Posttransplantation Encapsulating Peritoneal Sclerosis Contributes Significantly to Mortality after Kidney Transplantation

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD) and may present after kidney transplantation, a condition known as posttransplantation EPS. The prevalence and impact of posttransplantation EPS on survival after kidney transplantation is unknown. From January 1, 1996 until July 1, 2007, 1241 PD patients were transplanted. Thirty‐eight cases of posttransplantation EPS (3%) were identified from the Dutch multicenter EPS study. In EPS patients the mean pretransplant dialysis duration was longer than in the controls (71.4 ± 37.5 months vs. 34.7 ± 25.5, p < 0.0001). The majority of EPS cases were observed within the first 2 years after transplantation, but some cases appeared many years after transplantation. Two hundred and one (16.2%) patients died after transplantation, of which 17 were EPS patients. After infection (23.9%), cardiovascular disease (21.9%) and malignancy (10.9%), EPS (8.5%) was the fourth known cause of death after transplantation. Kaplan–Meier analysis showed a significant decreased survival for transplanted patients with posttransplantation EPS compared to transplanted patients without EPS. In conclusion, posttransplantation EPS is rare but carries a high mortality. A prolonged clinical vigilance and a high index of suspicion for the diagnosis are warranted, specifically in PD patients with a relatively long cumulative pretransplant duration of PD.     

Combined Intestine and Kidney Transplantation in a Patient With Encapsulating Peritoneal Sclerosis: Case Report

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis characterized by fibrosis and calcification of the intestine that, in severe cases, can progress to intestinal failure and total parenteral nutrition dependency. Medical and surgical interventions carry a poor prognosis in these patients. We describe a case of a 36‐year‐old female with end‐stage kidney disease and severe EPS not amenable to surgical intervention who underwent a combined intestinal and kidney transplantation. At 3 years posttransplantation, the patient has normal intestinal and kidney function. This represents, to our knowledge, the first report of severe EPS and end‐stage kidney disease treated with a combined transplant.     

Effect of peritoneal dialysis on expression of vascular endothelial growth factor, basic fibroblast growth factor and endostatin of the peritoneum in peritoneal dialysis patients

Aim: The aim of this study is to investigate the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (ES) in human peritoneum and investigate the relationship between them and peritoneum neoangiogensis in the patients with uraemia and peritoneal dialysis (PD). Methods: Peritoneal biopsies were obtained from normal subjects (n = 8), uraemic predialysis patients (n = 12) and PD patients (n = 10). The mRNA expression of VEGF, bFGF and ES in peritoneal tissues were measured through real‐time polymerase chain reaction. The protein expression of VEGF, bFGF and ES in peritoneal tissues were determined through western blot. Microvessel density (MVD) of peritoneal tissue was assessed using immunohistochemistry with CD34 monoclonal antibody. Results: The mRNA and protein of VEGF, bFGF and ES were expressed in all peritoneal samples. Compared with the normal control group, the mRNA and protein expression of VEGF and bFGF in peritoneal tissues were all significantly upregulated in the uraemic predialysis and PD group (all P < 0.05). Compared with the normal control group, the protein expression of ES were significantly upregulated in the uraemic predialysis and PD group (all (P < 0.05), but the mRNA expression of ES did not have obvious differences in the uraemic predialysis and PD group as compared to the normal control group (P > 0.05). MVD of peritoneal tissue were increased in the uraemic predialysis and PD group compared with the normal group (all P < 0.05). A significant positive correlation was found between VEGF mRNA expression and MVD, bFGF mRNA expression and MVD. Conclusion: The mRNA expression of VEGF and bFGF, the protein expression of VEGF, bFGF, and ES and microvessel density (MVD) are increased both in the uraemic predialysis and PD patients. These results show that uraemia circumstances and non‐physiological compatibility of peritoneal dialysis solution might increase VEGF, bFGF and ES expression and MVD, which might participate in the increment of the peritoneum neoangiogensis and ultrafiltration failure in PD patients.     

The cellular contribution to effluent potassium and its relation to free water transport during peritoneal dialysis.

