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Resumen Introduccion y objetivos La categorizacion de la capacidad de ultrafiltracion durante la prueba de equilibrio peritoneal (PEP) es parte habitual de la monitorizacion del funcionalismo peritoneal en pacientes tratados con dialisis peritoneal (DP). La estimacion del volumen residual (Vr) tras el cambio previo (Vrpre) y el de la propia PEP (Vrpost) podria ayudar a mejorar la precision de la prueba. Metodo Siguiendo un diseno prospectivo, estimamos el Vrpre y Vrpost en 116 pacientes incidentes o prevalentes en DP que fueron sometidos a una o dos (n = 27) PEP con solucion de glucosa al 3,86/4,25% y drenaje completo a los 60 minutos. Valoramos la consistencia del Vr comparando Vrpre y Vrpost y tambien estos parametros en PEP sucesivas. Analizamos la posible influencia de factores demograficos y clinicos en la cuantia del Vr, asi como el impacto de la correccion para Vr de la ultrafiltracion durante la PEP sobre la categorizacion de la capacidad de ultrafiltracion. Resultados El Vrpost fue mayor que el Vrpre, por lo que la ultrafiltracion corregida para Vr fue signficativamente mayor que la calculada por procedimiento estandar (494 vs. 449 mL, p 200 mL) de la ultrafiltracion corregida para Vr frente al valor estandar. Sin embargo, un 21,1% de los pacientes que cumplian criterio de fallo de ultrafiltracion por metodo estandar, no lo hacian si se aplicaba la correccion para Vr. Conclusiones La correccion para Vr modifica escasamente, como media, la estimacion de la capacidad de ultrafiltracion durante la PEP al 3,86/4,25%, aunque tiene un impacto significativo en 12,9% de las pruebas. No hemos detectado factores predictivos del Vr durante la PEP, lo que sugiere un componente de aleatoriedad en la mecanica del cambio peritoneal. Sugerimos que este parametro debe ser estimado si se observan inconsistencias en los resultados de la PEP en lo relativo a la capacidad de ultrafiltracion.

[Abstract] Preservation of the peritoneal membrane is an essential determinant of the long-term outcome of peritoneal dialysis (PD). Epithelial-to-mesenchymal transition (EMT) plays a central role in the pathogenesis of PD-related peritoneal membrane injury. We hypothesized that mitochondria may be implicated in the mechanisms that initiate and sustain peritoneal membrane damage in this setting. Hence, we carried out ex vivo studies of effluent-derived human mesothelial cells, which disclosed a significant increase in mitochondrial reactive oxygen species (mtROS) production and a loss of mitochondrial membrane potential in mesothelial cells with a fibroblast phenotype, compared to those preserving an epithelial morphology. In addition, in vitro studies of omentum-derived mesothelial cells identified mtROS as mediators of the EMT process as mitoTEMPO, a selective mtROS scavenger, reduced fibronectin protein expression induced by TGF-ß1. Moreover, we quantified mitochondrial DNA (mtDNA) levels in the supernatant of effluent PD solutions, disclosing a direct correlation with small solute transport characteristics (as estimated from the ratio dialysate/plasma of creatinine at 240 min), and an inverse correlation with peritoneal ultrafiltration. These results suggest that mitochondria are involved in the EMT that human peritoneal mesothelial cells suffer in the course of PD therapy. The level of mtDNA in the effluent dialysate of PD patients could perform as a biomarker of PD-induced damage to the peritoneal membrane. Instituto de Salud Carlos III; PI15/02218 Instituto de Salud Carlos III; PI18/01803 Instituto de Salud Carlos III; AGRUP2015/05 Instituto de Salud Carlos III; AGRUP2018/03

Introduction: Prior abdominal surgery may result in peritoneal membrane adhesions and fibrosis, compromising the success of peritoneal dialysis (PD). The impact of this factor on peritoneal membrane function and PD technique survival has not been adequately investigated. Methods: Following an observational, retrospective design, we studied 171 incident PD patients, with the main objective of analyzing the influence of prior abdominal surgical procedures (main study variable) on baseline and evolutionary peritoneal transport characteristics (main outcome) and PD patient and technique survival (secondary outcomes). Abdominal surgeries were categorized according to the degree of presumed injury to the peritoneal membrane. We also considered the additive effect of aggressions to the membrane during the first year on PD therapy. Results: All patients had a baseline peritoneal equilibration test with complete drainage at 60′, and 113 patients had a second study at the end of the first year. Sixty-one patients (35.7%) had a record of prior abdominal surgery, including 29 patients with at least one major intraperitoneal surgery, 22 having undergone minor intraperitoneal procedures, and 21 with a background of major abdominopelvic extraperitoneal surgery. We did not observe differences, at baseline or after 1 year, among patients with or without previous abdominal procedures regarding small solute transport, overall capacity of ultrafiltration, free water transport, small pore ultrafiltration, or peritoneal protein excretion. Stratified analysis, considering prior and first-year-on-PD peritoneal aggressions, did not reveal any differences, although in this case our analysis was hampered by a limited statistical power. Abdominal surgical events did not influence patient or PD technique survival. Conclusion: Prior abdominal surgical procedures do not appear to compromise peritoneal membrane function or technique survival in patients successfully started on PD.

Background and Aims Peritoneal infections remain as a significant source of morbidity and mortality in PD patients. A steady decline of their incidence has been accompanied by changes in the etiologic spectrum of these infections, during the last decades. We have undertaken a review of trends in the compared incidence of PD-related peritonitis in our centre during a 30-year period, with a particular interest in streptococcal infections. Method Following an observational, retrospective design, we analyzed trends in the incidence and outcomes of peritoneal infections diagnosed in our centre between January 1990 and October 2019. We mainly focused on the incidence, risk factors and outcomes of streptococcal peritonitis. We excluded fungal peritonitis (very low incidence), surgical enteric infections and non-infectious peritonitis. Treatment failure was defined by transfer to hemodialysis for at least 3 months after the infection or death related to peritonitis. We applied Cox’s model to define clinical predictors of streptococcal infection, and stepwise logistic regression to investigate predictors of treatment failure. Results We recorded 1026 episodes of peritoneal infection in 878 patients, including 234 (22.8%) streptococcal infections, 57 (5.6%) infections by Staphylococcus aureus (SAu), 285 (27.8%) infections by coagulase-negative staphylococci (CNSt), 182 (17.7%) infections by gram-negative bacteria, 135 (13.2%) infections with 2 or more microorganisms and 133 (13.0%) culture-negative cases. Remarkably, streptococci were also main components in polimicrobial infections (present in 58.2% of cases). The incidence of peritonitis decreased during the observation period, from 0.91 (1990-94) to 0.47 episodes (2015-19) per patient and year This decline affected preferentially infections by SAu (0.068 to 0.006) and CNSt (0.361 to 0.067), while the incidence of infections by other etiologic agents remained essentially stable. As a consequence, the relative clinical spectrum moved to a predominance of streptococcal (10.7 to 23.3%), polimicrobial (8.0 to 15.7%) and culture-negative infections (4.7 to 16.2%). On multivariate analysis, patients suffering streptococcal infections were older (p=0.019), and presented lower albumin levels (p=0.004), than either patients suffering infections of other etiologies or presenting a peritonitis-free clinical course. After logistic regression analysis, older age, longer time on dialysis at the time of the infection, comorbidity, previous immunosuppression and plasma albumin were most consistent predictors of peritonitis-related mortality and treatment failure. Streptococcal peritonitis showed more benign outcomes than SAu (p Conclusion Streptococcal and polimicrobial (often including streptococci) infections have become dominant in the clinical spectrum of PD-related peritonitis, after the decline in the incidence of staphylococcal infections. The clinical aggressiveness of these infections appears intermediate between that observed in Staphylococcus aureus and CNSt infections.

