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Worldwide, the number of elderly individuals receiving chronic hemodialysis is rising. The aim of our study was to evaluate several clinical and analytical biomarkers in chronically dialyzed patients and analyze how they change with age. A cross-sectional study was performed by evaluating 289 end-stage renal disease patients undergoing dialysis. We evaluated the hemogram, adipokines, the lipid profile, and several markers related to inflammation, endothelial function/fibrinolysis, nutrition, iron metabolism, and cardiac and renal fibrosis. Clinical data and dialysis efficacy parameters were obtained from all patients. The relationships between studied biomarkers and age were assessed by a statistical comparison between younger (adults with age < 65 years) and older (age ≥ 65 years) patients and by performing regression analysis. Participants presented a mean age of 68.7 years (±13.6), with 66.8% ( n = 193) being classified as older. Compared to younger patients, older patients presented the following: (a) significantly lower values of diastolic blood pressure (DBP) and ultrafiltration volume; (b) lower levels of phosphorus, uric acid, creatinine, and albumin; and (c) higher circulating concentrations of tissue-type plasminogen activator (tPA), D-dimer, interleukin-6, leptin, N -terminal pro B-type natriuretic peptide, and tissue inhibitor of metalloproteinase-1. In the multiple linear regression analysis, DBP values, tPA, phosphorus, and D-dimer levels were independently associated with the age of patients (standardized betas: -0.407, 0.272, -0.230, and 0.197, respectively; p < 0.001 for all), demonstrating relevant changes in biomarkers with increasing age at cardiovascular and nutritional levels. These findings seem to result from crosstalk mechanisms between aging and chronic kidney disease.

Introduction: Caring for a patient with end-stage renal disease undergoing in-centre haemodialysis can be a stressful experience, likely to involve significant burden. Within the context of the new coronavirus pandemic, these patients are highly vulnerable to infection by COVID-19, which might increase the care demands and burden of family caregivers., Aim: This study aimed to explore the subjective experiences of family caregivers of non-COVID-19 patients with end-stage renal disease undergoing in-centre haemodialysis during the COVID-19 lockdown., Study Design: A qualitative study was performed with a purposive sample., Methods: Semi-structured telephone interviews were conducted with 19 family caregivers (50.7 ± 14 years old) of patients undergoing in-centre haemodialysis in April 2020., Findings: Four major themes were identified: (1) emotional distress; (2) changes in caregiving responsibilities; (3) educational and supportive needs; and (4) coping strategies to deal with the outbreak and with the lockdown., Discussion: The findings suggest that family caregivers of patients undergoing in-centre haemodialysis have to manage several additional care responsibilities due to COVID-19 lockdown. The dialysis team should consider the development of educational and supportive interventions to meet family caregivers' needs, mitigate emotional distress, fears and concerns, and prevent caregiver burden during the COVID-19 pandemic., (© 2021 Nordic College of Caring Science.)

Chronic inflammation plays an important role in the progression and outcome of chronic kidney disease (CKD). The circulating levels of the inflammatory biomarkers interleukin 6 (IL6) and pentraxin 3 (PTX3) are enhanced in CKD patients, and are associated with the progression of the disease and with higher risk for cardiovascular events, the major cause of death in CKD patients. Our aim was to study how specific polymorphisms of IL6 and PTX3 encoding genes affect the inflammatory response and outcome of end-stage renal disease (ESRD) patients on dialysis. Methodology included the analysis of two single nucleotide polymorphisms (SNP), namely the IL6 (rs1800795) polymorphism in the promoter region (-174G > C), and the PTX3 (rs2305619) polymorphism in the intron 1 (+ 281A > G), which were analyzed in ESRD patients on dialysis and in a group of heathy individuals. The allelic frequencies, genotype distribution and their association with circulating levels of the inflammatory markers C-reactive protein (CRP), IL6, growth differentiation factor 15 (GDF15) and PTX3, were determined in ESRD patients. Events of death were recorded along one year, to assess the association of the studied SNPs with all-cause mortality and the inflammatory biomarkers, in ESRD patients. Results showed that the allelic frequencies and genotype distribution for IL6 and PTX3 SNPs in the control group and ESRD patients were similar and in agreement with other European reports. For the IL6 polymorphism, we found a trend towards higher levels of high-sensitivity (hs) CRP, IL6 and PTX3 in the homozygous genotypes; the CC genotype also showed the highest levels of GDF15. The mortality rate after the 1-year follow-up was 10.4%. The CC genotype (IL6 SNP) was associated to a higher risk of mortality and deceased patients carrying this genotype also showed the highest levels of hsCRP. Regarding the studied PTX3 SNP, the AA genotype was linked to an enhanced inflammatory response, showing the highest values of hsCRP and IL6. Nevertheless, this genotype had no significant impact on the mortality rate. In conclusion, both studied SNPs seem to modulate the inflammatory response in ESRD and may, therefore, be determinant on disease progression and patients' outcome. Our data also highlights the importance of research on genetic variants that, although less frequent, may have significant biological value., (© 2021. The Author(s).)

