Interpretation of Erythropoietin and Haemoglobin Levels in Patients with Various Stages of Chronic Kidney Disease

[Related factors of endogenous erythropoietin and its association with 10-year risks of cardiovascular disease in a community-based Chinese study]

OBJECTIVE

To investigate the associated factors of endogenous erythropoietin (EPO) and its association with 10-year risks of atherosclerotic cardiovascular disease in a Chinese community-based general population.

METHODS

The participants of this study were from an atherosclerosis cohort survey which was established by the Department of Cardiology, Peking University First Hospital in 2011. The cohort survey was performed in the Gucheng and Pingguoyuan communities of Shijingshan district in Beijing, China. The inclusion criteria of this study were: (1) endogenous EPO was measured; (2) health questionnaire data and other clinical data were complete; (3) participatants who had cardiovascular or cerebrovascular diseases (defined as self-reported coronary heart disease, stroke or transient ischemic attack) or anemia or estimated glomerular filtration rate (eGFR) < 60 mL/(min·1.73 m2) at baseline were excluded. Multivariate linear regression model was used to examine the associated factors of endogenous EPO. The participants were grouped into low (< 5%), moderate (5%-10%) and high risk (≥10%) groups, based on predicted 10-year cardiovascular disease risk using the prediction for atherosclerotic cardiovascular disease risk in China (China-PAR) equations.

RESULTS

A total of 4 013 participants were included. Mean age of them was (55.9±8.2) years, 62.2% (n=2 496) of them were female, and 46.3% (n=1 859), 70.9% (n=2 845), 21.9% (n=879) had hypertension, dyslipidemia and diabetes, individually. The average body mass index was (26.1±3.3) kg/m2. The median of EPO level was 12.8 (9.3-17.4) IU/L and 25.1% (n=998) were at high 10-years risk of cardiovascular disease. Hemoglobin (β=-0.05, 95%CI: -0.07 to -0.04) and eGFR ≥90 mL/(min·1.73 m2) (β=-0.05, 95%CI: -0.07 to -0.04) were associated with lower in transformed EPO levels while hypertension (β=0.08, 95%CI: 0.05 to 0.12) and obesity (β=0.14, 95%CI: 0.09 to 0.18) were associated with higher in transformed EPO levels in multivariate linear regression analyses. Ten-year cardiovascular disease risks were positively associated with in transformed EPO levels (β=0.07, 95%CI: 0.05 to 0.09). The participants at moderate and high cardiovascular disease risks had significant higher EPO levels than the low risk group (all P < 0.05).

CONCLUSION

In community-based Beijing populations, endogenous EPO was associated with hemoglobin, renal function, obesity and hypertension. Individuals at high 10-years cardiovascular disease risks have higher endogenous EPO levels. Endogenous EPO may be a potential risk marker of cardiovascular disease.

Metabolomics Assessment of Volume Overload-Induced Heart Failure and Oxidative Stress in the Kidney

The incidence of heart failure (HF) is increasing and is associated with a poor prognosis. Moreover, HF often coexists with renal dysfunction and is associated with a worsened outcome. In many experimental studies on cardiac dysfunction, the function of other organs was either not addressed or did not show any decline. Until now, the exact mechanisms for initiating and sustaining this interaction are still unknown. The objective of this study is to use volume overload to induce cardiac hypertrophy and HF in aortocaval fistula (ACF) rat models, and to elucidate how volume overload affects metabolic changes in the kidney, even with normal renal function, in HF. The results showed the metabolic changes between control and ACF rats, including taurine metabolism; purine metabolism; glycine, serine, and threonine metabolism; glycerophospholipid metabolism; and histidine metabolism. Increasing the downstream purine metabolism from inosine to uric acid in the kidneys of ACF rats induced oxidative stress through xanthine oxidase. This result was consistent with HK-2 cells treated with xanthine and xanthine oxidase. Under oxidative stress, taurine accumulation was observed in ACF rats, indicating increased activity of the hypotaurine-taurine pathway as a defense mechanism against oxidative stress in the kidney. Another antioxidant, ascorbic acid 2-sulfate, showed lower levels in ACF rats, indicating that the kidneys experience elevated oxidative stress due to volume overload and HF. In summary, metabolic profiles are more sensitive than clinical parameters in reacting to damage to the kidney in HF.

