European best practice guidelines for peritoneal dialysis. 9 PD and transplantation.
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Europe↗
Biomedical subjects
Rafael Selgas
Publications and source records attributed to Rafael Selgas.
Serum concentrations of leptin, adiponectin and resistin, and their relationship with cardiovascular disease in patients with end-stage renal disease.
BACKGROUND AND OBJECTIVE: High levels of some adipocytokines have been reported in patients with chronic renal failure, but little information is available on adipocytokine concentrations in uraemic patients under different modalities of therapy. Our aims were (1) to quantify the serum concentrations of leptin, adiponectin and resistin in uraemic patients on peritoneal dialysis (PD) and haemodialysis (HD), in comparison with patients on conservative management, and (2) to study the relationships between adipocytokine levels and previous atherosclerotic vascular disease. PATIENTS AND MEASUREMENTS: We studied 82 dialysis patients treated by PD (n = 44, 23 males and 21 females, mean age 54.4 +/- 1.8 years) or HD (n = 38, 22 males and 16 females, age 60.8 +/- 1.6 years). A group of 19 uraemic patients on conservative management served as the control. Serum concentrations of leptin, adiponectin and resistin were measured in all subjects. Information on vascular disease (cerebral vascular, peripheral vascular and heart disease) was obtained from a detailed medical history. RESULTS: PD patients showed significantly higher serum leptin concentrations [median (interquartile range), 28.7 (13.0-71.9) microg/l] than those found in patients on HD [9.7 (4.7-31.9) microg/l, P < 0.01] or in conservative management [5.9 (4.3-38.6) microg/l, P < 0.05]. Adiponectin concentrations were similar in the three groups of patients (mean +/- SEM, 48.0 +/- 4.5 mg/l in PD, 57.7 +/- 4.4 mg/l in HD, and 44.4 +/- 7.0 mg/l in controls, NS). Patients treated by both PD and HD exhibited resistin concentrations significantly higher than those found in controls (26.3 +/- 0.99 and 27.5 +/- 1.4 microg/l, respectively, vs. 17.3 +/- 1.0 microg/l, P < 0.001). Leptin concentrations were positively correlated with body mass index (BMI) (r = 0.287, P < 0.01) and adiponectin levels were negatively related to BMI (r = -0.416, P < 0.001) and the homeostatic model assessment (HOMA-R) index (r =-0.216, P < 0.05). Leptin, adiponectin and resistin levels in patients with previous vascular events were similar to those found in patients without these complications. Logistic regression analysis did not demonstrate any relationship between serum adipocytokine concentrations and the presence of vascular disease of any type. A significant relationship between resistin and heart disease [odds ratio (OR) 1.80 (1.03-3.15), P = 0.039] was found when analysing subgroups of patients. CONCLUSIONS: These data suggest that leptin levels are higher in PD patients, and resistin levels are higher in PD and HD patients in relation to patients on conservative management, whereas adiponectin concentrations are similar in the three groups. These results do not support the presence of a clinically relevant relationship between adipocytokines and previous episodes of vascular disease in the whole population or in patients classified in subgroups, with the only exception of a relationship between resistin levels and heart disease.
Adiponectin↗
Epithelial to mesenchymal transition as a triggering factor of peritoneal membrane fibrosis and angiogenesis in peritoneal dialysis patients.
Peritoneal fibrosis (or sclerosis) is a complication of peritoneal dialysis (PD) and includes a wide spectrum of peritoneal structural changes, ranging from mild inflammation to severe sclerosing peritonitis and encapsulating-sclerosing peritonitis. In parallel with fibrosis, the peritoneum shows a progressive increase in capillary number (angiogenesis) and vasculopathy, which are involved in both the elevation of small solute transport across the peritoneal membrane and ultrafiltration failure. The most important substances from the PD solutions responsible for peritoneal deterioration are glucose and glucose degradation products, which stimulate transforming growth factor (TGF)beta and vascular endothelial growth factor (VEGF) production by mesothelial cells (MCs). TGFbeta is a potent pro-fibrotic factor and induces epithelial-mesenchymal transition (EMT) of the MC. Local production of VEGF during PD appears to play a central role in the processes leading to peritoneal neo-angiogenesis and functional decline. This review discusses the mechanisms implicated in peritoneal structural alteration and points to EMT of MC as the protagonist and initiator of peritoneal membrane injury, through an increment of the submesothelial fibroblast population. We also propose possible mechanisms of regulation and new targets for inhibition of EMT.
