Benefits of switching from a conventional to a low-GDP bicarbonate/lactate-buffered dialysis solution in a rat model

BACKGROUND: Long-term exposure to standard peritoneal dialysis fluid (PDF) results in alterations in peritoneal morphology and function. Studies investigating the long-term effects on the peritoneum of a low-glucose degradation product (GDP) bicarbonate/lactate-buffered PDF demonstrated its superior biocompatibility. We examined the potential of the low-GDP bicarbonate/lactate-buffered solution to reverse or reduce standard PDF-induced peritoneal alterations. METHODS: Female Wistar rats received twice daily intraperitoneal infusions with either a lactate-buffered solution with 3.86% glucose at pH 5.5 (Dianeal, referred to as standard PDF), or a low-GDP bicarbonate/lactate-buffered solution with 3.86% glucose at physiologic pH (Physioneal, referred to as bicarbonate/lactate PDF) for different periods of time: (1) 12 weeks Dianeal (N= 9); (2) 12 weeks Physioneal (N= 9); (3) 20 weeks Dianeal (N= 11); (4) 20 weeks Physioneal (N= 10); (5) 12 weeks Dianeal followed by 8 weeks Physioneal (N= 10). RESULTS: Chronic standard PDF exposure resulted in loss of ultrafiltration capacity, increased VEGF expression and vascular density, higher advanced glycation end product (AGE) accumulation, up-regulation of TGF-beta expression, and development of fibrosis compared to low-GDP bicarbonate/lactate-buffered PDF. The PDF-induced alterations were time-dependent. Crossover from standard PDF to low-GDP bicarbonate/lactate PDF resulted in a less impaired ultrafiltration (UF), less pronounced VEGF expression and neoangiogenesis, and less severe AGE accumulation, TGF-beta expression, and fibrosis compared to continuous standard PDF exposure for 20 weeks. CONCLUSION: Low-GDP bicarbonate/lactate-buffered PDF has the potential to slow down standard PDF-induced peritoneal membrane damage.     

Better preservation of peritoneal morphologic features and defense in rats after long-term exposure to a bicarbonate/lactate-buffered solution.

The long-term effects of a standard lactate-buffered dialysis fluid and a new, two-chamber, bicarbonate/lactate-buffered dialysis fluid (with fewer glucose degradation products and a neutral pH) were compared in an in vivo peritoneal exposure model. Rats were given daily injections, via an access port, of 10 ml of standard solution or bicarbonate/lactate-buffered solution for 9 to 10 wk. The omentum, peritoneum, and mesothelial cell layer were screened for morphologic changes. In addition, the bacterial clearing capacity of the peritoneal cells was studied. Significantly more milky spots and blood vessels were observed in the omenta of animals treated with standard solution (P < 0.03 for both parameters). Electron-microscopic analysis demonstrated dramatic changes in the appearance of the vascular endothelial cells of the milky spots and a severely damaged or even absent mesothelium on the peritoneal membrane of the standard solution-treated animals. In contrast, the mesothelium was still present in the bicarbonate/lactate-buffered solution group, although the cells lost microvilli. Both peritoneal dialysis fluids significantly increased the density of mesothelial cells (per square millimeter) on the surface of the liver and the thickness of the submesothelial extracellular matrix of the peritoneum (both P < 0.04 for both fluids versus control). A significantly better ex vivo bacterial clearing capacity was observed with peritoneal cells from the bicarbonate/lactate-buffered solution group, compared with the standard solution group (P < 0.05 in both experiments). These results demonstrate that instillation of bicarbonate/lactate-buffered solution into rats for 9 to 10 wk preserves both morphologic and immune parameters much more effectively, compared with standard solution. These findings may be of considerable clinical importance.     

Biocompatibility pattern of a bicarbonate/lactate-buffered peritoneal dialysis fluid in APD: a prospective, randomized study.

