Electronegative LDL and lipid abnormalities in patients undergoing hemodialysis and peritoneal dialysis

Background: Oxidative modification of low-density lipoprotein (LDL) has been demonstrated in patients with end-stage renal disease, where it is associated with oxidative stress and plays a key role in the pathogenesis of atherosclerosis. In this context, the generation of minimally oxidized LDL, also called electronegative LDL [ LDL(-)], has been associated with active disease, and is a detectable sign of atherogenic tendencies. The purpose of this study was to evaluate serum LDL(-) levels and anti-LDL(-)IgG autoantibodies in end-stage renal disease patients on dialysis, comparing patients on hemodialysis (HD), peritoneal dialysis (PD) and a control group. In addition, the serum lipid profile, nutritional status, biochemical data and parameters of mineral metabolism were also evaluated. Methods: The serum levels of LDL(-) and anti-LDL(-) IgG autoantibodies were measured in 25 patients undergoing HD and 11 patients undergoing PD at the Centro Integradode Nefrologia, Rio de Janeiro, Brazil. Ten healthy subjects served as a control group. Serum levels of albumin, total cholesterol, triglycerides and lipoproteins were measured. Calculations of subjects` body mass index and measurements of waist circumference, triceps skin fold and arm muscle area were performed. Measurements of hematocrit, serum blood urea nitrogen, creatinine, parathyroid hormone, phosphorus and calcium were taken. Results: Levels of LDL(-) were higher in HD patients (575.6 +/- 233.1 mu g/ml) as compared to PD patients (223.4 +/- 117.5 mu g/ml, p < 0.05), which in turn were higher than in the control group (54.9 +/- 33.3 mu g/ml, p < 0.01). The anti-LDL(-) IgG autoantibodies were increased in controls (0.36 +/- 0.09 mu g/ ml) as compared to PD (0.28 +/- 0.12 mu g/ml, p < 0.001) and HD patients (0.2 +/- 0.1 mu g/ml, p < 0.001). The mean values of total cholesterol and LDL were considered high in the PD group, whereas the mean triceps skin fold was significantly lower in the HD group. Conclusion: Levels of LDL(-) are higher in renal patients on dialysis than in normal individuals, and are reciprocally related to IgG autoantibodies. LDL(-) may be a useful marker of oxidative stress, and this study suggests that HD patients are more susceptible to cardiovascular risk due to this condition. Moreover, autoantibodies reactive to LDL(-) may have protective effects in chronic kidney disease. Copyright (C) 2008 S. Karger AG, Basel.

Peritoneal Dialysis in Acute Kidney Injury: Lessons Learned and Applied

Peritoneal dialysis (PD) is a simple, safe, gentle, and efficient renal replacement therapy (RRT) method. It is able to correct acute kidney injury (AKI)-induced metabolic, electrolytic, and acid-base disorders and volume overload both in and out the intensive care unit setting. Some PD modalities, such as high-volume PD and continuous flow PD, can provide RRT doses and efficiency comparable to extracorporeal blood purification methods. PD is particularly suitable for children, patients with refractory heart failure or hemodynamically instable, conditions where systemic anticoagulation should be avoided, patients with difficulty for vascular access and hypo- and hyperthermia conditions. In the following manuscript, PD technical aspects and the possible advantages and limitations of this RRT method will be discussed, and the more recent literature on clinical experience with PD for treatment of AKI will be reviewed.

Flow-through peritoneal dialysis in neonatal enema-induced hyperphosphatemia

Fleet enemas are hypertonic solutions with an osmotic action and a high concentration of phosphate. When retained in the human body they have a great toxic potential, causing severe hydro-electrolyte disorders in children, especially in newborns. We report the case of a previously healthy 8-day-old newborn who needed neonatal intensive care treatment after the inadvertent administration of an osmotically active hypertonic phosphate enema. Taking into account that phosphate removal by peritoneal dialysis (PD) strongly depends on total dialysate turnover, we chose continuous flow PD (CFPD) as the treatment option, with a successful outcome. Clinical experience with this dialytic modality is limited to a few case reports in pediatric and adult patients. To the best of our knowledge, we report here the first description of CFPD in the setting of acute phosphate nephropathy in the neonatal period. The modality of PD described here has potential as an alternative management option as it is a highly efficient, methodologically simple, and low-cost method without any need for sophisticated equipment. Physicians and parents should be aware of the adverse effects of a hypertonic phosphate enema and should never use these medications in infants and newborns.

