[Risk factors for anemia in the early stages of chronic kidney disease]. / Faktory riska razvitiia anemii na rannikh stadiiakh khronicheskoi bolezni pochek.

AIM: To identify the early markers of anemia in chronic kidney disease (CKD) in patients with chronic glomerulonephritis (CGN) and glomerulonephritis (GN) in systemic diseases. SUBJECTS AND METHODS: Seventy-nine patients with some male preponderance who were aged 21 to 65 years (45.3±11.1 years) and had CKD (CGN and GN) in systemic diseases (systemic lupus erythematosus and Wegener's granulomatosis) in the early stages (Stages I-II) of CKD were examined. GN was diagnosed by a lifetime renal biopsy. Systemic diseases were diagnosed according to the criteria for each nosological entity. The stages of CKD were defined according to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) criteria; the glomerular filtration rate (GFR) was calculated using the CKD EPI equation (2012). According to the presence or absence of anemia, all the patients included in the study were divided into 2 groups: 1) 43 (54.4%) anemic patients; 2) 36 (45.6%) non-anemic patients (a control group). In addition to general clinical examination adopted for a nephrology department, special studies, such as determination of the serum levels of hepcidin, interferon-γ (IFN-γ), soluble Klotho protein (s-Klotho), as well as iron, ferritin, and transferrin saturation (TSAT) ratio, were performed to solve the set tasks. RESULTS: Forty-three anemic patients who had a hemoglobin level of 110 (100; 119) g/l and 36 control patients who had the similar values were noted to have statistically significantly (p<0.001) higher levels of IFN-γ (11 (10; 14) and 0.2 (0.09; 0.6) ng/ml), hepcidin (26 (25; 27) and 5.1 (3.8; 5.9) ng/ml) and C-reactive protein (1.5 (1.1; 2.1) and 0.3 (0.2; 0.6) mg/dl), and lower levels of s-Klotho protein (12 (10; 18) pg/ml) and TSAT (18 (14; 19)%. Forty-three patients with anemia were also found to have a statistically significantly (p<0.01) lower GFR (65 (62; 87) and 80.5 (62; 90) ml/min) and higher systolic blood pressure (145 (125; 160) and 120 (115; 16) mm Hg) as compared with those in 36 control patients. At the same time, the compared groups displayed no statistically significant differences in serum ferritin levels (123 (110; 150) and 115 (100; 140) µg/l). Among 43 CKD patients with anemia, its detection rate in the presence of systemic diseases was 3.2 times higher than that in CGN patients (41.7 and 12.7%). ROC analysis revealed that in the CKD patients with CGN and GN, the serum hepcidin level ≥ 25 ng/ml, with the sensitivity and specificity being of 89.7% and 74%, respectively (p > 0.001), was associated with the development of anemia. Moreover, the hemoglobin level of<120 g/ l was found to have an independent impact on the risk of reducing serum s-Klotho production. CONCLUSION: In Stage I-II CKD patients with CGN and GN in the presence of systemic diseases, elevated serum hepcidin levels should be regarded as a predictor for anemia of chronic disease (ACD). Herewith, the decrease in hemoglobin levels <120 g/l is associated with the reduced production of the nephroprotective factor s-Klotho. The treatment of ACD for Stages I-II CKD should encompass intravenous administration of iron in order to increase its content and availability for erythropoiesis.

[Impact of anemia correction on the production of the circulating morphogenetic protein α-Klotho in patients with Stages 3B-4 chronic kidney disease: A new direction of cardionephroprotection].

