Vladimír Teplan

Increased production of proinflammatory cytokines in adipose tissue of patients with end-stage renal disease.

OBJECTIVE The number of patients with end-stage renal disease (ESRD) is rising and these patients are at higher risk of cardiovascular disease. We studied the role of hormonal production of adipose tissue in the development of chronic inflammation in patients with ESRD before kidney transplantation. METHODS Fifteen women with ESRD and 17 healthy women (control) underwent single blood drawing and visceral and subcutaneous adipose tissue sampling during surgery (kidney transplantation in the ESRD group or cholecystectomy in the control group). Serum concentrations of C-reactive protein, interleukin-6, tumor necrosis factor-alpha, leptin, adiponectin, resistin, monocyte chemoattractant protein-1 were measured. Messenger RNA expression of the same hormones, adiponectin receptors 1 and 2 and immunocompetent cell marker CD68 in subcutaneous and visceral samples were measured using real-time polymerase chain reaction. Adipose tissue was examined immunohistochemically for CD68-positive cells. RESULTS Serum concentrations of C-reactive protein, adiponectin, resistin, interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1 were significantly higher in the ESRD versus control group. Subcutaneous and visceral mRNA expressions of tumor necrosis factor-alpha and CD68 were significantly increased in the ESRD versus control group. Adiponectin receptor-1 and monocyte chemoattractant protein-1 mRNA expressions were significantly higher in visceral but not in subcutaneous adipose tissue of the ESRD group. Messenger RNA expressions of resistin, leptin, adiponectin, interleukin-6, and adiponectin receptor-2 in both fat depots did not significantly differ between groups. Increased infiltration of subcutaneous and visceral adipose tissue with CD68-positive immunocompetent cells was found in the ESRD group by histologic examination. CONCLUSION Subcutaneous and visceral adipose tissues in ESRD express higher amounts of proinflammatory cytokines and may play a role in the development of systemic inflammation.

Keto Acid Therapy in Predialysis Chronic Kidney Disease Patients: Final Consensus

*Department of Nephrology, Centre Hospitalier Universitaire et Universitea Bordeaux II, Bordeaux, France.†Nephrology Dialysis and Renal Transplantation Unit, University Hospital ‘‘S. Giovanni di Dio e Ruggi d’Aragona’’, Salerno, Italy.‡Department of Nephrology, Hopital Pellegrin, Bordeaux, France.§Aurad-Aquitaine, Gradignan, France.{Nephrology Unit, Department of Internal Medicine, University of Pisa, Pisa, Italy.**Division of Nephrology, Department of Internal Medicine, Istanbul School of Medicine, Istanbul University, Capa, Istanbul, Turkey.††Departement de Nephrologie, H^opital E. Herriot, Lyon Cedex, France.‡‡‘‘Dr. Carol Davila’’ Teaching Hospital of Nephrology, Bucharest, Romania.§§Chinese Society of Nephrology, International Society of Nephrology, and Division of Nephrology, Huashan Hospital, Fudan University,Shanghai, People’s Republic of China.{{Division of Nephrology, Baylor College of Medicine, Houston, Texas.***Department of Nephrology, Institute for Clinical and Experimental Medicine and Institute for Postgradual Education, Prague, CzechRepublic.‡‡‡Dialysis Center No. 9, Health Care Service PLC, Euro Care Hungary, Szekesfehervar, Hungary.§§§The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People’s Republic of China.FinancialDisclosure:TheauthorsbelongtotheFreseniusKabiKetoanalogueAdvisoryBoardandparticipatedinthe5thInternationalAdvisoryBoardMeeting,Vevey,Switzerland,May29,2010.ConsultancyfeesandtravelgrantswerereceivedfromFreseniusKabi.Thearticleswerepub-lished as part of a supplement sponsored by an unrestricted educational grant from Fresenius Kabi.AddressreprintrequeststoPhilippeChauveau,ServicedeNephrologie,HopitalPellegrin,CHUdeBordeaux,PlaceAmelieRabaLeon,33000,Bordeaux, France.

