Peritoneal Equilibration Test Research Articles

Possible role of IL-6 and TIE2 gene polymorphisms in predicting the initial high transport status in patients with peritoneal dialysis: an observational study

ObjectivesThe aim of this study was to investigate the effect of interleukin (IL)-6 and TIE2 gene polymorphisms on baseline peritoneal transport property.DesignAn observational study.SettingRenji Hospital in Shanghai, China.ParticipantsThis study included...

A New Method to Increase Ultrafiltration in Peritoneal Dialysis: Steady Concentration Peritoneal Dialysis.

♦ Peritoneal dialysis (PD) has limited power for liquid extraction (ultrafiltration), so fluid overload remains a major cause of treatment failure. ♦ We present steady concentration peritonal dialysis (SCPD), which increases ultrafiltration of PD exchanges by maintaining a constant peritoneal glucose concentration. This is achieved by infusing 50% glucose solution at a constant rate (typically 40 mL/h) during the 4-hour dwell of a 2-L 1.36% glucose exchange. We treated 21 fluid overload episodes on 6 PD patients with high or average-high peritoneal transport characteristics who refused hemodialysis as an alternative. Each treatment consisted of a single session with 1 to 4 SCPD exchanges (as needed). ♦ Ultrafiltration averaged 653 ± 363 mL/4 h - twice the ultrafiltration of the peritoneal equilibration test (PET) (300 ± 251 mL/4 h, p < 0.001) and 6-fold the daily ultrafiltration (100 ± 123 mL/4 h, p < 0.001). Serum and peritoneal glucose stability and dialysis efficacy were excellent (glycemia 126 ± 25 mg/dL, peritoneal glucose 1,830 ± 365 mg/dL, D/P creatinine 0.77 ± 0.08). The treatment reversed all episodes of fluid overload, avoiding transfer to hemodialysis. Ultrafiltration was proportional to fluid overload (p < 0.01) and inversely proportional to final peritoneal glucose concentration (p < 0.05). ♦ This preliminary clinical experience confirms the potential of SCPD to safely and effectively increase ultrafiltration of PD exchanges. It also shows peritoneal transport in a new dynamic context, enhancing the influence of factors unrelated to the osmotic gradient.

Center-Specific Factors Associated with Peritonitis Risk-A Multi-Center Registry Analysis.

♦ Previous studies have reported significant variation in peritonitis rates across dialysis centers. Limited evidence is available to explain this variability. The aim of this study was to assess center-level predictors of peritonitis and their relationship with peritonitis rate variations. ♦ All incident peritoneal dialysis (PD) patients treated in Australia between October 2003 and December 2013 were included. Data were accessed through the Australia and New Zealand Dialysis and Transplant Registry. The primary outcome was peritonitis rate, evaluated in a mixed effects negative binomial regression model. Peritonitis-free survival was assessed as a secondary outcome in a Cox proportional hazards model. ♦ Overall, 8,711 incident PD patients from 51 dialysis centers were included in the study. Center-level predictors of lower peritonitis rates included smaller center size, high proportion of PD, low peritoneal equilibration test use at PD start, and low proportion of hospitalization for peritonitis. In contrast, a low proportion of automated PD exposure, high icodextrin exposure and low or high use of antifungal prophylaxis at the time of peritonitis were associated with a higher peritonitis rate. Similar results were obtained for peritonitis-free survival. Overall, accounting for center-level characteristics appreciably decreased peritonitis variability among dialysis centers (p = 0.02). ♦ This study identified specific center-level characteristics associated with the variation in peritonitis risk. Whether these factors are directly related to peritonitis risk or surrogate markers for other center characteristics is uncertain and should be validated in further studies.

