Abstract Introduction: Kidney transplant (KT) recipients have a high risk for adverse outcomes from infections, such as COVID-19. Methods: We have retrospectively reviewed all KT recipients with documented COVID-19 between March 1, 2020, and March 15, 2021, and analyzed patients’ characteristics, clinical course, treatment, and outcomes. Results: We identified 123 patients, 72% were male, with a mean age of 54.5±13.0 years. Twenty percent were asymptomatic, 7% had a nosocomial transmission, and 36% of the remainder required hospitalization. Almost all admitted patients received oxygen, 30% required invasive mechanical ventilation (IMV), more than a half had acute kidney injury, with 10% requiring dialysis, and 20% died. Incidence was comparable to that of the Portuguese population, but the mortality rate was almost four times higher (SMR of 3.768 (95% CI:1.723-7.154). Higher body mass index (OR 1.275, P=0.001), lower baseline graft function (OR 0.968, P=0.015), and nosocomial transmission (OR 13.836, P=0.019) were associated with oxygen demand, whereas female gender (OR 3.801, P=0.031) and lower baseline kidney graft function (OR 0.955, P=0.005), but not body mass index, were associated with IMV and/or death. Conclusion: Mortality rate in KT patients was higher than in the general population and lower baseline kidney function was the most consistent marker for adverse outcomes.

Resumo Introdução: Os receptores de transplante renal (TR) apresentam um alto risco para desfechos adversos de infecções, tais como a COVID-19. Métodos: Revisamos retrospectivamente todos os receptores de TR com COVID-19 documentada entre 1º de Março de 2020 e 15 de Março de 2021, e analisamos as características, curso clínico, tratamento e desfechos dos pacientes. Resultados: Identificamos 123 pacientes, 72% do sexo masculino, com uma média de idade de 54,5±13,0 anos. Vinte por cento eram assintomáticos, 7% apresentaram transmissão nosocomial, e 36% do restante necessitaram de internação. Quase todos os pacientes internados receberam oxigênio, 30% necessitaram de ventilação mecânica invasiva (VMI), mais da metade apresentou lesão renal aguda, com 10% necessitando de diálise, e 20% foram a óbito. A incidência foi comparável à da população portuguesa, mas a taxa de mortalidade foi quase quatro vezes superior (TMP de 3,768 (IC 95%: 1,723-7,154). Maior índice de massa corporal (OR 1,275; P=0,001), menor função do enxerto basal (OR 0,968; P=0,015), e transmissão nosocomial (OR 13,836; P=0,019) foram associados à demanda de oxigênio, enquanto sexo feminino (OR 3,801; P=0,031) e menor função do enxerto renal basal (OR 0,955; P=0,005), mas não índice de massa corporal, foram associados à VMI e/ou óbito. Conclusão: A taxa de mortalidade em pacientes com TR foi mais elevada do que na população em geral e a função renal basal mais baixa foi o marcador mais consistente para desfechos adversos.

ABSTRACT Older to older living kidney transplantation is an acceptable alternative to avoid dialysis, improve quality of life and maintain favorable long-term outcomes of patients with end-stage kidney disease. However, the management of these patients is complex and the acceptance of older donors and recipients to kidney transplantation remains controversial. The older recipients usually have several comorbidities that may complicate the postoperative course and increase the risk of end-stage kidney disease. We present a clinical case of living kidney transplantation between an older donor and recipient, both over 70 years old, who evolved to a stage 3 chronic kidney disease, without proteinuria, hypertension, or other complications, three years after transplantation. Our case reinforces favorable outcomes in older living transplantation, both for recipient and donor, as has been demonstrated in several published studies.

RESUMO Introdução: A taxa estimada de filtração glomerular (TFGe) com base na cistatina-C sérica (Cis-C) parece ser tão precisa quanto aquela baseada na creatinina sérica (Cr), mas cis-C parece ser um melhor preditor de resultados adversos. Nosso objetivo foi avaliar se a cis-C poderia ser uma ferramenta confiável para a previsão de desfechos adversos em pacientes idosos com doença renal crônica grave (DRC). Métodos: Um grupo de 348 pacientes idosos com DRC em estágio não terminal (estágios 1-4, de acordo com TFGe-EPI Cr e/ou Cis-C), encaminhados para nossa unidade de consulta durante 2016, foi estudado retrospectivamente e dividido em quatro categorias exclusivas: DRC_estágio 4 nenhum (TFGe-Cr≥30mL/min; TFGe -Cis-C≥30mL/min), DRC_estágio 4_Cr apenas (TFGe-Cr <30mL/min), DRC_estágio 4 _Cis-C_apenas (TFGe-Cis-C <30 mL/min), DRC_estágio4_combinado (TFGe-Cis-C <30mL/min. TFGe-Cr <30mL/min). Características basais, preditores de óbito e eventos clínicos (eventos cardiovasculares e internações por doenças cardiovasculares, lesão renal aguda ou eventos infecciosos) foram explorados até dezembro de 2018. Resultados: Uma coorte de 77 ± 7,4 anos, com índice de comorbidade de Charlson modificado (mCCI) de 3 (IQR: 1-4), foi acompanhada durante 29 (IQR: 26-33) meses. Não houve diferenças significativas entre as características dos grupos no estágio 4. A análise de sobrevida foi estratificada pelo acompanhamento aos 12 meses, sendo que no primeiro ano, as curvas de sobrevida dos grupos DRC_estágio4_Cis-C_apenas e DRC_estágio4_ combinado foram significativamente inferiores quando comparadas com os restantes grupos (p = 0,028). Ajustando para idade, sexo e mCCI, DRC_estágio4_Cis-C_apenas, ao contrário do grupo DRC_estágio4_Cr_apenas, teve maiores taxas de eventos clínicos (p <0,05) do que o grupo DRC_estágio4_nenhum. Conclusão: Em pacientes idosos com estadiamento discordante da DRC, a TFGe baseada na Cis-C parece ser um melhor preditor de resultados adversos do que a TFGe baseada na Cr. Pacientes com DRC em estágio 4, definida apenas por Cr, parecem se comportar de forma semelhante àqueles com DRC menos grave.