Anemia and Associated Risk Factors in Pediatric Patients

Anemia is the most common hematologic abnormality identified in children and represents a major global health problem. A delay in diagnosis and treatment might place patients with anemia at risk for the development of rare but serious complications, including chronic and irreversible cognitive impairment. Identified risk factors contributing to the development of anemia in children include the presence of nutritional deficiencies, environmental factors, chronic comorbidities, and congenital disorders of hemoglobin or red blood cells. Pediatricians, especially those in the primary care setting, serve a particularly critical role in the identification and care of those children affected by anemia. Prompt recognition of these risk factors is crucial for developing appropriate and timely therapeutic interventions and prevention strategies.

Characteristics of Japanese patients with non-dialysis-dependent chronic kidney disease initiating treatment for anemia: a retrospective real-world database study

OBJECTIVE

Anemia is a common complication of chronic kidney disease (CKD). The aim of this study was to evaluate hemoglobin levels at the initiation of erythropoiesis stimulating agent (ESA) therapy in patients with non-dialysis-dependent CKD (NDD-CKD) and anemia using a large-scale administrative database in Japan.

METHODS

The longitudinal data of adult patients who initiated ESA therapy between April 2008 and December 2018 were extracted from a hospital-based administrative database. The primary outcome was hemoglobin level at the initiation of ESA therapy, whereas the exploratory outcome was hemoglobin level recorded 6 months after the onset of the ESA therapy.

RESULTS

A total of 4939 patients were included in the primary analysis. The mean hemoglobin level at the initiation of ESA therapy was 9.1 g/dL, which was lower than the level (11 g/dL) recommended for the initiation of treatment by the current Japanese treatment guidelines. Moreover, 42.1% and 15.0% of the patients had hemoglobin levels <9.0 and <8.0 g/dL, respectively, at the initiation of ESA therapy. In 2964 patients for whom hemoglobin levels at 6 months after the initiation of ESA therapy were available, the mean hemoglobin level increased to 10.3 g/dL, and 61.9% and 31.1% of these patients had hemoglobin levels ≥10.0 and ≥11.0 g/dL, respectively.

CONCLUSION

This real-world database study revealed that hemoglobin levels at the initiation of ESA therapy in new users of ESA were lower than those recommended by treatment guidelines in Japan.

Phase Angle Association with Dietary Habits and Metabolic Syndrome in Diabetic Hypertensive Patients: A Cross-Sectional Study

Phase angle (PhA) levels are often lower than normal because both disease-specific parameters and disease-related inflammatory status, metabolic syndrome (MetS) included, can affect PhA. Therefore, the aim of this cross-sectional study was to compare body composition, metabolic profile and dietary patterns of participants with arterial hypertension (AH), type 2 diabetes mellitus (T2DM) and MetS with regard to PhA values. A total of 208 participants were included, of whom 53.6% were males. For each participant, data about body composition and anthropometric parameters, clinical and laboratory parameters, as well as food frequency questionnaire (FFQ) and Mediterranean Diet Serving Score (MDSS) were obtained. MC-780 Multi Frequency Segmental Body Mass Analyzer (Tanita) was used to assess body composition. Furthermore, waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. The results showed that 75 (36.06%) participants had low PhA values and 133 (63.94%) had high PhA values. Participants with higher PhA values had significantly higher body fat percentage (p = 0.04), fat-free mass (kg; p < 0.001), muscle mass (kg; p < 0.001), skeletal muscle mass (% and kg; p < 0.001), sarcopenic index (SMI; p < 0.001) and mid-upper arm circumference (MUAC; p = 0.04), as well as lower fat mass percentage (p = 0.04). Regarding food frequency consumption, significantly higher intakes of red meat (p = 0.003), poultry (p = 0.02) and fast food (p = 0.003) were noticed in participants with higher PhA values. Adherence to the Mediterranean Diet (MeDi) was exceptionally low in both groups of participants, with significantly higher fish intake noticed in participants with high PhA (p = 0.03). In conclusion, our results showed that body composition could be the indicator of PhA in MetS as well as overall low adherence to the MeDi principles. These findings highlight the importance of adequate nutritional strategies and novel approaches to maintaining optimal body composition and adopting proper eating habits within the framework of one’s disease.

[Assessment of the prevalence of anemia in patients with primary hyperparathyroidism: a single-center observational study]

BACKGROUND

The combination of primary hyperparathyroidism (PHPT) with anemia was first described in 1931. It remains unclear whether PHPT is the direct cause of anemia, or it develops due to PHPT's complications. The frequency of PHPT--associated anemia in the Russian population is unknown.

