[Peritoneal dialysis after renal graft loss: against maintenance of immunosuppression]. / Diálisis peritoneal tras pérdida del injerto renal: en contra de mantener la inmunosupresión.

It is well known that the existence of residual renal function (RRF) in peritoneal dialysis (PD) is related, amongst others, to improved results in nutrition, cardiovascular morbidity, and technique and patient survival. It appears natural to think that this fact, obvious in the population who starts replacement therapy, should also occur in dialysis patients in whom RRF depends on a transplant, which could justify maintenance of immunosuppressive treatment (IST). However, there are currently no studies showing a correlation between RRF of the graft and survival on dialysis. At the same time, IST maintenance in an attempt to preserve glomerular filtration rate would involve risks (cardiovascular morbidity, infections, etc.) that could counteract the theoretical beneficial effect on RRF or even worsen prognosis. The available literature analyzing this controversy is scarce and is mostly based on small and retrospective series providing conflicting results. The decision about what to do with IST and how to do it in patients with chronic kidney transplant dysfunction arriving to dialysis should be based on opinions. When faced with this situation, and because of the significant negative effects of IST at cardiovascular and infectious level, the main causes of morbidity and mortality in uremic patients, we advocate discontinuation of IST when PD is started until future studies on the subject are available.

Mammalian Target of Rapamycin Inhibitor Monotherapy: Efficacy in Renal Transplantation.

BACKGROUND: Calcineurin inhibitors (CNI) have failed to improve long-term outcomes in renal transplantation. Anti-proliferative and anti-angiogenic effects of mammalian target of rapamycin inhibitors (m-TOR) without nephrotoxicity could improve long-term survival in selected transplant recipients. METHODS: We examined the evolution of 98 low-immunological risk renal transplant recipients on m-TOR monotherapy: 7 patients had induction without CNI and 91 were switched to m-TOR at 12 (p25-p75: 4-36) months after transplant. RESULTS: Median follow-up time was 46 (p25-p75: 28.5-72.0) months. Fifteen recipients dropped out of the study (15.3%): 8 patients (8.2%) had to change their immunosuppressive treatment because of complications and 7 (7.1%) lost their grafts as a result of chronic rejection (4 cases) or death with a functioning graft (3 cases). At the end of follow-up, 83 of 98 (84.6%) recipients remained on monotherapy. The rates of recipient and graft survivals were 100% and 98.8% at 2 years and 96.9% and 93.5% at 4 years; the percentages of patients on monotherapy after 2 and 4 years were 95.2% and 85.2%, respectively. Renal function improved significantly and proteinuria decreased but not significantly. Those patients switched to m-TOR significantly received more erythropoietin, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and hypotensive agents than before starting m-TOR, whereas there were no significant changes related to the use of statins, body weight, or percentage of diabetic patients. No case of non-compliance was reported. CONCLUSIONS: This study supports the safety and efficacy of monotherapy with m-TOR in selected renal transplant recipients.

A prospective multicenter comparison of peritonitis in peritoneal dialysis patients aged above and below 65 years. Levante PD Multicenter Group.

Various authors have found peritonitis rates in older peritoneal dialysis (PD) patients to be higher, similar, or even lower when compared to rates in younger populations. We prospectively analyzed all episodes of peritonitis registered in the 381 patients (219 males, 162 females; mean age, 55.5 +/- 17.0 years) who were treated with PD during four years (1993-1996) in our multicenter group. Patients were distributed into two groups. Group A included 138 patients aged 65 years or over (mean age: 72.3 +/- 5.1 years); group B included 243 patients aged below 65 years (mean age: 46.0 +/- 13.6 years). No differences were seen in general PD characteristics. Normalized protein catabolic rate (nPCR) was higher in younger patients (p = 0.001). Patients in group A experienced more peritonitis (135 episodes; 1 episode per 16.7 patient-months) than patients in group B (198 episodes; 1 episode per 21.7 patient-months; p = 0.01). Although no differences were seen in the general characteristics of the peritonitis episodes, gram-negative peritonitis and peritonitis not achieving a cure were more commonly secondary to enteric bacteria in group A (p = 0.03). We conclude that PD patients aged 65 years or over are at higher risk of peritonitis. Also, in this age group, gram-negative peritonitis and peritonitis with any evolution except cure are more likely to be due to enteric bacteria.