BackgroundThe selective impact of strategies for prevention of PD-related peritonitis (PDrP) may have modified, in the long term, the causal spectrum, clinical presentation and outcomes of these infections.ObjectivesTo compare trends in the incidence of PDrP by different microorganisms during a 30-year period, with a particular focus on streptococcal infections. To analyze the clinical presentation and outcomes of these infections. Secondarily, to investigate how the isolation of different species of streptococci can influence the clinical course of PDrP by this genus of bacteria.MethodFollowing a retrospective, observational design we investigated 1061 PDrP (1990–2019). We used joinpoint regression analysis to explore trends in the incidence of PDrP by different microorganisms, and compared the risk profile (Cox), clinical presentation and outcomes (logistic regression) of these infections.Main resultsOur data showed a progressive decline in the incidence of PDrP by staphylococci and Gram negative bacteria, while the absolute rates of streptococcal (average annual percent change +1.6%, 95% CI -0.1/+3.2) and polymicrobial (+1.8%, +0.1/+3.5) infections tended to increase, during the same period. Remarkably, streptococci were isolated in 58.6% of polymicrobial infections, and patients who suffered a streptococcal PDrP had a 35.8% chance of presenting at least one other infection by the same genus. The risk profile for streptococcal infections was comparable to that observed for PDrP overall. Streptococcal PDrP were associated with a severe initial inflammatory response, but their clinical course was generally nonaggressive thereafter. We did not observe a differential effect of different groups of streptococci on the clinical presentation or outcome of PDrP.ConclusionsTime trends in the incidence of PDrP by different microorganisms have granted streptococci an increasing relevance as causative agents of these infections, during the last three decades. This behaviour suggests that current measures of prevention of PDrP may not be sufficiently effective, in the case of this genus of microorganisms.

Background: The prevalence of subclinical atherosclerosis and the main predictors of progression of this condition in patients undergoing peritoneal dialysis (PD) have been insufficiently investigated. Objectives and Method: Following a prospective, multicenter, observational design, we studied 237 patients who were treated with PD for ≥3 months, without any clinical background of cardiovascular (CV) disease. Our objectives were the following: (1) to investigate the prevalence of subclinical atherosclerosis, as compared to a control group of age- and sex-matched healthy individuals, and (2) to disclose PD technique-related predictors of progression of disease during a 24-month follow-up period. We used vascular ultrasound for characterization of subclinical atherosclerotic disease. Main Results: A total of 123 patients (51.9%) vs. 79 controls (33.5%) presented ≥1 carotid plaque, and 114 patients (48.3%) vs. 72 controls (30.5%) ≥1 femoral plaque, at baseline evaluation (p < 0.0005). Progression of disease, either in clinical or ultrasound (new plaques) terms, affected 62.6% of patients. Multivariate analysis identified age, carotid intima-media thickness, presence of ≥1 carotid plaque, and serum levels of 25OH vitamin D and C-reactive protein (CRP) at baseline as independent correlates of progression of atherosclerotic disease. On the contrary, PD technique-related variables did not show any association with this outcome. Conclusions: Atherosclerotic vascular disease is frequent among asymptomatic patients undergoing PD. Older age, pre-existent disease (assessed by vascular ultrasound), and serum levels of 25OH vitamin D and CRP are independent markers of the progression of this condition. These findings may contribute to improve identification of subpopulations with a high risk of CV events, deserving intensified measures of prevention.

Background: The evidence linking low serum sodium levels with the risk of mortality in peritoneal dialysis (PD) patients is controversial. Considering the different mechanisms contributing to hyponatremia in these patients, it is conceivable that the prognostic significance of this factor may vary, according to the clinical setting. Methods: Following a retrospective, observational design, we analyzed the association between hyponatremia and mortality in 748 patients incident on PD. We applied multivariate strategies of analysis, with the main objective of identifying subgroups of patients in whom hyponatremia could sustain different degrees of association with mortality (main outcome variable). For this purpose, we performed preliminary analyses to: (1) disclose predictors of serum sodium levels before and after (mean of first 3 months) initiation of PD (main study variable) and (2) investigate the overall prognostic significance of hyponatremia, in our patients. Results: Comorbidity, hypoalbuminemia, and lower glomerular filtration rate (GFR) were main predictors of hyponatremia. Use of icodextrin was another inverse correlate of serum sodium, and the only consistent predictor of a decline of natremia, once PD was started. Multivariate analysis confirmed early hyponatremia as an independent marker of survival. However, stratified analyses showed that this association was most apparent in specific subsets, namely, hypoalbuminemic, more anemic patients with higher baseline levels of GFR and C-reactive protein and faster peritoneal solute transport rates. Other factors potentially reinforcing the prognostic significance of hyponatremia included lower lean body mass levels, nonprescription of renin-angiotensin-aldosterone system antagonists, and use of icodextrin-based PD solution. On the contrary, baseline overhydration or categorization by classic predictors of mortality (age, comorbidity, diabetes) did not appear to influence the risk pattern associated with lower serum sodium levels. Conclusions: Our results suggest that hyponatremia performs as a consistent correlate of the risk of mortality mainly in PD patients manifesting direct or indirect signs of inflammation and wasting, while this association is not apparently linked to the presence of overhydration or nominal, preexisting comorbid conditions.

BackgroundPreservation of residual kidney function (RKF) is a relevant objective in peritoneal dialysis (PD) patients. The influence of dietary protein intake (PI) on this variable has not been adequately investigated.MethodsFollowing an observational design, we studied 336 patients incident on PD, with a minimum follow-up of 6 months. The main study variable was the mean PI [normalized rate of protein nitrogen appearance (nPNA)] during the first 4 months on PD. The main outcome variables were the absolute rate of decline of RKF and the proportion of patients presenting a >50% decay of their RKF during the first year of follow-up. We applied univariate and multivariate strategies of analysis, taking into consideration the main control variables bearing a correlation with nPNA and/or RKF.ResultsMean nPNA (first 4 months) was 1.23 ± 0.33 g/kg/day, while the overall rate of decline of RKF was −0.13 ± 0.29 mL/min/month; 69 patients (25.1%) had lost >50% of their initial RKF by the end of the first year. Univariate analysis disclosed consistent associations between the main study variable on one hand and baseline RKF (r = 0.32, P 50% of the baseline RKF during the first year of treatment (odds ratio 1.15 per 0.10 g/kg/day, 95% CI 1.04–1.27, P = 0.006).ConclusionHigher rates of PI during the first months of therapy are associated with a faster decline of RKF among patients incident on PD. Our results underline the convenience of keeping an adequate balance between sufficient protein ingestion, to prevent malnutrition and wasting, and sensible restriction in stable, adequately nourished individuals with rates of intake in the higher range or above-recommended allowances.