BACKGROUND: In chronic ambulatory peritoneal dialysis, bicarbonate-buffered fluids, with their neutral pH and less advanced glycosylation end-products (AGE) and glucose degradation products (GDP), have better biocompatibility than conventional peritoneal dialysis (PD) solutions. That difference may be more beneficial in automated peritoneal dialysis (APD), due to its more frequent exchanges and longer contact times with fresh dialysate. We performed a prospective, randomized study in APD patients to compare the biocompatibility of conventional and bicarbonate/lactate-buffered PD fluids. METHODS: We randomized 14 APD patients to have APD with either conventional or bicarbonate/lactate-based fluids. After 6 months, both groups changed to the other solution. The overall observation period was 12 months. After 1 and 5 months and again after 7 and 11 months, phagocytotic and respiratory burst capacities of effluent peritoneal macrophages were determined. Plasma interleukin (IL)-6 and C-reactive protein (CRP) as well as effluent IL-6, CRP, transforming growth factor (TGF)-beta 1, AGE and CA125 concentrations were measured. Inflow pain was quantified using a patient questionnaire. RESULTS: Respiratory burst capacity remained unchanged and phagocytotic activity increased significantly during APD (P<0.001) with the bicarbonate/lactate fluid. Effluent IL-6 release was significantly lower than with the lactate fluid (P<0.05). While in the effluent TGF-beta 1 was unaffected, AGE concentration was lower after bicarbonate/lactate treatment (P<0.05). Effluent CA125 concentration, an indicator of mesothelial cell integrity, was higher (P<0.05) in neutral effluents. Finally, patients' inflow pain diminished (P = 0.05) when using the neutral fluid. CONCLUSIONS: The use of a neutral PD fluid in APD improved patients' inflow pain as well as biocompatibility parameters reflecting enhanced phagocytotic activity of peritoneal macrophages, reduced constitutive inflammatory stimulation (IL-6), reduced AGE accumulation in the peritoneal cavity and better preservation of the mesothelial cell integrity. From the biocompatibility point of view, a neutral fluid with low GDP content can be recommended as the primary choice for APD.     

The in vitro biocompatibility performance of a 25 mmol/L bicarbonate/10 mmol/L lactate-buffered peritoneal dialysis fluid

The in vitro biocompatibility performance of a 25 mmol/L bicarbonate/10 mmol/L lactate-buffered peritoneal dialysis fluid. BACKGROUND: The biocompatibility profile of a new peritoneal dialysis (PD) solution (Physioneal 35) was determined using a selection of in vitro assay systems. Physioneal 35 is buffered by a combination of 25 mmol/L bicarbonate and 10 mmol/L lactate, thereby providing a solution with a total of 35 mmol/L of alkali to complement the currently available 25 mmol/L bicarbonate and 15 mmol/L lactate combination solution, Physioneal 40. In addition, the new solution contains a calcium concentration of 1.75 mmol/L rather than 1.25 mmol/L present in Physioneal 40. Physioneal 35 and 40 are manufactured in double chamber bag systems that permit separation of glucose from the buffer during sterilization. When the two chambers are mixed just before patient use, the resulting solution has a neutral pH and reduced glucose degradation content. Physioneal 35 was evaluated for its cytotoxicity potential using a murine fibroblast assay, its acute effect on human neutrophil and human peritoneal mesothelial cell function, and its in vitro potential to form advanced glycation end products (AGE). The biocompatibility characteristics of this new formulation were compared with that of a conventional, lactate-based solution and to that of its parent formulation, Physioneal 40. METHODS: Proliferation of murine fibroblasts was determined after exposure to dialysis fluids for 72 hours. Cell viability was assayed by the ability to take up neutral red dye. Human neutrophils were exposed for 15 minutes to dialysis fluids, and their ATP content and phorbol 12-myristate 13-acetate (PMA) stimulated chemiluminescence response was determined as a measure of viability and respiratory burst activity, respectively. Cellular interleukin (IL)-1beta-driven IL-8 synthesis by human mesothelial cells following acute exposure to dialysis fluids was also assessed. Advanced glycation end product formation in the dialysis fluids was measured after 5 and 20 days of incubation with human serum albumin (HSA) as the model protein. RESULTS: In all assays employed, the biocompatibility profile of Physioneal 35 was similar to that of the Physioneal 40 parent formulation. Physioneal 35 showed a significant improvement in biocompatibility performance compared to a pH neutralized conventional lactate-buffered peritoneal dialysis solution in the murine fibroblast assay. In the acute exposure assays, human neutrophil viability and respiratory burst were significantly improved compared with the acidic, conventional solution; however, no statistically significant improvement were seen in mesothelial cells. AGE formation, which is thought to be an important mechanism by which glucose and glucose degradation products cause structural and functional changes of the peritoneal membrane, was significantly lower in Physioneal 35 compared with the conventional dialysis solution. CONCLUSION: The biocompatibility profile of Physioneal 35 was similar to that of the original Physioneal 40 bicarbonate/ lactate-buffered dialysis solution, confirming that differences in both buffer content and calcium concentration do not affect biocompatibility performance. Both bicarbonate/lactate formulations (Physioneal 35 and Physioneal 40) were more biocompatible than a conventional lactate-buffered dialysis solution in this in vitro biocompatibility assessment.     