For individuals with end-stage renal disease (ESRD), the novel coronavirus can present several additional challenges in disease self-management. This study aimed to explore the impacts of the COVID-19 pandemic in non-COVID-19 patients with ESRD undergoing in-center hemodialysis (HD). A mixed-methods study was conducted with a purposive sample recruited from one dialysis unit in Portugal. Quantitative data were collected retrospectively from patients' medical records from February 2020 (T1-before the outbreak) and from April 2020 (T2-during lockdown). Semi-structured interviews were conducted with 20 patients (66.9 ± 11.9 years old) undergoing HD for an average of 46.1 months (±39.5) in April 2020. Overall results suggested that dialysis adequacy and serum albumin levels decreased significantly at T2, while phosphorus levels increased. The findings from thematic analysis suggested several psychosocial negative impacts and impacts on disease and treatment-related health behaviors (eg, difficulties managing dietary restrictions during the lockdown and diminished physical activity), which can partially explain these quantitative results. However, some patients were also able to find positive impacts in this experience and problem-focused and emotional strategies were identified to cope with the demands of COVID-19. Several recommendations have been made to mitigate patients' emotional, relational, and educational unmet needs during the current pandemic and in the event of new outbreaks., (© 2020 Wiley Periodicals LLC.)

Successful dialysis in end-stage renal disease (ESRD) largely depends on the patients' ability to adhere to several clinical requirements and life-style changes. Social support has been consistently linked to better health outcomes in a number of chronic diseases. The current study presents a systematic review of the literature on the relationship between social support and treatment adherence in ESRD. The search was performed on Web of Science, PsycInfo, ScienceDirect, and Scopus from January 19 to May 15, 2019. Two hundred and twenty-four records were identified. After quality assessment, 17 studies were included for qualitative synthesis. This review comprised a total of 2362 patients. Most patients were on hemodialysis (97.5%) for an average of 58.2 months. Results suggested an overall pattern of mixed findings regarding the association between social support and treatment adherence. Adherence to fluid restrictions was the type of adherence with more significant associations with social support (63%). Mixed results were found for adherence to dialysis sessions (50%) and to medication (50%). Associations between adherence to diet restrictions and social support were found in 44% of the included studies. No significant associations were found between social support and adherence to follow-up consults. All of the included studies combining several types of adherence into an overall score found significant associations with social support. Findings suggested that it might be particularly beneficial to focus future research and clinical efforts toward social support from family, significant others, and health professionals, to improve patient's with ESRD treatment adherence., (© 2019 Wiley Periodicals, Inc.)