Pancreatic lipase activity in overnight effluent predicts high transport status in peritoneal dialysis patients

BackgroundLong-term peritoneal dialysis (PD) causes peritoneal morphological and functional changes, resulting in high transport status featuring increased peritoneal permeability. High transport status is diagnosed by peritoneal equilibration test (PET), a reliable but time-consuming method. We identifed a reliable biomarker in peritoneal effluent to predict high transport status in PD patients. MethodsWe collected peritoneal effluent and serum from 33 PD patients and measured common laboratory test parameters. High transport status was determined by PET if the dialysate/plasma ratio of creatinine at 4h dwell (D/P Cr 4h) was ≥0.81. ResultsThere were significant correlations between D/P Cr 4h and some laboratory parameters in overnight effluent (pancreatic lipase activity, r=0.65, p<0.001; β2-microglobulin concentration, r=0.59, p<0.001; IL-6 concentration, r=0.53, p<0.001; and CA125 concentration, r=0.29, p=0.027). In a multivariate logistic regression analysis, the pancreatic lipase activity in overnight effluent was identified as an independent predictor of high transport status even after adjusting for age, PD duration, and glomerular filtration rate [OR=1.43 (95% CI: 1.11–1.83), p=0.005]. ConclusionsThe pancreatic lipase activity in overnight effluent is an independent predictor of high transport status in PD patients.

High mobility group box 1 and tumor growth factor β: useful biomarkers in pediatric patients receiving peritoneal dialysis

Background: Peritonitis, the most important limitation of peritoneal dialysis (PD), could be detected by biomarkers in dialysate effluent, representing a noninvasive method to indirectly assess the peritoneum status. The aim of our study was to test high mobility group box 1 (HMGB1) in PD patients, evaluating its role as precocious marker of peritoneum damage during peritonitis. Transforming growth factor (TGF)-β was correlated with peritoneal transport characteristics.Methods: Six patients, treated by ambulatory PD, were enrolled. Samples were collected at the onset of peritonitis (T1) and every day until its resolution (T-end). Serum (s) and peritoneal (p) white blood cell (WBC) count was also evaluated. Peritoneal Equilibration Test evaluated the filter activity of peritoneum.Results: In patients with acute peritonitis, the highest serum and peritoneal HMGB1 values (64 ± 3.6 and 70 ± 5.3 ng/mL, respectively) were assessed, with a progressive decrease of their levels at the resolution time (T-end: sHMGB1:36 ± 2.5; pHMGB1:30.5 ± 7.0 ng/mL). While no differences of sWBC and pWBC were observed between baseline and T-end values, pHMGB1 levels remained higher at T-end than those observed at T0 (pHMGB1:30.5 ± 7.0 versus 6.9 ± 3.6; p < 0.0001). TGF-β levels were higher in patients with low peritoneal permeability than in medium or high transporter patients (81 ± 15.5 versus 24.3 ± 7.5 pg/mL; p = 0.01). An inverse correlation was found between TGF-β levels and dialysate/plasmatic creatinine values (r = −0.83; p = 0.03).Conclusion: HMGB1 represents a useful biomarker for peritoneum evaluation in PD patients. A prognostic role of this alarmin, as a marker of response to therapy, could be hypothesized. TGF-β could predict the peritoneal transport status and dialysis technique adequacy.

Analysis of Ultrafiltration Failure Diagnosed at the Initiation of Peritoneal Dialysis with the Help of Peritoneal Equilibration Tests with Complete Drainage at Sixty Minutes. A Longitudinal Study.

♦ Ultrafiltration failure (UFF) diagnosed at the initiation of peritoneal dialysis (PD) has been insufficiently characterized. In particular, few longitudinal studies have analyzed the time course of water transport in patients with this complication. ♦ To investigate the time course of peritoneal water transport during the first year on PD in patients presenting UFF since the initiation of this therapy (study group). ♦ Prospective, observational, single-center design. We analyzed, at baseline and after 1 year of follow-up, peritoneal water transport in 19 patients incident on PD with UFF. We used incident patients without UFF as a control group. Water transport was characterized with the help of 3.86/4.25% dextrose-based peritoneal equilibration tests (PETs) with complete drainage at 60 minutes. ♦ The study group revealed a disorder of water transport affecting both small-pore ultrafiltration (SPUF) (p = 0.054 vs incident without UFF) and free water transport (FWT) (p = 0.001). After 1 year of follow-up, FWT displayed a general increasing trend in the study group (mean variation 48.9 mL, 95% confidence interval [CI] 15.5, 82.2, p = 0.012), while the behavior of SPUF was less predictable (-4.8 mL, 95% CI -61.4, 71.1, p = 0.85). These changes were not observed in incident patients without UFF. Neither initial clinical characteristics, baseline PET-derived parameters, or suffering peritoneal infections during the first year predicted the time course of the capacity of UF in the study group. Recovery from incident UFF was apparently linked to improvement of SPUF. ♦ Patients with UFF at the start of PD suffer a disorder of peritoneal water transport affecting both FWT and SPUF. Free water transport increases systematically in these patients after 1 year of follow-up. The evolution of SPUF is less predictable, and improvement of this parameter marks reversibility of this complication.