AIM

To assess the prevalence of anemia in patients with PHPT admitted to the Department of Parathyroid Glands Pathology in the Endocrinology Research Centre from January 2017 to August 2020.

MATERIALS AND METHODS

The study included patients with PHPT over 18 years old. A single-center observational one-stage one-sample uncontrolled study was carried out. We analyzed laboratory and instrumental data obtained during inpatient examination in accordance with the standards of medical care. Statistical analysis was performed using Statistica 13 (StatSoft, USA) and SPSS (IBM, USA) software packages.

RESULTS

The study included 327 patients with PHPT, 28 (9%) men and 299 (91%) women. The median age was 59 years [51; 66]. 26 patients (8%) with anemia were identified. Statistically significant differences between patients with and without anemia were found only in the GFR. Comparison of patients with and without anemia didn't reveal any significant differences in the incidence of PHPT's complications.Significant differences in serum hemoglobin concentration and average hemoglobin concentration in erythrocytes were revealed between patients with and without vertebrae fractures. In the group of patients without compression fractures these parameters were higher.In the subgroup of patients with total calcium concentration above 3 mmol/L and PTH above 3 normal values, the incidence of anemia reached 21% (95% CI: 10%; 35%). Within this group we revealed tendencies to higher levels of PTH, ionized calcium and osteocalcin in patients with anemia.

CONCLUSION

In general, there was no correlation between hypercalcemia, the degree of PTH elevation and the presence of anemia in patients with PHPT. However, in the subgroup of patients with severe hypercalcemia, there was a relationship between the concentration of PTH, ionized calcium and the presence of anemia. In patients with PHPT and vertebral fractures, significantly lower concentrations of blood hemoglobin and hemoglobin in erythrocytes were observed.

Hypoxia-inducible factor prolyl hydroxylase inhibitors: a paradigm shift for treatment of anemia in chronic kidney disease?

INTRODUCTION

The hypoxia-inducible factor prolyl hydroxylase (HIF-PH) pathway is responsible for regulating the biosynthesis of erythropoietin (EPO) and maintaining iron homeostasis. Investigational drugs that target the HIF-PH pathway are promising alternatives for treating anemia in Chronic Kidney Disease (CKD).

AREAS COVERED

This review summarizes recent advances focused on the clinical development of HIF-PH inhibitors (HIF-PHIs) as potentially novel therapies in the treatment of anemia in CKD based on publications available on PubMed and restricted Google searches. We provide a comparison between HIF-PHIs regarding their pharmacokinetics, dosing regimens and safety concerns, structure-activity relationships, and alterations in key laboratory parameters observed in animal models and clinical trials.

EXPERT OPINION

HIF-PHIs may be advantageous in some aspects compared to the conventional erythropoiesis-stimulating agents (ESAs). While ESAs could increase the risk of cardiovascular events due to rapid rises in ESA blood levels, HIF-PHIs have been reported to maintain EPO concentrations at levels that are closer to the normal physiological ranges. Although HIF-PHIs have been demonstrated to be relatively safe and effective in clinical trials, long-term safety data are needed in order to establish whether these therapeutic agents will lead to a major paradigm change in the treatment of anemia of CKD.

Population data provide evidence against the presence of a set point for hemoglobin levels or tissue oxygen delivery

Hemoglobin levels are believed to be regulated as per a set point model of regulation. This model of regulation, by which specific levels of a parameter are targeted and defended by physiological systems, implies a particular population correlation between the parameter and its controlling hormone. Empirical population correlations of other parameters and their controlling hormones, have denied the presence of such set point‐based regulation. To assess if hemoglobin is regulated according to a set point model we performed a systematic search of PubMed/MEDLINE and Web of Science identifying relevant reports published up to November 2018. Population hemoglobin/erythropoietin level correlations were retrieved, and these empirically derived correlations were compared with the positive correlation implied by a set point model of regulation. Authors of papers containing potentially suitable data were contacted with requests for further analyses, and a meta‐analysis was performed. Twelve correlations between hemoglobin and erythropoietin levels from eleven papers were analyzed. None of these correlations were significantly positive, three, restricted to the normal range of hemoglobin, were significantly negative. All but one of the other correlations showed a negative trend. New analyses of previously published data sets resulted in similar findings. In particular a new analysis of large data sets of males (n = 2417) and females (n = 2592) with normal range hemoglobin levels, revealed significantly negative correlations. A meta‐analysis of our results indicated that the data overall are not consistent with a positive relationship between hemoglobin and erythropoietin (P < 0.0001). Population data indicate that individuals do not have set point levels of hemoglobin.