Background: Soluble transferrin receptor (sTfR) is a biomarker of erythropoiesis, which is often impaired in dialysis patients. The aim of our study was to evaluate sTfR levels in chronically dialyzed patients and assess potential determinants of its levels. Methods: We performed a cross-sectional study by evaluating 246 end-stage renal disease patients undergoing dialysis and 32 healthy controls. Circulating levels of interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, hepcidin, sTfR, growth differentiation factor 15 (GDF15), and traditional iron metabolism markers were measured, as well as hemogram parameters. Clinical data was obtained from all patients. Results: Compared to controls, patients presented similar values of sTfR, reticulocytes and reticulocyte production index (RPI), and significantly higher levels of IL-6, CRP, ferritin, hepcidin, TNF-α, and GDF15. Iron, transferrin, hemoglobin levels, erythrocyte count, mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) values were significantly lower in dialysis group. Within patients, sTfR values were higher in diabetic patients and were positively and significantly correlated with reticulocytes and erythrocytes, RPI, and therapeutic doses of erythropoiesis stimulating agents (ESA) and intravenous iron; and inversely and significantly correlated with circulating iron, ferritin, transferrin saturation, hepcidin, MCH, and MCHC. In multiple linear regression analysis, ESA dose, RPI, serum iron, diabetes, and hepcidin levels were independently associated with sTfR levels in dialysis patients and, thus, with erythropoiesis. Conclusion: Our data suggest that, besides RPI and ESA dose, diabetes and hepcidin are closely related to erythropoiesis in dialysis patients. The influence of diabetes on sTfR levels deserves further investigation.

Persistent inflammation in end-stage renal disease (ESRD) patients is known to underlie the progression of chronic kidney disease and to be associated with multiple risk factors including malnutrition, atherosclerosis, and cardiovascular disease (CVD). The acute-phase protein pentraxin 3 (PTX3) has a proven potential as a local inflammatory biomarker, but its clinical utility in ESRD remains unclear. Circulating levels of PTX3 and classical inflammatory mediators, including the clinical prototypical C-reactive protein (CRP), were assessed in 246 ESRD patients on dialysis and analysed in relation to the lipid profile, adipokine levels, and nutritional, cardiac, and renal fibrosis markers. Occurrence of deaths was recorded for the following year. Contrarily to the classical inflammatory markers, PTX3 levels were negatively correlated with nutritional markers and associated with a less atherogenic lipid profile. Levels of the cardiac and renal fibrosis markers and of the oxidized LDL/LDL-C ratio were found to be independent determinants of PTX3 concentration. When comparing inflammatory mediators, the increase in the PTX3 levels was the only predictor of all-cause mortality in dialysis patients in a survival model adjusted to all markers under study, other than the inflammatory ones, besides common confounding factors in dialysis. Data support the clinical applicability of PTX3 as a broader inflammatory biomarker than the classical ones, presenting a close association with inflammation, malnutrition, CVD, and renal fibrosis and a great potential to predict all-cause mortality in dialysis patients. The pleiotropic character of PTX3 may be of clinical relevance, and it could be targeted to ameliorate the high morbidity and mortality associated with ESRD.

Cardiovascular disease (CVD) events are the main causes of death in end-stage renal disease (ESRD) patients on dialysis. The number and severity of CVD events remain inappropriate and difficult to explain by considering only the classic CVD risk factors. Our aim was to clarify the changes and the relationship of lipoprotein subfractions with other CVD risk factors, namely, body mass index (BMI) and adipokines, inflammation and low-density lipoprotein (LDL) oxidation, and the burden of the most prevalent comorbidities, diabetes mellitus (DM) and hypertension (HT). We studied 194 ESRD patients on dialysis and 22 controls; lipid profile, including lipoprotein subpopulations and oxidized LDL (oxLDL), C-reactive protein (CRP), adiponectin, leptin, and paraoxonase 1 activity were evaluated. Compared to controls, patients presented significantly lower levels of cholesterol, high-density lipoprotein cholesterol (HDLc), LDLc, oxLDL, and intermediate and small HDL and higher triglycerides, CRP, adiponectin, large HDL, very-low-density lipoprotein (VLDL), and intermediate-density lipoprotein- (IDL) B. Adiponectin levels correlated positively with large HDL and negatively with intermediate and small HDL, oxLDL/LDLc, and BMI; patients with DM ( n = 17) and with DM+HT ( n = 70), as compared to patients without DM or HT ( n = 69) or only with HT ( n = 38), presented significantly higher oxLDL, oxLDL/LDLc, and leptin and lower adiponectin. Obese patients ( n = 45), as compared to normoponderal patients ( n = 81), showed lower HDLc, adiponectin, and large HDL and significantly higher leptin, VLDL, and intermediate and small HDL. In ESRD, the higher adiponectin seems to favor atheroprotective HDL modifications and protect LDL particles from oxidative atherogenic changes. However, in diabetic and obese patients, adiponectin presents the lowest values, oxLDL/LDLc present the highest ones, and the HDL profile is the more atherogenic. Our data suggest that the coexistence of DM and adiposity in ESRD patients on dialysis contributes to a higher CVD risk, as showed by their lipid and adipokine profiles.

