Gabriel Mircescu

Evaluation of calcium acetate/magnesium carbonate as a phosphate binder compared with sevelamer hydrochloride in haemodialysis patients: a controlled randomized study (CALMAG study) assessing efficacy and tolerability

Background. Phosphate binders are required to control serum phosphorus in dialysis patients. A phosphate binder combining calcium and magnesium offers an interesting therapeutic option. Methods. This controlled randomized, investigator-masked, multicentre trial investigated the effect of calcium acetate/magnesium carbonate (CaMg) on serum phosphorus levels compared with sevelamer hydrochloride (HCl). The study aim was to show non-inferiority of CaMg in lowering serum phosphorus levels into Kidney Disease Outcome Quality Initiative (K/DOQI) target level range after 24 weeks. Three hundred and twenty-six patients from five European countries were included. After a phosphate binder washout period, 255 patients were randomized in a 1:1 fashion. Two hundred and four patients completed the study per protocol (CaMg, N = 105; dropouts N = 18; sevelamer-HCl, N = 99; dropouts N = 34). Patient baseline characteristics were similar in both groups. Results. Serum phosphorus levels had decreased significantly with both drugs at week 25, and the study hypothesis of CaMg not being inferior to sevelamer-HCl was confirmed. The area under the curve for serum phosphorus (P = 0.0042) and the number of visits above K/DOQI (≤1.78 mmol/L, P = 0.0198) and Kidney disease: Improving global outcomes (KDIGO) targets (≤1.45 mmol/L, P = 0.0067) were significantly lower with CaMg. Ionized serum calcium did not differ between groups; total serum calcium increased in the CaMg group (treatment difference 0.0477 mmol/L; P = 0.0032) but was not associated with a higher risk of hypercalcaemia. An asymptomatic increase in serum magnesium occurred in CaMg-treated patients (treatment difference 0.2597 mmol/L, P < 0.0001). There was no difference in the number of patients with adverse events. Conclusion. CaMg was non-inferior to the comparator at controlling serum phosphorus levels at Week 25. There was no change in ionized calcium; there was minimal increase in total serum calcium and a small increase in serum magnesium. It had a good tolerability profile and thus may represent an effective treatment of hyperphosphataemia.

Factors affecting the quality of life of haemodialysis patients from Romania: a multicentric study

BACKGROUND The quality of life (QoL) is an important predictor of outcome in end-stage renal disease (ESRD) patients. Therefore, QoL needs to be regularly assessed in this setting. Our study describes QoL, as well as demographic and clinical variables associated with QoL in chronic haemodialysis (HD) patients in Romania. METHODS All prevalent chronic HD patients (N = 709; mean age 51.7 +/- 12.6 years) in 12 dialysis centres from the three main regions of Romania were included in the study. Six hundred and six of these completed the Short-Form Health Survey (SF-36) and the Kidney Disease Quality of Life Questionnaire-Short Form (KDQOL-SF). RESULTS The mean physical component summary (PCS) score was 46.3 +/- 19.2, and the mean mental component summary (MCS) score was 55.1 +/- 19.3. These figures were lower than those previously described in non-dialysis age-matched Romanian individuals. The mean kidney disease summary component (KDSC) score was 68.3 +/- 11.3, similar to other studies. The worst dimension of QoL was work, whereas the best ones were cognitive function and quality of social interaction. We found older age, female gender, lower socio-economic status and higher educational level to be associated with lower QoL scores. CONCLUSIONS The QoL of HD patients in Romania is lower than that in the general population. Our results suggest that at least one-third of these patients might be considered for rehabilitation therapy, in order to try and prevent complications and mortality.