ResumenAntecedentesLa irisina es una adipomioquina con posibles efectos antiobesidad y antidiabéticos. Esta hormona ha sido insuficientemente estudiada en pacientes con enfermedad renal crónica (ERC) avanzada.ObjetivoRealizar un análisis exploratorio de los niveles séricos de irisina en pacientes con diferentes modalidades de tratamiento de la ERC.MétodoSegún diseño transversal, estimamos niveles de irisina en 95 pacientes con ERC manejados conservadoramente (ERCA), con diálisis peritoneal (DP) o con hemodiálisis, comparándolos con un grupo control de 40 individuos sanos. También investigamos las correlaciones entre irisina sérica y variables demográficas, clínicas, metabólicas y de composición corporal.ResultadosLos niveles de irisina fueron más bajos en cualquier grupo de pacientes que en los controles. El análisis univariante desveló correlaciones moderadas entre irisina, por un lado, y masa grasa (pero no magra), filtrado glomerular (GFR) y albúmina y bicarbonato plasmático, por otro. El análisis multivariante confirmó que los pacientes con ERCA (diferencia 111,1ng/mL), en DP (25,9ng/mL) o hemodiálisis (61,4ng/mL) (todos p

Un ensayo clinico aleatorizado de 36 meses de duracion, abierto, multicentrico, que incluyo 213 pacientes con enfermedad renal cronica sin dialisis (ERC-SD), estudio INDEPENDENT-CKD, comparo sevelamero con carbonato calcico (CC). El objetivo de este estudio fue evaluar el coste-efectividad de sevelamero frente a CC en pacientes con ERC-SD e hiperfosfatemia adaptando los resultados y los costes del estudio INDEPENDENT-CKD a la poblacion espanola. Se ha realizado analisis coste-utilidad mediante un modelo de Markov con tres estados de salud, desde la perspectiva del financiador y con un horizonte temporal de por vida. La mortalidad por todas las causas, el inicio de la dialisis, la hospitalizacion y la dosis de farmaco fueron obtenidos del estudio INDEPENDENT-CKD. Se utilizaron fuentes de costes unitarios de Espana y la puntuacion de utilidad se obtuvo de la literatura. Sevelamero logro 2,12 anos de vida y 1,61 anos de vida ajustados por calidad adicionales comparado frente a CC. La mayor supervivencia implica mayor tiempo en tratamiento y sesiones de dialisis, resultando en un incremento de coste de 28.139 €. La razon coste-efectividad incremental fue 13.280 € por ano de vida y 17.446 € por ano de vida ajustado por calidad. El analisis de sensibilidad ha mostrado que sevelamero es mas efectivo y con un menor coste que CC para horizontes temporales inferiores a 6 anos. Sevelamero es una estrategia coste-efectiva para el tratamiento de la hiperfosfatemia en pacientes con ERC-SD en Espana, con razon coste-efectividad por debajo de los 30.000–45.000 €, generalmente aceptadas.

Overhydration (OH) complicates frequently the clinical course of Peritoneal Dialysis (PD) patients, and keeps a controversial association with the risk of peritoneal infection. The main objective of this study was to disclose an association between persistent OH and the risk of enteric peritonitis in a relatively large sample of patients undergoing PD.Following a prospective design, we monitorized systematically body composition of patients treated with PD in our unit (2011-2016), searching for a correlation with the ensuing risk of peritonitis, with an emphasis on the association between persistent OH (main study variable) and the risk of infection by enteric pathogens (main outcome). Essential demographic, clinical and laboratory variables with a potential influence on the risk of peritonitis were recorded. We used multivariate survival analysis to clarify the specific effect of different body composition parameters on the main outcome.We included 139 patients for analysis (mean follow-up 24 months). Sixty-three patients suffered at least one peritonitis, and 17 had at least one diagnosis of enteric peritonitis. Univariate analysis disclosed a general trend to an increased risk of enteric peritonitis in overhydrated patients, as evidenced by associations of this outcome with mean extracellular water/intracellular water (ECW/ICW) (p=.007), OH/ECW (p=.033) and ECW/total body water (ECW/TBW) (p=.004) ratios, but not with absolute OH values. Multivariate analysis confirmed similar associations or trends (RR: 3.48, 95% CI: 1.03-14.59; p=.046, highest versus lowest tertile of ECW/ICW, RR: 2.31, 95% CI: 0.98-6.56; p=.061, highest versus lowest tertile of OH/ECW, and RR: 6.33, 95% CI: 1.37-19.37; p=.011, highest versus lowest tertile of ECW/TBW). On the contrary, no apparent association was detected between OH and the overall risk of peritoneal infection.Persistent overhydration portends a significant risk of peritoneal infection by enteric pathogens, among patients undergoing chronic PD.

Background Peritoneal infections of enteric origin (EntP) have been classically investigated using partial strategies, focused on particular subgroups of microorganisms. A more comprehensive approach may facilitate the definition of the nomenclature and clinical presentation of these infections. Objectives To investigate the clinical presentation and outcomes of a full spectrum of EntP, with a particular interest in the comparison between single-organism and polymicrobial infections. Method Following an observational design, we investigated 165 single-organism and 83 polymicrobial peritonitis episodes with isolation of at least 1 enteric bacteria ( Enterobacteriaceae, Enterococcus spp. and/or intestinal anaerobics). We compared the risk of treatment failure for these 2 types of infection and explored the significance of the isolation of specific microorganisms and of their antibacterial susceptibility patterns. Results Polymicrobial EntP was associated with higher rates of hospitalization, more changes to initial antibiotic therapy, more surgical explorations, and higher mortality and treatment failure rates than monobacterial EntP. However, stratified and multivariate analyses revealed that the burden of these differences rested on the isolation of intestinal anaerobics (odds ratio [OR] 12.05, 95% confidence interval [CI] 2.53–31.09, p < 0.001) and/or Enterococcus faecium (OR 3.37, 95% CI 1.02–11.30, p = 0.046), while other polymicrobial infections were more comparable with single-organism peritonitis, except for even higher mortality rates in the former group. Lower antibiotic susceptibility of the isolations (OR 1.18, 95% CI 0.51–2.70, p = 0.70) did not perform as a predictor of treatment failure. Conclusion A comprehensive approach to peritoneal infections by intestinal microorganisms may provide a focused perspective of the clinical presentation and outcomes of these complications of peritoneal dialysis.

