölcsönhatást, amely gátolja a RANTES transzkripciós folyamatát, a gyulladásos folyamatok csökkenését eredményezve A korábbi eredményeket erősítette meg az is, hogy a parikalcitol VDR up-regulációt okoz, így a VDR aktiválásnak valószínűleg aktív szerepe van a tubulusok épségének megőrzésében Tan X et al. J Am Soc Nephrol 2008;19:

14 intrarenális RAS gátlással társult A gyógyszeres kezelés kezdete
Losartan + parikalcitol normalizálta az albuminuriát egerek streptozotocin (STZ) indukálta diabéteszében intrarenális RAS gátlással társult Kontroll Losartan Losartan + Parikalcitol Vivőanyag Parikalcitol 2000 V A gyógyszeres kezelés kezdete 1500 L Vizelet albumin/kreatinin arány (µg/mg) Paricalcitol provides additional prevention against proteinuria. Combination therapy with the ARB, losartan, and the selective VDR activator, paricalcitol, markedly ameliorated renal injury in the streptozotocin (STZ)-induced diabetes model due to the blockade of the compensatory renin rise by the VDR activator, leading to more effective RAS inhibition. STZ-treated diabetic mice developed progressive albuminuria and glomerulosclerosis within 13 weeks, accompanied by increased intrarenal production of Ang II, fibronection, TGF-β, and MCP-1. Treatment of the diabetic mice with losartan or paricalcitol alone moderately ameliorated kidney injury; however, combined treatment with losartan and paricalcitol completely prevented albuminuria, restored glomerular filtration barrier structure, and markedly reduced glomerulosclerosis. The combined treatment suppressed the induction of fibronection, TGF-β, and MCP-1. These were accompanied by blockade of intrarenal renin and Ang II accumulation induced by hyperglycemia and losartan. These data demonstrate that inhibition of the RAS with combination of VDR activator and RAS inhibitors effectively prevents renal injury in diabetic nephropathy. Controls were nondiabetic mice. 1000 P 500 ** *** L+P * 3 8 13 hetek *p<0.05 (C vs. más csoportok); **p<0,01 (C és LP vs. V); ***p<0,001 (C és LP vs. V); n=4–6 Zhang Z et al. Proc Natl Acad Sci 2008;105:15896–901. Copyright 2008 National Academy of Sciences, USA

15 Losartan + parikalcitol csökkentette a glom
Losartan + parikalcitol csökkentette a glom.sclerosist egerek streptozotocin (STZ) indukálta diabéteszében Losartan + Parikalcitol Kontroll Vivőanyag Losartan Parikalcitol 3 Pathological sclerosis is used by clinicians to assess diabetic nephropathy; this model shows clear reductions in glomerular sclerosis, which almost return to non-diabetic appearances by the combination of losartan and paricalcitol. 2.5 *** 2 *** *** Glomeruscleroticus index 1.5 1 0.5 C V L P L+P ***p<0,001 (vs. vivőanyag) Zhang Z et al. Proc Natl Acad Sci 2008;105:15896–901. Copyright 2008 National Academy of Sciences, USA

16 Az angotenzin-II termelésének szupressziója a STZ diabéteszes vesében
Losartan + Parikalcitol Kontroll Vivőanyag Losartan Parikalcitol Tubulusok Glomerulus This image shows immunostaining of kidney in glomerular (A–E) and tubular (F–J) areas with Ang II-specific antibody. Zhang Z et al. Proc Natl Acad Sci 2008;105:15896–901. Copyright 2008 National Academy of Sciences, USA

