201
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Miyata T, Kurokawa K, VAN Ypersele DE Strihou C. Advanced glycation and lipoxidation end products: role of reactive carbonyl compounds generated during carbohydrate and lipid metabolism. J Am Soc Nephrol 2000; 11:1744-1752. [PMID: 10966500 DOI: 10.1681/asn.v1191744] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Toshio Miyata
- Molecular and Cellular Nephrology, Institute of Medical Sciences and Department of Internal Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Kiyoshi Kurokawa
- Molecular and Cellular Nephrology, Institute of Medical Sciences and Department of Internal Medicine, Tokai University School of Medicine, Isehara, Japan
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202
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Miyata T, Horie K, Ueda Y, Fujita Y, Izuhara Y, Hirano H, Uchida K, Saito A, van Ypersele de Strihou C, Kurokawa K. Advanced glycation and lipidoxidation of the peritoneal membrane: respective roles of serum and peritoneal fluid reactive carbonyl compounds. Kidney Int 2000; 58:425-35. [PMID: 10886591 DOI: 10.1046/j.1523-1755.2000.00182.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Advanced glycation of proteins has been incriminated in the progressive alteration of the peritoneal membrane during chronic peritoneal dialysis (PD). Advanced glycation end products (AGEs) result from a modification of proteins by reactive carbonyl compounds (RCOs). RCOs resulting from glucose breakdown are present in commercial PD fluid. They also accumulate in uremic plasma. The present study was undertaken to evaluate the respective contribution of these two sources of RCOs in the genesis of peritoneal AGEs. METHODS Three major RCOs formed during heat sterilization of PD fluid, that is, glyoxal, methylglyoxal, and 3-deoxyglucosone, and total RCOs were measured in commercial PD fluid and in PD effluent. The generation of pentosidine, used as a surrogate marker for AGEs, during one-week incubations of PD fluid and effluent samples fortified with bovine serum albumin (BSA) was measured by high-performance liquid chromatography. Peritoneal samples were stained with antibodies specific for two AGEs derived from carbohydrate-dependent RCOs, Nepsilon-(carboxymethyl)lysine (CML) and pentosidine, or for two advanced lipoxidation end products (ALEs) derived from lipid-dependent RCOs, malondialdehyde (MDA)-lysine and 4-hydroxynonenal (HNE)-protein adduct. RESULTS Glyoxal, methylglyoxal, and 3-deoxyglucosone were identified in commercial PD fluid. Their levels in PD effluents decreased with dwell time probably by diffusion into blood circulation. In contrast, the levels of total RCOs were initially low in commercial PD fluid, increased in PD effluent with dwell time probably by diffusion from circulation into the peritoneal cavity, and after 12 hours, reached values observed in uremic serum. The relevance of the rise in total RCOs for AGE formation is demonstrated by a parallel increase in the generation of pentosidine during incubations of PD effluents. In contrast with RCOs present in glucose-rich PD fluid, RCOs diffusing from uremic circulation originate from both carbohydrates and lipids. Their role in the modification of peritoneal proteins is demonstrated by the immunohistochemical study of peritoneal tissue. Two AGEs and two ALEs increase in parallel in the mesothelial layers and in vascular wall of small arteries in the peritoneum. CONCLUSIONS Protein modification of the peritoneum is determined not only by RCOs originating in PD fluid, but also by RCOs originating from the uremic circulation. The present data might be relevant to current attempts to improve PD fluid toxicity by lowering its glucose content.
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Affiliation(s)
- T Miyata
- Molecular and Cellular Nephrology, Institute of Medical Sciences, Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan
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203
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204
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Abstract
Recent studies have shown that patients with high peritoneal transport characteristics have substantially increased morbidity and mortality. This finding is counter-intuitive, since HTs will a priori achieve higher clearances. There are many possible causes: increased protein losses with consequent hypoalbuminemia; poor ultrafiltration capacity causing fluid retention, ventricular hypertrophy and hypertension; increased glucose absorption leading to anorexia, hyperinsulinism, and local AGE formation; and the development of an atherogenic lipid profile. While common pathogenic causes of high peritoneal transport and atherosclerosis have been hypothesized, it is more likely that CAPD as currently practiced is unsuitable for HTs, who should be switched to HD or NIPD. Renal and peritoneal clearances have different clinical effects and should be assessed separately. Current measures of dialysis adequacy, such as total Kt/V, do not therefore describe the patient's clinical situation accurately and are insufficient.
