Tissue distribution of hyalinazing vasculopathy lesions in peritoneal dialysis patients: an autopsy study.

Uremia is considered capable of inducing structural anomalies of the peritoneum, including hyalinizing vasculopathy (HV). To further elucidate the contribution of uremia to the severity of HV, we performed an autopsy study of peritoneal dialysis (PD) patients with severe peritoneal HV lesions. Uremia is a systemic condition and, if capable of inducing HV, it will be expected to be detected outside the peritoneum. Seven autopsy cases of PD patients showing prominent peritoneal HV lesions were selected. Histological slides from the peritoneum, abdominal organs, heart and pericardium, lungs, visceral pleura, and central nervous system were reviewed. Peritoneal lesions were intense in all patients with prominent HV, fibrosis, and a variable presence of inflammation, fibrin, and calcification. Except for focal HV lesions in the intestinal submucosa of one diabetic patient, HV lesions were limited to the peritoneal membrane. None of the other extraperitoneal tissues showed such lesions. In conclusion, extraperitoneal vessels of PD patients show no relevant HV lesions when compared to peritoneal ones. This observation suggests that PD-related factors are the main contributors to the severity of vasculopathy. Uremia may participate in the development of the lesion but it does not seem to be responsible for its severity.

Home training experience in peritoneal dialysis patients.

The objective of nursing is to increase health and well being, prevent morbidity and obtain the best physical and social rehabilitation. The nurse's role in Peritoneal Dialysis (PD) consists of promoting and supporting patients to perform self-care. In the'Text Book of Peritoneal Dialysis, published in 2000,the chapter dedicated to the nurses' role says:"Regular home visits are an important part of follow-up care, as the family and patient need to realize that continuing support is available... It is advisable that the first exchange after discharge from hospital is in the presence of a nurse... Early recognition and management of problems will assist in keeping the patient healthy and well rehabilitated, and will hopefully reduce hospital visits and inpatient stays" (1). Home care in Hospital Universitario La Paz has been developed with varying dedication over the years. Firstly, it was offered if significant problems appeared (1979-1990), later, home visits were started for some new PD patients (1990-1994) and follow up visits then ensued (1995-1996). In 1997, a project was undertaken which included home training for the first time in our unit, as well as periodic follow up visits. This project was shown to the Hospital Nurse Direction, and approved immediately. It started during the first term of 1997. There were several reasons which led us to undertake this project including the importance of providing PD at home and making it lifelong and it was felt that the hospital was an unfriendly environment in which to learn PD. The main objective was to establish early on, the patient's social environment and psychological status, and to assess how these influenced aspects of learning and adapting to PD. Most patients expressed a very good opinion about the home training. Only one patient rejected the presence of the nurse at home. The nursing team was very satisfied because early knowledge about the patient's psychosocial conditions and family environment was established. The incidence of peritonitis decreased.

Parathormone secretion in peritoneal dialysis patients with adynamic bone disease.

The prevalence of low-turnover lesions in patients undergoing peritoneal dialysis (PD) is high. Our aims are to evaluate the prevalence of adynamic bone disease (ABD) in PD patients, analyze risk factors, and define the association of serum parathyroid hormone (PTH) levels measured under different plasma calcium concentrations with this lesion. Fifty-seven patients were studied by bone biopsy (BB). ABD was found in 63.2%, and 36.8% showed high-turnover bone disease (HTBD). Patients with HTBD had a lower prevalence of diabetes, younger age, lower accumulated oral calcium salt intake, and greater calcitriol doses, serum osteocalcin level, and ultrafiltration than patients with ABD. Both mean baseline PTH levels from the previous year and PTH level at time of BB were greater in patients with HTBD than those with ABD (357 +/- 267 pg/mL versus 89 +/- 67 pg/mL; 390 +/- 337 pg/mL versus 88 +/- 78 pg/mL, respectively; P < 0.05). However, the magnitude of the increase from baseline serum PTH levels in response to hypocalcemia was greater in patients with ABD than in those with HTBD (166.4% +/- 134% versus 83.5% +/- 73.6%; P < 0.05). We found that PTH levels less than 150 pg/mL in patients with ABD showed a sensitivity of 91. 6%, specificity of 95.2%, and positive predictive value (PPV) of 97%. In the HTBD group, PTH levels greater than 450 pg/mL had a specificity and PPV of 100%. Our data confirm that ABD is the most prevalent lesion in PD patients, and PTH secretion capacity is maintained in these patients. The definitive diagnosis and management strategies for many patients requires a BB, especially when HTBD is unlikely.