Protein-restricted diets plus keto/amino acids--a valid therapeutic approach for chronic kidney disease patients.

Chronic kidney disease (CKD) is increasingly common, and there is an increasing awareness that every strategy should be used to avoid complications of CKD. Restriction of dietary protein intake has been a relevant part of the management of CKD for more than 100 years, but even today, the principal goal of protein-restricted regimens is to decrease the accumulation of nitrogen waste products, hydrogen ions, phosphates, and inorganic ions while maintaining an adequate nutritional status to avoid secondary problems such as metabolic acidosis, bone disease, and insulin resistance, as well as proteinuria and deterioration of renal function. This supplement focuses on recent experimental and clinical findings related to an optimized dietary management of predialysis, dialysis, and transplanted patients as an important aspect of patient care. Nutritional treatment strategies are linked toward ameliorating metabolic and endocrine disturbances, improving/maintaining nutritional status, as well as delaying the renal replacement initiation and improving outcomes in CKD patients. A final consensus states that dietary manipulations should be considered as one of the main approaches in the management program of CKD patients and that a reasonable number of patients with moderate or severe CKD benefit from dietary protein/phosphorus restriction.

Pregnancy-associated plasma protein a and soluble receptor for advanced glycation end products after kidney transplantation.

Background: Pregnancy-associated plasma protein A (PAPP-A) and soluble receptor for advanced glycation end products (sRAGE) are new markers related to vascular damage. Methods: Thirty-one patients who had undergone kidney transplantation (TX) in the year 2005 under tacrolimus-based immunosuppression were included in this prospective single-center study. PAPP-A and sRAGE were determined before TX and 2 and 6 weeks and 3 months after TX. The results were correlated with the 3-month protocol kidney graft biopsy findings. Results: Both PAPP-A and sRAGE decreased after TX (mean values in serum: PAPP-A 20.8, 13.7, 12.1, and 10.7 mIU/l, respectively, before and 2 and 6 weeks and 3 months after TX, p < 0.001; sRAGE 4,403.4, 2,512.7, 1,909.0, and 1,817.6 pg/ml, respectively, before and 2 and 6 weeks and 3 months after TX, p < 0.001) and were correlated with the graft function (PAPP-A vs. modification of diet in renal disease formula r = –0.52, p < 0.001; sRAGE vs. modification of diet in renal disease formula r = –0.54, p < 0.001). Additionally, the PAPP-A levels correlated with interstitial inflammation (r = 0.57, p < 0.05) and vascular intimal thickening (r = 0.47, p < 0.05), while sRAGE correlated with arteriolar hyalinosis (r = 0.49, p < 0.05). Conclusions: Our study demonstrates the role of the kidney in the metabolism and/or the removal of PAPP-A and sRAGE. After successful TX, these substances decrease, and, on the contrary, early chronic vascular changes in the kidney TX are associated with elevation of their serum levels.

Intrarenal Infusion of Angiotensin-(1–7) Modulates Renal Functional Responses to Exogenous Angiotensin II in the Rat