Systemic and Local Inflammation in Peritoneal Dialysis: Mechanisms, Biomarkers and Effects on Outcome

Thanks to the technological development in peritoneal dialysis (PD) during the last three decades, the most important problem nowadays for the nephrologists is the maintenance of the long-term function of the peritoneal membrane. Although PD may exert an early survival benefit as compared with hemodialysis (HD), long-term PD is often associated with histopathological alterations in the peritoneal membrane that are linked to peritoneal ultrafiltration deficit and increased mortality risk. These alterations are closely related to the presence of a chronic activated (local and systemic) inflammatory response. PD itself may have other factors associated that could further modulate the inflammatory response, such as the bioincompatibility of dialysis solutions, fluid overload and changes in the body composition. Understanding the pathophysiology of inflammation in PD is essential for the adoption of adequate strategies to improve both membrane and patient survival. Copyright (C) 2009 S. Karger AG, Basel

Roles assessment in families of children with chronic renal failure on peritoneal dialysis

Families with a child on chronic peritoneal dialysis have to assume a significant burden of care, intensifying the demands and the reorganization of roles in the families of children. The purpose of this study is to describe the implications of role changes in families of children with chronic renal disease on peritoneal dialysis. This is a case study of four families of children with chronic renal disease on peritoneal dialysis. Fourteen family members participate in the study. After the child`s chronic kidney failure and the start of treatment, each relative`s ways, acts and functions are changed, maintained or adapted to the new family dynamics, imposed by the child`s treatment conditions. Appropriate role assessment provides the nurse and the families of children with chronic renal failure on peritoneal dialysis with insight regarding current and potential health problems and aids in identifying the needs of the families.

Inflammation and Overweight in Peritoneal Dialysis: Is There an Association?

More than 30% of the patients on peritoneal dialysis show chronic systemic inflammatory activity with high levels of C-reactive protein. The purpose of this cross-sectional study was to investigate the influence of the inflammatory state on clinical and nutritional markers in patients on peritoneal dialysis. Twenty-seven patients were included: mean age was 57.6 +/- 19 years, 48% were male, and median time on peritoneal dialysis was 16.0 (8.3; 35.8) months. Clinical, dialytic, laboratory, anthropometric and electric bioimpedance data were collected with the sample stratified for C-reactive protein. In patients, the levels of Interleukin-6 and tumor necrosis factor-a were higher, while adiponectin levels were lower than in healthy individuals (p <= 0.001), indicating the presence of inflammatory activity in the sample. When compared to patients with C-reactive protein < 1 mg/dL, those with = 1mg/dL showed higher body mass index (29.4 +/- 6.1 vs. 24.4 +/- 4.5 kg/m(2); p = 0.009), percent of standard body weight (124.5 +/- 25.4 vs. 106.8 +/- 17.9 %; p = 0.012), and percent of body fat as assessed by both anthropometry (31.3 +/- 9.9 vs. 23.9 +/- 9.1%; p = 0.056) and bioimpedance (38.9 +/- 6.3 vs. 26.2 +/- 12.6 %; p < 0.001). Patients with C-reactive protein = 1mg/dL also exhibited higher levels of ferritin (701 +/- 568 vs. 532 +/- 356 ng/mL; p = 0.054) and lower total lymphocyte count (median 1838 vs. 1638 mm(3); p = 0.001). In conclusion, higher body mass index and body fat markers were associated with C-reactive protein = 1mg/dL, and higher C-reactive protein was associated with immunocompetence impairment evidenced by the lower total lymphocyte count. Our findings confirm the relationship between inflammation, body fat, and immunocompetence, which may be superimposed potentializing the inflammatory status.