17 Angiotenzin II fehérjeszint
A renin bioszintézis és az angotenzin II termelés szupressziója a STZ diabéteszes vesében L C V P L+P C V L P L+P Ang II Renin β-aktin β-aktin A nyilak a prorenin és renin sávokat jelölik 400 350 *** ** 350 300 VDR activation with VDR activators alone can directly suppress the high-glucose induction of TGF-β and MCP-1 in mesangial cells; this study showed that co-treatment with losartan and paricalcitol achieved better inhibition of these cytokines in vivo. Because TGF-β and MCP-1 are up-regulated by Ang II, the suppression of these factors by the co-treatment is likely mediated by the blockade of Ang II accumulation, as shown in this slide. 300 250 250 200 Angiotenzin II fehérjeszint Renin mRNS szint # 200 150 150 ** ** ## 100 100 ** 50 50 C V L P L+P C V L P L+P **p<0,01; ***p<0,001 (vs. V); #p<0,05; ##p<0,01 (vs. L); n=3–5 Zhang Z et al. Proc Natl Acad Sci 2008;105:15896–901. Copyright 2008 National Academy of Sciences, USA

18 A parikalcitol csökkentette a veseléziót, hipertóniát és a proteinuriát 5/6 NX patkányokban
Parikalcitol vagy vivőanyag Uraemiás (UC) 5/6 NX patkányok – 4 csoportban heti háromszori kezelés 8 hétig Operáció 200 a a a Szisztolés vérnyomás (Hgmm) UC + vivőanyag UC + kis dózisú parikalcitol (0,1 µg/kg, i.p.) UC + magas dózisú parikalcitol (0,3 µg/kg, i.p.) Imitált 160 120 b b b b 2 4 6 8 Parikalcitol vagy vivőanyag Hét Operáció ap≤0,001; bp≤0,05 vs. más csoportok b The effects of paricalcitol treatment on the progressive renal damage induced by renal ablation was evaluated in 5/6 nephrectomy (NX) rats without treatment (control group), NX rats with paricalcitol 0.1 or 0.3 μg/kg IP three times per week for 8 weeks. The SBP increased in all groups with renal ablation compared with sham rats, but was less pronounced in rats treated with either paricalcitol dose (0.1 and 0.3 μg/kg groups). Plasma creatinine, initially elevated in all groups with renal ablation, promptly declined after the second week in paricalcitol-treated rats to levels comparable to sham rats and significantly lower than in nontreated 5/6 NX rats. Proteinuria increased progressively in all nephrectomized groups but was distinctly lower in the groups treated with both doses of paricalcitol. Hypertension improved, most significantly at higher dose (51–73% reduction in the paricalcitol groups; p<0.01). Additionally, there were reductions in kidney hypertrophy, glomerulosclerosis, and tubulointerstitial injury, as well as renal renin and angiotensinogen mRNA, VEGF, and TGFβ. Cardiac mRNA atrial natriuretic peptide (ANP) and aortic PAI-1 were significantly reduced with paricalcitol (p<0.05; Freundlich F et al. ASN 2007;SA-PO871). All these results mean that paricalcitol decelerates renal histological damage and improves renal function, proteinuria, and systemic hypertension. These studies suggest that the beneficial cardiovascular and renal effects are likely mediated by genetic downregulation of renin and angiotensinogen in the kidney and ANP in the heart. 2 b b Parikalcitol vagy vivőanyag 100 b Plazma Kr (mg/dl) 80 Operáció 1 60 Protienuria (mg/nap) a b a 40 2 4 6 8 20 Hét c c ap≤0,05; bp≤0,001 vs. más csoportok 2 4 6 8 Hét ap≤0,05 vs, imitált és 0,1 μg/kg parikalcitol; bp≤0,05 vs. más csoportok; cp≤0,05 vs. más csoportok Freundlich M et al. Kidney International 2008;74:1394–402