Epithelium↗
Low vs standard calcium dialysate in peritoneal dialysis: differences in treatment, biochemistry and bone histomorphometry. A randomized multicentre study.
BACKGROUND: In patients undergoing peritoneal dialysis (PD), low-calcium dialysate (LCD) has been proposed as the first choice for a better control of renal osteodystrophy. Our aim was to compare the effects on bone metabolism of LCD (calcium: 1.25 mmol/l) with that of a standard calcium dialysate (SCD; calcium: 1.75 mmol/l). METHODS: Forty-four PD patients were randomized to receive LCD or continue on SCD for a period of 12 months. Bone biopsies were taken at baseline and at 12 months. Biochemical data and treatment were evaluated every 3 months. RESULTS: Twenty-four patients completed the study. In the SCD group (n = 10), nine out of the 10 patients were initially diagnosed with adynamic bone lesion (ABL). After 1 year, six continued having ABL and three patients moved to high-turnover bone lesion (HTBL). The other patient, initially diagnosed with HTBL, changed to ABL. In the LCD group (n = 14), 10 patients were initially diagnosed with ABL. At 1 year, six of them continued having ABL and four patients changed to HTBL. Four patients were initially diagnosed with HTBL and did not change. Comparison between LCD and SCD groups showed an increase in serum parathyroid hormone (PTH) levels starting at month 3 and a higher intake of calcium salts in the former group (P<0.01). Serum calcium, phosphate levels and bone histological outcome did not differ between the two groups. CONCLUSIONS: LCD use for 1 year was associated with an increase in PTH levels, but did not lead to histological changes different from those observed in SCD group. The LCD solution allowed a higher oral intake of calcium salts with a satisfactory control of the serum Calcium-Phosphorus product.
Bone and Bones↗
Immunohistochemical characterization of fibroblast subpopulations in normal peritoneal tissue and in peritoneal dialysis-induced fibrosis.
Peritoneal fibrosis is one of the most common morphological changes observed in continuous ambulatory peritoneal dialysis (CAPD) patients. Both resident fibroblasts and new fibroblast-like cells derived from the mesothelium by epithelial-to-mesenchymal transition are the main cells involved fibrogenesis. In order to establish markers of peritoneal impairment and pathogenic clues to explain the fibrogenic process, we conducted an immunohistochemical study focused on peritoneal fibroblasts. Parietal peritoneal biopsies were collected from four patient groups: normal controls ( n = 15), non-CAPD uremic patients ( n = 17), uremic patients on CAPD ( n = 27) and non-renal patients with inguinal hernia ( n = 12). To study myofibroblastic conversion of mesothelial cells, alpha-smooth muscle actin (SMA), desmin, cytokeratins and E-cadherin were analyzed. The expression of CD34 by fibroblasts was also analyzed. Fibroblasts from controls and non-CAPD uremic patients showed expression of CD34, but no myofibroblastic or mesothelial markers. The opposite pattern was present during CAPD-related fibrosis. Expression of cytokeratins and E-cadherin by fibroblast-like cells and alpha-SMA by mesothelial and stromal cells supports that mesothelial-to-myofibroblast transition occurs during CAPD. Loss of CD34 expression correlated with the degree of peritoneal fibrosis. The immunophenotype of fibroblasts varies during the progression of fibrosis. Myofibroblasts seem to derive from both activation of resident fibroblasts and local conversion of mesothelial cells.
Adult↗
Virus-specific effector CD4+ T-cell responses in hemodialysis patients with hepatitis C virus infection.