BACKGROUND: Aquaporin-1 (AQP-1) dysfunction is one of the valid theories for decreased free water transport (FWT) in long-term peritoneal dialysis (PD) ultrafiltration failure (UFF). We questioned whether apoptosis of peritoneal cells could be reflected in an increased release of cellular (CR) K(+) and explain AQP-1 dysfunction. If so, negative relationships between CR-K(+) and FWT would be expected. Therefore, we analysed CR-K(+) to total peritoneal K(+) removal, for possible relationships with FWT, the duration of PD, the presence of late UFF and effluent cancer antigen (CA) 125. METHODS: Standard peritoneal permeability analyses done with 3.86% glucose were investigated cross-sectionally in three extreme groups: group I: 19 patients <1 year on PD; group II: 20 patients >4 years on PD without UFF; group III: 19 patients >4 years on PD with UFF. RESULTS: Group III had the lowest values of FWT and CR-K(+) (P < 0.01). CR-K(+) had a positive correlation with FWT in groups I and II, but not in group III. These correlations were also present using much simpler methodologies: replacement of CR-K(+) by mass transfer area coefficient (MTAC)-K(+)/MTAC-creatinine ratio or dialysate over plasma (D/P)-K(+)/D/P-creatinine ratio and replacement of FWT by Na(+)-sieving. No relationship with CA125 was present. CONCLUSIONS: This study shows that other than diffusive and convectional, K(+) transport is not excluded in patients treated with conventional glucose-based PD solutions. We found evidence for release of K(+) from cells. In general, CR-K(+) was related to parameters of FWT, except for long-term patients with UFF. This suggests glucose-induced hypertonic cell shrinkage as a basic physiological phenomenon during PD. The absence of this relationship in long-term PD patients with UFF either suggests a reduction or inhibition of K(+)-channels and may be due to another mechanism than AQP-1 dysfunction. Most likely, CR-K(+) in UFF does not reflect apoptosis. However, the D/P-K(+)/D/P-creatinine ratio may be useful in detecting peritoneal changes.     

肾疏宁抑制腹膜透析腹膜纤维化大鼠基质及新生血管的实验研究

目的:观察中药肾疏宁对腹膜纤维化大鼠腹膜功能、腹膜组织基质积聚、新生血管、结缔组织生长因子(CT-GF)、血管内皮生长因子(VEGF)、肝细胞生长因子(HGF)及骨形态蛋白-7(BMP-7)表达的影响。方法:腹膜透析液+阿霉素注射法诱发SD大鼠腹膜透析腹膜纤维化模型,依体重随机分为4组,1.5%腹膜透析液模型组、4.25%腹膜透析液模型组、1.5%腹膜透析液+肾疏宁干预组及4.25%腹膜透析液+肾疏宁干预组,每组各15只,另设空白对照组(对照组,15只)。1.5%腹膜透析液+肾疏宁干预组及4.25%腹膜透析液+肾疏宁干预组予肾疏宁(按43.93g.kg-1.d-1)灌胃,对照组和模型组予等量生理盐水灌胃。检测腹透液葡萄糖浓度,计算超滤量(UF)及葡萄糖转运量(MGT)。观察腹膜病理形态学改变,分析腹膜厚度、腹膜血管计数、腹膜纤维连接蛋白(FN)及CTGF、VEGF、HGF、BMP-7表达。结果:治疗第6周末,1.5%腹膜透析液+肾疏宁干预组及4.25%腹膜透析液+肾疏宁干预组腹膜透析腹膜纤维化大鼠超滤量(-3.26±14.17)ml及(-2.04±10.74)ml、葡萄糖转运量(18.12±0.81)mmol/kg及(16.14±1.20)mmol/kg、腹膜厚度(74.68±15.33)μm及(211.75±58.23)μm、腹膜血管计数(8.21±2.66)个/mm2及(13.70±4.71)个/mm2、FN(152.47±36.94)%及(231.49±53.49)%、CTGF(708.67±127.22)%及(791.20±126.37)%、VEGF(0.42±0.08)%及(0.50±0.09)%、HGF(245.71±24.38)%及(222.05±23.43)%、BMP-7(351.27±31.99)%及(284.43±26.82)%,与同浓度透析液组比较,差异有统计学意义(P<0.05,P<0.01)。结论:肾疏宁可能通过调控CTGF、VEGF、HGF、BMP-7表达,阻抑基质过度积聚及新生血管生成,进而延缓腹膜透析大鼠腹膜纤维化进展。     

Glucose degradation products downregulate ZO-1 expression in human peritoneal mesothelial cells: the role of VEGF.