Hyperlipidemia in uremic children: response to peritoneal dialysis and hemodialysis.

Hemodialysis and hyperlipidemia have been associated in both adults and children. The present study indicates hyperlipidemia in uremic children treated with peritoneal dialysis and implies that the cardiovascular risk felt to exist with hemodialysis also exists in peritoneal dialysis. Thirty-eight children with chronic renal insufficiency or end-stage renal disease were followed serially under varying conditions of medical management, hemodialysis, peritoneal dialysis, and transplantation. Serum triglyceride concentrations in patients on peritoneal dialysis were not significantly different from those in patients on hemodialysis, but both were significantly higher (P less than 0.01) than concentrations in patients on medical management and transplantation.     

Clinical experience with two physiologic bicarbonate/lactate peritoneal dialysis solutions in automated peritoneal dialysis

Clinical experience with two physiologic bicarbonate/lactate peritoneal dialysis solutions in automated peritoneal dialysis. BACKGROUND: Patients on automated peritoneal dialysis (APD) usually receive larger volumes of dialysis solution and more frequent, shorter exchanges than patients on continuous ambulatory peritoneal dialysis (CAPD), and therefore are likely to derive greater benefit from more physiologic solutions. METHODS: Peritoneal dialysis solutions containing 25 mmol/L bicarbonate and either 10 or 15 mmol/L lactate were compared with standard lactate solutions (35 or 40 mmol/L) in two prospective, open-label studies of patients on APD. Each study included a 2-week baseline period (lactate solution), a 6-week treatment period (bicarbonate/lactate solution), and a 2-week follow-up period (same lactate solution as baseline). Biochemical analyses and assessments of vital signs and safety parameters were conducted at baseline, every 2 weeks during treatment, and at the end of the follow-up period. A product use questionnaire was administered in one study at the end of treatment. RESULTS: A statistically significant rise in plasma bicarbonate (approximately 2 mmol/L) occurred when patients switched from a lactate solution to the bicarbonate/lactate solution with equimolar buffer concentration (P < 0.001 for each solution). Plasma bicarbonate decreased by 1.16 mmol/L after a switch from lactate 40 mmol/L to bicarbonate/lactate 35 mmol/L (P < 0.001). When patients switched to bicarbonate/lactate 35, the majority of individual venous plasma bicarbonate values were in the normal range. A switch from a lower calcium (1.25 mmol/ L) lactate solution to a higher calcium (1.75 mmol/L) lactate/bicarbonate solution resulted in a statistically significant rise in serum calcium (0.06 mmol/L, P < 0.018). The product use questionnaire revealed improvements in symptoms, including reduced pain on infusion. CONCLUSION: Bicarbonate/lactate solutions may be used safely and effectively in patients on APD. The availability of 2 formulations with different buffer and calcium content provides flexibility for the control of acidosis as well as calcium balance.     

