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INTRODUCTION Urinary uromodulin excretion has been associated with kidney diseases. However, serum uromodulin concentrations have not been extensively studied in patients with chronic kidney disease (CKD), and the results of published studies are inconsistent. OBJECTIVES The aims of the study were to evaluate serum uromodulin concentrations in patients with CKD and to assess the utility of serum uromodulin measurements for diagnosing CKD stages. PATIENTS AND METHODS This observational study included 170 patients with CKD stages 1 to 5, not treated by renal replacement therapy, and 30 healthy individuals. The serum levels of creatinine, cystatin C, and uromodulin were measured, and estimated glomerular filtration rate (eGFR) was calculated according to the 2012 CKD Epidemiology Collaboration cystatin‑creatinine equation. RESULTS Among patients with CKD, serum uromodulin concentrations were significantly lower than in controls, and were strongly negatively correlated with renal retention markers (ie, serum creatinine and cystatin C) and strongly positively correlated with eGFR. An inverse, hyperbolic relationship between serum creatinine and uromodulin levels was analogous to the well‑known association between serum creatinine concentrations and eGFR. A receiver‑operating characteristic curve analysis showed a high diagnostic accuracy of the measurement of serum uromodulin concentrations in the assessment of CKD stages. CONCLUSIONS Serum uromodulin concentrations are closely correlated with eGFR, which is the recommended measure of renal function. As uromodulin is produced exclusively by renal tubular cells, the assessment of uromodulin levels in patients with CKD may be an alternative method for evaluating the number of functioning nephrons.

Aims. Diabetes is considered a state of increased oxidative stress. This study evaluates blood concentrations of selected markers of antioxidant defense in patients with type 2 diabetes.Methods. The study included 80 type 2 diabetes patients and 79 apparently healthy controls. Measured markers included ferric reducing ability of plasma (FRAP), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR),γ-glutamyltransferase (GGT) and uric acid serum, and plasma and/or hemolysate levels.Results. FRAP, uric acid, CRP, and GGT levels were significantly higher in patients with diabetes. Plasma and hemolysate GR was significantly higher whereas GPx activity was significantly lower in patients with diabetes. There were no significant differences in antioxidant defense markers between patients with and without chronic diabetes complications. Fasting serum glucose correlated with plasma GPx, plasma and hemolysate GR, FRAP, and serum GGT, and HbA1c correlated with serum GGT. Only FRAP and serum uric acid were significantly higher in obese (BMI>30 kg/m2) patients with diabetes than in nonobese patients.Conclusions. Some components of antioxidant defense such as GR, uric acid, and GGT are increased in patients with type 2 diabetes. However, the whole system cannot compensate for an enhanced production of ROS as reflected by the trend toward decreased erythrocytes GSH.

Background The objective of the study was to determine the relationship between common carotid artery intima-media thickness (CCA-IMT) and histologically assessed calcification of radial artery in relation to clinical features and laboratory markers of bone and mineral metabolism, inflammation, and oxidative stress in patients with stage 5 chronic kidney disease (CKD). Methods The study comprised 59 patients (36 hemodialyzed, 23 predialysis). CCA-IMT was measured by ultrasonography; the biochemical parameters examined were assessed using routine laboratory methods, ELISA micro-plate immunoassays and spectrophotometry. Fragments of radial artery obtained during creation of hemodialysis access were cryosectioned and stained for calcifications using von Kossa method and alizarin red. Results Glucose, osteoprotegerin, pentraxin 3 and Framingham risk score significantly correlated with CCA-IMT. In multiple regression analysis, OPG positively predicted CCA-IMT. Radial artery calcifications were found in 34 patients who showed higher CCA-IMT (0.98 ± 0.13 vs 0.86 ± 0.14 mm; P = 0.006). Higher CCA-IMT values were also associated with more advanced calcifications. CCA-IMT and the presence of plaques in common carotid artery were positive predictors of radial artery calcifications, independent of dialysis status, Framingham risk score, CRP and Ca x Pi [OR for calcifications 2.19 (1.08-4.45) per 0.1 mm increase in CCA-IMT]. The presence of radial artery calcifications was a significant predictor of mortality, independent of dialysis status and Framingham risk score [HR 3.16 (1.03-9.64)]. Conclusions In CKD patients, CCA-IMT examination can be used as a surrogate measure to assess the incidence and severity of arterial medial calcification which is associated with poor clinical outcome in these patients.

Objectives.Our aim was to determine whether vascular deposition of advanced glycation end-products (AGEs) is associated with arterial calcification and cardiovascular mortality in chronic kidney disease (CKD) patients and to assess the relationships between vascular content of AGEs and selected clinical and biochemical parameters.Materials and Methods.The study comprised 54 CKD patients (33 hemodialyzed, 21 predialyzed). Examined parameters included BMI, incidence of diabetes, plasma fasting glucose, AGEs, soluble receptor for AGEs and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, serum C-reactive protein (hsCRP), plasminogen activator inhibitor-1 (PAI-1), and fetuin-A. Fragments of radial artery obtained during creation of hemodialysis access were stained for calcifications using alizarin red. AGEs deposits were identified immunohistochemically and their relative content was quantified.Results.Vascular content of AGEs was positively correlated with BMI, hsCRP, fetuin-A, PAI-1, and DPPH scavenging in simple regression; only fetuin-A was an independent predictor in multiple regression. There was a significant positive trend in the intensity of AGEs immunostaining among patients with grades 1, 2, and 3 calcifications. AGEs immunostaining intensity predicted 3-year cardiovascular mortality irrespective of patient’s age.Conclusions.The present study demonstrates an involvement of AGEs in the development of medial arterial calcification and the impact of arterial AGE deposition on cardiovascular mortality in CKD patients.