Peritoneal kinetics of cancer antigen 125 in peritoneal dialysis patients: the relationship with peritoneal outcome.

Cancer antigen 125 (CA125) is a mesothelial product that has been directly related with mesothelial bulk in peritoneal dialysis (PD) patients. Here, we evaluate CA125 levels in peritoneal effluent over time on PD, and relate them to changes in peritoneal function. We analyzed 27 peritoneal kinetic studies in 20 stable PD patients. Three patients dropped out of PD for peritoneal membrane failure after the last kinetic study, and six patients required a peritoneal rest period as treatment for membrane failure type I. We recorded the standardized daily ultrafiltration capacity, net ultrafiltration during the kinetic study, peritoneal mass transfer coefficients, time from onset of PD, and incidence of peritonitis prior to the study. A linear increase in CA125 levels over time was observed, and a strong correlation appears among the levels at different dwell times (r: 0.85-0.98, p < 0.05). At 180 minutes, the mean CA125 concentration was 48.5 +/- 39.7 U/mL. We observed significant differences in CA125 levels in effluent between the group of patients who later required a peritoneal rest period and the group of stable patients (27.7 +/- 26.3 U/mL vs 55.7 +/- 41.5 U/mL respectively, p < 0.05). Patients who left PD showed lower CA125 levels in effluent (31.4 +/- 30.6 U/mL vs 52.3 +/- 41.1 U/mL, p < 0.1). No correlation was seen between CA125 levels in effluent and time on PD, episodes of peritonitis, accumulated days of peritoneal inflammation, ultrafiltration capacity, or urea and creatinine mass transfer coefficients (MTCs). In conclusion, we believe that serial determinations of peritoneal effluent CA125 levels may help in the early identification of patients who show abnormal responses to peritoneal dialysis or its complications.

Tumor necrosis factor alpha as a uremic toxin: correlation with neuropathy, left ventricular hypertrophy, anemia, and hypertriglyceridemia in peritoneal dialysis patients.

Tumor necrosis factor alpha (TNF alpha) is usually excreted by the kidney. In dialysis patients, it accumulates. TNF alpha has been implicated in the pathogenesis of malnutrition, diabetic neuropathy, and erythropoietin resistance. We studied TNF alpha plasma levels in 49 stable peritoneal dialysis (PD) patients, with the aim of correlating those levels with the presence and severity of peripheral neuropathy, hypertrophic cardiomyopathy, and anemia. Kt/Vurea' residual renal creatinine clearance (CrC), nutritional markers, and general biochemistry were also determined. The average plasma level of TNF alpha was 67 +/- 32 pg/mL (range: 18.1-156.3 pg/mL; normal value 3-20 pg/mL). No correlation was observed between TNF alpha and KT/Vurea' but a negative correlation with CrC was seen (r: -0.37, p < 0.05). TNF alpha levels were higher in patients with neuropathy as compared to patients with normal results (72.5 +/- 32 pg/mL vs 44 +/- 22 pg/mL, p < 0.05). Patients with neuropathy also showed a lower CrC value (1.5 +/- 1.7 mL/min vs 3.9 +/- 2.6 mL/min, p < 0.01). TNF alpha levels were higher in patients with left ventricular hypertrophy (LVH) with respect to normal individuals (70.4 +/- 32 pg/mL vs 38.5 +/- 20.8 pg/mL, p < 0.05). Patients with severe LVH showed the lowest CrC value. A direct, significant relationship was found between TNF alpha levels and weekly erythropoietin dose (r: 0.41, p < 0.05). Patients with hypertriglyceridemia or taking lipid-lowering agents showed a positive linear correlation between TNF alpha and triglycerides (r = 0.7, n = 14, p < 0.05). These data suggest that accumulation of TNF alpha may contribute to the development or maintenance of some neurologic, hematologic, and cardiac complications of uremic syndrome. Loss of residual renal function conditions an increment in TNF alpha levels. These data continue to add support to the idea that TNF alpha may be considered a uremic toxin.

Mitral annular calcification in CAPD patients with a low degree of hyperparathyroidism. An analysis of other possible risk factors.