Peritonitis before Peritoneal Dialysis Training: Analysis of Causative Organisms, Clinical Outcomes, Risk Factors, and Long-Term Consequences.

Peritonitis before peritoneal dialysis (PD) training (pretraining peritonitis [PTP]) is an uncommon event. The study aim was to examine the causative organisms, clinical outcomes, risk factors, and long-term consequences of PTP. In this single-center, retrospective, observational study involving all incident patients on PD who developed PTP between 1998 and 2012, we examined the causative organisms, primary response rate, complete cure rate, risk factors, and associations of PTP with peritoneal equilibration test (PET) and patient survival. For each patient in the PTP group, the patients who underwent catheter insertion immediately before and after the index case were identified as controls. Among 1252 incident patients on PD, 52 (4.2%) patients developed PTP, and 104 patients were identified as controls. The two groups were similar in age, sex distribution, comorbidities, and residual renal function, but the PTP group had significantly lower hemoglobin and serum albumin. Patients were followed up for a median of 37.5 months (interquartile range [IQR], 16.3-62.2 months). The most common causative organisms of PTP were Staphylococcus aureus (30.8%) and polymicrobial (21.2%); 25% had negative growth. The primary response and complete cure rates were 82.7% and 78.8%, respectively. In the PTP group, 7.7% of patients died, 9.6% of patients required catheter removal, and PD training was significantly delayed (median =42.0; IQR, 26.0-65.8 days versus 27.5; IQR, 23.0-35.0 days; P=0.01). Multivariate logistic regression analysis showed that serum albumin was the only predictor of PTP (adjusted odds ratio, 0.89 per 1-g/dl increase; 95% confidence interval, 0.82 to 0.97). There were no differences in PET results and dialysis adequacy (measured around 1 month after PD training). The PTP group had significantly worse patient survival (median =41.2; IQR, 21.8-60.5 months versus 55.8; IQR, 40.4-71.2 months; P=0.02). Technique failure occurred in 11.5% and 10.6% of patients in the PTP and control groups, respectively. S. aureus is the most common causative organism of PTP. Nutritional interventions in patients who are hypoalbuminemic before catheter insertion deserve additional study.

High glucose dialysate enhances peritoneal fibrosis through upregulating glucose transporters GLUT1 and SGLT1

Objective: To investigate the role of glucose transporter 1 (GLUT1) and sodium-glucose cotransporter 1 (SGLT1) in high glucose dialysate-induced peritoneal fibrosis. Methods: Thirty six male SD rats were randomly divided into 6 groups (6 in each):normal control group, sham operation group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorizin group (PD+Z group), PD+phloretin+phlorizin group (PD+T+Z group). Rat model of uraemia was established using 5/6 nephrotomy, and 2.5% dextrose peritoneal dialysis solution was used in peritoneal dialysis. Peritoneal equilibration test was performed 24 h after dialysis to evaluate transport function of peritoneum in rats; HE staining was used to observe the morphology of peritoneal tissue; and immunohistochemistry was used to detect the expression of GLUT1, SGLT1, TGF-β1 and connective tissue growth factor (CTGF) in peritoneum. Human peritoneal microvascular endothelial cells (HPECs) were divided into 5 groups:normal control group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorezin group (PD+Z group), and PD+phloretin+phlorezin group (PD+T+Z group). Real time PCR and Western blotting were used to detect mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF in peritoneal membrane and HPECs. Results:In vivo, compared with sham operation group, rats in PD group had thickened peritoneum, higher ultrafiltration volume, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly increased (all P<0.05); compared with PD group, thickened peritoneum was attenuated, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly decreased in PD+T, PD+Z and PD+T+Z groups (all P<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in peritoneum were positively correlated with the expressions of TGF-β1 and CTGF (all P<0.05). In vitro, the mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF were significantly increased in HPECs of peritoneal dialysis group (all P<0.05), and those in PD+T, PD+Z, and PD+T+Z groups were decreased (all P<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in HPECs were positively correlated with the expressions of TGF-β1 and CTGF (all P<0.05). Conclusion: High glucose peritoneal dialysis fluid may promote peritoneal fibrosis by upregulating the expressions of GLUT1 and SGLT1.