Better correction of metabolic acidosis, blood pressure control, and phagocytosis with bicarbonate compared to lactate solution in acute peritoneal dialysis

Lactate solution has been the standard dialysate fluid for a long time. However, it tends to convert back into lactic acid in poor tissue-perfusion states. The aim of this study was to evaluate the efficacy of magnesium (Mg)- and calcium (Ca)-free bicarbonate solution compared with lactate solution in acute peritoneal dialysis (PD). Renal failure patients who were indicated for dialysis and needed acute PD were classified as shock and nonshock groups, and then were randomized to receive either bicarbonate or lactate solution. Twenty patients were enrolled in this study (5 in each subgroup). In the shock group, there were more rapid improvements and significantly higher levels of blood pH (7.40 +/- 0.04 versus 7.28 +/- 0.05, p < 0.05), serum bicarbonate (23.30 +/- 1.46 versus 18.37 +/- 1.25 mmol/L, p < 0.05), systolic pressure (106.80 +/- 3.68 versus 97.44 +/- 3.94 mm Hg, p < 0.05), mean arterial pressure (80.72 +/- 2.01 versus 73.28 +/- 2.41 mm Hg, p < 0.05), percentages of phagocytosis of circulating leukocytes (65.85% +/- 2.22 versus 52.12% +/- 2.71, p < 0.05), and percentages of positive nitroblue tetrazolium (NBT) reduction test without and with stimulation (14.43 +/- 1.93 versus 9.43 +/- 2.12, p < 0.05 and 65.08 +/- 6.80 versus 50.23 +/- 4.21, p < 0.05, respectively) in the bicarbonate subgroup compared with the lactate subgroup. In the nonshock group, blood pH, serum bicarbonate, and phagocytosis assays in both subgroups were comparable. Lactic acidosis was more rapidly recovered and was significantly lower with bicarbonate solution for both shock and nonshock groups (3.63 +/- 0.37 versus 5.21 +/- 0.30 mmol/L, p < 0.05 and 2.92 +/- 0.40 versus 3.44 +/- 0.34 mmol/L, p < 0.05, respectively). Peritoneal urea and creatinine clearances in both subgroups were comparable for both shock and nonshock groups. There was no peritonitis observed during the study. Serum Mg and Ca levels in the bicarbonate subgroup were significantly lower, but no clinical and electrocardiographic abnormality were observed. We concluded that Mg- and Ca-free bicarbonate solution could be safely used and had better outcomes in correction of metabolic acidosis, blood pressure control, and nonspecific systemic host defense with comparable efficacy when compared to lactate solution. It should be the dialysate of choice for acute PD especially in the poor tissue-perfusion states such as shock, lactic acidosis, and multiple organ failure.     

Short-term effect of 4% hypertonic glucose as compared to 4% mixed hypertonic mannitol solution in conventional peritoneal dialysis

16 peritoneal dialyses were performed in 14 end-stage kidney disease patients; 6 had diabetic nephropathy, and, of the nondiabetic group, 7 had chronic glomerulonephritis, and 1 had polycystic kidney disease. The peritoneal dialysis performed with conventional 1.5% glucose solution, intervened by four consecutive exchanges using 4% hypertonic glucose solution, was compared to 4% mixed hypertonic mannitol solution in the diabetic and nondiabetic group. There was no significant change of serum glucose, when postdialysis with 1.5% glucose solution was compared to 4% mixed hypertonic mannitol solution; however there was a significant change of serum osmolality in both groups. Postdialysis with both 4% hypertonic solutions showed that there was no significant difference of ultrafiltration volume in both groups of patients, but there was a significant difference in serum glucose in the diabetic group. The transport mechanism of mixed hypertonic mannitol solution as compared to hypertonic glucose solution is discussed. The application of hypertonic mannitol solution for clinical use is not advised.     