Mild erythrocytosis as a presenting manifestation of PIEZO1 associated erythrocyte volume disorders

Piezo1, encoded by the gene PIEZO1, is an erythrocytic cellular membrane mechanoactivated cation channel. Mutations have been implicated in erythrocyte volume disorders (EVDs)-especially hereditary xerocytosis (HX)/dehydrated stomatocytosis (DHS). We identified three patients, all with novel PIEZO1 mutations, but only one displaying the HX/DHS phenotype. Retrospective review of three cases. Osmotic gradient red cell deformability (Osmoscan) was assessed via the Technicon Ektacytometer. Red cell band 3 content was estimated using Eosin-5'-Maleimide staining. Patient 1 was evaluated for polycythemia. Osmoscans suggested mild spherocytosis; a novel PIEZO1 mutation (p.Thr1589Ile, exon 35) was identified, causing mild erythrocytosis without hemolytic anemia. Patient 2 was evaluated for macrocytosis/reticulocytosis, normal-to-high hemoglobin, and indirect hyperbilirubinemia. Osmoscans suggested increased cellular hydration; a second novel PIEZO1 mutation (p.Arg1728Cys, exon 37) was identified, resulting in overhydrated stomatocytosis with well-compensated hemolysis. Patient 3 was evaluated for indirect hyperbilirubinemia only. Osmoscans suggested dehydrated stomatocytosis (DHS, xerocytosis); a third novel PIEZO1 mutation (p.Arg2279Cys, exon 47) was identified. All three patients' blood smears demonstrated stomatocytes and spherocytes. EVDs may be underdiagnosed due to the lack of "expected" anemia in a hemolytic disorder; two of three patients had high hemoglobin and red cell counts and one had high normal values for both parameters and the presence of stomatocytes/dehydrated cells lead to identification of causative PIEZO1 mutations. PIEZO1-associated EVDs may be more common than previously suspected and should be included in the diagnostic algorithms for mild erythrocytosis/unexplained jaundice.

Pathophysiological significance of clock genes BMAL1 and PER2 as erythropoietin-controlling factors in acute blood hemorrhage

This study aimed to characterize the pathophysiology, including possible correlations, of clock gene expression and erythropoietin (EPO) production in the acute stage of blood hemorrhage. Specimens of human cortical tissues (right and left kidneys) and cardiac blood were collected at autopsy from 52 cases following mortality due to acute-stage blood hemorrhage following sharp instrument injury. BMAL1 and PER2 mRNA levels were determined by reverse transcription-polymerase chain reaction; BMAL1 and PER2 protein levels were assessed using immunohistochemistry; BMAL1 protein levels were quantitatively measured by western blotting; and serum EPO levels were measured by chemiluminescent enzyme immunoassay. Separately, a rat model of hemorrhagic conditions was generated and used to confirm the results obtained with autopsy-derived specimens. A positive correlation was observed between BMAL1 protein and serum EPO levels, but not between BMAL1 mRNA levels and serum EPO levels. We also noted that Per2 mRNA expression became elevated in humans who survived for > 3 h after acute hemorrhagic events, with subsequent decreases in serum EPO levels. The rat model showed that even short (30-min) intervals of blood loss yielded increases in both Bmal1 mRNA and serum EPO levels; longer (60-min) intervals resulted in increases in Per2 mRNA expression along with decreases in serum EPO. Thus, the acute-stage human hemorrhage cases and the rat hemorrhage model yielded similar tendencies for clock gene expression and EPO secretion. In conclusion, our results indicated that clock genes are involved in the regulation of EPO production during the early stages of hypoxia/ischemia resulting from the acute hemorrhagic events.

Exploring Sirolimus Pharmacokinetic Variability Using Data Available from the Routine Clinical Care of Renal Transplant Patients - Population Pharmacokinetic Approach

Background

Due to wide intra- and inter-individual pharmacokinetic variability and narrow therapeutic index of sirolimus, the therapeutic drug monitoring (TDM) of sirolimus with detailed biochemical and clinical monitoring is necessary for dose individualization in kidney transplant patients. The purpose of the study was to explore and identify factors that contribute to pharmacokinetic variability by developing and validating a population model using routine TDM data and routinely monitored biochemical and clinical parameters.