ABSTRACT Introduction: Estimated glomerular filtration rate (eGFR) based on serum cystatin-C (sCys) seems as accurate as when based on serum creatinine (sCr), but sCys seems a better predictor of adverse outcomes. We aimed to study whether sCys could be a reliable tool for the prediction of adverse outcomes in elderly patients with severe chronic kidney disease (CKD). Methods: A group of 348 elderly patients with non-end-stage CKD (stages 1-4, according to eGFR-EPI sCr and/or sCys), referred to our consultation unit during 2016, was retrospectively studied and divided into four exclusive categories: CKD_stage4_neither (eGFR-sCr≥30mL/min; eGFR-sCys≥30mL/min), CKD_stage4_sCr_only (eGFR-sCr<30mL/min), CKD_stage4_sCys_only (eGFR-sCys<30mL/min) and CKD_stage4_combined (eGFRsCr<30mL/min; eGFR-sCys<30mL/min). Baseline characteristics, predictors of death, and clinical events (cardiovascular events and admissions for cardiovascular, acute kidney injury or infectious events) were explored until December 2018. Results: A 77±7.4 year-old cohort, with a modified Charlson Comorbidty Index (mCCI) of 3 (IQR:1-4), was followed-up during 29 (IQR: 26-33) months. There were no significant differences between the characteristics of the stage 4 groups. Survival analysis was stratified by follow-up at 12 months, and in the first year, survival curves of CKD_stage4_sCys_only and CKD_stage4_combined groups were significantly lower than the other groups (p=0.028). Adjusting for age, sex, and mCCI, CKD_stage4_sCys_only, conversely to CKD_stage4_sCr_only, had higher rates of clinical events (p<0.05) than CKD_stage4_neither group. Conclusion: In elderly patients with discordant CKD staging, sCys-based eGFR seems to be a better predictor of adverse outcomes than sCr-based eGFR. Patients with stage 4 CKD defined by sCr alone seem to behave similar to those with less severe CKD.

Background and objectives: To evaluate RRT benefits and risks and to inform patients and their families about ESRD treatment options, we have developed a prognostic score to predict 6-month mortality in elderly ESRD patients initiating dialysis. Five independent predictors were identified and a point system was constructed: age 75 years or older (2 points), coronary artery disease (2 points), cerebrovascular disease with hemiplegia (2 points), time of nephrology care before dialysis [< 3.0 months (2 points); ≥ 3 to < 12 months (1 point)], serum albumin levels [3.0 - 3.49 g/dL (1 point); < 3.0 g/dL (2 points)]. Model performance was good in both discrimination and internal validation. Before adopting our risk score into practice, our aim is to externally validate this initial predictive model by assessing its performance on a new data set. Methods: We apply the predictive score developed in a cohort of CKD patients, aged 65 years and over who started dialysis between 2009 and 2016, to an independent cohort of ESRD patients, aged 65 years and over who started dialysis between 2017 and 2019, in our Nephrology department. The performance of the prediction equation created in development cohort, was assessed using discrimination and calibration metrics in the validation cohort. Results: Our validation study cohort included 168 individuals, with a mortality rate of 12.5% (n=21) within 6-months of dialysis initiation. Model performance in the validation cohort had an acceptable discrimination [AUC of 0.79; (95% confidence interval, 0.70 to 0.88)]. The Hosmer and Lemeshow goodness-of-fit test was not statistically significant, indicating good calibration of the model (χ2, 5 degrees of freedom = 2.311; P = 0.805). Conclusions: Our predictive simple score based on readily available clinical and laboratory data demonstrates a good performance when externally validated, namely with respect to discrimination and calibration. Model validation is crucial for adequately informing patients and their families about ESRD treatment options and providing a more patient-centered overall approach to care. Before we start general implementation in clinical practice, our score needs further validation in larger patient cohorts.