19 A parikalcitol csökkentette a patkányok veseelégtelenségének progresszióját
* * Kreatinin (mg/dl) In an experimental model of chronic renal failure, paricalcitol prevents SHPT and ameliorates the histomorphometric changes induced by uremia and a high phosphorus diet. In addition, paricalcitol suppresses serum PTH and improves bone histology in uremic rats with established severe SHPT. These 2 studies assessed the efficacy of paricalcitol in the prevention (Protocol I) and treatment (Protocol II) of SHPT and renal osteodystrophy in uremic rats. In Protocol I, normal and uremic rats were fed a high phosphorus diet for 2 months; uremic rats were administered intraperitoneal injections of either vehicle or paricalcitol (200 ng three times a week). In Protocol II, normal and uremic rats were fed a high phosphorus diet for 4 months; 2 months after the onset of uremia, rats were administered either intraperitoneal vehicle or paricalcitol (200 ng three times a week). Creatinine levels were measures to indicate kidney disease progress. Paricalcitol was effective in delaying the progression of kidney disease as indicated by creatinine level changes. In both Protocol I and Protocol II, paricalcitol use can be associated with significantly less creatinine increase between the normal rats with high P diet and vehicle and uremic rats with high P diet and vehicle than between the normal rats with high P diet and vehicle and uremic rats with high P diet and paricalcitol. N-HP+V 2 hónap (n=9) U-HP+V 2 hónap (n=8) U-HP + parikalcitol 2 hónap (n=9) N-HP+V 4 hónap (n=8) U-HP+V 4 hónap (n=8) U-HP + parikalcitol 4 hónap (n=8) I. protokoll: Prevenció II. protokoll: Kezelés *p<0,05 vs. N-HP+V N, normál; U, uraemiás; HP, magas foszfortartalmú étrend; V, vivőanyag Forrás: Slatopolsky E et al. Kidney Int 2003;63:2020-7

20 TGF-β1/β-aktin (az NK-hoz képest)
Intersticium-térfogat és glomerulosclerosis az enalapril – parikalcitol kezelt, 5/6 nefrektomizált urémiás patkányokban IS - térfogat 4 hónapos E és P vagy E+P kombinációs terápia hatásai normál kontrollokhoz (NK) és uraemiás kontrollokhoz (UK) viszonyítva * * ‡ † % TGF-β1 fehérjeszint * NK UK E P E+P GS csökkenés Monotherapy with ACEIs has been shown to be beneficial in suppressing the progression of experimentally induced kidney diseases. This study investigated whether such therapy provides additional benefits when combined with VDR activator therapy. 5/6 Nx rats were treated with vehicle (UC), enalapril (30 mg/L in drinking water (E), paricalcitol (P; 0.8 μg/kg, 3x/week), or enalapril + paricalcitol (E+P). A group of normal rats served as control (NC). An increase in interstitial volume (23%) was also observed in UC rats (p<0.01 vs NC). Enalapril significantly limited the increase in interstitial volume (15%; p<0.05 vs UC) and, when combined with paricalcitol, produced a further improvement (10%; p<0.01 vs UC). Paricalcitol alone produced a significant decrease in the percentage of glomeruli that exhibited sclerotic changes (33%) compared with UC rats (p<0.01). The enalapril + paricalcitol group further decreased this parameter (12%). TGF-β1 mRNA expression in the kidneys of UC rats was significantly increased (23.7-fold) relative to NC rats (p<0.01). This increase was significantly blunted in uremic rats that were treated with paricalcitol (p<0.05 Thus, paricalcitol can suppress the progression of renal insufficiency via mediation of the TGF-β1 signaling pathway, and this effect is amplified when BP is controlled via renin-angiotensin system blockade. TGF-β1/β-aktin (az NK-hoz képest) * † † † *† % † NK UK E P E+P †¶ p=0,0423 ANOVA analízissel, TGF-β1; p=0, interstitialis térfogat p<0,0001, glomerulosclerosis ANOVA analízissel; *p<0,01 vs. NK; †p<0,01 és ‡p<0,05 vs. UK; §p<0,01 és ¶p<0,05 vs. parikalcitol NK UK E P E+P Mizobuchi M és mts., JASN 18: , 2007

