Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD) with a 50% mortality rate. EPS is characterized by progressive and excessive fibrotic thickening of the peritoneum, leading to encapsulation of the bowels and intestinal obstruction. At present, EPS cannot be detected with certainty during its early stages; however, a progressive loss of ultrafiltration capacity often precedes its development. Studies that attempted to elucidate the pathogenesis of EPS have shown that the duration of exposure to PD fluids is the most important risk factor for EPS, and that young age and possibly the effects of peritonitis are additional contributory factors. The pathophysiology of EPS is probably best described as a multiple-hit process with a central role for transforming growth factor β. A form of EPS that develops shortly after kidney transplantation has also been recognized as a distinct clinical entity, and may be a common form of EPS in countries with a high transplantation rate. Criteria have been developed to identify EPS by abdominal CT scan at the symptomatic stage, but further clinical research is needed to identify early EPS in asymptomatic patients, to clarify additional risk factors for EPS and to define optimal treatment strategies.

ORIGINAL ARTICLES♦ Objective: Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD) with a multifactorial pathophysiology and possible increasing incidence. The aim of the present study was to evaluate the independent associations of PD duration, age, dialysis fluids, and kidney transplantation with EPS. ♦ Methods: A multicenter case-control study was performed in the Netherlands from 1 January 1996 until 1 July 2007. The population comprised 63 patients with EPS and 126 control patients. Control patients were selected from the national registry and were matched for date of PD start. Associations were analyzed using a log linear regression model. Primary outcome was appearance of EPS. ♦ Results: Compared with control patients, patients with EPS were younger at the start of PD (34.7 ± 15.4 years vs. 51.5 ± 14.7 years, p < 0.0001). The cumulative period on PD was longer in EPS patients than in control patients (78.7 ± 37.8 months vs. 32.8 ± 24 months, p < 0.0001), and the cumulative period on icodextrin was also longer in EPS patients (32.7 ± 23.3 months vs. 18.1 ± 15.7 months, p = 0.006). Compared with control patients, more EPS patients underwent kidney transplantation (47 vs. 59, p < 0.0001). With regard to the period after transplantation, the yearly probability of EPS increased in the year after transplantation to 7.5% from 1.75%. In multivariate regression analysis, cumulative PD duration, age at PD start, transplantation, time from last transplantation to EPS, calendar time, time on icodextrin, and ultrafiltration failure were independently associated with EPS. Transfer from PD to hemodialysis for reasons other than suspected EPS could not be identified as a risk factor for EPS. ♦ Conclusions: Duration of PD, age at PD start, kidney transplantation, time since last transplantation, ultrafiltration failure, and time on icodextrin were associated with a higher risk of EPS. Perit Dial Int

Tamoxifen treatment in EPS patients is associated with lower mortality and shows a trend to an increased multivariate-adjusted survival. This supports additional use of tamoxifen to treat patients with severe EPS.

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication in patients on peritoneal dialysis (PD). We describe a cluster of 13 EPS cases occurring in 2 university hospitals in The Netherlands. Most of these cases were diagnosed after recent kidney transplantation, when the patients developed severe symptoms of bowel obstruction. This accumulation raised the question as to whether other than known risk factors, such as duration of PD treatment, could be involved in the development or course of EPS after transplantation. According to various publications, EPS has been diagnosed often after withdrawal from PD, suggesting that cessation in itself may be a risk factor. In addition, transplantation-related management should be considered to play a role, including the use of the profibrotic calcineurin inhibitors and the trend to reduce the load of corticosteroids in treatment regimes. To identify risk factors, further multicenter studies are required, paying special attention to alterations in immunosuppressive treatment regimens as well as PD prescriptions, including PD fluid characteristics. Transfer from PD to hemodialysis should be under serious consideration in patients eligible for kidney transplantation as soon as there are indications of ultrafiltration failure.

ObjectiveEncapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD). The aim of this study was to investigate whether dialysate levels of cancer antigen-125 (CA125), K+, interleukin (IL)-6, and vascular endothelial growth factor (VEGF) are early diagnostic markers of EPS. Therefore, we analyzed the time courses of the above described dialysate markers in EPS patients and controls.MethodsDialysate and serum samples of 11 EPS patients and 31 control patients, all treated with PD for at least 57 months, were longitudinally collected during standard peritoneal permeability analyses. CA125 and IL-6 were measured in dialysate only, K+and VEGF were measured in both dialysate and serum. CA125 and IL-6 are expressed as appearance rates (AR). The linear mixed model was used to analyze the time courses. Sensitivity and specificity were calculated based on the results of the last 2 time points.ResultsNo differences in the time courses of the different markers were present between the groups. For K+and VEGF attributed to local production, no differences between the groups were found. However, AR-CA125 was lower during the last 3 years prior to EPS ( p < 0.05) and AR-IL-6 tended to be higher 2 years prior to EPS ( p = 0.09). The combination of AR-CA125 < 33 U/min and AR-IL-6 > 350 pg/min had a sensitivity of 70% and a specificity of 89% for the development of EPS.ConclusionsCompared to controls, AR-CA125 showed lower values and AR-IL-6 tended to be higher during the last years prior to the diagnosis of EPS. The sensitivity and specificity of the combination of CA125 and IL-6 indicate their potential use for an early diagnosis of EPS.