Rituximab (RTX) is a chimeric anti-CD20 monoclonal antibody that has been associated with delayed pulmonary toxicity. In patients receiving RTX, hypersensitivity pneumonitis, although rare, should be considered in the appropriate clinical and radiographic setting. The authors present a case of hypersensitivity pneumonitis associated with a single dose of RTX treatment in a kidney transplanted patient with acute antibody-mediated rejection.

Introduction: ABO incompatibility was considered a barrier to kidney transplant. However, the shortage of available organs for transplantation and the excellent long-term results further establish ABO-incompatible (ABOi) as a safe and effective therapeutic strategy. The aim of the present study was to evaluate the outcomes of ABOi transplantation in terms of graft survival and function, rejection episodes and infections complications. Methods: The authors present a single-center retrospective observational study in a unit with approximately 370 living donor kidney transplants registered. This study includes the analysis of 12 patients who underwent ABOi living donor kidney transplantation between November 2014 and July 2019. Desensitization protocol consisted of intravenous Rituximab 375mg/m2 single dose administration 2 weeks pretransplant. Tacrolimus and Mycophenolate Mofetil were started before transplantation one week and 48 hours respectively. Plasmapheresis was performed to remove anti-A or B antibodies until their titers were <1:8 during the first post-operative week and <1:16 at the second. All kidney recipients of both ABOi grafts received Basiliximab (20mg on days 0 and 4) as antibody induction therapy. Maintenance immunosuppression consisted of Tacrolimus, Mycophenolate Mofetil and corticosteroid. Results: A total of 12 patients were included in the study, 75% male; 43 years (IQR 31-50). The most common blood group mismatch was A to O (n=4; 33%). In the first year, 2 of patients (25%) developed acute rejection. The follow-up time was 17 months (IQR 7-36). Five patients (42%) developed infectious complications. None patients developed cytomegalovirus or BK polyomavirus infections. At the end graft and patient survival were 100%. Conclusion: ABOi kidney transplantation has become a routine procedure. With this approach, about 30% of living donors who were refused in the past can now donate their kidneys and thereby significantly expand the living donor pool. The immunosuppressive protocol of this unit can be considered safe.

The passenger lymphocyte syndrome may cause hemolytic anemia after bone marrow and solid organ transplantation when there is minor erythrocyte antigen incompatibility in the donor/recipient pair. Anemia is usually self-limiting, frequently related to ABO antibodies and rarely to Rh mismatches. We report a rare case of passenger B lymphocyte syndrome mediated by Rh antibodies occurring after a donor living renal transplantation and discuss its clinical severity at presentation, the therapeutic decisions and their outcome.

RESUMO Introdução: Doença renal crônica (DRC) é fator de risco independente para vários desfechos desfavoráveis, incluindo doença cardiovascular (DCV), particularmente em idosos, o segmento de crescimento mais rápido da população com doença renal terminal (DRT). Portugal tem a maior incidência europeia não-ajustada e a maior prevalência de DRT. Neste artigo caracterizamos uma coorte de idosos com DRC, referenciados para a nefrologia, com particular ênfase para o risco e carga de doença cardiovascular. Métodos: Foram incluídos todos os pacientes com DRC com 65 anos ou mais encaminhados ao nosso departamento em 2012. Os dados basais incluíram: demografia, estágio da DRC, medicação e comorbidades. A taxa de filtração glomerular (TFGe) foi calculada pela fórmula CKD-EPI. Resultados: Metade dos 416 pacientes incluídos foram encaminhados por médicos da atenção primária; sua idade era 77 ± 7 anos; 52% eram homens; a TFGe mediana era de 32 mL /min/1,73 m2. Metade tinha diabetes (DM), 85% dislipidemia, 96% hipertensão; 26% eram fumantes atuais/ antigos; 24% tinham índice de massa corporal > 30 kg/m2. A prevalência de DCV foi de 62%, sendo maior entre pacientes nos estágios 4-5; em diabéticos, aumentou gradualmente com a progressão da DRC (estágio 3a < estágio 3b < estágio 4-5) (39%, 58%, 82%; p < 0,001). Conclusões: A coorte de idosos com DRC apresentava inicialmente maior carga de DCV. A prevalência de DCV foi maior que em outras coortes europeias com DRC. Níveis menores de TFGe foram associados a carga maior de DCV e foram mais pronunciados entre diabéticos, destacando a importância de objetivar estrategicamente a redução do risco cardiovascular nesses pacientes.

