Does prior abdominal surgery influence peritoneal transport characteristics or technique survival of peritoneal dialysis patients?

[Abstract] 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

Long-Term Trends in the Incidence of Peritoneal Dialysis-Related Peritonitis Disclose an Increasing Relevance of Streptococcal Infections: A Longitudinal Study

[Abstract} Background. The 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. Objectives. To 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. Method. Following 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 results. Our 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. Conclusions. Time 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

Influence of peritoneal residual volume on the results of the peritoneal equilibration test. Prospective study

Background: Categorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of Peritoneal Dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable. Method: Following a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n = 27) PET with 3,86/4,25% glucose-based PD solutions and complete drainage at 60 min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration. Results: As a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs. 449 mL, p 200 mL) between both methods of estimation of the capacity of utrafiltration in only 12,9% of the patients. However, 21,1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr. Conclusions: Correction for Vr of the capacity of ultrafiltration during a PET carries, as a mean, a minor impact on the categorization of this parameter. However, the results of the test can be significantly affected in 12,9% of the cases. We have been unable to detect demographic or clinical predictors of Vr, which suggests a random component for the mechanics of single peritoneal exchanges. We suggest that Vr should be estimated at the time of categorizing the capacity of ultrafiltration, whenever inconsistencies during serial PET studies are detected. Resumen: Introducción y objetivos: La categorización de la capacidad de ultrafiltración durante la prueba de equilibrio peritoneal (PEP) es parte habitual de la monitorización del funcionalismo peritoneal en pacientes tratados con Diálisis Peritoneal (DP). La estimación del volumen residual (Vr) tras el cambio previo (Vrpre) y el de la propia PEP (Vrpost) podría ayudar a mejorar la precisión de la prueba. Método: Siguiendo un diseño 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 solución de glucosa al 3,86/4,25% y drenaje completo a los 60 minutos. Valoramos la consistencia del Vr comparando Vrpre y Vrpost y también estos parámetros en PEP sucesivas. Analizamos la posible influencia de factores demográficos y clínicos en la cuantía del Vr, así como el impacto de la corrección para Vr de la ultrafiltración durante la PEP sobre la categorización de la capacidad de ultrafiltración. Resultados: El Vrpost fue mayor que el Vrpre, por lo que la ultrafiltración corregida para Vr fue signficativamente mayor que la calculada por procedimiento estándar (494 vs. 449 mL, p 200 mL) de la ultrafiltración corregida para Vr frente al valor estándar. Sin embargo, un 21,1% de los pacientes que cumplían criterio de fallo de ultrafiltración por método estándar, no lo hacían si se aplicaba la corrección para Vr. Conclusiones: La corrección para Vr modifica escasamente, como media, la estimación de la capacidad de ultrafiltración durante la PEP al 3,86/4,25%, aunque tiene un impacto significativo en un 12,9% de las pruebas. No hemos detectado factores predictivos del Vr durante la PEP, lo que sugiere un componente de aleatoriedad en la mecánica del cambio peritoneal. Sugerimos que este parámetro debe ser estimado si se observan inconsistencias en los resultados de la PEP en lo relativo a la capacidad de ultrafiltración

Low Incidence of Acute Antibody-Mediated Rejection after HLA Desensitization in Living Donor Kidney Transplant Recipients

Desensitization allows the performance of human leukocyte antigen (HLA)-incompatible transplants. However, the incidence of acute rejection (AR) is high. This study aims to analyze the incidence of AR after transplantation with HLA-incompatible living donors in patients who underwent desensitization. Patients were immunosuppressed with tacrolimus, mycophenolic acid derivatives, and steroids after being desensitized with rituximab, plasma exchange, and/or immunoadsorption with specific cytomegalovirus immunoglobulins. A negative complement-dependent cytotoxicity or flow cytometry crossmatch and a donor-specific antibody titer < 1000 mean fluorescence intensity (MFI) were used to determine desensitization efficacy. A total of 36 patients underwent desensitization, and 27 (75%) were transplanted. After a follow-up of 58 ± 58 months (Min–Max: 0.13–169.5), five episodes of AR occurred: two antibody-mediated and three T-cell-mediated. No differences were found in baseline calculated panel-reactive antibodies (cPRA), class I or II MFI, number of antibodies, or Relative Intensity Scale (RIS) between AR and non-AR patients. Patients with antibody-mediated AR had higher cPRA (NS), MFI class I (p = 0.07) and class II (p = 0.006), and RIS (p = 0.01). The two patients with antibody-mediated AR and one patient with T-cell-mediated AR lost their grafts. In conclusion, the incidence of acute antibody-mediated rejection after desensitization was 7.4%, which occurred early post-transplantation in patients with high MFI and was associated with early graft loss