21 ACE-gátló/ARB használók
A parikalcitol antiproteinuriás hatása „dipstick” pozitív ( 30 mg % ) proteinuria változása 220 KVB 3-4 beteg RC, kettősvak, placebo-kontrollált vizsgálata, 24 hét Parikalcitol Placebo p=0,004 22/42 11/41 p=0,025 52 27 ACE-gátló/ARB használók 27/51 0/7 p=0,012 53 iPTH-reszponderek 60 51 50 40 Olyan betegek, akiknél a tesztcsíkkal mért proteinuria csökkent (%) 30 25 Paricalcitol-treated patients with CKD Stage 3/4 had a reduction in dipstick proteinuria compared with placebo, which was independent of RAAS blockade with ACEI/ARB therapy. Three double-blind, randomized, placebo-controlled studies evaluated the safety and efficacy of oral paricalcitol capsules. 220 CKD stage 3 and 4 patients with SHPT were randomized to oral paricalcitol (n=107, mean dose 9.5 μg/week) or placebo (n=113) and followed for up to 24 weeks. The effect of paricalcitol on proteinuria was evaluated, which was measured by dipstick and read by an automated reader (reported as negative, trace, 1+, 2+ and 3+) at the beginning and end of trial. Reduction in proteinuria was an improvement in the dipstick reading at the end of the trial. At baseline, proteinuria was present in 57 patients randomized to oral paricalcitol and 61 patients randomized to placebo (NS). At the final visit, 29/57 (51%) of the paricalcitol patients compared with 15/61 (25%) placebo patients had reduction in proteinuria, p=0.004 (odds for reduction in proteinuria 3.2 times greater for paricalcitol patients, 95% CI 1.5–6.9). Further analysis revealed that of patients who were on ACEI/ARB therapy and had proteinuria at baseline had similar decreases in proteinuria as the overall group: 52% (22/42) of paricalcitol patients vs 27% (11/41) of placebo patients had a decrease in proteinuria (p=0.025) In the patients who achieved an iPTH response, more than half (53%) of those taking oral paricalcitol had reduction in proteinuria compared with none in the placebo group (p=0.012). The results shown here were a post-hoc analysis and the following slide will show the first RCT with any VDR activator looking at albuminuria. 20 10 29/57 15/61 22/42 11/41 27/51 Általános csoport PU csökkenés / placebo 3.2x-es. Az ACEi/ARB –nek nem volt additív hatása Agarwal R et al. Kidney Int 2005;68:2823-8

22 A proteinuria, mint vizsgálati végpont…
Fig. 1. a Association between albuminuria level and the risk for renal outcomes in different populations. Data show the risk for the occurrence of ESRD (death) for the general population (PREVEND [9] ), type 2 diabetes (ADVANCE [6] ) and hypertensive nephrosclerosis (AASK [7] ). The protein:creatinine ratio, measured in the AASK trial, was converted to the albumin:creatinine ratio. The center of the squares are placed on the average albuminuria level in each population. b Associations between the proportional change in albuminuria and the risk for renal outcomes. Renal endpoint in the IRMA-2 trial is diabetic nephropathy. The renal endpoint in the AASK trial is ESRD. The two x axes indicate the ranges of albuminuria reduction for the two different individual trials. Should Microalbuminuria Ever Be Considered as a Renal Endpoint in Any Clinical Trial - PRO : Heerspink HJL, deZeeuw D., CON : Glassock RJ Am J Nephrol 31:458–461, , 2010 Apr 22