Patients with chronic renal failure undergoing hemodialysis who are infected with hepatitis C virus (HCV) may test consistently anti-HCV negative. Because CD4(+) T-cells provide help for antibody production virus-specific effector CD4(+) T-cell responses were investigated in relation to anti-HCV positivity in 15 hemodialysis patients grouped according to HCV antibody and viremia. CD4(+) T-cell reactivity was studied in peripheral blood mononuclear cells by standard lymphocyte proliferation assay and phenotypic/functional characterization (cell-surface staining/cytokine secretion) by flow cytometry. HCV-specific CD4(+) T-cell proliferation in viremic hemodialysis patients was weak or absent independently of their anti-HCV status. Virus-specific CD4(+) T-cells displayed a memory phenotype and showed low to undetectable capacity to secrete effector interferon (IFN)-gamma. Impaired activation-induced cytokine secretion appeared to be Th1 (IFN-gamma) but not Th2 (interleukin-4)-directed and was virus-specific as cytomegalovirus responses were preserved. The frequency ex vivo of CD3(+)CD4(+)IFN-gamma(+) T-cells was independent of the HCV antibody status and comparable between viremic (range: 0.08-1.54%) or non-viremic (0.11-3.2%) hemodialysis patients and healthy donors (0.13-1.10%; P = 0.58). The numbers of CD3(+)CD4(+)IFN-gamma(+) T-cells augmented slightly (P = 0.047) in HCV-infected hemodialysis patients but markedly in only one (greater than ninefold) after HCV stimulation. In conclusion, hemodialysis patients show limited HCV-specific effector CD4(+) Th1-cell responses which nonetheless seem unrelated to the anti-HCV status and are not more impaired due to the ongoing hemodialysis.
Adult↗
Effect of recombinant human erythropoietin on inflammatory status in dialysis patients.
Under normal conditions, inflammatory status is regulated by a complex equilibrium between plasma and intracellular mediators. This equilibrium is broken in patients receiving dialysis, which can lead to chronic inflammation causing deleterious consequences on their organs and systems. During recent years, substances that can inhibit the effects of inflammation have been sought. The results of these investigations have produced controversial data on the effects of recombinant human erythropoietin (epoetin) and, in this review, the effects of epoetin on the inflammatory status of dialysis patients are discussed. Aspects discussed include biomarkers of inflammation, and the relationships between epoetin, growth factors, endothelial dysfunction, endothelial fibrinolytic capacity, endothelial damage and oxidative stress. Relationships between epoetin and inflammation in non-uraemic patients are also addressed, as are associations between the malnutrition-inflammation-atherosclerosis syndrome and endothelial dysfunction. It is concluded that although epoetin administration in non-uraemic rats has been shown to have an anti-inflammatory and cytoprotective effect, the mechanisms responsible for regulating inflammation in uraemia are very complex and partially contradictory. The changes in pro-thrombotic and pro-atherogenic factors in dialysis patients require further study to evaluate all the factors implicated in the atherogenic process.
Animals↗
Growth hormone, IGF-I and its binding proteins (IGFBP-1 and -3) in adult uraemic patients undergoing peritoneal dialysis and haemodialysis.