Non-adherence to medical plans is recognized as an important problem in dialysis patients, since it has been associated with increased morbidity and mortality, resulting in disproportionately high costs of care. The success of renal replacement therapy depends on the adherence of patients to the different aspects of the therapeutic strategy, which includes a complex drug regimen involving a wide variety of drugs and doses, several prescribed dialysis sessions with different durations, dietetic recommendations and restriction of fluid intake. In this work, we aimed to translate and validate a previously described self-reported end-stage renal disease questionnaire (ESRD-AQ) to the Portuguese language (PESRD-AQ). After ESRD-AQ translation, a validation was performed by experts and by using a cohort of 185 Portuguese dialysis patients. PESRD-AQ reliability analysis showed strong test-retest stability across all items, with an intra-class correlation of 0.931. The average of the item-level content validity index by experts for the 46 items was 0.98, ranging from 0.94 to 1. Moreover, we found that PESRD-AQ scores indicative of non-adherence were associated with alterations in some biological and biochemical markers of non-adherence, including interdialytic weight gain. In conclusion, our results showed that PESRD-AQ, which presented an acceptable reliability and validity, is a valid tool to be used for adherence evaluation by Portuguese-speaking dialysis patients.

The aim of this work was to evaluate the predictors of mortality in a group of end-stage kidney disease (ESRD) patients under dialysis, by performing a three-year follow-up study. From the 236 patients included in this study, 54 patients died during the three-year follow-up period. Our data showed that the risk of death was higher in patients presenting lower levels of mean cell hemoglobin concentration, transferrin, and albumin. Our study showed that poor nutritional status and an inflammatory-induced iron depleted erythropoiesis are important factors for mortality in these patients.

Introduction: Non-adherence to therapeutic regimens is a recognised problem in the dialysis population that compromises the opportunity to achieve maximum treatment effect and, therefore, might lead to increased morbidity and mortality. In this study, we aimed to evaluate the prevalence of self-reported medication non-adherence in patients with end-stage kidney disease (ESKD) undergoing online-haemodiafiltration (OL-HDF), as well as to evaluate the factors that could affect medication adherence., Patients and Methods: We evaluated 122 patients with ESKD undergoing OL-HDF. Patients' reported medication adherence was measured by the Measure Treatment Adherence (MTS) scale. Social support was evaluated by the abbreviated Lubben Social Network Scale (LSNS); depression status by the Geriatric Depression Scale (GDS). Socio-demographic, co-morbidity and clinical data were also evaluated., Results: Our results showed that 10.7% of patients with ESKD perceived themselves as non-adherent to medication. When two groups of patients (adherent and non-adherents) were compared, significantly higher levels of triglycerides, and higher diastolic and systolic blood pressure were found in the non-adherent group. Significant correlations were found between the MTS score, and diastolic blood pressure, age and GDS score. Multiple regression analysis identified age and the GDS score as independent variables significantly associated with the MTS score., Conclusions: Non-adherence to therapeutic regimens in patients with ESKD is associated with higher levels of triglycerides and higher blood pressure and are, therefore, at a higher cardiovascular risk. Moreover, we found that age and depression status are important variables in non-adherence to therapeutic regimens., (© 2015 European Dialysis and Transplant Nurses Association/European Renal Care Association.)