ABSTRACT Introduction: Chronic kidney disease (CKD) is an independent risk factor for several unfavorable outcomes including cardiovascular disease (CVD), particularly in the elderly, who represent the most rapidly growing segment of the end-stage kidney disease (ESKD) population. Portugal has the highest European unadjusted incidence and prevalence rates of ESKD. In 2012, we started to follow a cohort of elderly CKD patients, we describe their baseline characteristics, risk profile, and cardiovascular disease burden. Methods: All CKD patients aged 65 years and older referred to our department during 2012 were enrolled. Baseline data included: demographic, CKD stage, medication, comorbid conditions. Estimated glomerular filtration rate (eGFR) was calculated by the CKD-EPI formula. Results: A total of 416 patients, 50% referred by primary care physicians, aged 77 ± 7 years, 52% male, with a median eGFR of 32 mL/min/1.73m2 participated in the study. Fifty percent had diabetes (DM), 85% dyslipidemia, 96% hypertension; 26% were current/former smokers, and 24% had a body mass index > 30 kg/m2. The prevalence of CVD was 62% and higher in stage 4-5 patients; in diabetics, it gradually increased with CKD progression (stage 3a < stage 3b < stage 4-5) (39, 58, 82%; p < 0.001). Conclusions: At baseline, our CKD elderly cohort had a higher burden of CVD. The prevalence of CVD was greater than in other European CKD cohorts. Lower level of eGFR was associated with a greater burden of CVD and was more pronounced in diabetics, highlighting the importance of strategically targeting cardiovascular risk reduction in these patients.

Tubulointersticial nephritis and uveitis syndrome is an idiopathic and rare cause of acute kidney injury that should not overlooked, because it usually requires specific therapeutic interventions. We report two distinct cases: a young and an elder female. Both cases presented with unspecific constitutional symptoms but had different onset of renal and ocular involvement. Both were treated with topical and systemic corticoids and although there was a good initial response in both cases, an early relapse after steroids taper was observed in the younger patient and a persistent renal dysfunction in the older one. A high clinical suspicion and understanding of this disease is necessary for an adequate management and treatment of these patients. Recent data associates a worse renal prognosis when the disease appears inadvanced age. In both of our cases the outcome was good but we had a short follow-up. The histological presentation of this disease in our older patient was similar to that reported in the literature, with a high percentage of fibrosis and chronicity of renal tissue that can contribute to the higher grade of renal dysfunction in this type of patients

Alloantibodies against donor human leukocyte antigens (HLA), termed as donor-specific antibodies (DSA), are one of the most important factors for both early and late kidney allograft dysfunction. In the past, these antibodies were mainly detected through cell-based crossmatch tests. Recently, new techniques such as solid phase immunoassays (SPI) have revealed these antibodies in patient sera with a high degree of detail, previously unimaginable. They have allowed us to accurately determine recipients’ allosensitization status, improve pre-transplant risk assessment with a potential donor and post-transplant alloimmune monitoring. However, the high sensitivity of these new assays has also created areas of uncertainty about their clinical impact. In the pre-transplant setting, the presence of preformed DSA has been associated with an increased risk of antibody-mediated rejection (AMR) and subsequent allograft loss. Nevertheless, several studies have shown that not all DSA are deleterious. Hence, understanding the clinical correlations of DSA characteristics, namely strength, HLA class, complement-fixing ability or IgG subclasses, is paramount for an adequate stratification of the immunological risk at transplant. Furthermore, given that the number of allosensitized patients on waiting lists is increasing, the added information from these new SPI is essential to improve their chance of being transplanted with an admissible immunological risk. After transplantation, the appearance of de novo DSA (dnDSA) has also been associated with a deleterious effect on kidney allograft survival. Moreover, it has been acknowledged that a majority of late allograft failures are caused by alloantibody-driven injury. The current challenges, in this setting, are determining cost-effective DSA screening protocols and understanding which patients could benefit from specific interventions. Furthermore, although therapeutic strategies to control antibody-induced damage remain limited, the longitudinal surveillance of dnDSA emergence and the clinical correlations of their characteristics will play a crucial role in the improvement of late kidney allograft survival.

Abstract Patients who are candidates for a second kidney transplant (SKT) frequently have a higher level of panel reactive antibodies (PRA). We assessed the allosensitisation change after a first graft failure (GF), its predictors and impact on retransplantat outcomes. We retrospectively selected 140 adult patients who received a SKT. Recipient and donor characteristics were analyzed. We defined the delta PRA (dPRA) as the difference between peak PRA before the SKT and first one (cohort median value = +10%). Logistic regression analysis was used to determine risk factors for dPRA ≥ 10% and acute rejection (AR) in the SKT. Univariable and multivariable Cox analysis was applied to assess independent predictors of second GF. Risk factors for dPRA ≥ 10% at SKT were AR (OR = 2.57; P = 0.022), first graft survival <1 year (OR = 2.47; P = 0.030) and ABDR HLA mismatch (OR = 1.38 per each mismatch; P = 0.038). AR in the SKT was associated with dPRA ≥ 10% (OR = 2.79; P = 0.047). Induction with a lymphocyte-depleting agent had a protective effect (OR = 0.23; P = 0.010). SKT survival was lower (P = 0.008) in patients with a dPRA ≥ 10% (75.6%, 60.5% in dPRA ≥ 10%; 88.6%, 88.6% in dPRA < 10% patients at 5 and 10 years, post-transplant respectively). Multivariable Cox regression showed that dPRA ≥ 10% (HR = 2.38, P = 0.042), delayed graft function (HR = 2.82, P = 0.006) and AR (HR = 3.30, P = 0.001) in the SKT were independent predictors of retransplant failure. This study shows that an increased allosensitisation at retransplant was associated with the degree of HLA mismatch and led to poorer outcomes. De-emphasis of HLA matching in current allocation policies may be undesirable, particularly in patients with a higher chance of needing a SKT.