Ketoanalogue-Supplemented Vegetarian Very Low–Protein Diet and CKD Progression

Dietary protein restriction may improve determinants of CKD progression. However, the extent of improvement and effect of ketoanalogue supplementation are unclear. We conducted a prospective, randomized, controlled trial of safety and efficacy of ketoanalogue-supplemented vegetarian very low-protein diet (KD) compared with conventional low-protein diet (LPD). Primary end point was RRT initiation or >50% reduction in initial eGFR. Nondiabetic adults with stable eGFR<30 ml/min per 1.73 m(2), proteinuria <1 g/g urinary creatinine, good nutritional status, and good diet compliance entered a run-in phase on LPD. After 3 months, compliant patients were randomized to KD (0.3 g/kg vegetable proteins and 1 cps/5 kg ketoanalogues per day) or continue LPD (0.6 g/kg per day) for 15 months. Only 14% of screened patients patients were randomized, with no differences between groups. Adjusted numbers needed to treat (NNTs; 95% confidence interval) to avoid composite primary end point in intention to treat and per-protocol analyses in one patient were 4.4 (4.2 to 5.1) and 4.0 (3.9 to 4.4), respectively, for patients with eGFR<30 ml/min per 1.73 m(2) Adjusted NNT (95% confidence interval) to avoid dialysis was 22.4 (21.5 to 25.1) for patients with eGFR<30 ml/min per 1.73 m(2) but decreased to 2.7 (2.6 to 3.1) for patients with eGFR<20 ml/min per 1.73 m(2) in intention to treat analysis. Correction of metabolic abnormalities occurred only with KD. Compliance to diet was good, with no changes in nutritional parameters and no adverse reactions. Thus, this KD seems nutritionally safe and could defer dialysis initiation in some patients with CKD.

The safety and efficacy of intravenous ferric carboxymaltose in anaemic patients undergoing haemodialysis: a multi-centre, open-label, clinical study

Background. Patients with chronic kidney disease (CKD) often present with iron depletion and iron deficiency anaemia (IDA) because of frequent blood (and iron) loss. Therapy consists of repletion of iron stores and intravenous (i.v.) iron has become the standard care in this setting. However, older i.v. iron preparations have their limitations. This study primarily investigated the safety, and also the efficacy, of ferric carboxymaltose (FCM), a next-generation i.v. iron formulation, given as a bolus–push injection in patients with CKD undergoing maintenance haemodialysis (HD). Methods. Patients (aged 18–65 years) with IDA undergoing HD received 100–200 mg of iron as FCM via an i.v. bolus–push injection into the HD venous line, two to three times weekly for ≤6 weeks. Safety assessments included incidence of adverse events (AEs). Treatment responders were patients attaining ≥1.0 g/dl increase in haemoglobin (Hb) from baseline at any time during the study. Enrolled patients (safety population) receiving ≥1 dose of study medication were included in the efficacy analyses [intent-to-treat (ITT) population]. Results. Of 163 patients enrolled, 150 (92%) completed the study. The mean ± SD total cumulative dose of iron as FCM administered was 2133.3 ± 57.7 mg. In total, 193 AEs were reported in 89 out of 163 (54.6%) patients. Almost three-quarters of patients (73.6%) received erythropoiesis-stimulating agents (ESAs), but the dose remained stable during the study. Serious AEs occurred in 12 out of 163 (7.4%) patients and two patients died; none of these was considered by the investigator to be related to the study medication. Only five out of 163 (3.1%) patients discontinued study medication due to an AE. Overall, 100 out of 162 (61.7%; ITT population) patients were treatment responders, and mean Hb levels increased from 9.1 ± 1.30 g/dl at baseline to 10.3 ± 1.63 g/dl at follow-up. Conclusions. FCM is well-tolerated and effective in the correction of Hb levels and iron stores in patients with IDA undergoing HD. As changes in anaemia treatment other than i.v. FCM (e.g. increased ESA doses) were not permitted during the study, the clinically relevant increase in Hb in the majority of patients can be solely attributed to efficient iron utilization. The incidence of AEs was as expected for this population.