AIM: To investigate the impact of anemia correction with erythropoiesis stimulants on the serum level of the circulating morphogenetic protein α-Klotho in patients with Stages 3B--4 chronic kidney disease (CKD). SUBJECTS AND METHODS: 64 patients aged 42±8 years with Stages 3B--4 nondiabetic CKD were examined and divided into 2 groups: 1) 32 patients with anemia (the target hemoglobin levels could be achieved and kept with erythropoietin and iron saccharate in 20 patients (Group A) and those could not be done in 12 patients (Group 1B). A control group (Group 2) consisted of 32 non-anemic patients matched for gender, age, and degree of a glomerular filtration rate (GFR) reduction. Along with iron exchange indicators, the time course of changes in serum Klotho levels were examined in all the 64 patients during screening and one year after the end of the study. For correction of anemia, 32 patients with this condition (Groups 1A and 1B) took short-acting epoetin (hypodermic recormon 2,000 IU thrice per week + iron (intravenous venofer 5 ml of 100 mg once per week)) under control of hemoglobin levels and serum transferrin iron and ferritin saturation. After achieving the target hemoglobin level of 110-120 g/l, for its keeping, all the patients received, instead of short-acting epoetin, long-acting hypodermic darbepoetin-α 1.5 µg once every 2 months and intravenous iron saccharate 100 mg once every 2 weeks. RESULTS: Among the 32 anemic patients in Group 1, 20 (63%) (Group 1 A) could achieve the target hemoglobin level (110--120 g/l) and maintain it within this range, by performing therapy with epoitin-ß + iron saccharate; anemia (the hemoglobin level of <110 g/l) persisted in 12 (37%) patients (Group 1B) despite the fact that epoetin and iron saccharate had been administered. Group 1A was noted to have an increase in α-Klotho concentrations by an average of 100±11.6-pg/ml as compared to Group 1B (by only 72±4.2 pg/ml). At the same time, the α-Klotho levels in the control group by the end of the follow-up decreased by an average of 210±12.9 pg/ml as compared to the prescreening value. There was a direct correlation between hemoglobin and serum ferritin concentrations and iron ferritin saturation percentage and α-Klotho levels. It was ascertained that the hemoglobin concentration of ≥110 g/l with a sensitivity of 89% and a specificity of 75% could predict higher serum α-Klotho levels in CKD. The same patients were found to have an inverse relationship between the serum level of α-Klotho and the risk of cardiovascular events. CONCLUSION: The serum level of the protein Klotho is not only a marker for the severity of CKD and its complications (anemia, left ventricular hypertrophy, and heart failure), but also a pathogenetic factor of CKD progression. Anemia correction with erythropoiesis stimulants has been shown to enhance the renal and extrarenal production of α-Klotho.

[Role of the morphogenetic proteins FGF-23 and Klotho and the glycoprotein sclerostin in the assessment of the risk of cardiovascular diseases and the prognosis of chronic kidney disease].

UNLABELLED: AIM. To analyze changes in the serum concentrations of the morphogenetic proteins fibroblast growth factor 23 (FGF-23) and Klotho, as well as sclerostin, an osteocyte-secreted glycoprotein, in relation to the degree of hypertension, left ventricular (LV) hypertrophy, and arterial stiffness in patients with chronic kidney disease (CKD) at its different stages. SUBJECTS AND METHODS: Sixty-five patients (33 men and 32 women) aged 20-65 years, including 25 with chronic glomerulonephritis, 15 with tubulointerstitial nephritis, and 25 with hypertensive nephrosclerosis, were examined. A control group consisted of 15 healthy volunteers matched to the study group patients for age and gender. Serum FGF-23 concentrations and blood pressure (BP) were measured in the all subjects. Patients with BPs > 140/80 mm Hg underwent echocardiography, followed by determination of LV mass (LVM) and calculation of LVM index. Vascular circulation, pulse wave velocity, cardiac and vascular calcifications, and vascular functional properties were estimated. RESULTS: There was a strong direct Correlation between the serum concentration of FGF-23 and the stage of CKD and an inverse correlation between the levels of Klotho and sclerostin and the stage of CKD. As the glomerular filtration rate became lower, the concentration of FGF-23 increased and that of Klotho and sclerostin decreased just in Stage III CKD while hyperphosphatemia and elevated parathyroid hormone levels were noted in Stages IV-V CKD. As CKD progressed, the serum concentrations of Klotho and sclerostin were inversely correlated with the levels of phosphorus and parathyroid hormone. The degree of blood pressure elevation correlated positively with serum FGF-23 concentrations and inversely with Klotho levels. There was no significant correlation of the level of sclerostin with the degree of BP increase. The direct correlation between higher FGF-23 level and higher VLM is most pronounced in hypertensive patients. There was a strong direct relationship between FGF-23 and Klotho levels and a strong inverse relationship between sclerostin levels and pulse wave velocity. Lower Klotho concentrations were associated with the detection rate of calcifications in the heart valves and large arteries (the abdominal aorta). The reduced serum levels of Klotho and sclerostin were also correlated with concentric LV remodeling. CONCLUSION: It was demonstrated that there was a clear link between increased serum FGF-23 and decreased Klotho concentration as CKD progressed, and that between arterial stiffness and calcification and myocardial remodelling regardless of traditional risk factors. More experimental and clinical studies are required to clarify the role of sclerostin in CKD.