Purpose: Patients' perception of health-related quality of life (HRQOL) is a consistent and powerful predictor of the outcome of end-stage renal disease (ESRD) patients under dialysis. This study aims to identify factors that could affect the HRQOL of ESRD patients under online hemodiafiltration (OL-HDF)., Methods: We evaluated 322 ESRD patients under OL-HDF (59.63% males; 64.9 ± 14.3 years old) from five dialysis units in the north of Portugal. Socio-demographic data, comorbidities, hematological data, iron status, dialysis adequacy, nutritional and inflammatory markers were collected from patients records. Patient's reported HRQOL score was assessed by using the Kidney Disease Quality of Life-Short Form (KDQOL-SF)., Results: ESRD patients showed a mean (± SD) of 53.17% (± 15.31%) in SF-36 total score, 50.17% (± 9.51%) in the SF-36 mental component summary (MCS) and 49.75% (± 9.44%) in the SF-36 physical component summary (PCS). Red cell distribution width (RDW), feminine gender and diabetes were found as significant predictors of SF-36 total score of HRQOL, which accounts for 12% of the total explained variance. Patient satisfaction, RDW, body mass index and gender were identified as predictors for the PCS, which accounts for 22% of total explained variance. Furthermore, patient satisfaction and dry weight were found as predictors for MCS. These predictors accounted for 28% of the total explained variance., Conclusions: Our results showed that the coexistence of diabetes, gender and erythropoietic disturbances are predictors of HRQOL in patients under OL-HDF and suggest that more attention should be given to woman patients, to the improvement of anemia and to diabetic patients, who are more prone to perceive a worst HRQOL.

Purpose: The aim of this work is to evaluate the patient-reported health-related quality of life (HRQOL), according to the type and location of vascular access used for dialysis procedure., Methods: In this transversal study, 322 end-stage renal disease (ESRD) patients under online hemodiafiltration (OL-HDF, 59.63% males; 64.9±14.3 years) were enrolled. Arteriovenous fistula (AVF) was used by 252 patients (78.3%), whereas 70 patients (21.7%) had a central venous catheter (CVC). Besides AVF location, data on comorbidities, hematological data, iron status, dialysis adequacy, nutritional and inflammatory markers were collected. Moreover, the patients' reported HRQOL score, using the Kidney Disease Quality of Life-Short Form, was evaluated., Results: ESRD patients using CVC as vascular access presented a decrease in four SF-36 domain scores, namely physical functioning, emotional well-being, role-emotional and energy/fatigue when compared with those using AVF as vascular access. Additionally, these patients also showed significant differences in ESRD target areas, namely decline in cognitive function and quality of social interaction domains. When comparing the variables according to the localization of the AVF, significant differences were found in three SF-36 domain scores, namely physical functioning, pain and general health. Moreover, we also found significant differences in ESRD target areas, namely symptoms/problem list, effects of kidney disease and quality of social interaction domains., Conclusions: Our results showed that ESRD patients under OL-HDF using AVF as vascular access had higher HRQOL scores in several domains when compared with those using CVC. Additionally, we also found that dialysis patients using AVF in the left forearm presented with higher HRQOL scores.

We evaluated the potential cardiovascular risk protection of bilirubin in hemodialysis (HD) patients. An enlarged set of studies were evaluated in 191 HD patients, including hematological study, lipid profile, iron metabolism, nutritional, inflammatory markers, and dialysis adequacy. The TA duplication screening in the UDP-glucuronosyltransferase 1 A1 (UGT1A1) promoter region was also performed. The UGT1A1 genotype frequencies in HD patients were 49.2%, 42.4%, and 8.4% for 6/6, 6/7, and 7/7 genotypes, respectively. Although no difference was found in UGT1A1 genotype distribution between the three tertiles of bilirubin, significant differences were found with increasing bilirubin levels, namely, a decrease in platelet, leukocyte, and lymphocyte counts, transferrin, oxidized low-density lipoprotein (ox-LDL), ox-LDL/low-density lipoprotein cholesterol ratio, apolipoprotein (Apo) A, Apo B, and interleukin-6 serum levels and a significant increased concentration of hemoglobin, hematocrit, erythrocyte count, iron, transferrin saturation, Apo A/Apo B ratio, adiponectin, and paraoxonase 1 serum levels. After adjustment for age these results remained significant. Our data suggest that higher bilirubin levels are associated with beneficial effects in HD patients, by improving lipid profile and reducing the inflammatory grade, which might contribute to increase in iron availability. These results suggest a potential cardiovascular risk protection of bilirubin in HD patients.