Can the Response to Iron Therapy Be Predicted in Anemic Nondialysis Patients with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES Anemia is iron responsive in 30 to 50% of nondialysis patients with chronic kidney disease (CKD), but the utility of bone marrow iron stores and peripheral iron indices to predict the erythropoietic response is not settled. We investigated the accuracy of peripheral and central iron indices to predict the response to intravenous iron in nondialysis patients with CKD and anemia. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A diagnostic study was conducted on 100 nondialysis patients who had CKD and anemia and were erythropoiesis-stimulating agent and iron naive. Bone marrow iron stores were evaluated by aspiration. Hemoglobin, transferrin saturation index (TSAT), and ferritin were measured at baseline and 1 month after 1000 mg of intravenous iron sucrose. Posttest predictive values for the erythropoietic response (> or =1-g/dl increase in hemoglobin) of peripheral and central iron indices were calculated. RESULTS The erythropoietic response was noted in a higher proportion in bone marrow iron-deplete than in iron-replete patients (63 versus 30%). Peripheral iron indices had a moderate accuracy in predicting response. The positive (PPV) and negative predictive values (NPV) were 76 and 72% for a TSAT of 15% and 74 and 70% for a ferritin of 75 ng/ml, respectively. In the final logistic regression model, including TSAT and ferritin, the chances of a positive response increased by 7% for each 1% decrease in TSAT. CONCLUSIONS Because an erythropoietic response is seen in half of patients and even one third of those with iron-replete stores responded whereas peripheral indices had only a moderate utility in predicting response, the therapeutic trial to intravenous iron seems to be a useful tool in the management of anemia in nondialysis patients with CKD.

Effect of Low-Protein Diet Supplemented With Keto Acids on Progression of Chronic Kidney Disease

Hypoproteic diets are most often discussed for patients with chronic kidney disease (CKD) who do not receive dialysis. A very low-protein diet supplemented with ketoanalogues of essential amino acids (keto-diet) proved effective in ameliorating metabolic disturbances of advanced CKD and delaying the initiation of dialysis without deleterious effects on nutritional status. Several recent studies report that the keto-diet could also slow down the rate of decline in renal function, with better outcomes after the initiation of dialysis. Results of a single-center randomized controlled trial addressing the rate of CKD progression revealed a 57% slower decline in renal function with the keto-diet compared with a conventional low-protein diet (LPD). The keto-diet allowed the safe management of selected patients with stage 4-5 CKD, delaying dialysis for almost 1 year, with a major impact on patient quality of life and health expenditures. Therefore, the keto-diet could be a link in the integrated care model. Careful selection of patients, nutritional monitoring, and dietary counseling are required.

Is hepcidin-25 a clinically relevant parameter for the iron status in hemodialysis patients?

BACKGROUND Accumulating data suggest potential clinical relevant relationships between hepcidin-25 levels, iron stores, erythropoiesis effectiveness, and epoetin dose. The immunometric methods and mass spectroscopy are currently used to measure hepcidin-25, but no standard exists, and values, although similar in trends, differ in absolute value. OBJECTIVE To investigate hepcidin levels and their relationship with peripheral iron indices, inflammation, and anemia therapy in patients on hemodialysis (HD). METHODS A cross-sectional study in 78 patients from a single HD center. Hepcidin-25 was measured with enzyme-linked immunosorbent assay (ELISA), using a commercial kit (Bachem, UK). RESULTS Hepcidin-25 levels were similar to those previously reported in studies using the same antibody (median 113 [95% CI; 107-122 ng/mL]) and significant but weak correlations of hepcidin with transferrin (R2=0.06; p<0.04) and ferritin (R2=0.09; p<0.01) were found. A model of multiple regression analysis explained 57% of variation along hepcidin quartiles. Lower hepcidin levels were associated with higher transferrin levels (odds ratio 1.05 [1.01-1.09]), bigger iron doses (odds ratio 1.09 [1.02-1.15]), and an increased darbepoetin resistance index (odds ratio 4.3E+15 [11.15-1.6E+30]). An elevated serum C reactive protein was associated with increased hepcidin levels (odds ratio 0.70 [0.49-0.99]), while a higher ultrafiltration volume (odds ratio 4.30 [1.28-14.51]) and the male sex (odds ratio 0.04 [0.00-0.80]) were related to lower hepcidin levels. LIMITS Cohort number and composition. Hepcidin-25 ELISA assay. CONCLUSION A low hepcidin level in hemodialysis patients with high epoetin resistance index could be a useful marker of iron-restricted erythropoiesis, but confirmation by a therapeutical trial is necessary.