23 Parikalcitol hatása a gyulladásos aktivációra és az albuminuriára
RCT, 24 KVB 2-3 beteg,1 hónapos vizsgálata. Független volt a RR-tól és endothel-hatástól A kiinduláshoz viszonyított változás (%) A változások függetlenek a vérnyomás, GFR, ill. a PTH változásaitól Az első randomizált, kontrollos vizsgálat a parikalcitol, ill. más VDR aktivátorok anti-proteinuriás hatásaival kapcsolatosan Az endothel funckió tekintetében nincs különbség (FMD) Az ér simaizomzatának működése nem mutat változást This pilot trial showed that short exposure to paricalcitol results in an anti-inflammatory effect (as measured by CRP) and a 50% reduction in albuminuria in the CKD population; these changes are independent of changes in blood pressure, GFR, or PTH. This is the first RCT on the anti-proteinuric effects of paricalcitol or any VDR activator 24 patients with CKD (n=2 Stage 2, n=22 Stage 3) had baseline eGFR >30 mL/min and were on stable doses of ACEI or ARB for ≥1 month were randomized to 3 equal groups: placebo, paricalcitol 1 µg, or paricalcitol 2 µg (all oral) for 1 month Measurements were taken at baseline, 1 month after treatment exposure, and 2 weeks after treatment stopped. Hemodynamic effects: endothelial function* (by FMD), ambulatory BP, GFR, UAE Non-hemodynamic effects: serum CRP* (inflammatory marker) The magnitude and rapidity of improvement in hsCRP were impressive. The p-values (0.048 and ) indicate a statistically significant change after paricalcitol exposure, compared with no paricalcitol exposure (placebo group). There was no change seen in either endothelium-dependent or endothelium-independent vasodilatation with paricalcitol use. Longer-term and larger studies are needed because the CIs are wide and cannot exclude a true effect. Despite biological plausibility, there was no significant change in the systolic or diastolic BPs between the 3 groups. Reasons possible for the lack of BP response may include blocking of the renin-angiotensin system, the BP of the patients was already well controlled, and also the short duration of follow-up. BP findings are important because the change in albuminuria cannot be accounted for by BP, and the fall in albuminuria cannot be ascribed to changes in GFR. Because the reduction in albuminuria occurred independent of changes in GFR or BP, it appears that the reduction was mediated not by hemodynamic mechanisms but appear to be mediated by non-hemodynamic, non-PTH mechanisms, possibly podocyte repair or repair of tubulointerstitial injury. These data extend the observations of a posthoc analysis by Agarwal R et al (Kidney Int 2005;68:2823-8). It appears that the reductions in albuminuria and hsCRP were independent of the effect of paricalcitol on mineral metabolism. A reduction in inflammation and albuminuria within 1 month after treatment with paricalcitol in patients with CKD was seen, despite use of ACEIs and ARBs. Randomized, controlled trials with paricalcitol are under way to demonstrate whether paricalcitol will have antiproteinuric or cardioprotective effects in patients with CKD, and in the next section, trials that are underway to investigate the effect of paricalcitol on LVH and proteinuria are described. *Primary endpoints hsCRP Albuminuria p=0,048 csoportok közötti válozások p=0,0005 csoportok közötti válozások Alborzi P et al. Hypertension 2008;52:1-7

24 Szelektív VDR aktiválás a cardiorenalis szindrómában renalis hatások : összefoglalás
A parikalcitollal végzett hatékony VDR aktiváció csökkenti a tubulointersitialis fibrosist UUO egerekben (TGFβ útvonal) A szelektív VDR aktiváció az NF-ĸB aktivitás modulációjával csökkenti a gyulladást UUO egerekben, ami a RANTES és TNF-α faktorok csökkenéséhez vezet A parikalcitol a renin transzkripció direkt modulációjával gátolja az RAA-rendszert, és az angiotenzin II receptor blokkolókkal, ill. az ACE-gátlókkal szinergista hatást fejt ki Preklinikai vizsgálatokban a parikalcitol lassította a krónikus vesebetegség progresszióját A parikalcitol a krónikus vesebetegség állatkísérletes modelljeiben megelőzi a proteinuriát Krónikus vesebetegeknél elvégzett első randomizált, kontrollos vizsgálat parikalcitollal megerősíti a proteinuria regresszióját