OBJECTIVE: The GH/IGF axis is altered in chronic renal failure (CRF). CRF patients usually show normal or high serum concentrations of GH and IGF-I, whereas all IGF binding proteins (IGFBP-1 to -6), except IGFBP-5, considerably increase with declining renal function. The aims of the present study were to quantify serum concentrations of GH, IGF-I, IGFBP-1 and IGFBP-3 in a group of patients with CRF, and determine whether there were differences according to the type of dialysis, that is, peritoneal dialysis (PD) and haemodialysis (HD). DESIGN: A cross-sectional study in the setting of a dialysis unit of a general hospital. PATIENTS AND MEASUREMENTS: We studied 108 dialysis patients treated by PD (n = 54, 32 males and 22 females, mean age 61.0 +/- 1.4 years) or HD (n = 54, 31 males and 23 females, age 62.6 +/- 1.5 years). A group of 42 healthy subjects of similar age, sex and body mass index (BMI) served as the control group. Baseline serum concentrations of GH, insulin, IGF-I, IGFBP-1 and IGFBP-3 were measured in all patients and control subjects. RESULTS: Fasting serum concentrations of IGF-I and its binding proteins (IGFBP-1 and IGFBP-3) were significantly higher in dialysis patients than in subjects with normal renal function. IGF-I (248.9 +/- 23.4 vs. 205.5 +/- 15.5 micro g/l, NS), IGFBP-3 (5.6 +/- 0.4 vs. 5.5 +/- 0.2 mg/l, NS) and IGFBP-1 (36.1 +/- 5.9 vs. 44.1 +/- 6.5 micro g/l, NS) concentrations were similar in both groups of dialysis (PD vs. HD) patients. However, GH (2.3 +/- 0.3 vs. 1.1 +/- 0.1 micro g/l, P < 0.001) and insulin (40.4 +/- 4.5 vs. 30.1 +/- 3.1 micro U/ml, P < 0.05) levels were significantly higher in the PD group than in the HD group. Both groups of dialysis patients showed significantly higher levels of insulin than healthy subjects (14.7 +/- 1.9 micro U/ml, P < 0.0001 and P < 0.01 for PD and HD, respectively). In both groups of dialysis patients, IGF-I correlated inversely with IGFBP-1 (PD group r = -0.46, P = 0.0006; HD group r = -0.57, P = 0.0001) and directly with IGFBP-3 (PD group r = 0.44, P = 0.001; HD group r = 0.73, P = 0.001). No correlation between insulin and IGFBP-1 was found in any of the groups studied. CONCLUSIONS: These findings demonstrate that adult dialysis patients have elevated IGF-I, IGFBP-1 and IGFBP-3 serum concentrations compared with subjects with normal renal function. Only GH and insulin show statistically significant differences in relation to type of dialysis. Finally, the negative correlation between IGF-I and IGFBP-1 and the positive correlation between IGF-I and IGFBP-3 are maintained in both groups of adult dialysis patients.
Analysis of Variance↗
On the epithelial-mesenchymal transition of mesothelial cells.
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Epithelial Cells↗
Pathogenic significance of hypertrophic mesothelial cells in peritoneal effluent and ex vivo culture.
The presence of hypertrophic mesothelial cells (HMCs) in peritoneal effluent (PE) has been considered a possible marker for peritoneal sclerosis. We conducted the present study to evaluate if the presence of HMCs in PE or in culture was related to peritoneal function alterations or to the development of sclerosing peritonitis. We prospectively studied 32 new peritoneal dialysis (PD)patients every 4 months, determining the presence of HMCs in culture (completing 129 studies in total). We isolated mesothelial cells from nocturnal PE and cultured them ex vivo in T-25 flasks. Cell morphology was estimated using the May-Grünwald/Giemsa method. We also examined the histories of a large patient group to determine HMCs directly in PE, and we evaluated 4 of those patients (6%) who showed persistent HMCs. In 10 of 32 prospectively studied patients, we found HMCs during the culture phase. The cells appeared in the first evaluation in 4 patients and in subsequent cultures in the remaining 6 patients. Ultrafiltration (UF) and solute transport capacity in the 10 patients were similar to those of patients who did not show HMCs. Demographic parameters were not different between the two groups. None of the prospectively studied patients showed any clinical or peritoneal functional abnormality during the study. Cultures performed after the observation of HMCs showed very poor growth capacity. The evolution of the 4 patients in the historic group occurred as follows: We 1 patient transferred to hemodialysis 2 years after the observation of HMCs. 1 patient died of an unrelated cause after 1 year on PD. 1 patient received a successful kidney graft 5 years after the observation of HMCs. 1 patient developed type I UF failure 10 years after the first observation.
Adult↗
Ghrelin plasma levels and appetite in peritoneal dialysis patients.