Activation of lateral parabrachial afferent pathways and endocrine responses during sodium appetite regulation

Modulation of salt appetite involves interactions between the circumventricular organs (CVOs) receptive areas and inhibitory hindbrain serotonergic circuits. Recent studies provide support to the idea that the serotonin action in the lateral parabrachial nucleus (LPBN) plays an important inhibitory role in the modulation of sodium appetite. The aim of the present work was to identify the specific groups of neurons projecting to the LPBN that are activated in the course of sodium appetite regulation, and to analyze the associated endocrine response, specifically oxytocin (OT) and atrial natriuretic peptide (ANP) plasma release, since both hormones have been implicated in the regulatory response to fluid reestablishment. For this purpose we combined the detection of a retrograde transported dye, Fluorogold (FG) injected into the LPBN with the analysis of the Fos immunocytochemistry brain pattern after sodium intake induced by sodium depletion. We analyzed the Fos-FG immunoreactivity after sodium ingestion induced by peritoneal dialysis (PD). We also determined OT and ANP plasma concentration by radioimmunoassay (RIE) before and after sodium intake stimulated by PD. The present study identifies specific groups of neurons along the paraventricular nucleus, central extended amygdala, insular cortex, dorsal raphe nucleus, nucleus of the solitary tract and the CVOs that are activated during the modulation of sodium appetite and have direct connections with the LPBN. It also shows that OT and ANP are released during the course of sodium satiety and fluid reestablishment. The result of this brain network activity may enable appropriate responses that re-establish the body fluid balance after induced sodium consumption. (C) 2009 Elsevier Inc. All rights reserved.

What Is the Meaning of Homocysteine in Patients on Dialysis?

Objective: To evaluate the determinants of total plasma homocysteine levels and their relations with nutritional parameters, inflammatory status, and traditional risk factors for cardiovascular disease in renal failure patients on dialysis treatment. Design: The study was conducted on 70 clinically stable patients, 50 of them on hemodialysis (70% men; 55.3 +/- 14.5 years) and 20 on peritoneal dialysis (50% men; 62 +/- 13.7 years). Patients were analyzed in terms of biochemical parameters (serum lipids, creatinine, homocysteine [Hcy], creatine-kinase [Ck], folic acid, and vitamin B(12)), anthropometric data, markers of inflammatory status (tumor necrosis factor-alpha, C-reactive protein, interleukin-6), and adapted subjective global assessment. Results: The total prevalence of hyperhomocysteinemia (>15 mu mol/L) was 85.7%. Plasma folic acid and plasma vitamin B(12) were within the normal range. Multiple regression analysis (r(2) - 0.20) revealed that the determinants of total Hcy were type of dialysis, creatinine, Ck, folic acid, and total cholesterol. Hcy was positively correlated with albumin and creatinine and negatively correlated with total cholesterol, high density lipoprotein cholesterol, folic acid, and vitamin B(12). Conclusions: The determinants of total Hcy in the study sample were type of dialysis, creatinine, Ck, folic acid, and total cholesterol. Evidently, the small sample size might have had an effect on the statistical analyses and further studies are needed. However, Hcy in patients on dialysis treatment may not have the same effect as observed in the general population. In this respect, the association between malnutrition and inflammation may be a confounding factor in the determination of the true relationship between Hcy, nutritional status, and cardiovascular risk factors in this group. (C) 2011 by the National Kidney Foundation, Inc. All rights reserved.

Challenges of nutritional assessment in pediatric ICU

Purpose of review The nutritional assessment of children in the pediatric ICU is unique in view of the metabolic changes of the underlying disease. This review addresses the use and limitations of anthropometry and laboratorial and body composition markers in the diagnosis of the nutritional status of such patients. Recent findings The presence of inflammatory activity leads to body composition changes (lean mass reduction) and undernutrition. Nutritional assessment in pediatric ICU must prioritize anthropometric and laboratory markers that can differentiate body composition to detect specific macronutrient and micronutrient deficiencies and assessment of the inflammatory activity. Summary Nutritional assessment is one of the main aspects of the pediatric intensive care patient and is the most important tool to avoid hospital undernutrition. There is currently no gold standard for nutritional assessment in the pediatric ICU. The results of anthropometric and laboratory markers must be jointly analyzed, but individually interpreted according to disease and metabolic changes, in order to reach a correct diagnosis of the nutritional status and to plan and monitor the nutritional treatment.