Purpose: The aim of this work was to assess the effect of statin therapy on inflammatory and fibrinolytic/endothelial (dys)function markers in end-stage renal disease (ESRD) patients under hemodialysis (HD), according to the type of vascular access., Methods: This transversal study includes 191 ESRD patients under regular HD, divided into four groups according to vascular access and statin therapy: 87 patients with arteriovenous fistula (AVF) and no statins (AVF-NS), 61 with AVF and statins (AVF-S), 27 with central venous dialysis catheter (CVC) and no statins (CVC-NS) and 16 with CVC and statins (CVC-S). The basic lipid profile and fibrinolytic/endothelial cell function markers were assessed., Results: Patients with CVC presented significantly higher levels of D-dimers compared with AVF groups. CVC-NS patients also presented the highest IL-6 values, which were significantly higher than those presented by CVC-S patients. AVF-S patients presented significantly higher t-PA and PAI-1 values and lower adiponectin levels compared with AVF-NS., Conclusions: Our results demonstrate that patients with CVC, particularly those not under statin therapy, present a higher production and turnover of fibrin. We also found that statin therapy decreases inflammation in CVC patients but is associated with a reduction of adiponectin and increased endothelial function marker levels in AVF patients.

The aim of this work was to contribute to a better understanding of the relationship between resistance to recombinant human erythropoietin (rhEPO) therapy and body mass index (BMI) in hemodialysis (HD) patients. We evaluated 191 HD patients and 25 healthy individuals. Complete blood count, reticulocyte count, and circulating levels of ferritin, transferrin, iron, soluble transferrin receptor (sTfR), transferrin saturation, hepcidin, C-reactive protein (CRP), interleukin 6 (IL-6), albumin, and adiponectin were measured in all patients and controls. Non-responder patients (n = 16), as compared with responder patients (n = 175), showed statistically significant lower BMI values, an enhanced inflammatory and higher adiponectin levels, associated with disturbances in iron metabolism. Analyzing the results according to BMI, we found that underweight patients required higher rhEPO doses than normal, overweight, and obese patients, and a higher percentage of non-responders patients were found within the underweight group of HD patients. Moreover, underweight patients presented lower levels of transferrin and higher levels of adiponectin compared to overweight and obese patients, and lower levels of iron compared with normal weight patients. Multiple regression analysis identified the sTfR, hemoglobin, BMI, and albumin as independent variables associated with rhEPO doses. In conclusion, our work showed that HD patients resistant to rhEPO therapy present a functional iron deficiency and a higher degree of inflammation, despite their lower BMI values and higher levels of adiponectin. Actually, BMI is poorly related with markers of systemic inflammation, such as IL-6 and CRP, while adiponectin works a fairly good indirect marker of adiposity within HD patients.

Background: End-stage renal disease (ESRD) patients under hemodialysis (HD) have high mortality rate. Inflammation, dyslipidemia, disturbances in erythropoiesis, iron metabolism, endothelial function, and nutritional status have been reported in these patients. Our aim was to identify any significant association of death with these disturbances, by performing a two-year follow-up study., Methods and Results: A large set of data was obtained from 189 HD patients (55.0% male; 66.4 ± 13.9 years old), including hematological data, lipid profile, iron metabolism, nutritional, inflammatory, and endothelial (dys)function markers, and dialysis adequacy., Results: 35 patients (18.5%) died along the follow-up period. Our data showed that the type of vascular access, C-reactive protein (CRP), and triglycerides (TG) are significant predictors of death. The risk of death was higher in patients using central venous catheter (CVC) (Hazard ratio [HR] = 3.03, 95% CI = 1.49-6.13), with higher CRP levels (fourth quartile), compared with those with lower levels (first quartile) (HR = 17.3, 95% CI = 2.40-124.9). Patients with higher TG levels (fourth quartile) presented a lower risk of death, compared with those with the lower TG levels (first quartile) (HR = 0.18, 95% CI = 0.05-0.58)., Conclusions: The use of CVC, high CRP, and low TG values seem to be independent risk factors for mortality in HD patients.