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Affiliation(s)
- J Heaf
- Department of Nephrology B, Copenhagen University Hospital, Herlev, Denmark.
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205
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Combet S, Miyata T, Moulin P, Pouthier D, Goffin E, Devuyst O. Vascular proliferation and enhanced expression of endothelial nitric oxide synthase in human peritoneum exposed to long-term peritoneal dialysis. J Am Soc Nephrol 2000; 11:717-728. [PMID: 10752531 DOI: 10.1681/asn.v114717] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Long-term peritoneal dialysis (PD) is associated with alterations in peritoneal permeability and loss of ultrafiltration. These changes originate from increased peritoneal surface area, but the morphologic and molecular mechanisms involved remain unknown. The hypothesis that modifications of activity and/or expression of nitric oxide synthase (NOS) isozymes might play a role in these modifications, via enhanced local production of nitric oxide, was tested in this study. NOS activities were measured by the L-citrulline assay in peritoneal biopsies from seven control subjects, eight uremic patients immediately before the onset of PD, and 13 uremic patients on short-term (<18 mo, n = 6) or long-term(>18 mo, n = 7) PD. Peritoneal NOS activity is increased fivefold in long-term PD patients compared with control subjects. In uremic patients, NOS activity is positively correlated with the duration of PD. Increased NOS activity is mediated solely by Ca(2+)-dependent NOS and, as shown by immunoblotting, an upregulation of endothelial NOS. The biologic relevance of increased NOS in long-term PD was demonstrated by enhanced nitrotyrosine immunoreactivity and a significant increase in vascular density and endothelial area in the peritoneum. Immunoblotting and immunostaining studies demonstrated an upregulation of vascular endothelial growth factor (VEGF) mostly along the endothelium lining peritoneal blood vessels in long-term PD patients. In the latter, VEGF colocalized with the advanced glycation end product pentosidine deposits. These data provide a morphologic (angiogenesis and increased endothelial area) and molecular (enhanced NOS activity and endothelial NOS upregulation) basis for explaining the permeability changes observed in long-term PD. They also support the implication of local advanced glycation end product deposits and liberation of VEGF in that process.
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Affiliation(s)
- Sophie Combet
- Division of Nephrology, Université Catholique de Louvain Medical School, Brussels, Belgium
- Division of Cell Biology, Commissariat à l'Energie Atomique, Saclay, France
| | - Toshio Miyata
- Institute of Medical Science and Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan
| | - Pierre Moulin
- Department of Pathology, Université Catholique de Louvain Medical School, Brussels, Belgium
| | | | - Eric Goffin
- Division of Nephrology, Université Catholique de Louvain Medical School, Brussels, Belgium
| | - Olivier Devuyst
- Division of Nephrology, Université Catholique de Louvain Medical School, Brussels, Belgium
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206
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Witowski J, Korybalska K, Wisniewska J, Breborowicz A, Gahl GM, Frei U, Passlick-Deetjen J, Jörres A. Effect of glucose degradation products on human peritoneal mesothelial cell function. J Am Soc Nephrol 2000; 11:729-739. [PMID: 10752532 DOI: 10.1681/asn.v114729] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Bioincompatibility of conventional glucose-based peritoneal dialysis fluids (PDF) has been partially attributed to the presence of glucose degradation products (GDP) generated during heat sterilization of PDF. Most previous studies on GDP toxicity were performed on animal and/or transformed cell lines, and the impact of GDP on peritoneal cells remains obscure. The short-term effects of six identified GDP on human peritoneal mesothelial cell (HPMC) functions were examined in comparison to murine L929 fibroblasts. Exposure of HPMC to acetaldehyde, formaldehyde, glyoxal, methylglyoxal, furaldehyde, but not to 5-hydroxymethyl-furfural, resulted in dose-dependent inhibition of cell growth, viability, and interleukin-1beta (IL-1beta)-stimulated IL-6 release; for several GDP, this suppression was significantly greater compared with L929 cells. Although the addition of GDP to culture medium at concentrations found in PDF had no major impact on HPMC function, the exposure of HPMC to filter-sterilized PDF led to a significantly smaller suppression of HPMC proliferation compared to that induced by heat-sterilized PDF. The growth inhibition mediated by filter-sterilized PDF could be increased after the addition of clinically relevant doses of GDP. These effects were equally evident in L929 cells. In conclusion, GDP reveal a significant cytotoxic potential toward HPMC that may be underestimated in test systems using L929 cells. GDP-related toxicity appears to be particularly evident in experimental systems using proliferating cells and the milieu of dialysis fluids. Thus, these observations may bear biologic relevance in vivo where HPMC are repeatedly exposed to GDP-containing PDF for extended periods of time.