Background: There is controversy concerning the compared rates of decline of residual kidney function (RKF) in patients treated with continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). Objectives and Method: Following an observational, multicenter design, we studied 493 patients initiating peritoneal dialysis (PD) in four different Spanish units. We explored the effect of the PD modality on the rate of decline of RKF and the probability of anuria during follow-up. We applied logistic regression for intention-to-treat analyses, and linear mixed models to explore time-dependent variables, excluding those affected by indication bias. Main Results: Patients started on APD were younger and less comorbid than those initiated on CAPD. Baseline RKF was similar in both groups (p = 0.50). Eighty-seven patients changed their PD modality during follow-up. The following variables predicted a faster decline of RKF: higher (rate of decline) or lower (anuria) baseline RKF, younger age, proteinuria, nonprimary PD, use of PD solutions rich in glucose degradation products, higher blood pressure, and suffering peritonitis or cardiovascular events during follow-up. Overall, APD was not associated with a fast decline of RKF, but stratified analysis disclosed that patients with lower baseline RKF had an increased risk for this outcome when treated with this technique (HR: 2.26, 95% CI: 1.09-4.82, p = 0.023). Moreover, the probability of anuria during follow-up was overtly higher in APD patients (HR: 3.22, 95% CI: 1.25-6.69, p = 0.002). Conclusions: Starting PD patients directly on APD is associated with a faster decline of RKF and a higher risk of developing anuria than doing so on CAPD. This detrimental effect is more marked in patients initiating PD with lower levels of RKF.

Background: Volume overload is frequent in diabetics undergoing peritoneal dialysis (PD), and may play a significant role in the excess mortality observed in these patients. The characteristics of peritoneal water transport in this population have not been studied sufficiently. Method: Following a prospective, single-center design we made cross-sectional and longitudinal comparisons of peritoneal water transport in 2 relatively large samples of diabetic and nondiabetic PD patients. We used 3.86/4.25% glucose-based peritoneal equilibration tests (PET) with complete drainage at 60 min, for these purposes. Main Results: We scrutinized 59 diabetic and 120 nondiabetic PD patients. Both samples showed relatively similar characteristics, although diabetics were significantly more overhydrated than nondiabetics. The baseline PET disclosed lower ultrafiltration (mean 439 mL diabetics vs. 532 mL nondiabetics, p = 0.033) and sodium removal (41 vs. 53 mM, p = 0.014) rates in diabetics. One hundred and nine patients (36 diabetics) underwent a second PET after 12 months, and 45 (14 diabetics) underwent a third one after 24 months. Longitudinal analyses disclosed an essential stability of water transport in both groups, although nondiabetic patients showed a trend where an increase in free water transport (p = 0.033) was observed, which was not the case in diabetics. Conclusions: Diabetic patients undergoing PD present lower capacities of ultrafiltration and sodium removal than their nondiabetic counterparts. Longitudinal analyses disclose an essential stability of water transport capacities, both in diabetics and nondiabetics. The clinical significance of these differences deserves further analysis.

BackgroundUltrafiltration 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.ObjectiveTo 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).MethodProspective, 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.ResultsThe 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 (FW T) ( 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.ConclusionsPatients 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.

♦ BackgroundPeritoneal catheter tunnel and exit-site infection (TESI) complicates the clinical course of peritoneal dialysis (PD) patients. Adherence to recommendations for catheter insertion, exit-site care, and management of Staphylococcus aureus (SAu) carriage reduces, but does not abrogate the risk of these infections.♦ ObjectiveTo reappraise the risk profile for TESI in an experienced center with a long-term focus on management of SAu carriage and a low incidence of these infections.♦ MethodFollowing a retrospective, observational design, we investigated 665 patients incident on PD. The main study variable was survival to the first episode of TESI. We considered selected demographic, clinical, and technical variables, applying multivariate strategies of analysis.♦ Main resultsThe overall incidence of TESI was 1 episode/68.5 patient-months. Staphylococcus aureus carriage disclosed at inception of PD (but not if observed sporadically during follow-up) (hazard ratio [HR] 1.53, p = 0.009), PD started shortly after catheter insertion (HR 0.98 per day, p = 0.011), PD after kidney transplant failure (HR 2.18, p = 0.017), lower hemoglobin levels (HR 0.88 per g/dL, p = 0.013) and fast peritoneal transport rates (HR 2.92, p = 0.03) portended an increased risk of TESI. Delaying PD ≥ 30 days after catheter insertion markedly improved the probability of TESI. Carriage of methicillin-resistant SAu since the start of PD was associated with a high incidence of TESI by these bacteria. On the contrary, resistance to mupirocin did not predict such a risk, probably due to the use of an alternative regime in affected patients.♦ ConclusionsAdherence to current recommendations results in a low incidence of TESI in PD patients. Interventions on specific risk subsets have a potential to bring incidence close to negligible levels. Despite systematic screening and management, SAu carriage is still a predictor of TESI. Antibiotic susceptibility patterns may help to refine stratification of the risk of TESI by these bacteria. Early insertion of the peritoneal catheter should be considered whenever possible, to reduce the risk of later TESI.

Commentary

Background. A cost analysis of the Spanish Renal Replacement Therapy (RRT) programme in the year 2010, for end-stage renal disease (ESRD) patients, was performed from the perspective of the Public Administration. Methods. The costs associated with each RRT modality [hemodialysis (HD), peritoneal dialysis (PD) and kidney transplantation (Tx)] were analysed. The Spanish ESRD incidence and prevalence figures in the year 2010 were forecasted in order to enable the calculation of an aggregate cost for each modality. Costs were mainly computed based on a review of the existing literature and of the Official Bulletins of the Spanish Autonomous Communities. Data from Oblikue Consulting eSalud health care costs database and from several Spanish public sources were also employed. Results. In the year 2010, the forecasted incidence figures for HD, PD and Tx were 5409, 822 and 2317 patients, respectively. The forecasted prevalence figures were 22 582, 2420 and 24 761 patients, respectively. The average annual per-patient costs (incidence and prevalence) were V2651 and V37 968 (HD), V1808 and V25 826 (PD) and V38 313 and V6283 (Tx). Indirect costs amounted to V8929 (HD), V7429 (PD) and V5483 (Tx). The economic impact of the Spanish RRT programme on the Public Administration budget was estimated at ~V1829 million (indirect costs included): V1327 (HD), V109 (PD) and V393 (Tx) million. Conclusions. HD accounted for >70% of the aggregate costs of the Spanish RRT programme in 2010. From a costs minimization perspective, it would be preferable if the number of incident and prevalent patients in PD were increased.

BackgroundThe peritoneal equilibration test (PET) permits assessment of peritoneal protein transport, but this potential marker of outcome in peritoneal dialysis (PD) patients lacks adequate standardization.ObjectivesTo assess various approaches for estimation of peritoneal protein transport in PD patients during 2.27% and 3.86% glucose-based PETs, and to uncover the demographic, clinical, and biochemical correlates of this phenomenon.Patients and MethodsWe studied 90 PD patients who underwent 2.27% and 3.86% PETs in random order, and we used multivariate analysis to compare assessments of peritoneal protein transport in both tests, searching for correlations between D240′– D0′protein concentration (PETΔPConc), total peritoneal protein excretion (PET-PPE), or total protein clearance (PET-PC) on the one hand (the main study variables), and PET-derived markers of peritoneal function and selected demographic, clinical, and biochemical variables on the other.ResultsThe PETΔPConc was higher during the 2.27% PET (mean: 45.2 mg/dL vs 37.0 mg/dL for the 3.86% test; p = 0.003); the PET-PPE and PET-PC were comparable (1121.8 mg vs 1168.9 mg, p = 0.52, and 17.1 mL vs 17.8 mL, p = 0.66, respectively). All three variables sustained a significant, yet moderate correlation (all r2values < 0.30) with the 24-hour PPE rate. Multivariate analysis identified dialysate-to-plasma ratio (D/P240′) of creatinine, end-to-initial dialysate ratio (D240′/D0′) of glucose, current daily peritoneal glucose load, ultrafiltration during PET, systolic blood pressure, and previous cardiovascular events (3.86% test only) as independent predictors of protein transport during PET.ConclusionsEither PET-PPE or PET-PC seems preferable to PETΔPConc for characterization of peritoneal protein transport. Small-solute transport characteristics, ultrafiltration, and current peritoneal glucose load sustain independent correlations with peritoneal protein transport. The latter variable shows also a moderate association with markers of cardiovascular disease in PD patients.