Background/aims: Cardiovascular diseases are the major cause of morbidity and mortality in hemodialysis (HD) patients. These patients present reduced paraoxonase 1 (PON1) activity that depends on genetic and non-genetic factors; however, how these factors influence PON1 activity in HD patients is poorly clarified. Our aim was to evaluate the influence of two polymorphisms and non-genetic factors on PON1 activity in HD patients., Methods: We evaluated 183 HD patients under recombinant human erythropoietin (rhEPO) treatment and 22 healthy individuals. The lipid profile [total cholesterol, triglycerides, HDL-c, LDL-c, apolipoprotein (Apo) A-I, Apo B, lipoprotein(a) and oxidized low-density lipoprotein (Ox-LDL)], inflammatory markers [adiponectin, interleukin-6 (IL-6) and C-reactive protein (CRP)], PON1 activity and PON1 gene polymorphisms (L55M and Q192R) were evaluated., Results: HD patients presented higher levels of IL-6, CRP and Ox-LDL/LDL-c, and lower PON1 activity, total cholesterol, HDL-c, LDL-c, Apo A and Apo B; the most frequent genotype was heterozygosity for L55M polymorphism and homozygosity for the Q allele, the more frequent genotype of Q192R polymorphism. Multiple regression analysis identified heterozygosity and homozygosity for L55M and Q192R polymorphisms, very low-density lipoproteins, LDL-c, Apo A and CRP levels, time on dialysis and rhEPO dose, as the independent variables significantly associated with PON1 activity. The associations with CRP, rhEPO and time on dialysis were negative., Conclusion: Our results show that the reduced PON1 activity in HD patients who are not under statin therapy is strongly associated with inflammation, longer time on dialysis and high rhEPO doses, suggesting that the reduction in PON1 activity may worsen the prognosis of these patients., (Copyright © 2012 S. Karger AG, Basel.)

End-stage renal disease (ESRD) under hemodialyses (HD) is related with a higher propensity to infections, essentially due to T-cell lymphopenia. We postulated that HD procedure affects CD4(+) T cells, especially by inducing apoptotic death and that recombinant human erythropoietin (rhEPO) therapy may also play an important role in the modulation of the immune system in these patients. T-cell phenotype and apoptosis of HD patients and healthy controls were evaluated by flow cytometry using anticoagulated whole-blood samples. In 12 HD patients, these parameters were also analyzed before and immediately after HD procedure. HD patients showed a decrease in total circulating CD3(+) lymphocytes, especially in CD4(+) T cells (0.747 ± 0.410 vs. 0.941 ± 0.216 × 10(9)/L, p < 0.05), which could be a consequence of the higher proportion of CD3(+) and CD4(+) lymphocytes in the latest stage of apoptosis (or death) and of the higher proportion of apoptotic CD4(+) T cells observed in the patients immediately after HD procedure (2.91 ± 0.780 vs. 3.90 ± 1.96, p < 0.05). A positive and statistically significant correlation between CD3(+) and CD4(+) lymphocytes in latest stage of apoptosis (or death) with HD time was found (CD3(+): r = 0.592, p < 0.01; CD4(+): r = 0.501, p < 0.01). We also found a negative and significant correlation between weekly rhEPO doses and the number of CD4(+) T cells (r = -0.358, p < 0.05). In conclusion, HD procedure still contributes to the development of T-cell lymphopenia, at least in part, by apoptosis induction. It was also shown that rhEPO therapy is associated with the CD4(+) T-cell decline, possibly by immune modulation, eliminating atypical cells and helping to restore the CD4(+) T-cell subset.