Anorexia-associated malnutrition is a severe complication that increases mortality in peritoneal dialysis (PD) patients. Ghrelin is a recently-discovered orexigenic hormone with actions in brain and stomach. We analyzed, in 42 PD patients, the possible relationship between ghrelin and appetite regulation with regard to other orexigens [neuropeptide Y (NPY), NO3] and anorexigens [cholecystokinin (CCK), leptin, glucose-dependent insulinotropic peptide (GIP), tumor necrosis factor alpha (TNFalpha)]. All orexigens and anorexigens were determined in plasma. Eating motivation was evaluated using a visual analog scale (VAS). The patients were divided into three groups: those with anorexia (n = 12), those with obesity associated with high intake (n = 12), and those with no eating behavior disorders (n = 18). A control group of 10 healthy volunteers was also evaluated. Mean plasma levels of ghrelin were high (3618.6 +/- 1533 mg/mL), with 36 patients showing values above the normal range (< 2600 mg/mL). Patients with anorexia had lower ghrelin and NPY levels and higher peptide-C, CCK, interleukin-1 (IL-1), TNFalpha, and GIP levels than did the other patients. Patients with anorexia also had an early satiety score and low desire and pleasure in eating on the VAS and diet survey. We observed significant positive linear correlations between ghrelin and albumin (r = 0.43, p < 0.05), prealbumin (r = 0.51, p < 0.05), transferrin (r = 0.4, p < 0.05), growth hormone (r = 0.66, p < 0.01), NO3 (r = 0.36, p < 0.05), and eating motivation (VAS). At the same time, negative relationships were observed between blood ghrelin and GIP (r = -0.42, p < 0.05), insulin (r = -0.4, p < 0.05), leptin (r = -0.45, p < 0.05), and creatinine clearance [r = -0.33, p = 0.08 (nonsignificant)]. Ghrelin levels were not related to Kt/V or to levels of CCK and cytokines. Ghrelin plasma levels are elevated in PD patients. Uremic patients with anorexia show relatively lower ghrelin plasma levels than the levels seen in obese patients or in patients with normal appetite. The role of ghrelin in appetite modulation is altered in uremic PD patients, and that alteration is possibly associated with disorders in insulin and growth hormone metabolism.
Adult↗
Treatment of anorexia and malnutrition in peritoneal dialysis patients with megestrol acetate.
Anorexia and malnutrition are common complications and powerful predictors of morbidity and mortality in peritoneal dialysis (PD) patients. Megestrol acetate (MA) is a progestogen that has been demonstrated to increase appetite and weight in patients with cancer or acquired immunodeficiency syndrome. To determine whether MA might benefit PD patients, we treated 32 patients with 160 mg MA daily. Treatment lasted a mean of 5.93 +/- 5.12 months (range: 1 - 23 months). In 68.8% of the patients, appetite improved. Weight gain was statistically significant starting in the third month (initial weight: 66.5 +/- 11.4 kg; weight at third month: 68 +/- 10.4 kg; p < 0.05). We observed a nonsignificant increase in serum albumin at the third treatment month (initial serum albumin: 3.44 +/- 0.27 g/L; serum albumin at third month: 3.54 +/- 0.27 g/L; p = 0.45). No side effects were observed. Our experience suggests that treatment with 160 mg MA daily in PD patients leads to an increase in appetite, serum albumin, and weight gain in most patients, with no negative side effects.
Anorexia↗
Peritoneal dialysis and epithelial-to-mesenchymal transition of mesothelial cells.