Elimination of NTproBNP in peritoneal dialysis patients. Does peritoneal membrane type make a difference in plasma level and elimination of NTproBNP?

Brain natriuretic peptide and its derivative peptide NTproBNP are utilized to exclude cardiac diseases, and predicting risk of mortality in dialysis patients. Our aim was to evaluate both elimination of NTproBNP through dialysate and a possible relationship between plasma and/or dialysate NTproBNP level and membrane transport status of peritoneal dialysis patients. 57 plasma (P) and dialysate (D) samples of 44 peritoneal dialysis (PD) patients were analyzed for NTproBNP. Modified peritoneal equilibration test (PET) results and other variables were obtained from the charts. Median (IQR) NTproBNP concentrations (pg/mL × 1,000) in P and D were 3.3 (1 - 13) and 0.5 (0.2 - 3.6), respectively. There was a linear correlation between P-NTproBNP and D-NTproBNP (r = 0.928, p = 0.0001; regression equation was y = 0.897*x -0.28). Mean P/D-NTproBNP ratio was 5.5 ± 0.5. Median P and D-NTproBNP levels by the membrane transport status were aligned as high (H) > high average (HA) > low average (LA), and the difference between H and LA was statistically significant (p < 0.001). Mean arterial pressure (MAP), residual Kt/V and dialysate/plasma ratio of crearinine (D/P Cr) were significant predictors of D-NTproBNP; whereas only MAP and residual Kt/V were significant predictors of P-NTproBNP in multiple regression analysis. Both P- and D-NTproBNP have significant and similar size of correlations with MAP, albumin, D/P Cr ratio, and Na. D-NTproBNP level is ~ 1/5 of P-NTproBNP, and the issue of relationship between membrane transport status and natriuretic peptide levels needs more work.

Clinical efficacy of combined therapy with peritoneal dialysis and hemodialysis

Combined therapy with peritoneal dialysis (PD) and hemodialysis (HD) represents a treatment option for PD patients who cannot maintain adequate solute and fluid removal. It has rapidly gained popularity in Japan, and 15 years of accumulated experiences is available. Serum creatinine, serum β2 microglobulin (β2m), body weight, and blood pressure decreased, whereas hemoglobin increased after initiating combined therapy. These results indicated that both adequacy of dialysis and hydration status were significantly improved. In addition, dialysate-to-plasma ratio of creatinine (D/P Cr) as obtained from peritoneal equilibration test (PET) was decreased, probably due to the functional and histological improvements of the peritoneal membrane. Combined therapy may have a good impact on the prevention of cardiovascular disease through reduction of blood pressure, correction of fluid overload, and improvement of left ventricular hypertrophy. Quality of life may improve as a result of decreases in uremic symptomatology and freedom from bag exchanges. On the other hand, combined therapy with PD and HD has some concerns. A reduction in urine volume during combined therapy indicates a decline in residual renal function, and may have potential negative impacts on life expectancy. Furthermore, induction of combined therapy would increase the overall duration of PD treatment and susceptibility to peritonitis. We have to pay attention to the development of encapsulating peritoneal sclerosis, as the most serious complication of PD, because both prolonged PD duration and increased number of peritonitis episodes are independent risk factors. Here, we propose criteria for the indication and discontinuation of combined therapy. Under these criteria, Kt/V, serum β2m, and uremic symptoms including nutritional status, erythropoiesis-stimulating agent-hyporesponsive anemia, and restless legs syndrome were used as markers of dialysis adequacy. On the other hand, higher blood pressure, heart enlargement or pleural effusion on chest X-ray, and persistent peripheral edema were used as markers of hydration status. Further studies, particularly prospective cohort studies with a large group of cases, are needed to confirm the clinical efficacy of combined therapy with PD and HD.