[MORPHOGENETIC PROTEINS--FIBROBLAST GROWTH FACTOR AND KLOTHO, IN THE SERA OF PATIENTS WITH CHRONIC RENAL DISEASE].

The aim of the study was to evaluate the role of morphogenetic proteins--fibroblast growth factor-23 (FGF-23) and extracellular form (alpha) of Klotho protein, present in the sera of patients with chronic renal disease (CRD) as markers of cardiovascular risk. The study included 130 patients (64 men and 66 women) with stage I-VD CRD. The patients'age was 20-65 (mean 41 ± 6.7) years. 30 of them had chronic glomerulonephritis, 23 chronic tubulointerstitial nephritis, 28 hypertensive nephrosclerosis, 22 polycystic kidneys, 27 type 2 diabetes mellitus. Inclusion and exclusion criteria were standardfor clinical studies of CRD patients. Control group contained 30 healthy volunteers matched for age and sex. The patients were uniformly distributed by stages of CRD in terms of age and sex (18-20 per group). All of them were followed up during 1 year Standard clinical and laboratory examination was supplemented by the measurement of the parathyroid hormone (PTH), Ca and P levels. Serum FGF-23 and Klotho levels were determined by ELISA before and 1 year after onset of the study. Blood pressure including brachial (peripheral) and aortic (central) one as swell as the pulse wave velocity was measured by a Sphygocorr apparatus (Australia). Other studies included ECG, EchoCG, and X-ray of abdominal aorta in the lateral projection using the Kaupilla method. Comparison of FGF-23 and Klotho levels in patients at different stages of CRD revealed their decrease with decreasing glomerular filtration rate that started before (at IIIA stage) a rise in the serum P and PTG levels (IV-V stage). Negative relationship was documented between the Klotho level and the degree of cardiac calcinosis estimated from a semi-quantitative scale (r = 0.64; p < 0.01). Serum FGF-23 significantly correlated wiht myocardial remodeling (r = 0.612; p < 0.01). Multiple regression analysis showed that patients with elevated FGF-23 and P levels, high central systolic pressure and pulse wave velocity had greater left ventricular myocardium mass. ROC-analysis demonstrated that FGF-23 level over 412 pg/ml is indicative of left ventricular hypertrophy with sensitivity 80% and specificity 76%. Patients undergoing hemodialysis who died within 1 year after the onset of the treatment had a higher FGF-23 level than survivals on hemodialysis. The risk of death during the first year on hemodialysis correlated with the FGF-23 level (r = 0.564, p < 0.01). ROC-analysis showed that Klotho levels below 387 pg/ml suggested an increased risk of myocardiym calcification with sensitivity 80% and specificity 75%. It is concluded that morphogenetic proteins, fibroblast growth factor and Klotho, not only play an important role in mineral metabolism in patients with CRD but also produce pleiotropic effects on the development of cardiovascular complications (via involvement in cardiac and vascular calcification and remodeling). It provides a basis for the use of these proteins as early markers of cardiovascular risk in CRD patients.