Alleviation of sleep apnea in patients with chronic renal failure by nocturnal cycler-assisted peritoneal dialysis compared with conventional continuous ambulatory peritoneal dialysis

Nocturnal hemodialysis has been shown to improve sleep apnea in patients who receive conventional hemodialysis. It was hypothesized that nocturnal peritoneal dialysis (NPD) also is effective in correcting sleep apnea in patients who receive continuous ambulatory PD (CAPD). Overnight polysomnography (PSG) was performed in 46 stable NPD and CAPD patients who were matched for demographic and clinical attributes. The prevalence of sleep apnea, defined as an apnea-hypopnea index (AHI; or frequency of apnea and hypopnea per hour of sleep) > or =15, was 52% for NPD patients and 91% for CAPD patients (P = 0.007). The mean (+/-SD) AHI in NPD and CAPD patients was 31.6 +/- 25.6 and 50.9 +/- 26.4 (P = 0.025), respectively. For validation of the efficacy of NPD in alleviating sleep apnea, a fixed sequence intervention study was performed in which 24 incident PD patients underwent one PSG study during mandatory cycler-assisted NPD while awaiting their turn for CAPD training and a second PSG recording shortly after they were established on stable CAPD. The prevalence of sleep apnea was 4.2% during NPD and 33.3% during CAPD (P = 0.016). AHI increased from 3.4 +/- 1.34 during NPD to 14.0 +/- 3.46 during CAPD (P < 0.001). With the use of bioelectrical impedance analysis, total body water content was significantly lower during stable NPD than CAPD (32.8 +/- 7.37 versus 35.1 +/- 7.35 L; P = 0.004). NPD delivered greater reductions in total body water (-2.81 +/- 0.45 versus -1.34 +/- 0.3 L; P = 0.015) and hydration fraction (-3.63 +/- 0.64 versus -0.71 +/- 0.52%; P = 0.005) during sleep. Pulmonary function tests remained unchanged before and after conversion from NPD to CAPD. These findings suggest that NPD may have a therapeutic edge over CAPD in sleep apnea that is associated with renal failure as a result of better fluid clearance during sleep.     

Disproportionally low clearance of macromolecules from the plasma to the peritoneal cavity in a mouse model of peritoneal dialysis.

BACKGROUND: This study was performed to establish a model for quantitative measurements of a number of basic peritoneal transport parameters, particularly transperitoneal clearances (Cl) of macromolecules, during mouse peritoneal dialysis. METHODS: Mice were anaesthetized using 3% isofluorane inhalation anaesthesia. The right jugular vein and the left femoral artery were cannulated for infusion and sampling purposes and for registration of (mean) arterial blood pressure. Access to the peritoneal cavity occurred via a thin abdominal catheter (? 0.7 mm). About 2.5 ml of either 4% (n = 9) or 1.5% (n = 5) glucose containing PD-fluid were instilled intraperitoneally (i.p.). Dialysate volume was followed vs time using i.p. RISA ((125)I human serum albumin) as a volume marker, after correcting for RISA mass disappearance from the peritoneum, assessed separately (n = 11). Microsampling (10 microl) of plasma and dialysate was performed for determinations of glucose, haematocrit, radioactivity (RISA and (51)Cr-EDTA) and Ficoll. RESULTS: The i.p. volume vs time curves [V(D)(t)] were, after scaling, similar to those observed in humans (and in rats). Clearance of RISA out of the peritoneal cavity (Cl(out)) was 9.33 +/- 0.83 microl/min and the clearance of RISA to plasma (Cl-->P) and the RISA clearance to the peritoneal cavity (Cl-->D) were 1.49 +/- 0.13 and 0.084 +/- 0.008 microl/min, respectively. The peritoneal transport coefficients for (51)Cr-EDTA and glucose, as well as Cl(out) and Cl-->P, were 13-17% of those previously assessed in 300 g rats, whereas Cl-->D was only approximately 2% of that in rat. CONCLUSIONS: All peritoneal transport parameters measured, except Cl-->D, scaled very well to the corresponding human data. The mechanisms of the disproportionally low clearance of macromolecules from the plasma to the peritoneal cavity in mice remain elusive and warrant further study.     

Multidirectional approach to study peritoneal dialysis fluid biocompatibility in a chronic peritoneal dialysis model in the rat.

