Erythropoietin Resistance Development in Hemodialysis Patients: The Role of Oxidative Stress

The influencing factors of the erythropoietin resistance index and its association with all-cause mortality in maintenance hemodialysis patients

Anemia is a common complication of chronic kidney disease with major option treatment of erythropoiesis-stimulating agents (ESAs). This study aimed to investigate the influencing factors of erythropoietin resistance index (ERI) and its association with mortality in maintenance hemodialysis (MHD) patients. Patients enrolled from China Dialysis Outcomes and Practice Patterns Study (DOPPS) 5 were included. ERI was calculated as follows: ESA (IU/week)/weight (kg, post-dialysis)/hemoglobin level (g/dL). The Cox regression model was used to analyze the influencing factors on survival outcomes. Stepwise multivariate logistic regression was used to identify the related risk factors, and subgroup analyses were performed. A total of 1270 MHD subjects (687 males and 583 females) were included, with an average age of 60 (49.0, 71.0) years. All subjects were divided into two groups by the median ERI of 14.03. Multivariate logistic regression showed that dialysis vintage (OR 0.957, 95% CI: 0.929-0.986), white blood cells (OR 0.900, 95% CI: 0.844-0.960), high flux dialyzer use (OR 0.866, 95% CI: 0.755-0.993), body mass index (OR 0.860, 95% CI: 0.828-0.892), males (OR 0.708, 95% CI: 0.625-0.801), and albumin (OR 0.512, 95% CI: 0.389-0.673) had a negative association with high ERI baseline (all p < 0.05). There were 176 (13.9%) deaths in total including 89 cardiac/vascular deaths during follow-up. Cox regression analysis showed that ERI was positively associated with all-cause mortality, especially in some subgroups. ERI was associated with increased all-cause mortality in MHD patients, indicating the possibility of death prediction by ERI. Patients with high ERI warrant more attention.

Design of the Functional Dialysis Membrane with a Catalase Pseudoactive Center on the Surface

Here, we have designed a functional dialysis membrane with a catalase pseudoactive center on the surface. To make the catalase pseudoactive center, we have modified the regenerated cellulose dialysis membrane with methylated or octylated poly(1-vinylimidazole) (PVIm-Me or PVIm-Oc), followed by manganese or iron tetrakis(4-carboxyphenyl)porphyrin (Mn- or Fe-TCPP), using the layer-by-layer (LbL) method. As a result of the optimization, the dialysis membrane modified with 25 mol % methylated poly(1-vinylimidazole) [PVIm-Me(25)] and Mn-TCPP produced the highest amount of oxygen (O2) from hydrogen peroxide (H2O2) without the decomposition of Mn-TCPP. Conversely, Mn- and Fe-TCPP were decomposed under other experimental conditions in the presence of H2O2. These results suggest the conversion of H2O2 to O2 by catalase catalytic activity on the surface coated with PVIm-Me(25) and Mn-TCPP.

A clinical study on roxadustat for anemia in diabetic nephropathy: a 8-week study

PURPOSE

The development of roxadustat is a standard treatment for renal anemia, and multiple clinical trials have proved its safety and efficacy. However, less information is available from trials of the population with diabetic nephropathy (DN). This study aimed to determine whether roxadustat is effective for treating DN.

METHODS

This was a single-center, retrospective, institutional review board-approved cohort study. The patients with DN were chosen and given roxadustat or erythropoietin (EPO) for 8 weeks. The mean hemoglobin (Hb) level after 8 weeks of treatment served as the primary outcome. Alterations in the iron index and lipid levels were considered secondary objectives. Sub-group analysis was performed to observe the impact of inflammation and glycemic status on Hb.

