Residual renal function in chronic dialysis is not associated with reduced erythropoietin-stimulating agent dose requirements: a cross-sectional study

On the importance of the interplay of residual renal function with clinical outcomes in end-stage kidney disease

Chronic kidney disease (CKD) is one of the most important public health concerns of the century, and is associated with high rates of morbidity, mortality and social costs. CKD evolving towards end-stage kidney disease (ESKD) is on the rise resulting in a greater number of patients requiring peritoneal dialysis (PD) and hemodialysis (HD). The aim of this manuscript is to review the current literature on the interplay of residual renal function (RRF) with clinical outcomes in ESKD. The persistence of RRF is one of the most important predictors of decreased morbidity, mortality, and better quality of life in both PD and HD patients. RRF contributes to the well-being of ESKD patients through various mechanisms including higher clearance of solutes, maintenance of fluid balance, removal of uremic toxins and control of electrolytes. Furthermore, RRF has beneficial effects on inflammation, anemia, malnutrition, diabetes mellitus, obesity, changes in the microbiota, and cardiac diseases. Several strategies have been proposed to preserve RRF, such as blockade of the renin-angiotensin-aldosterone system, better blood pressure control, incremental PD and HD. Several clinical trials investigating the issue of preservation of RRF are ongoing. They are needed to broaden our understanding of the interplay of RRF with clinical outcomes in ESKD.

Efficacy, Safety and Pharmacoeconomic Analysis of Intravenous Ferric Carboxymaltose in Anemic Hemodialysis Patients Unresponsive to Ferric Gluconate Treatment: A Multicenter Retrospective Study

Patients undergoing hemodialysis with iron deficiency anemia (IDA) receiving treatment with erythropoiesis-stimulating agents (ESAs) who were intolerant or non-responsive to intravenous (i.v.) ferric gluconate (FG) (hemoglobin; Hb values < 10.5 g/dL or increase in <1 g/dL) or % transferrin saturation; TSAT of <20%) in the previous 6 months were switched to i.v. ferric carboxymaltose (FCM). Changes in iron status parameters, economic and safety measures were also assessed. Seventy-seven hemodialysis patients aged 68 ± 15 years were included. Erythropoietin resistance index decreased from 24.2 ± 14.6 at pre-switch to 20.4 ± 14.6 after 6 months of FCM treatment and Hb levels ≥10.5 g/dL improved from 61% to 75.3% patients (p = 0.042). A 1 g/dL increase in Hb levels was also seen in 26% of patients as well as a 37.7% increase in patients achieving >20% increase in TSAT after FCM. Levels of Hb, TSAT and ferritin parameters increased during FCM treatment with a concomitant decrease in ESA. A mixed-model analysis, which also considered gender, confirmed these trends. Safety variables remained stable, no hypersensitivity reaction was recorded and only one patient reported an adverse event after FCM. FCM treatment was associated with a cost saving of 11.11 EUR/patient/month. These results confirm the efficacy, safety and cost-effectiveness of FCM in correcting IDA in hemodialysis patients.

Plasma erythropoietin level and heart failure in patients undergoing peritoneal dialysis: a cross-sectional study

Background

Renal anemia is the important complication in patients undergoing peritoneal dialysis (PD), and heart failure (HF) is the important complication in patients on dialysis. Decreasing endogenous erythropoietin (EPO) in patients with chronic kidney disease is a major cause of renal anemia. On the other hand, high levels of EPO have been associated with the prognosis of patients with chronic HF. The association between plasma EPO and HF in patients on PD remains unclear. This study was designed to test our hypothesis that the plasma EPO level in patients on PD was associated with the markers of HF.

Methods

We investigated 39 patients undergoing PD at our hospital. We measured plasma EPO before erythropoiesis-stimulating agent (ESA) administration at the regular outpatient visits and then at 2 weeks after the final dose of ESA was administered and investigated the clinical factors. We estimated the correlations between the plasma EPO and the other parameters, and constructed univariate and multivariate logistic regression models for the risk for HF to estimate the effectiveness of plasma EPO and other factors on HF treatment in patients undergoing PD.

Results

The plasma EPO concentration was positively correlated with the ESA dose and negatively correlated with serum ferrum, transferrin saturation, and body mass index and showed no correlation with other factors, such as the New York Heart Association (NYHA) classification and ferritin level. In univariate analysis, the factors significantly associated with HF risk were N-terminal pro-brain natriuretic peptide (NT-pro BNP), cardiothoracic ratio (CTR), serum creatinine (Cr), serum beta 2 microglobulin, dialysate dose, left ventricular mass index, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, and weekly Kt/V. We performed a multivariate analysis with NT-pro BNP, Cr, and CTR, and all three factors were significant in the analysis.

Conclusion

The plasma EPO level in patients undergoing PD was positively correlated with the monthly ESA dose and was not significant as a marker of HF, as judged with the NYHA classification. Therefore, the plasma EPO level may not be a useful marker for HF in patients undergoing PD.

Drug-drug interaction of atazanavir on UGT1A1-mediated glucuronidation of molidustat in human

Molidustat is an oral inhibitor of hypoxia‐inducible factor (HIF) prolyl‐hydroxylase enhancing the erythropoietin (EPO) response to HIF; it is in clinical development for the treatment of anaemia related to chronic kidney disease. The predominant role of glucuronidation for molidustat clearance (formation of N‐glucuronide metabolite M1) and subsequent renal excretion was confirmed in a human mass balance study, with about 85% of the drug being excreted as M1 in urine. The inhibitory effects of 176 drugs and xenobiotics from various compound classes on the UGT‐mediated glucuronidation of molidustat in human liver microsomes (HLMs) were investigated. Based on preclinical findings, glucuronidation of molidustat was predominantly mediated by the 5'‐diphospho‐glucuronosyltransferase (UGT) isoform UGT1A1. Therefore, atazanavir, which is a potent inhibitor of UGT1A1, was chosen for the evaluation of pharmacokinetics and EPO release following a single oral dose of 25 mg molidustat. Molidustat exposure increased about twofold upon coadministration with atazanavir when considering area under plasma concentration‐time curve from zero to infinity (AUC) and maximum plasma concentration (C_max). Baseline‐corrected increase of EPO was 14% and 34% for C_max and AUC (calculated over 24 hours), respectively. Coadministration of molidustat and atazanavir was well tolerated.

Quality assessment of unsaturated iron-binding protein capacity in Iraqi patients undergoing hemodialysis

Hemodialysis is autoimmune disease result from inflammation, oxidative stress, and fibrosis. It is characterized by renal glomeruli damage, podocyte injury, tubule interstitial, and proteinuria. Electrolyte balance is the main function of the renal and any form of electrolyte disorders may lead to excess blood volume, hypertension, and difficulty in maintaining natural blood sodium. Renal erythropoietin has an important role in the balance of vascular active substances, such as prostaglandins and thromboxanes; therefore, patients undergoing hemodialysis observe decreased production of erythropoietin with iron loss through hemodialysis machine as well as weakened iron absorption and mobilization from the intestine to the bloodstream. Ferritin, total iron-binding capacity (TIBC), unsaturated iron-binding protein capacity (UIBC), iron free, and transferrin are used to confirm iron status. According the clinical characterization of the results, no normality was observed in patients undergoing hemodialysis. There was hypertension, anemia, lean symptoms and equal distribution of age parallel with developed disease, there was significant increased in renal function except albumin, it was decreased in the patients compared with control groups. In addition, there was a decreased level of iron status in all parameters such as packed cell volume (%), TIBC, UIBC, iron free, and transferrin except ferritin; there was an increased level of iron status in all parameters in patients compared with control groups.