Resumen Los pacientes candidatos a un segundo trasplante de riñón (STR) tienen a menudo un nivel superior de panel reactivo de anticuerpos (PRA). Evaluamos el cambio de alosensibilización después de un primer fracaso del injerto, sus predictores y repercusión en los resultados del retrasplante. Elegimos retrospectivamente a 140 pacientes adultos que recibieron un STR. Analizamos las características de los receptores y de los donantes. Definimos el delta PRA (dPRA) como la diferencia entre el pico de PRA antes del STR y el primero (cohorte mediana = +10%). Se aplicó análisis de regresión logística para determinar los factores de riesgo para dPRA ≥ 10% y rechazo agudo (RA) en STR y análisis univariado y multivariado de Cox para evaluar predictores independientes de fallo del retrasplante. Los factores de riesgo para dPRA ≥ 10% fueron: RA (OR = 2,57; p = 0,022), supervivencia del primero injerto menor a un año (OR = 2,47; p = 0,030) e incompatibilidad HLA ABDR (OR = 1,38 por cada mismatch; p = 0,038). El RA en el STR fue asociado con dPRA ≥ 10% (OR = 2,79; p = 0,047). La inducción con un agente depletor de linfocitos tuvo un efecto protector (OR = 0,23; p = 0,010). La supervivencia del STR fue menor en pacientes con dPRA ≥ 10% (75,6; 60,5% en dPRA ≥ 1 0%; y 88,6; 88,6% en dPRA < 10%; a los 5 y 10 años). La regresión multivariada de Cox mostró que dPRA ≥ 10% (HR = 2,38; p = 0,042), función retardada de injerto (HR = 2,82; p = 0.006) y RA (HR = 3,30; p = 0,001) en STR fueron factores predictores independientes de fracaso en el retrasplante. Este estudio muestra que un incremento en la alosensibilización de retrasplante se ha asociado con el grado de incompatibilidad HLA y puede conducir a resultados más pobres en STR. La falta de énfasis en la compatibilidad de HLA en las políticas actuales de asignación puede no ser deseable, especialmente en pacientes con una mayor probabilidad de necesitar un STR.

Introduction: Kidney transplant improves survival even in highly-sensitized(HS) patients. To overcome their disadvantage in accessing transplantation, those with high Complement Dependent Cytotoxic PRA (CDC-PRA) receive additional points during allocation. Whether this strategy reaches all HS patients and how long they wait for a transplant is largely undetermined. Methods: Patients on our unit’s active wait-list for kidney transplantation in the year 2014 were analyzed. CDC-PRA and calculated PRA (cPRA) were recorded. To obtain cPRA, antibodies in the last serum available specific for HLA-A,-B or -DR with an intensity > 1000 MFI were considered. Results: The cPRA values in the population (N=551) were 0% (N=312), 1-79% (N=118) and ≥ 80% (22%; N=121). Among these groups, the proportion of women (29.5, 55.9 and 61.2%, P<0.001), prior sensitizing events (43.3, 80.5 and 96.7%, P<0.001) and time on dialysis (median of 3.9, 4.1 and 6.0 years, P<0.001) increased with cPRA, respectively. In most of those with a cPRA ≥ 80%, the CDC-PRA raised no suspicion of HS status (median 0%, P25-75 0-8%) and only 35 (28.9%) or 12 patients (9.9%) had a CDC-PRA in the peak serum higher than 50 or 80%, respectively (cut-offs needed to obtain additional points during allocation). HS patients by cPRA corresponded to 71% vs 15% of patients waiting for ≥ or <8 years, respectively (P<0.001). Even after exclusion of patients with a CDC-PRA above 50%, this disproportionate representation remained (58% versus 13%, P<0.001). Conclusion: HS patients as measured by cPRA remained longer on the wait-list, both in the primary analysis and when excluding those with a CDC-PRA> 50%. Moreover, only 30% of HS by cPRA patients received the extra points designed to improve their transplantability. We consider that both CDC-PRA and cPRA should be taken into account when defining HS status