Arteriovenous fistula for chronic hemodialysis in pediatric candidates for renal transplantation: Technical details and refinements

AVFs may be considered the best type of venous access for chronic hemodialysis in pediatric patients with more than 20 kg who are not likely to receive a kidney transplant or be transitioned to peritoneal dialysis within one yr. The aim of the study was to report the experience in the creation of AVFs in pediatric candidates for renal transplantation using microsurgical vascular techniques, with emphasis on the details of the surgical technique. Forty children underwent 50 fistula creations - 31 radial-cephalic, 11 brachial-cephalic, five brachial-basilic and three saphenous-femoral. The vein was anastomosed to the artery in an end-to-lateral fashion by using two separate 8/0 prolene running sutures. The overall patency rate was 76.0%:22 (70.9%) of the radial-cephalic fistulas, nine (81.8%) of the brachial-cephalic, five (100.0%) of the brachial-basilic and two (66.6%) of the saphenous-femoral. There was no significant difference in patency rates between the brachial-cephalic, brachial-basilic and radial-cephalic fistulas. The incidences of fistula patency were not different for patients weighing < 20 kg compared with patients weighing > 20 kg. AVF remains as a satisfactory method for providing hemodialysis in children. The utilization of microsurgical techniques with some technical refinements described herein permits the achievement of high fistula patency rates.

Different Patterns in a Cohort of Patients with Severe Leptospirosis (Weil Syndrome): Effects of an Educational Program in an Endemic Area

The aim of this study is to investigate the changes in clinical pattern and therapeutic measures in leptospirosis-associated acute kidney injury; a retrospective study with 318 patients in Brazil. Patients were divided according to the time of admission: 1985-1996 (group I) and 1997-2010 (group II). Patients were younger in group I (36 +/- 13 versus 41 +/- 16 years, P = 0.005) and the numbers of oliguria increased (21% versus 41% in group II, P = 0.014). Higher frequency of lung manifestations was observed in group II (P<0.0001). Although increased severity, there was a significant reduction in mortality (20% in group I versus 12% in group II, P = 0.03). Mortality was associated with advanced age, low diastolic blood pressure, oliguria, arrhythmia, and peritoneal dialysis, besides a trend to better mortality with penicillin administration. Leptospirosis is occurring in an older population, with a higher number of oliguria and lung manifestations. However, mortality is decreasing and can be the result of changes in treatment.

Anti-Inflammatory Effects of Peritoneal Lavage in Acute Pancreatitis

Objectives: Intraperitoneal administration of trypsin stimulates the production of cytokines from peritoneal macrophages. Removing the pancreatitis-associated ascitic fluid from the peritoneal cavity may decrease the systemic inflammatory response in acute pancreatitis (AP). We investigated the effect of peritoneal lavage on the systemic inflammatory response in severe AP. Methods: Acute pancreatitis was induced in Wistar rats by 5% taurocholate intraductal injection. Peritoneal lavage was performed for 4 hours after onset of AP. At 4 hours after induction of AP, serum samples were assayed for amylase and inflammatory cytokines (tumor necrosis factor alpha, interleukin-6 [IL-6], and IL-10). Expression of pancreatic cyclooxygenase-2 and inducible nitric oxide synthase, liver mitochondrial function, and pulmonary myeloperoxidase activities were determined. Results: Peritoneal lavage after AP led to a decrease in serum levels of tumor necrosis factor alpha and IL-6 and an increase in IL-10. In the pancreas, this treatment reduced cyclooxygenase-2 and inducible nitric oxide synthase expression. Liver mitochondrial dysfunction was also reduced. There were no differences on serum amylase levels and pulmonary myeloperoxidase between groups with AP. Conclusions: Peritoneal lavage has a systemic anti-inflammatory effect in severe AP and may be able to decrease the severity of severe AP.