BACKGROUND: Peritoneal dialysis causes the functional and morphological changes in the peritoneum that result from the bioincompatibility of dialysis solutions. We present a model of chronic peritoneal dialysis in the rat that can be used for testing the biocompatibility of dialysis fluids. Methods and Results. Long-term exposure of the peritoneum to dialysis solutions can be performed in rats with implanted peritoneal catheters. Sampling of the dialysate allows the evaluation of intraperitoneal inflammation by examining cell differential and dialysate cytokine levels. Peritoneal permeability can be evaluated at designed time intervals with the peritoneal equilibration test (PET). At the end of dialysis, peritoneal histology is studied with light and electron microscopy. CONCLUSIONS: Such a multidirectional approach is an effective way to test biocompatibility of dialysis solutions.     

丙酮酸盐腹膜透析液对酸碱平衡、电解质代谢、腹腔巨噬细胞功能及腹膜间皮的影响

目的：观察丙酮酸盐腹膜透析液对尿毒症大鼠代谢性酸中毒、电解质代谢、腹膜巨噬细胞功能及腹膜间皮的影响,并与乳酸盐腹膜透析液比较。方法：分两期对大鼠行5／6肾切除,3个月后分别用丙酮酸盐腹膜透析液（PBPDF）、乳酸盐腹膜透析液（LBPDF）及含相同葡萄糖浓度的平衡盐水（GNS）进行腹腔内注射,4h后引流、分离透出液中的巨噬细胞进行孵育,测定用LPS刺激后细胞超氧阴离子及肿瘤坏死因子α（TNF-α）的产量。首次透前及透析5周后做动脉血气分析及血清生化检查,并在光镜及电镜下观察腹膜间皮形态。结果：透析5周后PBPDF组大鼠动脉血pH、HCO3^-浓度、腹膜巨噬细胞超氧阴离子及TNF－α的产量均高于LBPDF组,并且腹膜间皮损伤也较轻,而两组血清K^ 、Na^ 、Cl^ 水平差异无显著性意义。结论：丙酮酸盐腹膜透析液较乳酸盐腹膜透析液能更有效地纠正尿毒症大鼠的代谢性酸中毒,对腹膜巨噬细胞的抑制作用较轻,也能更好地维持腹膜间皮的完整性。     

IgG2 deficiency in uremic children is not restricted to peritoneal dialysis treatment

  To date there are no data concerning IgG subclasses in children with preterminal chronic renal failure (CRF), although a reduction of total serum IgG, including its major subclasses IgG1 and IgG2, has been demonstrated in patients on peritoneal dialysis (PD). Therefore we studied total IgG, IgA, IgM, and IgG subclasses in preterminal CRF (n = 25), PD (n = 22) patients, and 13 age-matched healthy children and also compared results with age-related normal values previously established in 226 healthy children. While total IgG, IgA, IgM, and IgG 1 were comparable, there was a significant deficiency of IgG2 in children both with preterminal CRF and on PD compared with controls. Moreover, the prevalence of IgG2 deficiency compared with age-related normal values was significantly increased not only in PD but also in preterminal CRF patients. We conclude that there are alterations in serum IgG subclasses in children with CRF, with IgG2 deficiency not restricted to PD, but being present in the preterminal state as well. Received November 6, 1996; received in revised form March 25, 1997; accepted March 31, 1997     

Improved patient/technique survival and peritonitis rates in patients treated with automated peritoneal dialysis when compared to continuous ambulatory peritoneal dialysis in a Mexican PD center