Influence of Epoietinum Therapy on the Oxidative Stress in Haemodialysis Patients

Background: The causes of oxidative stress in haemodialysis (HD) patients are still controversial. Beside the uraemic state and dialysis-related factors, adjuvant drug therapies such as epoietinum (rHuEpo) and intravenous iron were involved. Methods: Several parameters related to oxidative stress were assessed by spectrophotometry in stable HD patients, treated for at least 2 months with epoietinum (n = 14; mean dose = 97.7 ± 19.1 U/kg/week) or not (n = 15), none of them on iron therapy, and in 13 controls. Plasma thiobarbituric acid-reactive substances (TBARS) were used as markers of reactive species generation. Erythrocyte and plasma antioxidant systems, reflected by non-protein erythrocyte thiols, and erythrocyte enzyme activities – superoxide dismutase (SOD), glutathione peroxidase, catalase and plasma total thiols, respectively – were also investigated. Results: There were no differences between HD subgroups regarding haemoglobin levels. Plasma TBARS was increased in all HD patients as opposed to controls, irrespective of rHuEpo therapy. In addition, no change in antioxidant status parameters between rHuEpo-treated and -untreated patients was observed. Except for SOD, the other antioxidant indices were higher in all HD patients versus controls. Conclusions: These results suggest that (1) chronic HD patients appear to have simultaneously enhanced reactive species generation and antioxidative systems efficiency, and (2) epoietinum therapy did not change their oxidative status, at least in the absence of concomitant iron supplementation and at similar haemoglobin levels.

Antiphospholipase A2 Receptor Autoantibodies: A Step Forward in the Management of Primary Membranous Nephropathy

Since the identification of PLA2R (M-type phospholipase A2 receptor) as the first human antigenic target in primary membranous nephropathy (MN), perpetual progress has been made in understanding the pathogenesis of this disease. Accumulating clinical data support a pathogenic role for the anti-PLA2R antibodies (PLA2R ABs), but confirmation in an animal model is still lacking. However, PLA2R ABs were related to disease activity and outcome, as well as to response therapy. Accordingly, PLA2R ABs assay seems to be promising tool not only to diagnose MN but also to predict the course of the disease and could open the way to personalize therapy. Nevertheless, validation of a universal assay with high precision and definition of cut-off levels, followed by larger studies with a prolonged follow-up period, are needed to confirm these prospects.

Does Dialysis Modality Influence the Oxidative Stress of Uremic Patients

Background/Aims: Since peritoneal membrane is more compatible and residual renal function better preserved during peritoneal dialysis, we questioned whether the oxidative burden in chronic kidney disease (CKD) is influenced by dialysis modality. Methods: 49 stable CKD patients, 17 on continuous ambulatory peritoneal dialysis (CAPD), 16 on hemodialysis (HD), and 16 non-dialyzed, and 13 healthy subjects were enrolled. Plasma thiobarbituric acid-reactive substances (TBARS; nmol/g protein), serum total antioxidant activity (TAA), total plasma-free thiols (Pt-SH; µmol/g protein), albumin and uric acid were measured by spectrophotometry. Serum residual antioxidant activity (RAA) was calculated. Results: TBARS were higher in HD (78.3 ± 20.3) versus both non-dialyzed (53.1 ± 27.9, p = 0.007) and CAPD groups (58.3 ± 19.8, p = 0.008). Pt-SH was reduced in CKD patients, but showed comparable values between dialysis groups. TAA and RAA were similarly increased in HD and CAPD patients than in the other two groups. Conclusion: Oxidative stress occurs in all CKD patients and worsens as renal function declines. Lipid peroxidation seems more augmented during chronic HD as compared to CAPD, but the plasma antioxidant status did not differ between the investigated dialysis methods. Therefore, dialysis modality appears to influence lipid peroxidation without changing the extracellular antioxidant defense of CKD patients.