Background. Analysis of the dialysate sodium concentration during a peritoneal equilibration test (PET) provides information on the rates of water and solute transport through different membrane pathways. A hypertonic (3.86%) glucose-based dialysate may enhance the accuracy of analysis. There are still gaps in our knowledge regarding this question, in the clinical setting. Objective. The aim of this study was to compare the categorization of the sodium sieving effect in peritoneal dialysis (PD) patients by 2.27% and 3.86% PETs, and to disclose clinical correlates of this phenomenon. Method. Ninety PD patients underwent prospectively 2.27% and 3.86% modified (dialysate samples at 0, 60, 90, 120 and 240 min) PETs, in a random order. We searched for differences in the time profiles of sodium sieving and its categorization. We correlated sodium sieving with ultrafiltration (UF) and solute transport capacity, as also with selected clinical and demographic variables, using a multivariate approach. Results. The maximum dip in the dialysate sodium concentration (11.1 mM/L, 3.86% versus 7.1 mM/L, 2.27%, P < 0.001) was most common after 90 min in the 3.86% PET, with the 2.27% test somewhere between 60 and 90 min. Low sodium sieving (defined by a dip < 5m M/L at 60 min) was observed in 8.9% of the patients in the 3.86% test. The same limit categorized 34.4% of the patients as low sieving in the 2.27% test (100.0% sensitivity and 72.0% specificity, using 3.86% as a reference). UF and D/P240 min creatinine were independent predictors of the sodium sieving effect in both tests. Moreover, multivariate analysis disclosed a consistent inverse correlation between GFR and sodium sieving in both the 2.27% (B =− 0.23, 95% CI −0.40, −0.07, P = 0.006) and 3.86% PET (B =− 0.46, 95% CI −0.65, −0.26, P < 0.0005). Conclusions. The standard 2.27% PET permits some categorization of sodium sieving in PD patients. However, the information provided by this test lacks the discriminatory capacity of the 3.86% PET, which should be considered the one for reference for this purpose. GFR keeps a consistent inverse correlation with the intensity of sodium sieving in both the 2.27% and 3.86% PET.

Background There is controversy about the preferred initial antibiotic therapy for peritoneal dialysis (PD)-related peritonitis. Quinolones have been used extensively in this setting, yet their long-term effectiveness is unknown. Aim To analyze the results of a protocol of treatment of PD-related peritonitis with ciprofloxacin, maintained over two decades. Method We analyzed the clinical outcome of 682 episodes of bacterial peritonitis treated with intraperitoneal ciprofloxacin monotherapy, and the time course of bacterial susceptibility to this antimicrobial, in a historical cohort of 641 PD patients (1988-2007). Main outcome variables included changes to initial therapy and rates of hospital admission, catheter removal, relapse, reinfection, PD dropout, and mortality. For comparisons we divided the study period into phases A (1988-1994), B (1995-2000), and C (2001-2007). Results The incidence of Staphylococcus aureus peritonitis decreased, while the incidences of polymicrobial and negative-culture peritonitis increased after phase A. In vitro susceptibility to ciprofloxacin decreased significantly only among coagulase-negative staphylococci (87.0% susceptible strains in phase A vs 70.0% in B and 70.1% in C, p = 0.006). Overall success rates (catheter not removed and ongoing PD after the episode) remained stable, at over 85%. However, the proportion of patients treated solely with ciprofloxacin declined from 75.7% (A) to 47.3% (B) to 32.4% (C) ( p < 0.0005) and admission rates increased from 12.7% to 16.8% to 24.9% respectively ( p = 0.001). These changes affected all the etiologic groups except culture-negative peritonitis. In vitro resistance to ciprofloxacin was a marker of multiresistance and correlated strongly with clinical outcome of peritonitis. Among isolates susceptible to ciprofloxacin, changing initial therapy for any reason also predicted a poor outcome. Conclusions Following satisfactory early results, the effectiveness of ciprofloxacin as monotherapy for PD-related peritonitis has declined markedly in the long term. This decline cannot be explained solely by a decrease of in vitro susceptibility to this antimicrobial, which was significant only among coagulase-negative staphylococci. Resistance to ciprofloxacin is a strong marker of in vitro multiresistance and poor clinical outcome of peritonitis.