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Affiliation(s)
- Janusz Witowski
- Department of Nephrology and Medical Intensive Care, Universitätsklinikum Charité, Campus Virchow-Klinikum, Medizinische Fakultät der Humboldt-Universität zu Berlin, Germany
- Department of Pathophysiology, University Medical School, Poznan, Poland
| | | | - Justyna Wisniewska
- Department of Pathophysiology, University Medical School, Poznan, Poland
| | | | - Gerhard M Gahl
- Department of Nephrology and Medical Intensive Care, Universitätsklinikum Charité, Campus Virchow-Klinikum, Medizinische Fakultät der Humboldt-Universität zu Berlin, Germany
| | - Ulrich Frei
- Department of Nephrology and Medical Intensive Care, Universitätsklinikum Charité, Campus Virchow-Klinikum, Medizinische Fakultät der Humboldt-Universität zu Berlin, Germany
| | | | - Achim Jörres
- Department of Nephrology and Medical Intensive Care, Universitätsklinikum Charité, Campus Virchow-Klinikum, Medizinische Fakultät der Humboldt-Universität zu Berlin, Germany
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207
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Shioshita K, Miyazaki M, Ozono Y, Abe K, Taura K, Harada T, Koji T, Taguchi T, Kohno S. Expression of heat shock proteins 47 and 70 in the peritoneum of patients on continuous ambulatory peritoneal dialysis. Kidney Int 2000; 57:619-31. [PMID: 10652040 DOI: 10.1046/j.1523-1755.2000.00883.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Peritoneal sclerosis, characterized by collagen accumulation, is a serious complication in continuous ambulatory peritoneal dialysis (CAPD) therapy. Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperon and is closely associated with collagen synthesis. METHODS We determined the expression of HSP47 and HSP70 (nonspecific for collagen synthesis) by immunohistochemistry in peritoneal tissues of patients on CAPD. The tissue for collagen III, alpha-smooth muscle actin (alpha-SMA), and CD68 (a marker for macrophages) were also stained. Thirty-two peritoneal samples were divided into three groups (group A1, 11 patients who had no ultrafiltration loss; group A2, 9 patients who had ultrafiltration loss; and group B, 12 specimens who had end-stage renal disease prior to induction of CAPD. RESULTS In group B, staining for HSP47, HSP70, and collagen III in peritoneal tissues was faint, and only a few cells were positive for alpha-SMA and CD68. In contrast, HSP47, HSP70, and collagen III were expressed in areas of thickened connective tissues in fibrotic peritoneal specimens of CAPD patients. The expression level of HSP47, HSP70, collagen III, and alpha-SMA and the number of CD68-positive cells in group A2 were significantly higher than those in groups A1 and B. HSP47/HSP70-positive cells were mesothelial cells, adipocytes, and alpha-SMA-positive myofibroblasts. Furthermore, the expression level of HSP47 was significantly higher in peritoneal specimens from patients with refractory peritonitis than without it and was significantly higher in patients with more than 60 months of CAPD therapy than that in patients with less than 60 months of CAPD. CONCLUSION Our results indicate that CAPD therapy may induce HSPs in the peritoneal tissue, and that peritonitis in CAPD patients may be associated with the progression of peritoneal sclerosis at least through HSP47 expression and chronic macrophage infiltration. Our data also suggest that the progression of peritoneal sclerosis in such patients is associated with deterioration of peritoneal ultrafiltration function.