BACKGROUND: Glucose degradation products (GDPs) are formed during heat sterilization of peritoneal dialysis fluid and, to a lesser extent, during their prolonged storage. In vitro studies have demonstrated that GDPs impair functions of peritoneal mesothelial cells, including proliferation, viability and cytokine release. In the present study, we studied the acute effect of GDPs on the expression of tight junction-associated protein, zonula occludens protein 1 (ZO-1), in human peritoneal mesothelial cells (HPMC). The role of the vascular endothelial growth factor (VEGF) induced by GDPs in the expression of ZO-1 was also examined. METHODS: HPMC were cultured with GDPs, including 2-furaldehyde (FurA), methylglyoxal (M-Glx) and 3,4-dideoxyglucosone-3-ene (3,4-DGE). The expression of ZO-1 and the synthesis of VEGF were examined. To define the role of VEGF on the regulation of ZO-1 expression, HPMC were cultured with GDPs in the presence or absence of neutralizing antibody to VEGF. The signal pathways involved in VEGF synthesis induced by GDPs were also characterized. RESULTS: ZO-1 expression in HPMC was downregulated in a time- and dose-dependent manner following culture with subtoxic concentrations of GDPs (FurA, M-Glx and 3,4-DGE). All three GDPs increased VEGF synthesis in HPMC. Exogenous VEGF downregulated the expression of ZO-1 and neutralizing anti-VEGF antibody reversed the effect of GDPs on ZO-1 expression in HPMC, suggesting the action of GDPs on ZO-1 expression was mediated by VEGF. All three GDPs activated the p42/p44 mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) signal transduction pathways. The GDP-induced VEGF and transforming growth factor (TGF)-beta synthesis in HPMC was partially reduced by either the p42/p44 MAPK inhibitor (PD98059) or the PKC inhibitor (staurosporine). More importantly, the VEGF and TGF-beta synthesis induced by GDPs in HPMC was completely blocked by synergistic action of both inhibitors. CONCLUSIONS: We have demonstrated that short-term exposure to GDPs downregulates ZO-1 expression in HPMC through the generation of VEGF. Our study provides evidence that GDPs can directly induce VEGF and TGF-beta production in HPMC through the activation of p42/44 MAPK and PKC signal transduction pathways.     

Plasma Ghrelin Levels Are Associated with Coronary Microvascular and Endothelial Dysfunction in Peritoneal Dialysis Patients

Cardiovascular (CV) disease is the main cause of death in peritoneal dialysis (PD) patients, and endothelial dysfunction (ED) is an early sign of vascular pathology. Ghrelin, a gastric peptide with CV actions, has been shown to inhibit proatherogenic changes in experimental models. However, another peptide hormone, leptin, may mediate deleterious effects on the CV system. The aim of this study is to evaluate the relationship between plasma ghrelin and leptin levels, and their association with coronary microvascular and endothelial functions in PD patients. Twenty-four (14 females and 10 males; mean age 44 ± 12 yr) nondiabetic PD patients, between 18 and 70 years of age, were enrolled. In addition to demographic, clinical, and laboratory parameters, plasma concentrations of ghrelin and leptin were evaluated. Endothelial functions of the coronary arteries were determined by coronary flow reserve (CFR) measurement using transthoracic Doppler echocardiography (TTDE). A CFR value of < 2 was used as an evidence for ED. When the study group was divided according to CFR measurements as CFR < 2 and ≥ 2, there were no significant differences considering age, gender, etiology of renal disease, body mass index (BMI), duration of dialysis, PD modality, PD solution type, history of peritonitis, mean arterial pressure, ejection fraction, and biochemical parameters between the two subgroups. Plasma ghrelin levels (129.4 ± 82.1 pg/mL) in patients with CFR ≥ 2 were significantly higher than those in patients with CFR< 2 (63.3 ± 35.8 pg/mL) (p = 0.03). However, no significant differences in plasma leptin levels were found between these groups [31.39 ± 37.81 ng/mL vs. 63.95 ± 72.83 ng/mL (p = 0.28)]. No correlation existed between plasma ghrelin levels and age, BMI, duration of dialysis, mean arterial pressure, ejection fraction, plasma leptin levels, and biochemical parameters. Decreased plasma ghrelin levels may contribute to the development of atherosclerosis in PD patients by causing ED.     