In the present study we investigated the possible role of angiotensin-(1–7) [Ang-(1–7)] in modulating renal functional responses to intrarenal (i.e.) infusion of angiotensin II (ANG II) in normotensive anesthetized rats. ANG II (6 ng/min, n = 14) decreased glomerular filtration rate (GFR), renal plasma flow (RPF), absolute and fractional sodium excretion by –24 ± 5, –25 ± 6, –44 ± 6 and –28 ± 7%, respectively (p < 0.05). i.r. infusion of Ang-(1–7) (50 ng/min, n = 13) did not significantly alter GFR (+6 ± 4%) but reduced RPF by –19 ± 7% (p < 0.05). Ang-(1–7) increased absolute and fractional sodium excretion by +36 ± 6 and +37 ± 8%, respectively (p < 0.05). Infusion of Ang-(1–7) did not prevent the decreases in GFR and RPF but completely blunted the decreases in absolute (–2 ± 2%) and fractional sodium excretion (–4 ± 4%) induced by ANG II (n = 11). Blockade of the Ang-(1–7) receptor by [7-D-Ala]-Ang-(1–7) (5 µg/min, n = 11) significantly decreased GFR, RPF, absolute and fractional sodium excretion by –28 ± 7, –20 ± 5, –32 ± 7 and –24 ± 4%, respectively (p < 0.05), suggesting that the action of endogenous ANG II is unopposed by compensatory effect of endogenous Ang-(1–7). i.r. infusion of Ang-(1–7) (n = 10) did not alter the effect of Ang-(1–7) receptor blockade on RPF (–21 ± 6%) but blunted its effects on GFR (+4 ± 3%) and absolute (+7 ± 5%) and fractional (+6 ± 4%) urinary sodium excretion probably by displacing the receptor blocker. While exogenous ANG II during blockade of the Ang-(1–7) receptor and the AT2 receptor (by PD 123319; 1 µg/min i.r., n = 9) resulted in the same decreases in absolute and fractional sodium excretion (–39 ± 8 and –38 ± 6%, respectively, p < 0.05) as did ANG II in the absence of Ang-(1–7) receptor blockade. These results suggest that in normotensive rats high i.r. Ang-(1–7) concentration attenuates the tubular, i.e. sodium reabsorptive effect, but not the vascular effect of exogenous i.r. ANG II. Results obtained during blockade of Ang-(1–7) and of AT2 receptors imply that AT2 receptors play a role in tubular sodium reabsorption in the presence of high ANG II concentration

Effects of Anesthesia on Plasma and Kidney ANG II Levels in Normotensive and ANG II-Dependent Hypertensive Rats

Background: Previous studies have implicated that normotensive rats with normal renal renin activity respond to anesthesia and surgery with greater increases in plasma and kidney angiotensin II (ANG II) concentrations than ANG II-dependent hypertensive rats with intrarenal renin depletion. In the present study, we therefore compared plasma and kidney ANG II levels in anesthetized and conscious normotensive and ANG II-dependent hypertensive rats. Methods: Salt-replete Hannover-Sprague-Dawley rats (HanSD) served as controls. As models of ANG II-dependent hypertension we used: 1st, transgenic rats harboring the Ren-2 renin gene (TGR); 2nd, two-kidney, one-clip (2K1C) Goldblatt hypertensive rats, and, 3rd, ANG II-infused hypertensive rats. As additional model with enhanced renin-angiotensin system (RAS) activity, salt-depleted HanSD and TGR were employed. Results: In anesthetized salt-repleted HanSD, plasma and kidney ANG II levels were higher than in salt-repleted TGR, ANG II-infused and 2K1C rats. Salt depletion caused marked increases in ANG II levels in HanSD but did not alter them in TGR. In contrast, in conscious animals immediately after decapitation plasma and kidney ANG II levels were similar in salt-repleted and salt-depleted TGR, in ANG II-infused rats, in the clipped kidney of 2K1C rats and in salt-depleted HanSD and in all these groups they were significantly higher than in salt-repleted HanSD. Conclusions: These findings indicate that anesthesia increases plasma and kidney ANG II levels in HanSD to a greater degree than in ANG II-dependent models of hypertension. Therefore, the results from studies employing anesthetized animals must be interpreted with caution.

Do Ketoanalogues Still Have a Role in Delaying Dialysis Initiation in CKD Predialysis Patients