Peritoneal inflammation precedes encapsulating peritoneal sclerosis: results from the GLOBAL Fluid Study.

Encapsulating peritoneal sclerosis (EPS) is an uncommon condition, strongly associated with a long duration of peritoneal dialysis (PD), which is itself associated with increased fibrosis in the peritoneal membrane. The peritoneal membrane is inflamed during PD and inflammation is often associated with fibrosis. We hypothesized that patients who subsequently develop EPS might have a more inflamed peritoneal membrane during PD. We performed a nested, case-control study identifying all EPS cases in the UK arm of the GLOBAL Fluid Study and matching them by centre and duration of PD with two to three controls. Dialysate and plasma samples were taken during repeated peritoneal equilibration tests prior to cessation of PD from cases and controls. Samples were assayed by electrochemiluminescence immunoassay for interleukin-1β (IL-1β), tumour necrosis factor α (TNF-α), interferon-γ (IFN-γ) and IL-6. Results were analysed by linear mixed models adjusted for age and time on PD. Eleven EPS cases were matched with 26 controls. Dialysate TNF-α {0.64 [95% confidence interval (CI) 0.23, 1.05]} and IL-6 [0.79 (95% CI 0.03, 1.56)] were significantly higher in EPS cases, while IL-1β [1.06 (95% CI -0.11, 2.23)] and IFN-γ [0.62 (95% CI -0.06, 1.29)] showed a similar trend. Only IL-6 was significantly higher in the plasma [0.42 (95% CI 0.07, 0.78)]. Solute transport was not significantly different between cases and controls but did increase in both groups with the duration of PD. The peritoneal cavity has higher levels of inflammatory cytokines during PD in patients who subsequently develop EPS, but neither inflammatory cytokines nor peritoneal solute transport clearly discriminates EPS cases. Increased systemic inflammation is also evident and is probably driven by increased peritoneal inflammation.

Assessment of satisfaction in peritoneal equilibration test: a study on the validity and reliability of the peritoneal equilibration satisfaction scale

Aim: This study has been designed to develop an assessment tool to be used in determining the patients’ satisfaction level with the peritoneal equilibration test (PET) procedure. Materials and Methods: The development and validation of the peritoneal equilibration test Satisfaction Scale (PETSS) was completed in two phases. Phase I focused on instrument construction and included item development and establishment of concurrent validity. Phase II included the factor analysis and psychometric assessment of the scale. In statistical evaluation of the data descriptive statistics and non-paratmetric tests were used. Results: The first version of the scale that has 3.62 Content Validity Index value was composed of 20 items. It was found that the latest version of the scale that has 14 items explained 46% of the variance. It was found that the Cronbach alfa value of this scale, which has 0.52-0.89 coefficient of item-total correlation was 0.96. Psychometric assessment of the scale revealed that except for type of the PET application, none of the demographic and clinical characteristics effect patients level of satisfaction during the PET application. Conclusion: This preliminary study showed that PETSS was a valid and reliable scale that can be used for determining satisfaction level of patients during PET application.

Serum Cystatin C Does Not Predict Mortality or Treatment Failure in Peritoneal Dialysis: A Prospective Study.