Methods

The data obtained by routine monitoring of 38 patients over a period of one year from the sirolimus treatment initiation, were collected from patients' records. Population analysis was performed using the software NONMEM^®. The validity of the model was tested by the internal and external validation techniques.

Results

The pharmacokinetic variability was partially explained with patient's age and liver function. CL/F was found to decrease with age. According to the developed model, sirolimus CL/F decreases by, in average, 37% in patients with aspartate aminotransferase (AST) greater than 37 IU/L. The internal and external validation confirmed the satisfactory prediction of the developed model.

Conclusions

The population modeling of routinely monitored data allowed quantification of the age and liver function influence on sirolimus CL/F. According to the final model, patients with compromised liver function expressed via AST values require careful monitoring and dosing adjustments. Proven good predictive performance makes this model a useful tool in everyday clinical practice.

Serum Lactate As Reliable Biomarker of Acute Kidney Injury in Low-risk Cardiac Surgery Patients

Background

Cardiac surgery-associated acute kidney injury (CSA-AKI) frequently occurs in patients assessed as low-risk for developing CSA-AKI. Neutrophil Gelatinase-Associated Lipocalin (NGAL), Kidney Injury Molecule-1 (KIM-1) and lactate are promising biomarkers of CSA-AKI but have not yet been explored in low-risk patients.

Aim

To evaluate urinary NGAL (uNGAL), KIM-1 and lactate as biomarkers of CSA-AKI in patients with low-risk for developing CSA-AKI.

Methods

This prospective, observational study included 100 adult elective cardiac surgery patients assessed as low-risk for developing CSA-AKI. UNGAL, KIM-1 and lactate were measured preoperatively, at the end of cardiopulmonary bypass (CPB) and 3, 12, 24 and 48 h later.

Results

Fifteen patients developed CSA-AKI. Patients with CSA-AKI had significantly higher lactate but similar uNGAL and KIM-1 levels compared to patients without CSA-AKI. Unlike uNGAL and KIM-1, postoperative lactate was good biomarker of CSA-AKI with the highest odds ratio (OR) 2.7 [1.4–4.9] 24 h after CPB. Peak lactate concentration ≥ 4 mmol/L carried dramatically higher risk for developing CSA-AKI (OR 6.3 [1.9–20.5]).

Conclusions

Unlike uNGAL and KIM-1, postoperative lactate was significant independent predictor of CSA-AKI with the highest odds ratio 24 h after CPB.

Dual Roles of the Mineral Metabolism Disorders Biomarkers in Prevalent Hemodilysis Patients: In Renal Bone Disease and in Vascular Calcification

Background

Vascular calcification (VC) is highly prevalent in dialysis (HD) patients, and its mechanism is multifactorial. Most likely that systemic or local inhibitory factor is overwhelmed by promoters of VC in these patients. VC increased arterial stiffness, and left ventricular hypertrophy. Thus, the present study aimed to investigate the association of VC and myocardial remodeling and to analyze their relationship with VC promoters (fibroblast growth factor 23-FGF23, Klotho, intact parathormon-iPTH, vitamin D) in 56 prevalent HD patients (median values: age 54 yrs, HD vintage 82 months).

Methods

Besides routine laboratory analyzes, serum levels of FGF 23, soluble Klotho, iPTH, 1,25-dihydroxyvitamin D3; pulse wave velocity (PWV); left ventricular (LV) mass by ultrasound; and VCs score by Adragao method were measured.

Results

VC was found in 60% and LV concentric or eccentric hypertrophy in 50% patients. Dialysis vintage (OR 1.025, 95%CI 1.007–1.044, p=0.006) FGF23 (OR 1.006, 95% CI 0.992–1.012, p=0.029) and serum magnesium (OR 0.000, 95%CI 0.000–0.214, p=0.04) were associated with VC. Changes in myocardial geometry was associated with male sex (beta=-0.273, 95% CI -23.967 1.513, p=0.027), iPTH (beta 0.029, 95%CI -0.059–0.001, p=0.027) and vitamin D treatment (beta 25.49, 95%CI 11.325–39.667, p=0.001). Also, patients with the more widespread VC had the highest LV remodeling categories. PWV was associated patient’s age, cholesterol, diastolic blood pressure, LV mass (positively) and serum calcium (negatively), indicating potential link with atherosclerotic risk.