Can the creatinine dialysate-to-plasma ratio from the peritoneal equilibration test be replaced by the sodium dialysate-to-plasma ratio and the sodium level in the dialysate?

The peritoneal equilibration test (PET) is a useful tool that categorizes peritoneal transport. However, the method has some inconveniences. Some authors suggest that measuring the sodium level in the dialysate (NaD) or the dialysate-to-plasma ratio for sodium (D/PNa) can substitute for the PET. We applied a mathematical analysis [Fisher intraclass correlation coefficient (FICC)] to 43 PETs performed in 43 peritoneal dialysis patients (29 males, 14 females) with a mean age of 55.3 years (range: 28-85 years). Determinations of NaD, of sodium level in plasma (NaP), and of D/PNa at times 0, 30, 60, 120, and 240 minutes were added to the usual PET determinations. After using the NaD240 and the D/PNa240 values to calculate the cut-off values for the various peritoneal transport categories, we obtained a transport distribution very similar to that of the PET dialysate-to-plasma ratio for creatinine after 240 minutes (D/PCr240). At the same time, the FICC showed good (0.69) and excellent (0.77) correlation of NaD240 and D/PNa240 respectively with the D/PCr240. Therefore either of these two methods, which are cheaper and quicker than a PET, can be used to categorize peritoneal transport with a high degree of reliability.

Importance of residual renal function in continuous ambulatory peritoneal dialysis: its influence on different parameters of renal replacement treatment.

OBJECTIVE: To study the influence of residual renal function (RRF) on different parameters of the renal substitutive treatment offered by peritoneal dialysis. METHODS: We analyzed the impact of RRF on dialysis dose, nutrition parameters, anemia and phosphocalcic metabolism in 37 patients with end-stage renal disease (ESRD) treated by continuous ambulatory peritoneal dialysis (CAPD). Analytical controls were done every 6 months after an initial assessment at the end of the first month of treatment. Multiple lineal regression models were used as the statistical method to analyze the influence of RRF on different theoretically dependent factors. RRF was calculated as a mean of creatinine and urea clearances. Three observations per patient were used: one at the end of the first month of treatment; a final one at the end of follow-up (mean time 24.2 +/- 11.4 months), and at a mean time between them (13.4 +/- 6.7 months), with a final number of 111 observations. RESULTS: Dialysis dose: RRF was the most important factor in terms of creatinine clearance (r(2) = 0.94; beta = 0.999), KT/V (r(2) = 0. 68; beta = 0.819) and beta(2)-microglobulin levels (r(2) = 0.46; beta = -0.489). Nutrition parameters: RRF was a determinant factor for normalized protein catabolic rate (r(2) = 0.53; beta = 0.471), percent lean body mass (r(2) = 0.45; beta = 0.446) and albumin levels (r(2) = 0.25; beta = 0.229). Anemia: RRF was the most important factor when studying hemoglobin levels (r(2) = 0.28; beta = 0.407). Phosphocalcic metabolism: Between the analyzed factors, RRF was the only one which reached significance on serum phosphate levels (r(2) = 0.19; beta = -0.594). RRF did not show any relationship with either calcium or PTH levels. CONCLUSIONS: Independent of other factors, RRF in CAPD is positively and directly related to dialysis dose, beta(2)-microglobulin levels, nutrition parameters (albumin, normalized protein catabolic rate and percent lean body mass, hemoglobin and serum phosphate levels.

Prevalence and risk factors for hepatitis C virus infection in continuous ambulatory peritoneal dialysis patients.