Early versus later start of dialysis is still a matter of debate. Low‐protein diets have been used for many decades to delay dialysis initiation. Protein‐restricted diets (0.3–0.6 g protein/kg/day) supplemented with essential amino acids and ketoanalogues (sVLPD) can be offered, in association with pharmacological treatment, to motivated stage 4–5 chronic kidney disease (CKD) patients not having severe comorbid conditions; they probably represent 30–40% of the concerned population. A satisfactory adherence to such dietary prescription is observed in approximately 50% of the patients. While the results of the studies on the effects of this diet on the rate of progression of renal failure remain inconclusive, they are highly significant when initiation of dialysis is the primary outcome. The correction of uremic symptoms allows for initiation of dialysis treatment at a level of residual renal function lower than that usually recommended. Most of the CKD‐associated complications of cardiovascular and metabolic origin, which hamper both lifespan and quality of life, are positively influenced by the diet. Lastly, with regular monitoring jointly assumed by physicians and dietitians, nutritional status is well preserved as confirmed by a very low mortality rate and by the absence of detrimental effect on the long‐term outcome of patients once renal replacement therapy is initiated. On account of its feasibility, efficacy and safety, sVLPD deserves a place in the management of selected patients to safely delay the time needed for dialysis.

Increased proinflammatory cytokine production in adipose tissue of obese patients with chronic kidney disease