RESULTS

A total of 80 patients were enrolled, 40 in each group. After 8 weeks of treatment, the Hb levels in the roxadustat group were higher than those in the control group. The number of patients who achieved Hb response was higher in the roxadustat group than in the control group (77.5% versus 27.5%; P < 0.001). In addition to lowering total cholesterol and low-density lipoprotein cholesterol, roxadustat decreased ferritin and elevated total iron-binding capacity. Compared to the control group, roxadustat was more beneficial for patients with an inflammatory condition and poor glycemic control.

CONCLUSIONS

Roxadustat treatment remarkably corrected anemia in patients with DN, and its effectiveness was unaffected by inflammation or glycemic control levels. In addition, roxadustat can also reduce a patient's blood lipid level and enhance the body's use of iron.

CLINICAL TRIAL REGISTRATION

ChiCTR2200057232.

Variations of Redox Balance in Different Stages of Childhood Immune Thrombocytopenic Purpura

BACKGROUND

 Few previous studies indicated the role of oxidative stress in the pathogenesis of childhood idiopathic thrombocytopenic purpura (ITP), but there are little data regarding changes in redox balance in different forms of the disease, and changes after therapeutic procedures. We aimed to investigate the values of pro-oxidants and antioxidative capacity in various forms of ITP before and after the applying therapy.

MATERIALS AND METHODS

 The research included 102 children, classified into the following groups: (1) newly diagnosed ITP (ndITP), (2) persistent ITP, (3) chronic ITP (chITP), and (4) control groups: (A) healthy control and (B) previously experienced ITP-healthy children who had been suffering from ITP earlier. During the clinical assessment, a blood sample was taken from the patients, from which the value of pro-oxidants (index of lipid peroxidation measured as TBARS, nitrites [NO2 -], as measurement of nitric oxide [NO] production, superoxide anion radical [O2 -], and hydrogen peroxide [H2O2]) and the capacity of antioxidant protection (activity of superoxide dismutase and catalase, and quantity of reduced glutathione) were determined spectrophotometrically.

RESULTS

 Our results demonstrated that values of pro-oxidants, especially reflected through the TBARS and O2 -, were the highest in the ndITP and exacerbated chITP groups. Also, the activity of the endogenous antioxidative defense system was the lowest in these groups. Intravenous immunoglobulin therapy in the ndITP group exerted the most prominent effect on the redox balance.

CONCLUSION

 It can be concluded that severity and exacerbation of the ITP are closely related to the redox status.

Relation between erythropoietin resistance and metabolic syndrome in hemodialysis patients: A multicentric propensity score matched analysis

Erythropoietin (EPO) resistance is frequently reported in hemodialysis (HD) patients. Metabolic syndrome (MetS) is a common biochemical condition that comprises central obesity, dyslipidemia, hypertension, and hyperglycemia. The present study aimed to assess the relation between MetS and EPO resistance in HD patients. The present multicentric study included 150 patients with EPO resistance and 150 patients without EPO resistance. Short-acting EPO resistance was diagnosed if the erythropoietin resistance index is ≥1.0 IU/kg/gHb. Comparison between patients with EPO resistance and patients without resistance revealed that the former group had significantly higher body mass index, lower hemoglobin levels, lower albumin levels, higher ferritin levels, and higher high-sensitivity C-reactive protein (hsCRP) levels. In addition, patients in the EPO resistance group had significantly higher frequency of MetS (75.3% vs 38.0%, p < 0.001) and higher number of MetS components (2.7 ± 1.3 vs 1.8 ± 1.6, p < 0.001). Multivariate logistic regression analysis identified lower albumin levels (OR (95% CI): 0.072 (0.016-0.313), p < 0.001), higher ferritin levels (OR (95% CI): 1.05 (1.033-1.066), p< 0.001), higher hsCRP levels (OR (95% CI): 1.041 (1.007-1.077), p = 0.018), and MetS (OR (95% CI): 36.68 (2.893-465.05), p = 0.005) as predictors of EPO resistance in the studied patients. The present study identified MetS as a predictor of EPO resistance in HD patients. Other predictors include serum ferritin, hsCRP, and albumin levels.