♦ Small solute clearance, especially that derived from residual renal function (RRF), is an independent risk factor for death in peritoneal dialysis (PD) patients. Assessment of solute clearance is time-consuming and prone to multiple errors. Cystatin C is a small protein which has been used as a glomerular filtration rate (GFR) marker. We investigated whether serum cystatin C concentrations are related to mortality in patients receiving PD. ♦ New and prevalent PD patients (n = 235) underwent assessment of Kt/Vurea, RRF, weekly creatinine clearance (CCr), normalized protein catabolic rate (nPCR) and a peritoneal equilibration test (PET) at intervals. Blood was collected simultaneously for cystatin C measurement. Patients were followed for a median of 1,429 days (range 12 to 2,964 days) until death or study closure. Cause of death was recorded where given. Cox regression was performed to determine whether cystatin C had prognostic value either independently or with adjustment for other factors (age, sex, dialysis modality, diabetic status, cardiovascular comorbidity, Kt/V, CCr, RRF, nPCR or 4 h dialysate to plasma creatinine ratio (4 h D/Pcr) during the PET). The primary outcomes were all-cause mortality and treatment failure. ♦ There were 93 deaths. Increasing age and 4 h D/Pcr ratio, decreased RRF and presence of diabetes were significantly [p < 0.05] negatively associated with survival and treatment failure. Serum cystatin C was not related to either outcome. ♦ Serum cystatin C concentration does not predict mortality or treatment failure in patients receiving PD.

Matrix metalloproteinase-2 as a superior biomarker for peritoneal deterioration in peritoneal dialysis

To investigate the efficacy of effluent biomarkers for peritoneal deterioration with functional decline in peritoneal dialysis (PD). From January 2005 to March 2013, the subjects included 218 PD patients with end-stage renal disease at 18 centers. Matrix metalloproteinase-2 (MMP-2), interleukin-6 (IL-6), hyaluronan, and cancer antigen 125 (CA125) in peritoneal effluent were quantified with enzyme-linked immunosorbent assay. Peritoneal solute transport rate was assessed by peritoneal equilibration test (PET) to estimate peritoneal deterioration. The ratio of the effluent level of creatinine (Cr) obtained 4 h after injection (D) to that of plasma was correlated with the effluent levels of MMP-2 (ρ = 0.74, P < 0.001), IL-6 (ρ = 0.46, P < 0.001), and hyaluronan (ρ = 0.27, P < 0.001), but not CA125 (ρ = 0.13, P = 0.051). The area under receiver operating characteristic curve for the effluent levels of MMP-2, IL-6, and hyaluronan against high PET category were 0.90, 0.78, 0.62, and 0.51, respectively. No patient developed new-onset encapsulating peritoneal sclerosis for at least 1.5 years after peritoneal effluent sampling. The effluent MMP-2 level most closely reflected peritoneal solute transport rate. MMP-2 can be a reliable indicator of peritoneal deterioration with functional decline.

Peritoneal Fluid Transport rather than Peritoneal Solute Transport Associates with Dialysis Vintage and Age of Peritoneal Dialysis Patients.

During peritoneal dialysis (PD), the peritoneal membrane undergoes ageing processes that affect its function. Here we analyzed associations of patient age and dialysis vintage with parameters of peritoneal transport of fluid and solutes, directly measured and estimated based on the pore model, for individual patients. Thirty-three patients (15 females; age 60 (21–87) years; median time on PD 19 (3–100) months) underwent sequential peritoneal equilibration test. Dialysis vintage and patient age did not correlate. Estimation of parameters of the two-pore model of peritoneal transport was performed. The estimated fluid transport parameters, including hydraulic permeability (LpS), fraction of ultrasmall pores (α u), osmotic conductance for glucose (OCG), and peritoneal absorption, were generally independent of solute transport parameters (diffusive mass transport parameters). Fluid transport parameters correlated whereas transport parameters for small solutes and proteins did not correlate with dialysis vintage and patient age. Although LpS and OCG were lower for older patients and those with long dialysis vintage, αu was higher. Thus, fluid transport parameters—rather than solute transport parameters—are linked to dialysis vintage and patient age and should therefore be included when monitoring processes linked to ageing of the peritoneal membrane.