ZusammenfassungHINTERGRUND: Die Adipositas ist ein Hochrisikofaktor sowohl für die Entwicklung von Gefäßerkrankungen als auch für chronische Niereninsuffizienz (CKD). Ziel dieser Studie ist es, den Einfluss des Fettgewebes auf den Entzündungsstatus bei adipösen Patienten mit CDK zu erfassen. PATIENTEN UND METHODEN: In einer prospektiven Querschnitt-Studie analysierten wir 40 CDK (Stadium 3–4) Patienten mit milder Proteinurie (2,3–3,5 g/Tag): 20 Patienten mit Adipositas (Gruppe 1) und 20 normalgewichtigen Patienten (Gruppe 2) wurde während einer elektiven Abdominaloperation (laparoskopische Cholecystektomie) einmalig Blut abgenommen, sowie Proben des subkutanen und des viszeralen Fettgewebes entnommen. Die Serumkonzentrationen folgender Parameter wurden bestimmt: Asymmetrisches Dimethylarginin (ADMA), Adiponektin (ADPN), C-reaktives Protein (CRP), Interleukin-6-(IL-6), Tumor Nekrose Faktor-α (TNF-α), Pentosidin, Monocyte Chemoattractant Protein-1 (MCP-1). Mit Hilfe von Real-Time-PCR wurde die Expression der Messenger RNA (mRNA) von TNF-α, MCP-1 und der Adiponektin Rezeptoren 1 und 2 sowie des immunkompetenten Zellmarkers CD68 im subkutanen sowie im viszeralen Fettgewebe bestimmt. Das Fettgewebe wurde immunhistochemisch auf CD68 positive Zellen geprüft. Außerdem wurden in beiden Gruppen folgende weitere biochemische Parameter bestimmt: Insulin, HbA1c, Cholesterin, LDL-Cholesterin, und Triglyzeride. ERGEBNISSE: Die Serumkonzentrationen von ADMA, CRP, Pentosidin, Interleukin-6, TNF-α, and MCP-1 waren bei den adipösen CDK-Patienten signifikant höher. Das Adiponektin war signifikant im Vergleich zur Kontrollgruppe erniedrigt. Die subkutane und viszerale mRNA Expression von TNF-α, CD68, Adiponektin Rezeptor-1 and MCP-1 war bei den adipösen CDK Patienten signifikant erhöht. Die mRNA Expressionen waren im viszeralen Fettgewebe signifikant höher als im subkutanen Fettgewebe (p < 0,01 vs. p < 0,05). Die Expressionen der mRNA von Adiponektin, Interleukin-6, und des Adiponektin Rezeptors-2 beider Fettdepots waren nicht unterschiedlich in den beiden Gruppen. Bei den adipösen CDK-Patienten wurde im subkutanen und im viszeralen Fettgewebe eine erhöhte Infiltration mit CD68 positiven immunkompetenten Zellen gefunden. Die Fettstoffwechsel-Parameter waren in der Gruppe 1 gering, aber signifikant (p < 0,02) erhöht. Ausgeprägter waren die Veränderungen in den Triglyzeriden (p < 0,01). Ein ähnlicher Anstieg wurde bei den Insulin und HbA1c Werten der Gruppe 1 beobachtet (p < 0,02). SCHLUSSFOLGERUNGEN: Im Fettgewebe adipöser Patienten mit CKD im Stadium 3–4 wurde eine erhöhte Expression von proinflammatorischen Zytokinen und eine gesteigerte Infiltration mit immunkompetenten Zellen gefunden. Diese hinauf-regulierte Entzündung könnte zur Auslösung eines systemischen proinflammatorischen Zustands bei Patienten mit CDK beitragen und das Fortschreiten der Störung der Nierenfunktion beschleunigen.SummaryBACKGROUND: Obesity is a known high-risk factor for the development of vascular diseases and chronic kidney disease (CKD). In this study we aimed to elucidate the impact of adipose tissue on the inflammatory state in CDK patients with obesity. PATIENTS AND METHODS: A cohort of 40 patients with CKD (stages 3–4) with mild proteinuria (2.3–3.5 g/day) were analyzed in a prospective cross-sectional study: single blood samples and visceral and subcutaneous samples of adipose tissue were taken from 20 patients with obesity and 20 without obesity (control group) during elective abdominal surgery (laparoscopic cholecystectomy). Serum concentrations of asymmetric dimethylarginine (ADMA), adiponectin, C-reactive protein, interleukin-6, tumor necrosis factor-α, pentosidine and monocyte chemoattractant protein-1 were measured. Messenger RNA expression of tumor necrosis factor-α, monocyte chemoattractant protein-1, adiponectin receptors 1 and 2, and immunocompetent cell marker CD68 was measured in subcutaneous and visceral fat samples using real-time PCR. Adipose tissue was examined immunohistochemically for CD68-positive cells. Other biochemical parameters (insulin, glycated hemoglobin, cholesterol, LDL cholesterol, and triglycerides) were assessed in the two groups of patients at the same time. RESULTS: Serum concentrations of ADMA, C-reactive protein, pentosidine, interleukin-6, tumor necrosis factor-α and monocyte chemoattractant protein-1 were significantly higher in obese CKD patients than in the control group; adiponectin was lower in the obese group. Subcutaneous and visceral mRNA expressions of tumor necrosis factor-α, CD68, adiponectin receptor-1, and monocyte chemoattractant protein-1 were significantly increased in the obese patients, whereas expression of adiponectin, interleukin-6, and adiponectin receptor-2 did not significantly differ between the patient groups. In general, mRNA expressions were higher in visceral than in subcutaneous samples (P < 0.01 vs. P < 0.05). Increased infiltration of subcutaneous and visceral adipose tissue by CD68-positive immunocompetent cells was found in the obese CKD group. With respect to lipid metabolism parameters, a small but significant increase in levels was found in the obese patients (P < 0.02). Changes in triglycerides were more marked in this group (P < 0.01) and a similar increase was noted in insulin and HbA1c levels (P < 0.02). CONCLUSION: Increased expression of proinflammatory cytokines and increased infiltration by immunocompetent cells were found in adipose tissue of obese patients with CKD stages 3–4. This upregulated inflammation may contribute to the induction of a systemic proinflammatory state in patients with CKD and could accelerate the progression of renal dysfunction.

Glomerular Filtration Rate Estimation in Patients with Advanced Chronic Renal Insufficiency Based on Serum Cystatin C Levels