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Affiliation(s)
- K Shioshita
- The Second Department of Internal Medicine, Nagasaki University School of Medicine, Sakamoto, Japan
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208
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Rosenberg ME. Peritoneal dialysis: diabetes of the peritoneal cavity. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1999; 134:103-4. [PMID: 10444022 DOI: 10.1016/s0022-2143(99)90113-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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209
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Zweers MM, de Waart DR, Smit W, Struijk DG, Krediet RT. Growth factors VEGF and TGF-beta1 in peritoneal dialysis. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1999; 134:124-32. [PMID: 10444025 DOI: 10.1016/s0022-2143(99)90116-6] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The morphologic alterations in the kidney and the retina that can be present in patients with diabetic microangiopathy are mediated by growth factors. Vascular endothelial growth factor (VEGF) is a mediator of neoangiogenesis in diabetic retinopathy. Transforming growth factor-beta (TGF-beta) is involved in the extracellular matrix proliferation in diabetic nephropathy. The aim of the present study was to investigate the presence of VEGF and TGF-beta1 in peritoneal effluents of patients undergoing continuous ambulatory peritoneal dialysis who are being treated with glucose-containing dialysis solutions in relation to parameters of peritoneal transport. Standard peritoneal permeability analyses with 3.86% glucose dialysate were performed in 16 stable patients undergoing peritoneal dialysis (PD) (median duration of PD 39 months, range 1 to 104 months). The power relationship that is present between dialysate/serum (D/S) ratios of serum proteins that are transported only across the peritoneal membrane and their molecular weights was used to predict the D/S ratios when diffusion would be the only explanation for the measured dialysate concentration. It was assumed that all TGF-beta1 in the circulation was bound to alpha2-macroglobulin. The D/S ratios of VEGF (P < .0005) and TGF-beta1 (P < .015) were significantly higher than expected when VEGF and TGF-beta1 would have been transported from the circulation only by diffusion. No relationship was present between the effluent concentration attributed to the local production of VEGF (LVEGF) and that of TGF-beta1 (LTGF-beta1). LVEGF correlated with the mass transfer area coefficient (MTAC) creatinine value (r = 0.69, P < .007), MTAC urate value (r = 0.60, P < .02), and glucose absorption value (r = 0.75, P < .004), all reflections of the peritoneal vascular surface area. A negative correlation was observed between the transcapillary ultrafiltration (926 mL/4 h, 394 to 1262 mL/4 h) and LVEGF (r = -0.52, P < .045). This negative tendency was also observed between the net ultrafiltration (622 mL/4 h, -43 to 938 mL/4 h) and LVEGF (r = -0.48) but did not reach significance. LVEGF and the duration of treatment did not correlate, possibly because of the relatively small number of patients. LTGF-beta1 showed no relationship with transport parameters or duration of treatment. In conclusion, we found evidence for the local production of both VEGF and TGF-beta1 in the peritoneal membrane of patients undergoing long-term peritoneal dialysis with glucose-based dialysate solutions. The analogy with VEGF in diabetic retinopathy suggests a pathogenetic role of high dialysate glucose concentrations in the development of these alterations in the peritoneal membrane.