BACKGROUND: During continuous ambulatory peritoneal dialysis, the peritoneum is exposed to bioincompatible dialysis fluids that cause denudation of mesothelial cells and, ultimately, tissue fibrosis and failure of ultrafiltration. However, the mechanism of this process has yet to be elucidated. METHODS: Mesothelial cells isolated from effluents in dialysis fluid from patients undergoing continuous ambulatory peritoneal dialysis were phenotypically characterized by flow cytometry, confocal immunofluorescence, Western blotting, and reverse-transcriptase polymerase chain reaction. These cells were compared with mesothelial cells from omentum and treated with various stimuli in vitro to mimic the transdifferentiation observed during continuous ambulatory peritoneal dialysis. Results were confirmed in vivo by immunohistochemical analysis performed on peritoneal-biopsy specimens. RESULTS: Soon after dialysis is initiated, peritoneal mesothelial cells undergo a transition from an epithelial phenotype to a mesenchymal phenotype with a progressive loss of epithelial morphology and a decrease in the expression of cytokeratins and E-cadherin through an induction of the transcriptional repressor snail. Mesothelial cells also acquire a migratory phenotype with the up-regulation of expression of alpha2 integrin. In vitro analyses point to wound repair and profibrotic and inflammatory cytokines as factors that initiate mesothelial transdifferentiation. Immunohistochemical studies of peritoneal-biopsy specimens from patients undergoing continuous ambulatory peritoneal dialysis demonstrate the expression of the mesothelial markers intercellular adhesion molecule 1 and cytokeratins in fibroblast-like cells entrapped in the stroma, suggesting that these cells stemmed from local conversion of mesothelial cells. CONCLUSIONS: Our results suggest that mesothelial cells have an active role in the structural and functional alteration of the peritoneum during peritoneal dialysis. The findings suggest potential targets for the design of new dialysis solutions and markers for the monitoring of patients.
Cell Movement↗
Gastrointestinal and pancreatic function in peritoneal dialysis patients: their relationship with malnutrition and peritoneal membrane abnormalities.
BACKGROUND: Malnutrition is frequent in peritoneal dialysis (PD) patients, but the contribution of gastrointestinal (GI) dysfunction has not been well established. METHODS: We studied GI function in 49 stable PD patients to ascertain its relationship with malnutrition. After an overload fat diet, fecal fat, sugar, starch and nitrogen, intestinal protein permeability (alpha(1)-antitrypsin fecal clearance [C-alpha(1)-AT]), fecal chymotrypsin (CT), GI hormones and gastrin, pepsinogen I and II, cholecystokinin (CCK), gastrin releasing peptide (GRP), and neuropeptide Y (NPY) were measured. Vasoactive intestinal polypeptide (VIP), substance P (SP), and tumor necrosis factor (TNF-alpha) and biochemical nutritional markers were evaluated. RESULTS: All patients showed high fecal sugar. Elevated fecal nitrogen was found in 21 patients, 6 with high C-alpha(1)-AT. High fecal starch levels appeared in 21, fat in 20, and low fecal CT in 39 patients. These determinations showed inverse relation with nutritional markers. Increased fecal C-alpha(1)-AT values were associated with lower serum albumin. Fecal CT values showed a negative linear correlation with serum albumin and were inversely associated with retinol-binding protein, normalized protein nitrogen appearance, and serum iron. High plasma levels of pancreatic stimulating hormones were found: gastrin, CCK, and VIP. These levels were higher in patients with a worse pancreatic exocrine function. Higher values of other GI hormones, gastrin, pepsinogen I and II, CCK, GRP, and TNF-alpha. Normal concentrations of NPY, VIP, and PS were observed. CONCLUSION: GI abnormalities (malabsorption, maldigestion, pancreatic dysfunction, and protein losing enteropathy) are present in an important number of PD patients. These features are negatively associated to nutrition.
Adult↗
Regulation of apoptosis by lethal cytokines in human mesothelial cells.
BACKGROUND: Dysregulation of peritoneal cell death may contribute to the complications of peritoneal dialysis (PD). Chronic peritoneal dialysis and acute peritonitis are both associated with loss of mesothelial cells. In addition, acute peritonitis is characterized by sudden changes in the number of peritoneal leukocytes. However, the factors regulating peritoneal cell survival are poorly understood. METHODS: Peritoneal effluent cells and mesothelial cells cultured from peritoneal dialysis patients were studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry were used to assess the expression of FasL and Fas mRNA and protein. Western blot was used to assess FasL and tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL). RT-PCR was used to study TRAIL and TRAIL receptor mRNA. Apoptosis was quantified by flow cytometry of DNA content and confirmed by morphology. RESULTS: Apoptotic cells, including apoptotic mesothelial cells, were present in the peritoneal effluent of stable peritoneal dialysis patients and patients with bacterial peritonitis. The lethal cytokines FasL and TRAIL were expressed by peritoneal effluent cells, while cultured mesothelial cells expressed FasL, Fas, and TRAIL receptors. Cultured mesothelial cells were sensitive to FasL-induced apoptosis. IFNgamma increased the cell surface expression of Fas and the sensitivity of mesothelial cells to FasL-induced apoptosis. In contrast to the effect of FasL, TNFalpha and TRAIL did not induce apoptosis in human mesothelial cells from peritoneal dialysis patients. CONCLUSION: Lethal cytokines, such as FasL, may contribute to peritoneal cell turnover and the loss of mesothelium in peritoneal dialysis. The role of other cytokines, such as TRAIL, remains undefined. Approaches in limiting mesothelial cell injury that interferes with apoptosis should be considered.