Objective.The objective of the study was to assess the relationship between selected clinical and biochemical parameters of end stage renal disease (ESRD) patients and arterial calcification.Materials and Methods.The study comprised 59 stage 5 chronic kidney disease patients (36 hemodialyzed and 23 predialysis). The examined parameters included common carotid artery intima-media thickness (CCA-IMT), BMI, incidence of diabetes and impaired fasting glucose (IFG), dyslipidemia, hypertension, and 3-year mortality. Plasma levels asymmetric dimethylarginine (ADMA), osteopontin (OPN), osteoprotegerin (OPG), and osteocalcin (OC) were also measured. Fragments of radial artery obtained during creation of hemodialysis access were stained for calcifications using von Kossa method and alizarin red.Results.Calcification of radial artery was significantly associated with higher prevalence of IFG and diabetes (P=0.0004) and older age (P=0.003), as well as higher OPG (P=0.014) and ADMA concentrations (P=0.022). Fasting glucose>5.6 mmol/l (IFG and diabetes) significantly predicted vascular calcification in multiple logistic regression. The calcification was also associated with higher CCA-IMT (P=0.006) and mortality (P=0.004; OR for death 5.39 [1.20–24.1] after adjustment for dialysis status and age).Conclusion.Combination of renal insufficiency and hyperglycemic conditions exerts a synergistic effect on vascular calcification and increases the risk of death.

WSTĘP. W ostatnio opublikowanych badaniach wykazano istotną rolę czynników wzrostowych i cytokin prozapalnych w rozwoju nefropatii cukrzycowej. Celem pracy była ocena wpływu wybranych czynników wzrostowych i markerów stanu zapalnego na rozwój zmian w nerkach u pacjentów z nefropatią cukrzycową. MATERIAŁ I METODY. Badaniami objęto 50 chorych z nefropatią w przebiegu cukrzycy typu 2, w tym 25 poddano obserwacji prospektywnej trwającej 36 miesięcy. U wszystkich pacjentów oznaczono stężenie czynników zapalnych i wzrostowych we krwi oraz parametry wydolności nerek. WYNIKI. Chorzy z nefropatią cukrzycową charakteryzowali się istotnie wyższym stężeniem fibrynogenu, hsCRP, IL-6 i sTNF-RII w porównaniu z wartościami referencyjnymi. W badaniu wyjściowym stwierdzono, że podwyższone stężenia IL-6 i sTNF-RII wiązały się ze spadkiem wartości GFR (r = –0,3; p = 0,01 oraz r = –0,7; p < 0,0001). Po 36 miesiącach obserwacji wykazano związek stężenia hsCRP, sTNF-RII z albuminurią (r = 0,5; p = 0,008 i r = 0,5; p = 0,02) oraz VEGF z wartością GFR (r = –0,4; p = 0,03). WNIOSKI. W niniejszej pracy wykazano, że u chorych z nefropatią cukrzycową, w stosunku do wartości referencyjnych, występują istotnie wyższe stężenia markerów zapalnych. W badaniu prospektywnym wzrost wartości stężeń markerów zapalnych wiązał się z progresją nefropatii - obniżeniem GFR i wzrostem albuminurii. BACKGROUND. Presently published research points to an essential role of growth and pro-inflammatory cytokines in the development of diabetic nephropathy. The aim of the study was to evaluate influence of certain growth factors and inflammatory markers on the progression of kidney changes in patients with diabetic nephropathy. MATERIAL AND METHODS. Material included 50 patients with diabetic nephropathy, 25 out of them re-evaluated after 36 months. Inflammatory and growth factors were measured along with renal parameters in all patients. RESULTS. Patients with diabetic nephropathy were characterized with significantly higher values of fibrinogen, hsCRP, IL-6 and sTNF-RII in comparison to reference values. In the initial examination, increased concentrations of IL-6 and sTNF-RII were associated with decreased values of GFR (r= –0.3; p = 0.01, as well as r = –0.7; p < 0.0001). After 36 months of observation - an association was found between concentrations of hsCRP, sTNF-RII and albuminuria (r = 0.5; p = 0.008 and r = 0.5; p = 0.02); as well as between VEGF and GFR values (r = –0.4; p = 0.03). CONCLUSIONS. Research showed that patients with diabetic nephropathy in comparison to reference values had significantly higher concentrations of inflammatory markers. In the prospective examination - changes of inflammatory markers were associated with progression of nephropathy (decrease of GFR and increase of albuminuria).