肝细胞生长因子对维持性腹膜透析患者腹膜微炎症状态及超滤量的影响

目的：观察肝细胞生长因子（HGF）对腹膜透析微炎症状态和超滤量的影响。方法：选择稳定的持续非卧床腹膜透析（CAPD）患者20例,采用双盲交叉对照设计,患者随机腹透液内分别加入HGF或生理盐水治疗3个月,再经1个月的洗脱期后交换处理因素,分别观察患者的腹膜微炎症状态、腹膜通透性和超滤量的变化。结果：与处理前和生理盐水处理后相比,HGF可降低透析液CRP、IL-6、TNF-α和TGF-β的水平（P〈0．05）,降低透析液肌酐／血肌酐（D/PCr）比值,降低透析液尿素／血尿素（D／Purea）比值以及透析液白蛋白／血白蛋白比率。HGF可增加4h、0h透析液葡萄糖比率（D4／D0 glucose）及24h超滤量（P〈0．05）,患者周总KT／V和总Ccr／ml无明显变化（P〉0.05）。结论：PD患者腹透液内使用HGF可改善腹腔微炎症状态,降低腹膜对小分子通透性,增加腹膜的超滤量。     

Hemodynamic Studies in Long-Term Peritoneal Dialysis Patients

A study was undertaken to evaluate the acute hemodynamic effects in ten patients from this clinic's long-term peritoneal dialysis program. With a Swan-Ganz catheter, the following parameters were measured in each patient during peritoneal dialysis: cardiac index, pulmonary artery pressure, right atrial pressure, inferior vena cava pressure, heart rate and arterial pressure. Mean predialysis cardiac index, stroke volume index and heart rate were normal. Predialysis pulmonary artery pressure and arterial pressure were slightly elevated. Mean weight loss during peritoneal dialysis was 1.6 kg. The most striking post-dialysis changes were a significant 20% decrease of the cardiac index and a 17% decrease of the pulmonary artery pressure. Heart rate and arterial pressure remained constant due to a 25% increase of total peripheral resistance. After filling the abdomen with one, two and three liters of dialysate, intra-abdominal pressure and inferior vena cava pressure increased up to 150 and 100%, respectively, whereas central hemodynamic parameters (pulmonary artery pressure, cardiac index, stroke volume index, heart rate and arterial pressure) were unchanged.     

Diffusive and Convective Solute Transport in Peritoneal Dialysis with Glucose as an Osmotic Agent

Abstract: To investigate possible effects of glucose concentration, dwell time, and peritoneal reabsorption on the combined diffusive and convective peritoneal solute transport, dialysate to plasma concentration ratios (D/P) and solute clearances were evaluated for 6-h peritoneal dwell studies with 1.36, 2.27, and 3.86% glucose solutions. The diffusive mass transport coefficient, K_BD, and sieving coefficient, S, were estimated using the Babb-Randerson-Farrell model of peritoneal transport. Dialysate volumes over time and peritoneal reabsorption rates, K_R, were assessed using radiolabeled iodinated serum albumin (RISA). The transport parameters were estimated with and without peritoneal reabsorption of solutes taken into account. To test the stability of the transport parameters throughout a single peritoneal dwell, K_BD and S values were estimated for the initial 3–120 min, the final 120–360 min, and the entire 3–360 min dwell period for dialysis with 3.86% glucose solution. The transport parameters did not differ between the three dialysis fluids although clearances of small solutes were higher with the 3.86% solution. Values of K_BD, but not S, were dependent on the correction for peritoneal reabsorption of solutes. Computer simulations showed that S could be estimated even with the 1.36% glucose solution. A significant change of the transport parameters, with increased values of K_BD during the initial period of the dwell, was found for urea, potassium, sodium, and total protein during dialysis with the 3.86% solution. S values for urea and potassium were close to 1 during the initial period whereas unphysical (higher than 1) S values were found for the whole dwell period. The transient increase of K_BD during the initial part of the dwell may reflect changes in the peritoneal barrier possibly induced by fresh dialysis fluid. In conclusion, the transport parameters K_BD and S are not influenced by the concentration of glucose in the dialysis fluid. Moreover, the estimation of K_BD but not of 5 is dependent on the assumed rate of peritoneal reabsorption. Finally, the current results challenge the assumption that K_BD and S are constant throughout a peritoneal dialysis exchange.     