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Affiliation(s)
- M M Zweers
- Department of Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
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210
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Abstract
Peritoneal dialysis has now become an established form of renal replacement therapy; nearly half the patients on dialysis in the UK are treated in this way. Survival of patients is now equal to that with haemodialysis. However, long-term peritoneal dialysis (>8 years) is limited to a small percentage of patients because of dropout to haemodialysis for inherent complications of peritoneal dialysis--peritonitis, peritoneal access, inadequate dialysis, and patient-related factors. However, improvements in the understanding of the pathophysiological processes involving the peritoneal membrane have paved the way for advances in the delivery of adequate dialysis, more biocompatible dialysis fluids, and automated peritoneal dialysis. Other technical advances have led to a reduction in peritonitis. Peritoneal dialysis is an important dialysis modality and should be used as an integral part of RRT programmes.
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Affiliation(s)
- R Gokal
- Department of Renal Medicine, Manchester Royal Infirmary, UK
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211
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Affiliation(s)
- Y Kawaguchi
- Dialysis and Transplantation, Second Department of Medicine, Jikei University School of Medicine, Tokyo, Japan
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212
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Krediet RT. Prevention and treatment of peritoneal dialysis membrane failure. ADVANCES IN RENAL REPLACEMENT THERAPY 1998; 5:212-7. [PMID: 9686632 DOI: 10.1016/s1073-4449(98)70034-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A review is given on the definition of peritoneal membrane failure, its pathogenesis, mechanisms of impaired ultrafiltration, and prevention and treatment of membrane failure. In the absence of clinical signs of peritoneal sclerosis and of nonresolving peritonitis, membrane failure is best defined as net ultrafiltration of less than 400 mL/4 hours on a 3.86% glucose-based dialysis solution. Evidence has been accumulating that glucose is a major pathogenetic factor. Reduced exposure to glucose is the most important preventive measurement. Strategies for treatment are discussed. The use of icodextrin-based dialysis solutions is an attractive possibility to reduce glucose exposure.
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Affiliation(s)
- R T Krediet
- Department of Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
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213
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Selgas R, Bajo MA, Paiva A, Del Peso G, Diaz C, Aguilera A, Hevia C. Stability of the peritoneal membrane in long-term peritoneal dialysis patients. ADVANCES IN RENAL REPLACEMENT THERAPY 1998; 5:168-78. [PMID: 9686627 DOI: 10.1016/s1073-4449(98)70029-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
One of main challenges of peritoneal dialysis (PD) is the functional and vital long-term stability of the peritoneal membrane. Few longitudinal and controlled studies on peritoneal function have been published, and the results are somewhat contradictory. We have performed a longitudinal study with 90 patients. The overall analysis has shown that creatinine mass transfer coefficient (MTC) significantly increases and ultrafiltration (UF) capacity decreases over time. Nevertheless, urea MTC remained unaltered and MTC ratios significantly decreased after the third year. Subsequently, we examined the clinical outcomes and identified 19 patients who required peritoneal resting periods for Type I UF failure and 71 patients who did not require such a procedure. The latter patients did not show any significant functional change over time, whereas the former 19 patients showed an increase of peritoneal creatinine transport and a loss of UF capacity. These data corroborate changes in long-term peritoneal function in approximately 20% of PD patients. These changes consist of an increase in effective exchange area, peritoneal permeability, or both, accompanied by signs suggestive of mesothelial regenerative capacity loss. Infectious peritoneal injuries, especially appearing during late PD periods, are deleterious to the peritoneum. The remainder of the functional-structural changes are related to the effects of currently used dialysate. Early diagnosis, preemptive, and therapeutic measures should permit better management of long-term PD patients. The particular response to these injuries has individual characteristics that when addressed permit PD to be used long-term.
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Affiliation(s)
- R Selgas
- Hospital Universitario de la Princesa, Madrid, Spain
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214
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Abstract
The evaluation of ultrafiltration failure is embarked upon when a patient has persistent problems with symptoms and signs of fluid overload. Fluid overload is a common problem in peritoneal dialysis (PD) patients and the risk of its occurrence increases with time on dialysis. Although often attributed to changes in peritoneal membrane function (membrane failure), there are a number of potential, and frequently more common factors that can contribute to the failure of adequate fluid removal in patients on PD. Many of the causes of ultrafiltration failure may be apparent after an initial informal evaluation. However, if after this the etiology remains unexplained, a systematic approach to the differential diagnosis of this problem can be utilized with the use of the peritoneal equilibration test. Once a diagnosis is confirmed, a logical therapeutic plan can be formulated.