The aim of the present work was to further clarify leukocyte activation due to hemodialysis (HD) procedures and to investigate its relationship with recombinant human erythropoietin resistance. Therefore, we studied the expression of CXCR1 and CD11b on neutrophils, as well as the monocyte expression of CD11b, HLA-DR, and CD14. We studied 34 chronic kidney disease (CKD) patients under HD and recombinant human erythropoietin treatment (26 responders and 8 nonresponders to recombinant human erythropoietin therapy). All CKD patients' blood samples were collected before and immediately after the HD procedure. Eighteen healthy individuals (blood donors) were also studied as a control group. Hematological data, neutrophil (CD11b and CXCR1), and monocyte (CD11b, HLA-DR, and CD14) cell surface markers were measured in all patients (before and after the HD procedure) and controls. When compared with the controls, CKD patients presented a significant decrease in CXCR1 neutrophil expression, and in CD14 monocyte expression, accompanied by a significant increase in HLA-DR monocyte expression. When comparing the 2 groups of patients, we found that nonresponders showed an additional decrease in CXCR1 neutrophil expression. After the HD procedure, a statistically significant increase in CD14 and CD11b monocyte surface markers and a decrease in CXCR1 neutrophil expression and in HLA-DR monocyte expression was found. These data further strengthen our previous studies, showing that neutrophils and monocytes are activated in CKD patients, particularly in nonresponder patients. Moreover, this activation is due, at least in part, to the HD procedure, although we should not exclude that it can also be due to the enhanced inflammatory process observed in nonresponder patients.

Background: Resistance to recombinant human erythropoietin (rhEPO) occurs in some chronic kidney disease (CKD) patients, which may be due to enhanced systemic inflammatory response and to the erythropoiesis-suppressing effect of pro-inflammatory cytokines, some of which are produced by T cells., Aim of Study: The aim of this study was to investigate the relationship between resistance to rhEPO therapy in hemodialysis CKD patients and inflammatory markers [C-reactive protein (CRP), soluble interleukin (IL)-2 receptor (sIL2R), and serum albumin levels], blood cell counts, T-cell phenotype, cytokine production by T cells, and serum cytokine levels., Materials and Methods: We studied 50 hemodialysis CKD patients, 25 responders and 25 nonresponders to rhEPO, and compared them to each other and with 25 healthy controls. When compared to controls, CKD patients showed increased serum levels of CRP, IL-6, and sIL2R and a T-cell lymphopenia, due to decreased numbers of both CD4+ and CD8+ T cells. T cells from CKD patients had an immunophenotype compatible with chronic T-cell stimulation as shown by the increased percentage of CD28-, CD57+, HLA-DR+, CD28-HLA-DR+, and CD57+ HLA-DR+ T cells and produce higher levels of IL-2, INF-gamma, and TNF-alpha after short-term in vitro stimulation, although Th1 cytokines were not detectable in serum. Statistically significant differences were found between responders and nonresponders to rhEPO therapy for total lymphocyte and CD4+ T-lymphocyte counts, albumin (lower in nonresponders) and CRP (higher in nonresponders) levels., Conclusion: CKD patients under hemodialysis present with raised inflammatory markers and decrease of total lymphocyte and CD4+ T-lymphocyte counts when compared with controls. Some of those markers are even further enhanced in nonresponders to rhEPO therapy patients, but resistance to this therapy cannot be justified by a Th1 polarized T-cell response.

Our aim was to evaluate red blood cell (RBC) membrane protein composition in chronic kidney disease (CKD) stage 5 patients under haemodialysis (HD) and recombinant human erythropoietin (rhEPO) therapy, and its linkage to rhEPO hyporesponsiveness. We evaluated in 63 CKD stage 5 patients (32 responders and 31 non-responders to rhEPO therapy) and in 26 healthy controls RBC count, haematocrit, haemoglobin concentration, haematimetric indices, reticulocyte count, reticulocyte production index, RBC osmotic fragility test and membrane protein analyses. CKD stage 5 patients presented significant changes in membrane protein composition, namely a reduction in spectrin, associated to altered protein 4.1/spectrin and spectrin/band 3 ratios. Non-responder CKD stage 5 patients were more anaemic, with more microcytic and anisocytic RBCs, than responders; significantly altered ankyrin/band 3 and spectrin/ankyrin ratios were also observed. CKD stage 5 patients under HD are associated with an altered protein membrane structure, which seems to the disease itself and/or to the interaction with HD membranes., (Copyright 2008 S. Karger AG, Basel.)