Since its introduction in Mexico in 1998, the use of automated peritoneal dialysis (APD) has grown steadily and now 35% of Mexican patients are being treated with it. Peritonitis continues to be the most important infectious cause of drop out in peritoneal dialysis (PD) programs and naturally has an impact on technique survival. The objective of this study was to compare patient and technical survival as well as peritonitis rates in APD vs continuous ambulatory peritoneal dialysis (CAPD) in our hospital PD program. We included all patients who initiated therapy between January 2003 and December 2005. Data at the beginning of therapy, causes of end-stage renal disease, gender, age, dialysis modality, drop out reasons, as well as peritonitis rate and date of presentation of first peritonitis event were collected and analyzed. For Kaplan-Meier survival analysis, patient status (alive, dead, or lost to follow up) at December 2005 was used as the observational end point. Modality differences were analyzed using a Cox regression model. A total of 237 patients were evaluated: 139 on CAPD and 98 on APD. The median age was 62 years on CAPD and 59 years on APD (P<0.031), and the percentage of diabetics was, respectively, 77 and 70% (P=NS). The CAPD drop out causes were death (57%), transfer to HD (29%), and other causes (16%), whereas in APD, 62% were due to death, 24% to transfer to HD, and 14% to other causes. APD/CAPD patient survival for year 1, 2, and 3 was 82/62, 62/49, and 56/42%, respectively. In conclusion, both therapies are considered good renal replacement therapy options in our hospital, but APD is the most attractive one as demonstrated by the positive results presented here.     

Improvement of peritoneal calcification after parathyroidectomy in a peritoneal dialysis patient

Peritoneal calcification is one of the complications of peritoneal dialysis (PD). It can become serious, leading to severe abdominal pain and even death. Possible mediators of peritoneal calcification in PD patients are assumed to include acetate buffer, overdosage of vitamin D, repeated peritonitis, hypertonic dialysate, calciphylaxis and secondary hyperparathyroidism (SHPT). However, the mechanism and treatment of peritoneal calcification are controversial. Few reports have appeared on improvement of peritoneal calcification after parathyroidectomy (PTX) for SHPT of long duration. We report herein the case of a 48-year-old man on dialysis for 17 years including PD for 14 years. In 1989, he was admitted to hospital because of end-stage renal disease (ESRD), and started treatment with PD. Abdominal computed tomography (CT) first showed peritoneal calcification in August 2002. Peritoneal calcification did not improve despite conventional treatment including discontinuation of PD, control of calcium phosphate product to less than 55 mg2/dl2, removal of the peritoneal catheter and empirical prednisolone (PSL) usage. The intact parathyroid hormone (i-PTH) level was increased over 1,000 pg/ml and extra-osseous calcification occurred. Total PTX was performed in November 2004. Postoperatively, the i-PTH level decreased immediately and calcium phosphate product was maintained in the reference range. Abdominal CT after PTX showed improvement of peritoneal calcification in September 2005. It appeared that PTX could be used to treat patients with persistent peritoneal calcification not responding to conventional treatment. It was postulated that SHPT might play a crucial role in accelerating peritoneal calcification in PD patients.     

Early peritoneal macrophage function after laparoscopic surgery compared with laparotomy in a mouse mode

Background The authors previously demonstrated postoperative preservation of the immune function measured by delayed-type skin reaction and tumor growth after laparoscopic surgery, as compared with laparotomy. For further elucidation of the origin of the demonstrated immune preservation, peritoneal macrophage (PMo) function was investigated 1 h after different surgical procedures. Methods Female NMRI mice were divided into five groups: anesthesia only, abdominal skin incision, laparotomy, peritoneal carbon dioxide (CO₂) insufflation, and peritoneal air insufflation. Escherichia Coli phagocytosis, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin-10 (IL-10) release of isolated PMo were investigated. Results All invasive interventions reduced the PMo phagocytosis by factors of approximately 2 to 4.7, as compared with the sham control group. Spontaneous ex vivo TNF-α release was significantly increased whenever the abdominal cavity was exposed to ambient air. The macrophage’s ability to release TNF-α after E. coli exposure was diminished in the abdominal air exposure groups, as compared with the CO₂ insufflation group. Conclusion Reduced phagocytosis 1 h after surgical interventions suggests a contribution of PMo to the altered immune function. When exposed to CO₂, PMo show a decreased basal TNF-α release. However, PMo also show an increased TNF-α release after a second immune stimulation (E. coli), suggesting a greater competency of interaction in an immune defense reaction after CO₂ exposure. Both authors contributed equally to the work. An erratum to this article is available at .