Effect of Initial PET Status on Clinical Course in Peritoneal Dialysis Patients

Abstract Introduction. To investigate the effect on mortality of initial peritoneal equilibration test (PET) in PD patients (pts). Methods. We included patients who initiated therapy between 2001-2014. Patients underwent initial PET in the first three months. They were divided into four groups according to the initial PET (high, high-average, lowaverage, low transport). Sociodemographic data, clinical courses and infectious complications between groups were compared, and the reasons for PD withdrawal were obtained. Technique survival analyses of patients were done. Results. In a total of 367 pts were PD was started, 104 pts were excluded. Data of the remaining 263 patients were evaluated. Thirty-seven pts (23F, mean age 44.6±16.5 years, mean follow-up 30.5±20.8 months) had high transport, 90 pts (49F, mean age 41.5±16 years, mean followup 42.6±27.7 months) had high-average transport, 91 pts (55F, mean age 44.5±14.9 years, mean follow-up 50±29.2 months) had low-average transport and 45 pts (17F, mean age 43.5±14 years, mean follow-up (63.4±34.5 months) had low transport. There was no difference between groups in terms of age, gender, body mass index, initial daily urine and ultrafiltration volume, initial albumin levels, presence of diabetes mellitus (p&gt;0.05). Peritonitis and catheter exit-site/tunnel infection attacks were higher in patients with high transport (p=0.01 and 0.008, respectively). There was a difference between groups with respect to the last status of patients (p&lt; 0.009). The major causes of deaths were peritonitis and/or sepsis and cardiovascular causes in all patients. The mortality and technique survival rate was found higher in patients with high transport (log rank: 0.004 and 0.027, respectively). Age (OR:1.045, p&lt;0.001), initial albumin (OR: 0.482, p= 0.007), daily urine volume (OR: 1.045, p&lt;0.001) and presence of catheter exit-site/tunnel infection (OR: 0.249, p&lt;0.001) were found to predict patient survival. Only presence of catheter exit-site/tunnel infection (OR: 0.452, p=0.013) were found to predict patient survival. Conclusions. Initial PET has effects on PD patient survival; patients with high transport have the worst survival and frequent infectious complications.

Peritoneal dialysate effluent and serum CA125 concentrations in stable peritoneal dialysis patients.

CA125 in peritoneal dialysis (PD) effluent dialysate has been used as a surrogate biomarker for the health of the peritoneum in PD patients. However CA125 is synthesised by epithelial cells and as such is not specific for the peritoneum, and most studies have only measured peritoneal CA125, without serum CA125 values. As such we wished to determine the factors which influenced PD effluent CA125 in a large contemporaneous cohort. We measured dialysate effluent CA125 in PD patients attending for routine assessment of peritoneal membrane function with a peritoneal equilibration test (PET), with corresponding serum CA125. Serum and dialysate CA125 were measured in 205 PD patients; 59.0±16.8years, median PD treatment 3 (2-20) months, 59% male, 42.4% diabetic, with 31.2% treated by continuous ambulatory peritoneal dialysis, 22% by automated overnight peritoneal dialysis cycler (APD) and 46.8% by APD with a day time exchange. The median serum CA125 was 21 (13-38) U/ml, with an effluent 4h PD PET effluent of 20 (11.5-36.5) U/ml. PET PD effluent dialysate was associated with PET dialysate total protein (β 12.9, p<0.001), serum CA125 (β 0.109, p=0.002), residual renal function (β 0.53, p=0.018) and age (β 0.145, p=0.042) and negatively with the number of PD cycles/day (β -2.19, p=0.001). There was no association with prior peritonitis episodes. PD effluent CA125 concentrations were associated with peritoneal protein losses and increased by the usage of higher glucose dialysates to compensate for loss of residual renal function.

Risk factor(s) related to high membrane permeability in peritoneal dialysis

Aim: Peritoneal dialysis (PD) patients have different peritoneal membrane permeability (transport) characteristics. High peritoneal membrane permeability is associated with increased mortality risk in the patient population. In this study, we aimed to investigate possible risk factor(s) related to high peritoneal membrane permeability. Patients and method: The study included 475 PD patients (46.1 ± 14.5 years of mean age; 198 female and 277 male). The patients were divided two groups according to peritoneal equilibration test (PET) result: high-permeability group (high and high-average) and low- permeability group (low-average and low). Results: In both the univariate and multivariate logistic regression analyses, it was found that diabetes mellitus and hypoalbuminemia was significantly associated with high peritoneal membrane permeability [relative risk (RR): 1.90, 95% confidence interval (CI): 1.26–2.86, p: 0.002 and RR: 2.14, 95% CI: 1.44–3.18, p<0.001, respectively]. Conclusion: Diabetes mellitus and hypoalbuminemia were closely associated with high peritoneal membrane permeability. Diabetic patients had 1.9 times the likelihood of having high permeability. However, the relationship between hypoalbuminemia and high peritoneal permeability appears to be a result rather than cause.