Modulation of peritoneal macrophage activity by the saturation state of the fatty acid moiety of phosphatidylcholine

To determine the effects of saturated and unsaturated fatty acids in phosphatidylcholine (PC) on macrophage activity, peritoneal lavage cells were cultured in the presence of phosphatidylcholine rich in saturated or unsaturated fatty acids (sat PC and unsat PC, respectively), both used at concentrations of 32 and 64 µM. The treatment of peritoneal macrophages with 64 µM unsat PC increased the production of hydrogen peroxide by 48.3% compared to control (148.3 ± 16.3 vs 100.0 ± 1.8%, N = 15), and both doses of unsat PC increased adhesion capacity by nearly 50%. Moreover, 64 µM unsat PC decreased neutral red uptake by lysosomes by 32.5% compared to the untreated group (67.5 ± 6.8 vs 100.0 ± 5.5%, N = 15), while both 32 and 64 µM unsat PC decreased the production of lipopolysaccharide-elicited nitric oxide by 30.4% (13.5 ± 2.6 vs 19.4 ± 2.5 µM) and 46.4% (10.4 ± 3.1 vs 19.4 ± 2.5 µM), respectively. Unsat PC did not affect anion production in non-stimulated cells or phagocytosis of unopsonized zymosan particles. A different result pattern was obtained for macrophages treated with sat PC. Phorbol 12-miristate 13-acetate-elicited superoxide production and neutral red uptake were decreased by nearly 25% by 32 and 64 µM sat PC, respectively. Sat PC did not affect nitric oxide or hydrogen peroxide production, adhesion capacity or zymosan phagocytosis. Thus, PC modifies macrophage activity, but this effect depends on cell activation state, fatty acid saturation and esterification to PC molecule and PC concentration. Taken together, these results indicate that the fatty acid moiety of PC modulates macrophage activity and, consequently, is likely to affect immune system regulation in vivo.

Mast cell repopulation of the peritoneal cavity: contribution of mast cell progenitors versus bone marrow derived committed mast cell precursors

Background: Mast cells have recently gained new importance as immunoregulatory cells that are involved in numerous pathological processes. One result of these processes is an increase in mast cell numbers at peripheral sites. This study was undertaken to determine the mast cell response in the peritoneal cavity and bone marrow during repopulation of the peritoneal cavity in rats. Results: Two mast cell specific antibodies, mAb AA4 and mAb BGD6, were used to distinguish the committed mast cell precursor from more mature mast cells. The peritoneal cavity was depleted of mast cells using distilled water. Twelve hours after distilled water injection, very immature mast cells could be isolated from the blood and by 48 hours were present in the peritoneal cavity. At this same time the percentage of mast cells in mitosis increased fourfold. Mast cell depletion of the peritoneal cavity also reduced the total number of mast cells in the bone marrow, but increased the number of mast cell committed precursors. Conclusions: In response to mast cell depletion of the peritoneal cavity, a mast cell progenitor is released into the circulation and participates in repopulation of the peritoneal cavity, while the committed mast cell precursor is retained in the bone marrow.

The Lectin ArtinM Induces Recruitment of Rat Mast Cells from the Bone Marrow to the Peritoneal Cavity

Background: The D-mannose binding lectin ArtinM is known to recruit neutrophils, to degranulate mast cells and may have potential therapeutic applications. However, the effect of ArtinM on mast cell recruitment has not been investigated. Methodology: Male Wistar rats were injected i.p. with ArtinM or ConA (control). The ability of the lectin to degranulate peritoneal and mesenteric mast cells was examined. Recruitment of mast cells to the peritoneal cavity and mesentery after ArtinM injection was examined with or without depletion of peritoneal mast cells by distilled water. Results: ArtinM degranulated both peritoneal and mesentery mast cells in vitro. Three days after i.p. injection of the lectin there were reduced numbers of mast cells in the peritoneal lavage, while at 7 days post injection of ArtinM, the number of peritoneal mast cells was close to control values. Since immature mast cells are recruited from the bone marrow, the effect of the lectin on bone marrow mast cells was examined. Injection of ArtinM resulted in an increased number of mast cells in the bone marrow. To determine if degranulation of mast cells in the peritoneal cavity was required for the increase in bone marrow mast cells, the peritoneal cavity was depleted of mast cells with ultrapure water. Exposure to ArtinM increased the number of mast cells in the bone marrow of rats depleted of peritoneal mast cells. Conclusions: The ArtinM induced recruitment of mast cells from the bone marrow to the peritoneal cavity may partially explain the therapeutic actions of ArtinM.