Peritoneal loss of insulin-like growth factor-I and binding proteins in end-stage renal disease

The kinetics of peritoneal transport of insulin-like growth factor (IGF) system-related proteins during dialysis is not well characterized. We studied temporal changes in dialysate and serum concentrations of IGF-I and IGF-II as well as IGF binding protein (BP)-1, -2, and -3 in ten children with end-stage renal disease (ESRD) undergoing continuous cycling peritoneal dialysis (CCPD) during a 4-h peritoneal equilibration test (PET). Dialysate concentrations of IGF-I, IGF-II, and all three IGFBPs demonstrated a time-dependent increase during PET. Despite their transport, the serum concentrations of these proteins did not change significantly during the PET. Dialysate/serum ratios for IGF-I, IGF-II, and IGFBP-1, -2, and -3 were significantly increased at 2 h and increased further at 4 h, at which time values averaged 1.3±0.2%, 3.1±0.5%, 6.2±1.0%, 2.4±0.2%, and 1.3±0.2% of serum levels, respectively. The transperitoneal clearance (μl/min per 1.73 m²) of the three IGFBPs was inversely related to both their molecular weight and plasma concentration. However, peritoneal clearance of IGF-I and -II was similar to that of the larger and more-abundant IGFBP-3. Mass transfer rates (μg/h per 1.73 m²) for the IGFs and their binding proteins were directly proportional to their prevailing plasma concentration. Based on estimates of mass transfer, only a small molar excess of IGFBPs was removed from the circulation relative to the combined molar concentration of IGF-I and IGF-II. Hence, it seems unlikely that any beneficial effect of CCPD on growth in children with ESRD is mediated via a preferential loss of IGFBPs into the dialysate fluid. Received August 15, 1997; received in revised form January 7, 1998; accepted January 9, 1998     

Increased expressions of vascular endothelial growth factor （VEGF）, VEGF-C and VEGF receptor-3 in prostate cancer tissue are associated with tumor progression

Aim： To investigate the differences in microvessel densities （MVD） and the expressions of vascular endothelial growth factor （VEGF）, VEGF-C and VEGF receptor-3 （VEGFR-3） between prostate cancer （PCa） tissues and adjacent benign tissues, and to explore the correlations among MVD, Jewett-Whitmore staging, Gleason scores and expressions of VEGF, VEGF-C and VEGFR-3 in the progression of PCa. Methods： An immunohistochemical approach was adopted to detect the expressions of CD34, VEGF, VEGF-C and VEGFR-3 in both cancer areas and peripheral benign areas of 71 primary prostatic adenocarcinoma specimens. A statistic analysis was then performed according to the experimental and clinic data. Results： Significantly upregulated expressions of VEGF, VEGF-C and VEGFR-3 were all found in malignant epithelium/cancer cells compared with adjacent benign epithelium （P 〈 0.01）. Patients in stage D had a significantly higher score than patients in stage A, B or C when comparing the expression of VEGF-C or VEGFR-3 in the tumor area （P 〈 0.01）. In addition, significant correlations were observed between Jewett-Whitmore staging and VEGF-C （rs = 0.738, P 〈 0.01）, clinical staging and VEGFR-3 （rs = 0.410, P 〈 0.01）, VEGF-C and Gleason scores （rs = 0.401, P 〈 0.01）, VEGFR-3 and Gleason scores （rs = 0.581, P 〈 0.001） and MVD and VEGF （rs = 0.492, P 〈 0.001）. Conclusion： Increased expressions of VEGF and VEGF-C were closely associ- ated with progression of PCa. The main contribution of increased VEGF expression for PCa progression was to upregulate MVD, which maintained the growth advantage of tumor tissue. However, the chief role of increased expressions of VEGF-C and VEGFR-3 was to enhance lymphangiogenesis and provide a main pathway for cancer cells to disseminate. （Asian J Androl 2006 Mar; 8： 169-175）     

胃癌淋巴管生成与淋巴管密度的相关性研究

胃癌的发病率日益增加,而淋巴转移是导致患者最终死亡的重要原因之一.血管内皮生长因子C(VEGF-C)、血管内皮生长因子D(VEGF-D)与其特异性的受体血管内皮生长因子受体3(VEGFR-3)结合能够促进淋巴管生成,并促进淋巴管转移,并且与肿瘤的淋巴管密度密切相关.近年来对于胃癌的淋巴管的研究正在开展,本文就胃癌淋巴管生成机制、淋巴管生成与淋巴管密度关系的最新研究进展以及此项研究的临床意义加以综述.