Aged↗
Nephrotic syndrome in a bone marrow transplant recipient after cyclosporine withdrawal.
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Bone Marrow Transplantation↗
Peritoneal dialysis solutions inhibit the differentiation and maturation of human monocyte-derived dendritic cells: effect of lactate and glucose-degradation products.
Peritoneal dialysis (PD) is a well-established therapy for end-stage renal failure, but its efficiency is limited by recurrent peritonitis. As PD solutions impair local inflammatory responses within the peritoneal cavity, we have analyzed their influence on the in vitro maturation of human monocyte-derived dendritic cells (MDDC). Evaluation of MDDC maturation parameters [expression of adhesion and costimulatory molecules, receptor-mediated endocytosis, allogeneic T cell activation, production of tumor necrosis factor alpha, interleukin (IL)-6 and IL-12 p70, and nuclear factor (NF)-kappaB activation] revealed that currently used PD solutions differentially inhibit the lipopolysaccharide (LPS)-induced maturation of MDDC, an inhibition that correlated with their ability to impair the LPS-stimulated NF-kappaB activation. Evaluation of PD components revealed that sodium lactate and glucose-degradation products impaired the acquisition of maturation parameters and NF-kappaB activation in a dose-dependent manner. Moreover, PD solutions impaired monocyte-MDDC differentiation, inhibiting the acquisition of DC markers such as CD1a and DC-specific intercellular adhesion molecule-3 grabbing nonintegrin (CD209). These findings have important implications for the initiation of immune responses under high lactate conditions, such as those occurring within tumor tissues or after macrophage activation.
Antigens, CD1↗
Clinical experience with tamoxifen in peritoneal fibrosing syndromes.
Peritoneal sclerosis is one of the most important complications of peritoneal dialysis (PD) treatment. Encapsulating peritoneal sclerosis (EPS) represents the most advanced stage of that disease and has a high mortality. No therapy of choice has been established for sclerosing peritonitis, although many have been proposed, with variable results. Tamoxifen has been successfully used in the treatment of patients with fibrosing diseases, mainly retroperitoneal fibrosis. Our purpose in the present study was to investigate whether treatment with tamoxifen in PD patients with peritoneal sclerosis has a beneficial effect. Among more than 450 patients treated in our program since 1980, 23 were diagnosed with peritoneal sclerosis. Of those 23.9 were treated with tamoxifen [20 mg every 12 hours: tamoxifen group (TG)] for a mean period of 14.5 +/- 7 months (range: 6-30 months). The other 14 patients received no treatment and were considered the control group (CG). Both groups were similar in demography and peritoneal antecedents. Follow-up was longer in CG than in TG (mean: 47 months vs. 29 months), but the difference did not reach statistical significance. Mild thrombopenia in 1 patient was the only toxic effect observed with the use of tamoxifen. In CG, 4 patients developed EPS and died--3 of them during the first 6 months after diagnosis. No patient treated with tamoxifen developed EPS. Overall mortality was significantly higher in CG (71% vs. 22%, p = 0.03). Although follow-up was longer in CG, half the patients in that group died during the first 2 years after diagnosis. Our experience suggests that treatment with tamoxifen of patients diagnosed with peritoneal sclerosis diminishes the related complications and significantly reduces mortality, at least in the short- to mid-term. However, a prospective therapeutic trial is required to confirm our results.
Adult↗