BACKGROUND: Studies on hepatitis C virus antibodies (Anti-HCV) in CAPD patients are scarce and include a small number of patients. Nevertheless, risk factors related to Anti-HCV in these patients are still subject to controversy. Purpose of the study. To analyse the incidence and risk factors associated with the presence of Anti-HCV in CAPD patients. METHODS: We studied 255 patients from five different treatment centres of our region. The analysis was repeated after excluding 161 patients who had previously received haemodialysis treatment at least once. Anti-HCV testing was made by the 2nd-generation ELISA: As a supplementary test we used RIBA-4 in three centers and INNOLIA in the other two. Risk factors were analysed using logistic regression model for multivariate analysis. RESULTS: In the whole group, 29 patients (11.4%) were anti-HCV positive. Logistic regression analysis determined the following variables as independent risk factors: hepatitis previous to CAPD (P<0.001, odds ratio (OR):44.9), Anti HBc positivity (P=0.019, OR:9. 24), blood transfusions previous to CAPD (P=0.015, OR:1.05) and CAPD duration were excluded, the prevalence of HCV antibodies was 8.5% (8/94). In this group multivariate analysis showed that Anti-HCV positivity correlated with hepatitis previous to CAPD (P<0.0003, OR: 126) and Anti HBc positivity (P=0.002, OR:41.9). CONCLUSIONS: Our prevalence of hepatitis C virus (HCV) infection in CAPD patients was lower than other renal replacement therapy modalities, and correlated to events occurring mainly before starting CAPD treatment. This technique could be considered as low risk for HCV infection.

Diálisis peritoneal tras pérdida del injerto renal: en contra de mantener la inmunosupresión / No disponible

Es bien sabido que la existencia de función renal residual(FRR) en diálisis peritoneal (DP) se relaciona, entre otros, con mejores resultados en nutrición, morbilidad cardiovascular y supervivencia de técnica y paciente. Parece lógico pensar que este hecho, evidente en la población que inicia tratamiento sustitutivo, debería también producirse en enfermos dializados en los que la FRR dependa de un trasplante, lo que podría justificar el mantenimiento del tratamiento inmunosupresor (TIS). No obstante, en el momento actual no hay trabajos que hayan demostrado una correlación entre FRR del injerto y supervivencia en diálisis. Al mismo tiempo, el mantenimiento del TIS para intentar conservar el filtrado glomerular conllevaría unos riesgos(morbilidad cardiovascular, infecciones, etc.) que podrían contrarrestar el teórico efecto beneficioso sobre la FRR o incluso empeorar el pronóstico. A día de hoy, la literatura dedicada a analizar esta controversia es escasa y se basa, en la mayoría de casos, en series cortas y retrospectivas con resultados contrapuestos, por lo que la decisión sobre qué hacer y cómo con el TIS del paciente con disfunción crónica de trasplante renal que llega a diálisis debe basarse en opiniones. Ante esta situación, y dados los importantes efectos negativos que el TIS tiene a nivel cardiovascular e infeccioso, principales causas de morbimortalidad del enfermo urémico, nos mostramos partidarios de suspender su administración al iniciar DP hasta disponer de futuros estudios al respecto (AU)

It is well known that the existence of residual renal function(RRF) in peritoneal dialysis (PD) is related, amongst others, to improved results in nutrition, cardiovascular morbidity, and technique and patient survival. It appears natural to think that this fact, obvious in the population who starts replacement therapy, should also occur in dialysis patients in whom RRF depends on a transplant, which could justify maintenance of immunosuppressive treatment (IST). However, there are currently no studies showing a correlation between RRF of the graft and survival on dialysis. At the same time, IST maintenance in an attempt to preserve glomerular filtration rate would involve risks (cardiovascular morbidity, infections, etc.) that could counteract the theoretical beneficial effect on RRF or even worsen prognosis. The available literature analyzing this controversy is scarce and is mostly based on small and retrospective series providing conflicting results. The decision about what to do with IST and how to do it in patients with chronic kidney transplant dysfunction arriving to dialysis should be based on opinions. When faced with this situation, and because of the significant negative effects of IST at cardiovascular and infectious level, the main causes of morbidity and mortality in uremic patients, we advocate discontinuation of IST when PD is started until future studies on the subject are available (AU)