[Resumen] Introducción. El péptido YY (PYY) tiene 36 aminoácidos y lo sintetizan fundamentalmente las células L del intestino. El PYY aumenta tras las comidas y alcanza su nadir tras el ayuno. Tras la ingestión se liberan dos formas: PYY1-36 y PYY3-36. Se ha demostrado que el PYY3-36 reduce la ingesta en humanos y roedores. Hay poca información sobre los valores plasmáticos de PYY, especialmente de PYY3-36, en respuesta a la ingestión y su relación con la respuesta de ghrelina. Objetivos. Estudiar la respuesta secretora de PYY1-36 y PYY3-36 en sujetos normales tras ingerir una comida mixta y su relación con la secreción de ghrelina total y acilada. Sujetos y métodos. Estudiamos a 8 sujetos sanos, 4 mujeres y 4 varones, con una mediana de edad de 53 (intervalo, 36-59) años. Tras el ayuno nocturno, recibieron en 2 días diferentes y de forma aleatoria: una comida oral mixta estándar, que consistía en 400 ml de Isosource Energy (159 kcal/100 ml) o placebo por vía oral (400 ml de agua). Se obtuvieron muestras sanguíneas en los tiempos 0, 30, 45, 60 y 120 min para la determinación de PYY1-36, PYY3-36, ghrelina total y ghrelina acilada. Las comparaciones se realizaron mediante la prueba de Wilcoxon. Las correlaciones numéricas se analizaron mediante la prueba de correlación de Spearman. Se consideró significativo un valor de p ≤ 0,05. Resultados. Tras ingerir la comida, se produce un máximo de PYY1-36 (mediana [intervalo]) de 141,5 (81-198) pg/ml y no hay respuesta tras placebo, con un máximo de 92,5 (46-219) pg/ml (p = 0,04). Los valores del área bajo la curva (ABC) de PYY1-36 tras la ingesta fueron 14.865 (8.032-19.822) pg/ml/min y tras placebo, 8.992 (4.455- 21.382) pg/ml/min (p = 0,06). Tras ingerir la comida se produce un máximo de PYY3-36 de 92,5 (59-135) pg/ml y no hay respuesta tras placebo, con un máximo de 46,5 (30- 66) pg/ml (p = 0,02). Los valores del ABC de PYY3-36 tras la ingesta fueron 9.086 (6.412-14.970) pg/ml/min y tras placebo, 4.984 (3.142-6.772) pg/ml/min (p = 0,012). El cociente nadir de ghrelina total/máximo de PYY1-36 disminuye de forma marcada tras la ingestión; los valores preprandiales son 7,44 (3,64-14,56) y los posprandiales, 3,55 (1,64-7,16) (p = 0,03), mientras que no se modifica tras placebo. El cociente nadir de ghrelina acilada/máximo de PYY3-36 disminuye de forma marcada tras la ingestión, y los valores preprandiales son 2,03 (0,92-3) y los posprandiales, 0,73 (0,26-1,27) (p = 0,02), mientras que no se modifican tras placebo. Conclusiones. En sujetos normales, PYY1-36 y PYY3-36 aumentan de forma paralela tras ingerir una comida mixta; simultáneamente, los valores de ghrelina total y acilada disminuyen. El cociente entre el nadir de ghrelina acilada y el máximo de PYY3-36 disminuye tras ingerir una comida mixta. Este conjunto de datos indica su posible participación en la regulación aguda del apetito tras la comida. [Abstract] Background. Peptide YY (PYY) is a 36 amino acid peptide synthesized mostly by intestinal L cells. This peptide reaches its nadir during fasting and increases immediately after meals. After food intake, two molecular forms are released, PYY1-36 and PYY3-36. PYY3-36 reduces food intake in both humans and rodents. There is scarce information about plasmatic concentrations of PYY, especially of PYY3-36, after food ingestion, and their relationship to ghrelin. Objectives. To study PYY1-36 and PYY3-36 secretory response after a mixed meal, and its relationship to total and acylated ghrelin secretion in healthy subjects. Subjects and method. We studied eight healthy subjects, 4 women and 4 men, with a median age of 53 (range, 36-59) years. After an overnight fast, the subjects received either a mixed standard meal (400 ml Isosource Energy® [159 kcal/100 ml]) or placebo (400 ml of water) orally in random order on two different days. Blood samples were obtained at 0, 30, 45, 60 and 120 min for measurement of PYY1-36, PYY3-36, total ghrelin and acylated ghrelin. Comparisons were made by Wilcoxon's test. Numerical correlations were performed using Spearman's test. P-values ≤ 0.05 were considered significant. Results. After a mixed meal, PYY1-36 reached a peak of (median [range]) 141.5 (81-198) pg/ml. There was no response to placebo, with a peak of 92.5 (46-219) pg/ml (p = 0.04). The area under the curve (AUC) of PYY1-36 levels after a mixed meal were 14,865 (8,032-19,822) pg/ml/min and after placebo were 8,992 (4,455-21,382) pg/ml/min (p = 0.06). After ingestion of a mixed meal, PYY3-36 reached a peak of 92.5 (59-135) pg/ml, with no response to placebo (46.5 [30-66] pg/ml) (p = 0.02). The AUC of PYY3-36 levels after a mixed meal were 9,086 (6,412-14,970) pg/ml/min, and after placebo were 4,984 (3,142-6,772) pg/ml/min (p = 0.012). The quotient between nadir total ghrelin/peak PYY1-36 was markedly diminished after food ingestion, with preprandial values of 7.44 (3.64-14.56) and postprandial values of 3.55 (1.64-7.16) (p = 0.03). The former quotient was unmodified by placebo. The quotient between nadir acylated ghrelin/peak PYY3-36 was markedly diminished after ingestion of a mixed meal, with preprandial values of 2.03 (0.92-3) and postprandial values of 0.73 (0.26-1.27) (p = 0.02). This quotient was unmodified by placebo. Conclusions. In healthy subjects, blood levels of both PYY1-36 and PYY3-36 increase after ingestion of a mixed meal. Simultaneously, total and acylated ghrelin levels diminish. The quotient between nadir acylated ghrelin/peak PYY3-36 diminishes after a mixed meal. All these data suggest the possible contribution of these peptides to appetite regulation after ingestion. Instituto de Salud Carlos III, PI051024 Instituto de Salud Carlos III, PI070413 Xunta de Galicia, PGIDT05PXIC91605PN Xunta de Galicia, PS07/12

Background. Icodextrin is a glucose polymer derived by hydrolysis of cornstarch. The different biocompatibility profile of icodextrin-containing peritoneal dialysis (PD) solutions may have a positive influence on peritoneal host defence. Furthermore, cases of sterile peritonitis potentially associated with icodextrin have been reported. Methods. The primary objective of this multicentre, longitudinal, observational, non-interventional, prospective cohort study, which included 722 PD patients, was to evaluate the incidence of overall peritonitis in patients treated with icodextrin-containing PD solutions (Extraneal™) used during one long-dwell exchange/day compared with those treated with non-icodextrin-containing PD solutions. The secondary objective was to determine if culture-negative peritonitis rates differed between patients treated with icodextrin from two independent manufacturers. All peritonitis episodes were assessed by a Steering Committee in a blind manner. Results. There was no significant difference between icodextrin-treated and control patients in the adjusted overall, culture-positive or culture-negative peritonitis rates. When stratified by the icodextrin supplier, there was no significant difference in the adjusted rate of culture-negative peritonitis episodes between groups. Conclusion. Subjects receiving icodextrin as part of their PD regimen experienced neither a higher rate of culture-negative peritonitis nor a lower rate of infectious peritonitis compared with non-icodextrin users. There was no significant influence of the icodextrin raw material supplier on peritonitis rates.

Resumen Tras desarrollarse durante los ultimos 25 anos del pasado siglo, la dialisis peritoneal afronta en el presente 2 grandes desafios: consolidarse como opcion inicial de tratamiento sustitutivo renal y optimizar sus resultados a largo plazo en cuanto a supervivencia de tecnica y pacientes, con el fin de equipararse plenamente a la hemodialisis. El primer objetivo demandara la asimilacion por parte de la comunidad nefrologica del concepto de tratamiento integrado de la uremia, que contempla las distintas modalidades de tratamiento sustitutivo como opciones complementarias, y en ningun caso competitivas. Tambien sera necesaria la generalizacion de la eleccion informada por parte de los pacientes respecto a sus opciones de tratamiento, un objetivo que ha de cumplirse en unidades especificas de atencion a enfermos con insuficiencia renal cronica avanzada. La mejoria en los resultados de la dialisis peritoneal a largo plazo pasara, con toda probabilidad, por 3 mecanismos. En primer lugar, las mejoras en la biocompatibilidad de las soluciones de dialisis y en la prevencion de peritonitis ayudaran a preservar la membrana peritoneal. En segundo lugar, los objetivos de adecuacion deberan redefinirse en los proximos anos, con especial atencion al control del volumen extracelular. Por ultimo, las mejoras en la adaptacion de las tecnicas domiciliarias a las condiciones sociales y laborales de cada caso permitiran, sin duda, optimizar la calidad de vida de los pacientes.