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Affiliation(s)
- S M Korbet
- Section of Nephrology, Rush-Presbyterian-St Luke's Medical Center, Chicago, IL, USA
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215
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Park MS. Factors increasing severity of peritonitis in long-term peritoneal dialysis patients. ADVANCES IN RENAL REPLACEMENT THERAPY 1998; 5:185-93. [PMID: 9686629 DOI: 10.1016/s1073-4449(98)70031-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Peritonitis is the most frequent complication and a leading cause of discontinuation of peritoneal dialysis (PD). Intact epithelial lining, sufficient blood flow, and adequate immunologic responses are vital to eradicate infection. In long-term PD, various pathological changes such as denudation of peritoneal mesothelial cells, duplication of submesothelial and/or capillary basement membranes, submesothelial fibrin deposit, and peritoneal fibrosis have been reported. Causes of these changes of the peritoneum are multifactorial. Commonly used dialysis solutions that are acidic, hypertonic, containing high concentrations of glucose and lactate, contaminated by glucose and/or plastic degradation products are not biocompatible and may induce chronic immune reactions in the peritoneal cavity. Long-term exposure of the peritoneum to dialysis solutions, the peritoneal catheter, and recurrent episodes of peritonitis all contribute to peritoneal injury. In addition, long-term exposure of peritoneal cells such as macrophages, mesothelial cells, and fibroblasts to dialysis solutions may also alter the normal immunologic reactions against bacteria. Peritoneal concentrations of opsonins such as Ig, complement, and protease are approximately 1% of the serum levels and far below the level sufficient to eradicate bacteria due to continuous peritoneal lavage and dilution with dialysis solutions. Furthermore, glycation of IgG induces chronic activation of macrophages and decreases normal opsonic activities against bacteria. Fibrin deposits, collagen accumulation, and cellular desert of the peritoneum observed in long-term peritoneal dialysis patients may serve as a safe shelter for bacteria from contact with inflammatory cells and opsonin and delay eradication of bacteria. In conclusion, peritonitis is often more severe in patients on long-term PD. In this setting, peritonitis needs special attention to prevent life-threatening infection and further damage of the peritoneum.
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Affiliation(s)
- M S Park
- Hyonam Kidney Laboratory, Soon Chun Hyang University, Seoul, Korea
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216
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Degenhardt TP, Grass L, Reddy S, Thorpe SR, Diamandis EP, Baynes JW. Technical note. The serum concentration of the advanced glycation end-product N epsilon-(carboxymethyl)lysine is increased in uremia. Kidney Int 1997; 52:1064-7. [PMID: 9328946 DOI: 10.1038/ki.1997.429] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Advanced glycation end products (AGEs) such as pentosidine and N epsilon-(carboxymethyl)lysine (CML) have been traditionally quantified by HPLC or gas chromatography--mass spectrometry (GC/MS). Enzyme-linked immunosorbent assays (ELISA) have been introduced as a convenient alternative to simplify the detection and measurement of AGEs in proteins and tissues, but some of these studies are limited by the lack of information on the structure of the epitopes recognized by antibodies to AGE-proteins. In this work we demonstrate that an antibody used in a previous study, reporting increased levels of AGEs in patients with diabetes or on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD), recognizes CML as its major epitope. We also show that there is a significant correlation between the concentration of AGEs in serum measured by ELISA and a GC/MS assay for CML in serum proteins. Both analyses yielded comparable results, with patients on CAPD and HD having about threefold higher AGE- or CML-concentrations in their serum. Our data suggest that ELISA assays for CML should be useful for the clinical measurement of AGEs in serum proteins.
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Affiliation(s)
- T P Degenhardt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, USA
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