Introdução e Objetivos: A diálise peritoneal (DP) é uma técnica substitutiva da função renal (TSFR) com eficácia semelhante à hemodiálise (HD); no entanto, ainda permanece subutilizada em qualquer idade. Os médicos temem o elevado drop-out da técnica e a sua menor sobrevida, particularmente nos doentes idosos. Os autores pretenderam explorar causas de drop-out e sobrevida da técnica ao longo das últimas três décadas, em diferentes faixas etárias, centrando uma atenção particular no idoso. Métodos: Foram usados dados do registo prospetivo do programa hospitalar de doentes adultos incidentes em DP. Tendo em conta as diferentes épocas, os doentes foram divididos em 6 coortes (5 anos de intervalo) de acordo com o ano de admissão no programa (1985-2014). Usaram-se modelos de regressão tendo em conta a análise de riscos competitivos para identificar potenciais fatores de prognóstico para a morte e transferência para HD (ajustados para a idade, género, diabetes, era, tipo de técnica e primeira modalidade de TSFR). Posteriormente, os doentes foram estudados de acordo com a idade à admissão do programa: A (18-44 anos); B (45-64 anos); C (≥ 65 anos de idade). Foram avaliadas as taxas de transferência para HD usando a análise de Poisson. As taxas de incidência de drop-out foram comparadas em diferentes épocas e entre os grupos etários, focando particular atenção no doente idoso. Resultados: Foram avaliados 525 pacientes: 211 eram do sexo masculino (40,2%), com idade média de 48 ± 15,7 anos, com follow-up mediano de 23 meses (IQR 9-41,5). A maior causa de drop-out da técnica foi a transferência para HD (35,4%), seguida do transplante renal (27,6%) e de morte (21,7%). A probabilidade de falência técnica e transplantação renal aos 2 e aos 5 anos foi 19,2% e 18,1% e 34,2%; 27,4%, respetivamente. A probabilidade de morte aos 2 e aos 5 anos foi 12,7%, e 21,8%, respetivamente. A coorte mais recente associou-se a menor risco de mortalidade e menor transferência para HD. O modelo de regressão Fine & Gray mostrou que a idade avançada se associou a maior mortalidade, contudo não se associou a maior falência técnica. Nos idosos, a taxa de transferência para HD foi 11,2 episódios/100 doentes-ano (em comparação com 15 e 14 episódios/100 doentes-ano nos grupos A e B, respectivamente, p = 0,33). Não houve diferenças significativas nas causas de transferência para HD entre os diferentes grupos etários. As taxas de drop-out por falência de acessos e por falência de ultrafiltração diminuíram no grupo mais velho e na coorte mais recente, contudo as diferenças não foram estatisticamente significativas entre os grupos. Conclusões: O drop-out por falência técnica diminuiu significativamente na década mais recente. A idade de admissão na diálise peritoneal não mostrou ser um fator de comprometimento da sobrevida da técnica

Introduction and Aims: Peritoneal dialysis (PD) is an efficient renal replacement therapy (RRT), but still remains underutilized at any age. Clinicians fear the rate of dropouts and lower technique survival, particularly in elderly patients. The authors aimed to explore such outcomes over the past 3 decades, in different age and era cohorts. Methods: Consecutive incident patients starting PD were identified from an ongoing registry-base prospective study of quality assessment. In order to control for an era effect, patients were assigned to 6 cohorts (5 years interval) according to the admission year between 1985 and 2014. Regression models taking competing risks into account were performed to identify potential prognostic factors for death and transfer to haemodialysis (HD) (adjusted for age, gender, diabetes, cohort era, automated peritoneal dialysis (APD) use, and first treatment modality - PD first, PD after HD, PD after renal transplant (RT). Then the patients were studied according to age at enrolment in the programme: A (18-44 years; n = 193) ; B (45-64 years; n = 176); C (≥ 65 years old; n = 75). The HD transfer rates using Poisson analysis were evaluated. The incidence of dropout rates was compared at different timesand between age groups, focusing particular attention on the elderly. Results: A total of 525 patients were evaluated: 211 male (40.2%), aged 48 ± 15.7 years old, on PD for 23 (IQR 9 - 41.5) months. The major cause of dropout technique was transfer to HD (35.4%), followed by renal transplantation (27.6%)and death (21.7%). The probability of technical failure and renal transplantation at 2 and 5 years was19.2% and 18.1% and 34.2%; 27.4%, respectively. Probability of death at 2 and 5 years was 12.7%, and 21.8%, respectively. The contemporary cohort was associated with a lower risk of mortality and lower risk of transfer to haemodialysis, with greater access to renal transplantation. The regression model Fine & Gray showed that older age was associated with increased mortality, but was not associated with greater technical failure. Transfer to HD occurred in the elderly at a rate of 11epy/100 patient-year (in comparison to 15 and 14 epy/100 patient-year in non-elderly groups A and B, respectively P = 0.33). The proportions of specific causes of technique failure did not change significantly according to age cohort. The dropoutrates due to access-related-infection and ultrafiltration failure decreased in the elderly group in the morecontemporary cohort, despite the differences were not statistically significant. Conclusions: The dropoutby technique failure decreased significantly in the recent decade. Age at admission in peritoneal dialysisdid not show to be a compromising factor of the technique survival