MicroRNA expression profiling in peritoneal fibrosis.

Peritoneal fibrosis (PF) is an intractable complication leading to peritoneal membrane failure in peritoneal dialysis (PD). The aim of this study was to identify microRNAs (miRNAs) involved in PF. Peritoneal tissue from a PF rat model was screened for miRNA expression using microarray analysis. The expression levels of differentially expressed miRNAs were evaluated in serum and drained dialysate and associated with peritoneal membrane functions, as measured by the peritoneal equilibrium test in 33 PD patients. Furthermore, an miRNA inhibitor (anti-miRNA-21-5p locked nucleic acid (LNA): anti-miRNA-21-LNA) was intraperitoneally injected to PF model mice to investigate its effects on PF. The initial profiling study of PF rat peritoneal tissue identified 6 miRNAs (miRNA-142-3p, miRNA-21-5p, miRNA-221-3p, miRNA-223-3p, miRNA-34a-5p, and miRNA-327) whose expression was increased more than 2-fold and no miRNAs whose expression was decreased more than half. Among them, serum levels of miRNA-21-5p, miRNA-221-3p, and miRNA-327 and drained dialysate levels of miRNA-221-3p and miRNA-34a-5p were significantly correlated with peritoneal membrane functions in PD patients. Anti-miRNA-21-LNA significantly inhibited miRNA-21-5p expression in the PF mouse peritoneum, inhibited peritoneal fibrous thickening, and maintained peritoneal membrane functions. These results suggest that several miRNAs are involved in PF and that they may be useful as novel diagnostic biomarkers and therapeutic targets for PF.

Hydrogen Sulfide Alleviates Peritoneal Fibrosis via Attenuating Inflammation and TGF-β1 Synthesis

Background/Aims: Peritoneal fibrosis is one of the long-term complications in peritoneal dialysis (PD) patients. Recent evidences have suggested that hydrogen sulfide (H₂S) is beneficial in treating various fibrotic diseases, including pulmonary fibrosis, cirrhosis, kidney fibrosis and cardiac hypertrophy. However, no information is known about the effect of H₂S on peritoneal fibrosis. In the present study, we investigated the effect of H₂S on peritoneal fibrosis and explored its potential mechanisms. Methods: We developed a model of peritoneal fibrosis by intraperitoneally injecting 4.25%-glucose PD fluids and lipopolysaccharide to Sprague-Dawley rats. The rats received daily intraperitoneal injections of NaHS (56 μg/kg), an H₂S donor. After 28 days, the peritoneal equilibration test (PET) was used to assess peritoneal function. At the end of dialysis, the rats were killed and parietal peritoneum was harvested for microscopic examination and immunohistochemistry. Results: On the 28th day, the parietal peritoneum of the PD rats markedly thickened as a result of increased depositions of type III collagen and fibronectin. Moreover, the number of ED-1-positive cells and the expressions of monocyte chemoattractant protein-1, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin and CD31 were significantly increased in the fibrotic peritoneum. Administration of NaHS markedly decreased the biomarkers of inflammation, fibrosis and angiogenesis in the peritoneum. NaHS also improved peritoneal function assessed by PET. Conclusion: Exogenous H₂S ameliorates the pathologic process of peritonitis via attenuating inflammatory events and TGF-β1 synthesis. These results suggest that H₂S may be a potential therapy against peritoneal fibrosis during chronic PD. In the future, compounds releasing H₂S at controlled rate will be assessed as potential candidates to treat peritoneal fibrosis.