Conclusions

Despite to different risk factors for VC and myocardial remodeling, obtained results could indicate that risk factors intertwine in long-term treatment of HD patients and therefore careful and continuous correction of mineral metabolism disorders is undoubtedly of the utmost importance.

Clinical Significance of Increased Serum Neopterin in Chronic Kidney Failure as a Biomarker of Cell-mediated Immunity

Background

Neopterin is a pyrazino-pyrimidine compound which is used as a marker of cell-mediated immunity in a variety of diseases. It is known that neopterin levels increase in diseases where interferon-gamma (IFN-g) stimulation is present, and also as a result of deficiencies in renal function, given that the primary means of elimination of neopterin is through the kidneys. In this study, we aimed to investigate the role of increased neopterin levels as a prognostic biomarker in patients with impaired renal function.

Methods

A total of 90 individuals including 63 patients with chronic kidney failure (CKF) and 27 healthy volunteers were included in the study. Serum neopterin concentrations were measured using the enzyme-linked immunosorbent assay. A Mann-Whitney U test and a Pearson Correlation Test were used in the statistical analysis, with a p value of <0.05 being considered statistically significant.

Results

The mean age was 52.21±0.16 years in the patient group and 56.55±0.32 years in the control group. In the CKF patients, serum neopterin levels increased to a significantly greater degree than in the control group (p<0.001), while no statistically significant correlation was identified between serum neopterin levels and age (p>0.05).

Conclusions

A significant increase was found in the serum neopterin levels in the CKF patients, due to both the triggering of the disease and the reduction of neopterin elimination.

VHL Dependent Expression of REDD1 and PDK3 Proteins in Clear-cell Renal Cell Carcinoma

Background

Sporadic clear-cell renal cell carcinoma (ccRCC) is associated with mutations in the VHL gene, upregulated mammalian target of rapamycin (mTOR) activity and glycolytic metabolism. Here, we analyze the effect of VHL mutational status on the expression level of mTOR, eIF4E-BP1, AMPK, REDD1, and PDK3 proteins.

Methods

Total proteins were isolated from 21 tumorous samples with biallelic inactivation, 10 with monoallelic inactivation and 6 tumors with a wild-type VHL (wtVHL) gene obtained from patients who underwent total nephrectomy. The expressions of target proteins were assessed using Western blot.

Results

Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. Tumors with monoallelic inactivation of VHL underexpressed REDD1 in comparison to wtVHL tumors (P = 0.042), tumors with biallelic VHL inactivation (P < 0.005) and control tissue (P = 0.004). Additionally, REDD1 expression was higher in tumors with VHL biallelic inactivation than in control tissue (P = 0.008). Only in wt tumor samples PDK3 was overexpressed in comparison to tumors with biallelic inactivation of VHL gene (P = 0.012) and controls (P = 0.016). In wtVHL ccRCC, multivariate linear regression analysis revealed that 97.4% of variability in PDK3 expression can be explained by variations in AMPK amount.

Conclusion

Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. We have shown for the first time VHL dependent expression of PDK3 and we provide additional evidence that VHL mutational status affects REDD1 expression in sporadic ccRCC.

Serum Concentration of Hepcidin as an Indicator of Iron Reserves in Children

Background

Anemia represents a significant cause of maternal and perinatal mortality, as well as child mortality. The aim of the research was to determine the serum concentration of hepcidin in children aged 6 months to 2 years and adolescents aged 11 to 19 years which suffer from iron deficiency anemia and compare it with the serum concentration of hepcidin in the control groups, as well as to determine its connection with the parameters of the iron metabolism.

Methods

The research included 173 examinees, 89 of them suffered from iron deficiency anemia and 84 did not suffer from iron deficiency anemia (the latter represented the control group). Blood samples were collected from all study participants. The samples were analyzed for complete blood count and parameters of iron metabolism. ELISA method was used for establishing serum hepcidin levels.

Results

The research showed that the concentration of hepcidin is statistically lower in children (4.4 ng/mL) and adolescents (4.1 ng/mL) who suffer from iron deficiency anemia in comparison with the control group (14 ng/mL, 10 ng/mL, respectively). The positive correlation between serum hepcidin level and iron in the serum, ferritin, the mean corpuscular volume and transferrin saturation was confirmed, but the negative one occurred in serum hepcidin level, transferrin and reticulocytes.