Introdução: O fator de crescimento do fibroblasto 23 (FGF-23) induz fosfatúria. A sua importância clínica ultrapassa o seu impacto na doença óssea da doença renal, associando-se, segundo alguns autores, à calcificação vascular e à mortalidade. Nos doentes em diálise peritoneal (DP), a função renal residual (FRR) é responsável por uma fracção significativa da excreção do fósforo. O nosso objectivo foi testar se o FGF -23 se relaciona com o débito do filtrado glomerular (DFG) e a excreção de fosfato nesta fase tardia da DRC(5d), focando a sua relação com calcificação vascular. Métodos: O FGF-23 (C terminal) foi medido em 40 doentes prevalentes em DP com função renal residual, com idade de 61.5 (51,0-67,0) anos, em tratamento substitutivo da função renal há 43,5 (23-80,0) meses. Destes doentes, 36,6% eram do sexo feminino 19,5 % tinham diabetes mellitus e 37,5% estavam sob regime de DP automática; 80% iniciaram diálise com DP; apenas 20% estiveram previamente sob outra técnica substitutiva da função renal. Foram exploradas variáveis clínicas relevantes, nomeadamente fosfato dietético, parâmetros ósseos, 25-hidroxivitamina D, magnésio (Mg), DFG, fosfatúria, fração excrecional de fosfato (FEP), albumina, proBNP e o score de calcificação vascular de Adragão. Resultados: Os valores medianos (IQ 25-75) das variáveis séricas foram: FGF-23 1997 (1623-2149) RU/ mL, Mg 0,9 (0,8-1,0) mmol/L, 25-hidroxivitamina D 30 (18-47) nmol/L, cálcio 2,2 (2,0-2,4) mmol/L, fósforo 1,7 (1,3-1-,9) mmol/L, PTH 429 (309-626) pg/mL. O FGF-23 correlacionou-se positivamente com o fósforo sérico (r = 0,39, p = 0,013) e negativamente com o volume de urina (r = -0,48, p = 0,001), fosfatúria (r = -0,594, p < 0,0001) e DFG (r = -0,61, p < 0,0001). No entanto, não se verificou qualquer relação significativa com idade, tempo em terapêutica da substituição da função renal, fósforo dietético, FEP, Mg ou 25-hidroxivitamina D. O grupo com valor elevado de FGF-23 apresentava aumento da FEP. O DFG foi preditor independente de aumento do FGF-23. Por outro lado, nem o FGF-23 nem o rácio baixo FEP/FGF-23 se associaram significati- vamente com o score de calcificação vascular. A albumina (baixa), o magnésio (baixo) e o proBNP (elevado) foram significativamente diferentes em doentes calcificados quando comparados com não calcificados (todos com p < 0,05). Conclusões: No nosso estudo não foi confirmada a associação do FGF-23 com a calcificação vascular. O DFG foi o único preditor independente do aumento de FGF-23 em doentes sob diálise peritoneal com função renal residual. O aumento do FGF-23 sinaliza um processo fosfatúrico ativo, compensatório face à perda de FRR, tal como é expresso pelo aumento da fracção excrecional de fósforo. Poderá alertar para oportuna optimização da dieta e da terapêutica no âmbito do metabolismo fosfocálcico. No entanto a sua associação com calcificação vascular permanece por validar

Introduction and Aims: Fibroblast growth factor 23 (FGF-23) induces phosphaturia. Its clinical impact is beyond mineral bone disease in chronic kidney disease (CKD), being coupled with vascular calcification and mortality. Residual renal function (RRF) is associated with significant capacity to excrete phosphate in peri- toneal dialysis (PD). Besides testing whether FGF-23 is still related with glomerular filtration rate (GFR) and phosphate excretion in this late stage of CKD (5d), we aimed to explore its link with vascular calcification. Subjects and Methods: FGF-23 (C terminal) was measured in forty prevalent PD patients with RRF, aged 61.5 (51.0-67.0) years old, in renal replacement therapy (RRT) for 43.5 (23-80.0) months; 36.6% were female, 19.5% had diabetes mellitus and 37.5% were under automated PD regimen; 80% were on PD first, and only 20% had previous RRT. Relevant variables including dietary phosphate (P) intake, CKD-bone laboratory parameters, serum 25-hydroxyvitamin D, magnesium (Mg) levels, GFR, urinary phosphate, fractional excretion of phosphorus (FEP), albumin, proBNP and Adragão vascular calcification score were explored. Results: Median levels (25-75% range) of serum variables were: FGF-23 1997 (1623-2149) RU/mL, Mg 0.94 (0.8-1.0) mmol/L, 25-hydroxyvitamin D 30 (18-47) nmol/L, calcium 2.2 (2.0-2.37) mmol/L, phosphorus 1.69 (1.30-1.90) mmol/L, PTH 429 (309-626) pg/mL. FGF-23 correlated positively with serum phosphate (r = 0.39, p = 0.013) and negatively with urine volume (r = -0.48, p = 0.001), phosphaturia (r = -0.594, p < 0.0001) and GFR (r =-0.61, p < 0.0001). However, FGF-23 was not significantly correlated with age, total time of RRT, dietary P, FEP, Mg, nor 25-hydroxyvitamin D. High FGF-23 group had higher FEP. GFR was the single inde- pendent predictor of increased FGF-23. On the other hand, neither FGF-23 nor low FEP/FGF-23 ratio were significantly associated with the vascular calcification score. Only albumin (lower), magnesium (lower) and proBNP (higher) levels significantly differed in calcified versus non-calcified patients (all with p < 0.05). Conclusions: In our population, FGF-23 was not associated with vascular calcification. GFR was the single independent predictor of increased FGF-23 in patients with diuresis. Increment of FGF-23 in PD patients signalizes an active endocrine phosphaturic process compensating renal function loss, as expressed by higher fractional excretion of phosphorus. It alerts for dietetic and therapy optimization. However, its link with vascular calcification still lacks validation