Chronic renal failure has been suggested as a risk factor for mitral annular calcification (MAC), a degenerative process of the mitral annulus. The objective of the present study was to define MAC risk factors at the start of dialysis and 'de-novo' appearance after medium- or long-term CAPD, in a non-selected population (135 patients) with a low degree of secondary hyperparathyroidism. Echocardiographic studies were performed at the beginning of CAPD and every 1-1.5 years thereafter. Diagnosis of MAC was established by M mode and 2-D study. Seventeen of 135 patients studied at the start of dialysis showed MAC. Patients who showed MAC were older and presented a higher mean systolic blood pressure. The other anthropometric/demographic parameters did not show statistically significant differences. MAC thickness: mean 6.21 +/- 3.65 mm (range 3-17.2 mm). The posterior annulus was universally affected and in four patients the anterior annulus was involved. Seventeen of 76 patients included in the follow-up study developed MAC. No significant differences for demography, except age, with MAC patients being older, were found. Mean time on CAPD until de-novo MAC diagnosis was 49.7 +/- 26.9 months. MAC thickness: mean 4.97 +/- 1.6 mm (range 3-8.42 mm). The posterior annulus was affected in all patients except for one and in four patients the anterior annulus was involved. The most remarkable echocardiographic feature is the almost constant association of MAC with left atrial dilatation (LAD). The last one does not seem a consequence of mitral insufficiency, or systolic dysfunction. Left ventricular hypertrophy was universally found, with no different intensities for patients with or without MAC. In conclusion, a high incidence of mitral annular calcification has been found in CAPD patients. Our data do not confirm the role of classical invoked risk factors. Blood CaP product under 75, a moderate to mild degree of hyperparathyroidism and/or hypertension with left ventricular hypertrophy do not seem to be isolated risk factors during the CAPD period. Length of time on CAPD, for unknown reasons, seems to favour the appearance of MAC. At starting dialysis, high systolic blood pressure and left ventricular hypertrophy seem to be related to MAC. Diabetes appears to represent an additional risk factor. Further research on mitral annular calcification pathogenesis and its consequences is urgently required.

Cell populations present in the nocturnal peritoneal effluent of patients on continuous ambulatory peritoneal dialysis and their relationship with peritoneal function and incidence of peritonitis.

OBJECTIVE: To study the relationship between peritoneal effluent cells and infection rate and to relate this population with functional characteristics. DESIGN: Prospective, longitudinal, and comparative study. SETTING: Outpatient continuous ambulatory peritoneal dialysis (CAPD) unit of a university medical center. PARTICIPANTS: Seventy-one uninfected patients, treated for 0-156 months on CAPD, in stable condition were studied (33 female, 38 male). INTERVENTIONS: Nocturnal peritoneal effluent (NPE) was drained with EDTA (2.5 mmol/L) at 37 degrees C and centrifuged at 2500 rpm for 9 minutes. MEASUREMENTS: Accumulated peritoneal inflammation days/year and ultrafiltration/diffusion (mass transfer coefficients (MTCs) for small molecules) capacities were recorded. Cellular count (cells/night) was performed using a Neubauer chamber. Macrophage function was assessed by cytochemical (lysosomal enzyme content: ANAE, beta-glucuronidase, acid phosphatase) and immunohistochemical procedures (expression of membrane antigens, CD4, 11b, 11c, 14, 16, 25, 35, and 71). RESULTS: The macrophage is the most frequently appearing cell in the NPE. Cell count decreases over time on CAPD (from 20 x 10(6) to 5 x 10(6) after the first year). Intrapatient variability was low, but interpatient differences were marked. Mesothelial cell count remained stable over time (0.25-0.5 x 10(6)). Four of our patients showed a "transforming" change in these cells. Previous incidence of peritonitis and values of functional measurements did not correlate with cell count or expressions of macrophage function (lysosome enzyme content and percentage of cells expressing different membrane antigens). CONCLUSION: There is difficulty interpreting the results on peritoneal effluent cells and their relationship with the incidence of peritonitis and functional characteristics of the peritoneum. No definite conclusions can be drawn other than the great interpatient and intrapatient variability. The presence of abnormal peritoneal cells with undetermined origin and function suggests the need for periodic studies of peritoneal effluent cells on long-term CAPD patients.