Conclusions

The age of the examinees does not influence the level of serum hepcidin which makes it a more sensitive indicator of the level of iron in the body. Besides this, serum hepcidin is a reliable biological marker for the assessment of iron deficiency anemia.

Gut microbiota and inflammation in chronic kidney disease and their roles in the development of cardiovascular disease

The health and proper functioning of the cardiovascular and renal systems largely depend on crosstalk in the gut-kidney-heart/vessel triangle. Recent evidence suggests that the gut microbiota has an integral function in this crosstalk. Mounting evidence indicates that the development of chronic kidney and cardiovascular diseases follows chronic inflammatory processes that are affected by the gut microbiota via various immune, metabolic, endocrine, and neurologic pathways. Additionally, deterioration of the function of the cardiovascular and renal systems has been reported to disrupt the original gut microbiota composition, further contributing to the advancement of chronic cardiovascular and renal diseases. Considering the interaction between the gut microbiota and the renal and cardiovascular systems, we can infer that interventions for the gut microbiota through diet and possibly some medications can prevent/stop the vicious cycle between the gut microbiota and the cardiovascular/renal systems, leading to a decrease in chronic cardiovascular and renal diseases.

Comparison of Widely Used Biochemical Analytes in the Serum and Saliva Samples of Dialysis Patients

Background

The aim of this study is to determine whether the saliva analysis is an alternative to routine biochemical and immunoassay analyses in patients undergoing perito - neal dialysis (PD) or hemodialysis (HD).

Methods

Study group consisted of 40 healthy control, 44 PD and 44 HD patients. Routine biochemical analytes, thyroid stimulating hormone (TSH), free T3, free T4, vitamin B12, ferritin and folic acid were measured.

Results

Compared to pre-HD, urea, creatinine, uric acid, potassium levels were lower in post-HD, and calcium, magnesium, vitamin B12 levels were higher in post-HD both in saliva and serum. Positive correlations between saliva and serum were found for TSH and ferritin in control; urea, LDH, K in PD; urea, creatinine, alkaline phosphatase in pre-HD, and gamma-glutamyl transferase, iron, TSH in post-HD. There was a negative correlation only for creatine kinase and Mg in pre-HD and calcium in post-HD. In all groups, a positive correlation was found for urea, creatinine and a negative correlation was found for magnesium.

Conclusions

Our study showed higher salivary urea and creatinine levels in patient groups, consistent with serum levels. Based on these results, salivary urea and creatinine levels may be useful in the evaluation of azotemia in dialysis patients.

Preoperative blood morphology and incidence of acute kidney injury after on-pump coronary artery bypass grafting - a single-center preliminary report

Introduction

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) performed in cardiopulmonary bypass (CPB) may complicate the postoperative course and has a negative impact on outcome. In some cases, postoperative AKI develops in spite of normal baseline creatinine concentration and estimated glomerular filtration rate (eGFR).

Aim

To examine whether there is any association between the preoperative blood morphology and incidence of post-operative AKI.

Material and methods

The study involved 62 consecutive patients with the mean age of 64.0 ±7.4 years who underwent CABG in CPB. Before surgery, blood morphology and biochemistry were analyzed. Patients with eGFR below 60 ml/min/1.73 m² were excluded. After the operation, parameters of renal function were checked systematically. Acute kidney injury was defined according to the Acute Kidney Injury Network (AKIN) classification.

Results

Twenty-one (33.9%) patients presented AKI (group AKI), although in the majority of them (n = 16) it was temporary and medical management was enough to cure AKI. Only in 1 (1.6%) case was renal replacement therapy necessary. In group AKI, patients’ preoperative hemoglobin concentration (8.46 ±0.72 mM/l), red blood cell count (4.51 ±0.39 × 10¹²/l) and hematocrit (0.40 ±0.04) were significantly lower (p < 0.05) than in group C (9.07 ±0.57 mM/l; 4.78 ±0.36 × 10¹²/l; 0.43 ±0.03, respectively). Interestingly, the baseline parameters of renal function were comparable between groups.

Conclusions

Hemoglobin concentration and red blood cell counts close to the lower limit of the normal range may enable identification of patients at risk of AKI early after CABG in CPB among individuals with normal preoperative biochemical parameters of renal function.