Peritonitis is a well-known cause of mortality in peritoneal dialysis (PD) patients. We carried out a retrospective study to disclose the clinical spectrum and risk profile of peritonitis-related mortality. We analyzed 693 episodes of infectious peritonitis suffered by 565 patients (follow-up 1149 patient-years). Death was the final outcome in 41 cases (5.9% of episodes), peritonitis being directly implicated in 15.2% of the global mortality and 68.5% of the infectious mortality observed. In 41.5% of patients with peritonitis-related mortality, the immediate cause of death was a cardiovascular event. Highest mortality rates corresponded to fungal (27.5%), enteric (19.3%), and Staphylococcus aureus (15.2%) peritonitis. Multivariate analysis disclosed that the baseline risk of peritonitis-related mortality was significantly higher in female [relative risk (RR) 2.13, 95% confidence interval (CI) 1.24 – 4.09, p = 0.02], older (RR 1.10/year, CI 1.06 – 1.14, p < 0.0005), and malnourished patients (RR 2.51, CI 1.21 – 5.23, p = 0.01) with high serum C-reactive protein (s-CRP) levels (RR 4.04, CI 1.45 – 11.32, p = 0.008) and a low glomerular filtration rate (RR 0.75 per mL/minute, CI 0.64 – 0.87, p < 0.0005). Analysis of risk after a single episode of peritonitis and/or subanalysis restricted to peritonitis caused by more aggressive micro-organisms disclosed that overall comorbidity [odds ratio (OR) 1.21, CI 1.05 – 1.71, p = 0.005], depression (OR 2.35, CI 1.14 – 4.84, p = 0.02), and time on PD at the time of the event (OR 1.02/month, CI 1.00 – 1.03, p = 0.02) were other predictors of mortality. In summary, the etiologic agent is a definite marker of peritonitis-related mortality but gender, age, residual renal function, inflammation (s-CRP), malnutrition, and depression are other significant correlates of this outcome. Most of these risk factors are common to cardiovascular and peritonitis-related mortality, which may explain the high incidence of cardiovascular event as the immediate cause of death in patients with peritonitis-related mortality.

Background. Ghrelin has been characterized as a relevant physiologic regulator of appetite and body weight in humans. However, the potential relationships between ghrelin levels, inflammation and malnutrition in dialysis patients have not been adequately studied. Methods. We used a cross-sectional design to study 20 haemodialysis (HD) and 21 peritoneal dialysis (PD) patients, and compared their plasma ghrelin (PGhr) levels with that of an age-matched control group. We also explored correlations between ghrelin and selected hormonal, renal adequacy, nutritional and inflammation markers in both groups. Results. PGhr levels were higher in HD (median 119.8 pg/ml, range 71.1–333.7, P ¼ 0.001) and PD (99.3, range 45.8–578.5, P ¼ 0.045) patients than in healthy controls (78, range 29–158) (HD vs PD, not significant). Ghrelin levels were strongly and inversely correlated with age (r ¼� 0.46, P ¼ 0.02 for patients; r ¼� 0.61, P ¼ 0.001 for controls). Except for a positive correlation between ghrelin and growth hormone (r ¼ 0.48, P ¼ 0.002), univariate analysis failed to detect associations between PGhr and the measured hormonal values, renal adequacy, nutritional indicators and markers of inflammation. However, multivariate analysis revealed significant inverse correlations between PGhr levels and nutritional markers, including subjective global assessment (P ¼ 0.013), albumin (P ¼ 0.001), transferrin (P ¼ 0.01) and protein nitrogen appearance (as an estimate of protein intake) (P ¼ 0.035), after controlling for the confounding effect of age. Conclusions. PGhr levels were moderately and similarly increased in patients undergoing HD and PD. Age was a strong determinant of PGhr levels, both in uraemic patients and in healthy controls. Dialysis adequacy, residual renal function and inflammation did not appear to influence ghrelin levels in these patients. The negative correlation between PGhr and nutritional markers suggests that low dietary intake causes increases in ghrelin secretion in dialysis patients.

Objective To determine the incidence and significance of peritoneal eosinophilia (PEo) during peritoneal dialysis (PD)-related peritonitis. Design Retrospective observational study. Setting Tertiary-care public hospital. Patients and Method We performed a cytological study of dialysate at the start of 465 cases of peritonitis diagnosed between January 1987 and May 2002. Cases associated with PEo (> 10% eosinophils) were classified according to their infectious or seemingly noninfectious origin. We compared the two groups, trying to disclose differentiating patterns of presentation. Results We found PEo in 42 cases. Infectious peritonitis was the final diagnosis in 22 of the 42 cases; a diagnosis of idiopathic eosinophilic peritonitis was finally established in 20 cases. The etiologic spectrum of infectious peritonitis with PEo did not differ markedly from the global spectrum of peritonitis in our unit. Infectious peritonitis with PEo tended to appear later in the course of PD therapy, presented with more severe clinical symptoms, displayed higher total peritoneal leukocyte and neutrophil counts, and showed lower degrees of PEo than idiopathic eosinophilic peritonitis, but overlap between the groups was significant. Conclusions Peritoneal eosinophilia is infrequent but not rare during infectious PD-related peritonitis. Our findings agree with established concepts on idiopathic eosinophilic peritonitis, but overlap in presentation with infectious eosinophilic peritonitis is significant, which should be taken into consideration at the time of planning therapy for this condition.

Background. Nasal and pericatheter colonization by Staphylococcus aureus portends an increased risk of peritonitis and exit-site infection for peritoneal dialysis (PD) patients. The aim of the present study was to examine the incidence of colonization by other peritoneal pathogens, and more specifically by Gramnegative bacteria (GNB), among PD patients, and to disclose its potential correlation with PD-related infections. Method. Over a 3-year period, we prospectively screened 152 PD patients and 99 partners every other month for nasal and pericatheter bacterial colonization (total follow-up for patients 3182 months). We performed 1089 studies in patients and 561 in partners. Results. Although S. aureus and coagulase-negative Staphylococcus spp. predominated both in patients and partners, we recovered GNB from 15.8% (nares) and 22.4% (pericatheter) of the patients and from 29.3% of the partners. Most isolations of GNB were transient and only 7.2% of the patients and 7.1% of the partners had the same GNB isolated in at least two controls from the same sampling site. Older age, male gender, longer follow-up on PD, previous immunosuppressive therapy, low socioeconomic conditions, and a high global incidence of peritonitis were predictive of colonization by GNB. Previous pericatheter mupirocin therapy was also associated with later colonization by GNB. Nasal or pericatheter colonization by bacteria other than S. aureus, particularly GNB, had a poor predictive power for PD-related infections. Conclusion. Nasal and pericatheter bacterial colonization is protean in PD patients and their partners, and includes the significant presence of potentially pathogenic GNB. Colonization by GNB was not clearly associated with an increased risk of peritonitis or exit-site infection in these patients.