Introdução: O efeito deletério dos anticorpos para antigénios MICA (major histocompatibility class I chainrelated A) na incidência de rejeição aguda e sobrevida do enxerto ainda não está consensualmente estabelecido. Metódos: Estudo retrospetivo de 554 transplantados renais. A análise comparativa entre doentes positivos e negativos para anticorpos anti-MICA pré-formados foi realizada para avaliar eventos sensibilizadores. A incidência de rejeição aguda no primeiro ano pós transplante renal e a sobrevida do enxerto renal foram determinadas consoante o resultado da citometria de fluxo pré-transplante para anticorpos anti-MICA e/ou anti- HLA (anti-human leukocyte antigen). Aplicou-se um modelo de análise multivariada para identificação de preditores independentes para rejeição aguda. Resultados: Foram identificados 41 doentes (7.4%) com anticorpos anti-MICA pré formados. A sensibilização para HLA, as transfusões sanguíneas e gestações prévias foram mais frequentes nos doentes MICA + mas apenas a presença de anticorpos anti-HLA classe I apresentou uma associação independente (OR 2.67, p = 0.02). Comparativamente ao grupo MICA-/HLA-, o grupo MICA-/HLA+ apresentou menor sobrevida livre de rejeição ao 1º ano (78.6% vs. 89.3%, p < 0.01), maioritariamente ocorrida nos primeiros seis meses, enquanto que nenhuma diferença foi encontrada com o grupo MICA+/HLA- (88.9% vs. 89.3%, p = ns). Apenas o status MICA-/HLA+ teve impacto independente na incidência de rejeição (OR 2.09, p = 0.03), ao contrário do status MICA+/HLA- (OR 1.08, p = ns). O grupo MICA-/HLA+ apresentou menor sobrevida do enxerto censurada para a morte aos 4 anos (85.8% vs. 95.3%, p = 0.03), não se verificando diferenças no grupo MICA+/HLA- (95.1% vs. 95.3%, p = ns). Conclusão: Os nossos resultados não suportam um efeito deletério dos anticorpos pré-formados para MICA, independente da sensibilização HLA, na incidência de rejeição aguda no 1º ano pós transplante e na sobrevida do enxerto

Background: Evidence supporting deleterious effect of preformed major histocompatibility class I chain-related A (MICA) antibodies in rejection incidence and graft survival is still unclear. Methods: Retrospective analysis of 554 kidney transplanted patients. Comparison between positive or negative for MICA antibodies patients was performed to characterize sensitizing triggers. Further classification according to pre-transplant flow cytometry-recorded anti-MICA and/or anti-human leukocyte antigen (HLA) antibodies was made to determine first year rejection incidence and graft survival. Multivariate analysis was applied to determine predictors for acute rejection. Results: Pre-formed anti-MICA antibodies were detected in 41 patients (7.4%). HLA sensitization, blood transfusions and pregnancies were frequently found in anti-MICA+ patients but only pre-formed anti-HLA class I antibodies showed independent association (OR 2.67, p = 0.02). Comparing to MICA-/HLA-, MICA-/HLA+ group presented significantly lower first year rejection-free survival (78.6% vs. 89.3%, p < 0.01), mostly occurred in the first six months, while no difference was found in MICA+/HLA- (88.9% vs. 89.3%, p = ns). MICA-/HLA+ showed independent impact in rejection (OR 2.09, p = 0.03), while no evidence was found in MICA+/HLA- (OR 1.08, p = ns). At 4 years, MICA-/HLA+ group presented lower graft survival (85.8% vs. 95.3%, p = 0.03). Again, no difference was found in MICA+/HLA- group (95.1% vs. 95.3%, p = ns). Conclusion: Our results do not support HLA-independent deleterious pathogenic role of pre-formed MICA antibodies on first year rejection incidence and graft survival