Background: Cystatin C has an obvious advantage in the recognition of the initial stages of renal impairment. It is questionable whether cystatin C possesses the same benefit in follow-up of pre-dialysis patients. If cystatin C were also a sensitive marker of GFR in pre-dialysis patients, then it could be expected that, for the same degree of a decrease in GFR, the increase in S_cyst would be higher than in S_cr because of the significant increase in tubular secretion of creatinine in residual nephrons. The aim of this study was to evaluate whether S_cyst in patients with GFR ≤40 ml/min/1.73 m² provides a more accurate estimate of GFR than S_cr does. Methods: The study was performed in 67 patients (mean age 41.5 ± 7.6 years) with chronic renal insufficiency (GFR = 19.8 ± 9.9 ml/min/1.73 m²) caused by various chronic renal diseases (predominantly by chronic glomerulonephritis and chronic interstitial nephritis). GFR was measured by inulin clearance under conditions of stabilized plasma concentrations and water loading. Creatinine clearance and serum cystatin C concentration (using immunonephelometry) were measured at the same time. For statistical evaluation, linear regression analysis, receiver-operating characteristic (ROC) curves analysis and the method of Bland and Altman were used. Results: A significant correlation (r = 0.813, p < 0.001) was demonstrated between 1/S_cyst and C_in as well as between 1/S_cr and C_in (r = 0.815, p < 0.001). There were no significant differences between the regression coefficients and the intercepts of regression straight lines characterizing these relationships. ROC curves analysis using the cut-off values for C_in = 20 ml/min/1.73 m² and C_in = 10 ml/min/ 1.73 m² did not show significant differences of corresponding AUC values for S_cyst and S_cr although there was a trend for superiority of S_cyst in comparison with S_cr. The multiples of upper reference values of S_cyst and S_cr in examined patients did not differ significantly. There was a highly significant linear correlation between C_in and C_cr in pre-dialysis patients (r = 0.921, p < 0.001). The regression coefficient of this relation (1.279) was significantly higher than 1.0 (p < 0.001) and the value of intercept (6.50 ml/min/1.73 m²) was significantly higher than zero (p < 0.001). The average of C_cr/C_in in patients with C_in <10 ml/min/1.73 m² was 2.11 (± 0.29) and 1.72 (± 0.35) for those with C_in 10–20 ml/min/1.73 m². Conclusions: The findings suggest that in patients with advanced chronic renal insufficiency (CRI) for the same decrease in GFR the increase of S_cyst is not significantly higher than that of S_cr, although the tubular secretion of creatinine is significantly increased. Further studies (especially those focused on nonrenal elimination of cystatin C) are needed to elucidate the lack of difference between changes in S_cyst and S_cr in patients with CRI.

Estimation of glomerular filtration rate in obese patients with chronic renal impairment based on serum cystatin C levels.

BACKGROUND Serum cystatin C (Scyst) has an obvious advantage in recognizing the initial stages of renal impairment. However, several recent studies suggest that Scyst may also be affected by some nonglomerular factors such as thyroid dysfunction, glucocorticoid administration or metabolic status of the diabetic patient. The aim of this study was to evaluate whether obesity could affect Scyst. PATIENTS AND METHODS The study was performed in 33 patients (mean age 49.1 +/- 6.3 years) with chronic renal disease (Scr = 227 +/- 118 micromol/l) and BMI = 35.6 +/- 1.8 kg/m2, and in 78 patients (mean age 43.4 +/- 5.1 years) with chronic renal disease (Scr = 245 +/- 111 micromol/l) and BMI = 24.0 +/- 1.8 kg/m2. Glomerular filtration rate (GFR) was determined using renal inulin clearance (Cin) under conditions of stabilized plasma concentrations and water loading. Scyst was measured using immunonephelometry. For statistical evaluation, linear regression analysis and receiver-operating characteristic (ROC) curve analysis were used. RESULTS A significant correlation (r = 0.956, p < 0.001) between l/Scyst and Cin was demonstrated in patients with BMI > or = 30 kg/m2 (Group A). Similarly, a significant correlation (r = 0.900, p < 0.001) between l/Scys and Cin was found in patients with BMI < 30 kg/m2 (Group B). There was no significant difference between the regression straight lines characterizing these relationships. ROC curve analysis (using a cut-off value for Cin = 30 ml/min/1.73 m2) did not show significant differences in AUC, sensitivity and specificity for Scyst between obese and nonobese patients. CONCLUSION The results suggest that evaluation of GFR based on Scyst in obese patients need not differ from that in nonobese ones.