Background Diabetes mellitus, especially if complicated by poor glycemic control, portends an increased risk of infection. The significance of this association in the case of diabetic patients undergoing peritoneal dialysis (PD) has not been assessed. Methods Using a retrospective observational design, we analyzed the association between glycemic control at the start of PD (estimated from glycosylated hemoglobin levels) and the risk of peritoneal and catheter tunnel and exit-site infections during follow-up in 183 incident patients on PD. We used the median value of glycosylated hemoglobin to classify patients into good (group A) or poor (group B) glycemic control groups. We applied multivariate strategies of analysis to control for other potential predictors of PD-related infection. Results Groups A and B differed significantly in age, dialysis vintage, use of insulin, and rate of Staphylococcus aureus carriage. Neither the incidence (0.60 episodes in group A vs 0.56 episodes in group B per patient–year) nor the time to a first peritoneal infection (median: 42 months vs 38 months) differed significantly between the study groups. In contrast, group B had a significantly higher incidence of catheter tunnel and exit-site infections (0.23 episodes vs 0.12 episodes per patient–year) and shorter time to a first infection episode (64 months vs 76 months, p = 0.004). The difference persisted in multivariate analysis (adjusted hazard ratio: 2.65; 95% confidence interval: 1.13 to 6.05; p = 0.013). We observed no differences between the study groups in the spectrum of causative organisms or in the outcomes of PD-related infections. Conclusions Poor glycemic control is a consistent predictor of subsequent risk of catheter tunnel and exit-site infection, but not of peritoneal infection, among diabetic patients starting PD therapy.

Background: Serum leptin levels are increased in chronic renal failure (CRF) and may potentially contribute to protein malnutrition in this disorder. Method: Following a cross-sectional design, we performed a nutritional survey in a wide sample of uremic patients treated conservatively (n = 87), with peritoneal dialysis (n = 71) and with hemodialysis (n = 53). Then, we analyzed the correlation between serum leptin levels and markers of protein malnutrition. We used a multivariate approach, taking into consideration the confounding effect of other factors on the correlation between hyperleptinemia and protein malnutrition. Main Results: Both univariate and multivariate analysis disclosed a poor correlation between hyperleptinemia and markers of protein malnutrition. In fact, there were trends to a positive correlation between leptinemia and body protein stores, as estimated from the scrutinized markers. Persistence of the basic correlation between general intake, fat mass and leptin in CRF could partially explain these findings, but neither a negative correlation between leptin levels nor protein nutritional state could be disclosed after controlling for this factor. Conclusions: Our results do not support a first-line role for hyperleptinemia in the genesis of protein malnutrition of uremia.

Objective To compare the incidence of peritonitis and exit-site infection in an ample group of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis in a single center during a 10-year period. Design Nonrandomized, prospective study. Setting Public, tertiary care hospital providing peritoneal dialysis care to a population of (approximately) 750 000 people. Patients We studied 213 patients on CAPD and 115 on automated peritoneal dialysis (APD) starting therapy between January 1989 and August 1998, with a minimum follow-up of 3 months. Main Outcome Measures Using a multivariate approach, we compared the incidence, clinical course, and outcome of peritonitis and exit-site infections in both groups, controlling for other risk factors for the complications studied. Results The incidence of peritonitis was higher in CAPD than in APD (adjusted difference 0.20 episodes/ patient/year, 95% confidence interval 0.08 – 0.32). There was a trend for CAPD patients to present earlier with peritonitis than APD patients, yet the incidence of and survival to the first exit-site infection were similar in both groups. The etiologic spectrum of infections displayed minor differences between groups. Automated PD patients were more frequently hospitalized for peritonitis, but otherwise, the complications and outcome of peritonitis and exit-site infections did not differ significantly between patients on CAPD and those on APD. Conclusions Automated PD is associated with a lower incidence of peritonitis than is CAPD, while exit-site infection is similarly incident under both modes of therapy. The etiologic spectrum, complications, and outcome of peritonitis and exit-site infection do not differ markedly between CAPD and APD. Prevention of peritonitis should be included among the generic advantages of APD over CAPD.

We studied 733 cadaveric renal transplant patients (747 transplants) under cyclosporin immunosuppression, to: (i) establish the risk profile for acute renal failure (ARF) after renal transplantation in a unit using many sub-optimal donors; (ii) assess the long-term prognostic relevance of ARF; and (iii) explore the synergistic prognostic significance of delayed graft function and acute rejection during the early post-transplant period. Transplanting from a non-heart-beating or elderly donor, protracted cold ischaemia, haemodialysis immediately before transplant surgery, poor HLA matching, and grafting to a hypersensitized recipient without residual renal function, all independently predicted delayed graft function. This delay had no detrimental effect on patient or graft survival, but prolonged ARF was associated with increased mortality from infection. Late markers of graft dysfunction (poor graft function, proteinuria, hypertension) were highly prevalent among grafts affected by ARF, specially in prolonged ARF. Delayed graft function and early acute rejection showed a definite, albeit not strong, additive impact on late graft survival, and also on the prevalence of late markers of graft dysfunction.

There is currently no registry that gives a complete and overall view of the peritoneal dialysis (PD) situation in Spain. However, a report on PD in Spain was developed for various conferences and meetings over several years from data provided by each registry in the autonomous communities and regions. The main objective of this study is to analyse this data in aggregate and comparatively to obtain a representative sample of the Spanish population on PD in recent years, in order that analysis and results in terms of demographic data, penetration of the technique, geographical differences, incidence and prevalence, technical aspects, intermediate indicators, comorbidity, and outcomes such as patient and technique survival may be extrapolated to the whole country. DESIGN, MATERIAL AND METHOD: Observational cohort study of autonomous PD registries, covering the largest possible percentage of the adult Spanish population (over 14 years of age) on PD, at least in the last decade (1999-2010), and in the largest possible geographical area in which we were able to recruit. A precise data collection strategy was followed for each regional registry. Once the information was received and clarified, they were added as aggregate data for statistical study.The regional registries that participated represent a total geographical area that encompasses 32,853,251 inhabitants over 14 years of age, 84% of the total Spanish population older than that age. The mean annual rate of incidents per million inhabitants (ppm) was variable (between 17.81 ppm in Andalusia and 29.90 ppm in the Basque Country), with a discrete and permanent increase in the overall PD incidence in Spain being observed in recent years. The mean annual prevalence per million population (ppm) was very heterogeneous (from 42 to 99 ppm). A mean progressive increase in the use of automated peritoneal dialysis (APD) was observed. The peritonitis rate was approximately one episode every 25-30 months/patient, with a slight decrease being observed in recent years. The causes of discontinuing PD were distributed fairly evenly between communities; almost a third was due to patient death (mean 28%), a third was due to renal transplantation (mean 39%) and a third was due to transfer to haemodialysis (technique failure: mean 32%). The main comorbidities were cardiovascular disease (30.2%) and diabetes mellitus (24.2%). The overall accumulated mean survival was 92.2%, 82.8%, 74.2%, 64.8% and 57% after one, two, three, four and five years respectively. There was significantly and independently worse survival for older patients and those with cardiovascular disease, patients with diabetes mellitus, those on continuous ambulatory peritoneal dialysis (vs. APD), those who started PD before 2004 (analysed in Andalusia and Catalonia), and patients with lower residual renal function at the start of PD (analysed in the Levante registry). Similarly, the technique survival has improved, showing a mean figure above 50% after 5 years.The incidence and prevalence of PD in Spain are growing moderately and in a generalised manner and continue to maintain an irregular distribution by autonomous community. Both patient and technique survival were greater than 50% after 5 years, with an improvement being observed in recent years, and are comparable to countries with better results in this treatment.