Portuguese Journal of Nephrology & Hypertension

Validation of a model to predict six-month mortality in incident elderly dialysis patients

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.

SARS-CoV-2 infection in hemodialysis patients: Preliminary data from a Portuguese hospital center

Background: In December 2019, a new form of coronavirus was identified (COVID-19) and quickly became a worldwide pandemic. Previous data reported a more severe disease in older patients, with high comorbidities, which are common features in hemodialysis patients. Scarce data is available about the clinical presentation and outcomes in this population. For this reason, we aim to report the characteristics of COVID-19 disease in hemodialysis patients admitted to our center. Methods: We retrospectively reviewed all patients on chronic hemodialysis admitted with a laboratory-confirmed COVID-19 infection from March 2nd to May 20th of 2020. Baseline characteristics, clinical, laboratory and radiological presentation were registered and treatment and outcomes Results: Fourteen patients were included, 57% female, with a median age of 81 years old and a high number of comorbidities. Cough and fever were the most common symptoms and lymphocytopenia, increased inflammatory parameters and coagulation dysregulation were frequently registered. Ground-glass opacities were present in each thorax computerized tomography performed. Five patients developed respiratory insufficiency, but none needed invasive ventilation or ICU admission. In a significant proportion, discharge was postponed due to the impossibility of ensuring social isolation. Median viral shedding was 38 days. Discussion and conclusion: Hemodialysis patients who required hospitalization were very old and had multiple comorbidities. Even so, the impaired immune response of this population seems to cause a less severe course of the disease and a longer time of viral shedding. HD units have required a reformulation of their circuits in order to avoid disease spreading.

Kidney disease in tuberous sclerosis complex: A single-center experience

Introduction: Tuberous sclerosis complex is an autosomal dominant neurocutaneous disorder which is characterized by multisystem involvement, including the kidney. Since renal disease is one of the causes of morbidity and mortality, close management is essential. Subjects and Methods: In this retrospective observational,single-center study, authors analyse patients with a definite diagnosis of tuberous sclerosis complex who attended Pediatric Nephrology consultation between 1998 and 2019. Results: 20 patients were included. The median age at the time of the diagnosis was 3 years, mostly after seizures and the median age of the first Pediatric Nephrology consultation was 9 years. Seventeen patients had renal disease, the majority with angiomyolipomas and a smaller number with cysts. None had hypertension or history of acute kidney failure. Systemic mTOR inhibitors were used in three patients. Discussion: The present results were similar to those found in the literature regarding presentation features and kidney disease. The authors emphasized the importance of early diagnosis of renal involvement in order to reduce renal morbidity and mortality (especially when these patients reach adulthood) and highlighted the need for early guidance for pediatric nephrology consultation.

Antibody mediated rejection. Evidence based medicine. What is the current evidence?

Antibody mediated rejection (ABMR) is a major cause of kidney graft loss. The ideal treatment remains unknown, is not standardized and there is little evidence to support the use of any specific therapy. This paper aims to reflect on the current state of this challenging diagnosis, either active or chronic active ABMR, and its treatment options. The current treatments encompass plasma exchange, steroids, intravenous immunoglobulin, rituximab, bortezomib, eculizumab, C1 inhibitors, IL 6 inhibitors and IgG-degrading enzyme of Streptococcus pyogenes among others. We will try to analyze the main studies that sustain or reject the current and future use of these techniques and drugs.

Acute kidney injury in SARS-COV-2 infection

The current pandemic of COVID-19 - Coronavirus Disease-19, caused by the pathogen SARS-Cov-2, responsible for thousands of deaths in 2020, has mobilized the scientific community, who aim to understand the different aspects of the disease and propose new treatments and prevention modalities. Research in several areas is evaluating the extent of infection and kidney disorders related to the virus. The aim of this study is to describe the effects of COVID-19 on the renal system. Final considerations point to the main complications of the effects of infection and renal disorders caused by COVID-19, such as acute kidney injury and a consequent increase in the diseases poor prognosis.

New treatments in membranous glomerulopathy - from the pitfalls of rituximab to a new era of biological treatments

Primary membranous nephropathy (PMN) is the main cause of nephrotic syndrome in adults. The recognition that this kidney-specific disease is the result of an autoimmune process has changed diagnostic and therapeutic approaches. The determination of anti-phospholipase A2 receptor and thrombospondin type-1 domain containing 7A, when available, are part of the diagnostic and therapeutic monitoring workup. More recently, more putative antigens have been discovered. Treatment of PMN relies on optimal supportive care but immunosuppression is indicated in patients at risk of progressive kidney injury. Immunosuppression schemes commonly used are cyclophosphamide/steroids (modified Ponticelli), calcineurin inhibitors/steroids and, after the MENTOR trial, rituximab has also been considered a first-line agent in non-severe cases. However, even in the MENTOR trial, 40% of patients did not achieve remission. Rituximab-resistant PMN cases have been published. Many mechanisms have been implicated in rituximab resistance, such as the development of anti-drug antibodies, interindividual variability in drug levels, consumption of drug by internalization of the complex rituximab-CD20, the pool of autoreactive B-cells that is in circulation available for drug action, drug wasting in urine through proteinuria and also epitope spreading. Recognition and knowledge of some of these specific mechanisms of resistance has led to the use of other biologic agents. New monoclonal antibodies targeting CD20 have been developed and can be a rescue therapy for resistance PMN cases. However, as even these new-generation agents do not target memory plasma cells, therapies targeting these cells are promising. Inhibition of factors that activate autoreactive B-cells may also become an option. Additionally, a better understanding of the complement-mediated mechanisms of injury in PMN may bring to the pipeline novel biological therapies for this disease.

Rescuing the nephrologist’s main central vein - placement of a right jugular vein catheter in a patient with thoracic central venous occlusion by use of the Surfacer^® device

Introduction: Central venous stenosis can be the main obstacle to the creation of a vascular access. The Surfacer® device was developed to solve the problem of complete occlusions of the right internal jugular vein, right brachiocephalic vein and superior vena cava, allowing for the placement of a vascular access in this venous axis. Case Report: We present the case of a 77-year-old patient on long-term hemodialysis with a long history of failed vascular accesses and of central vein stenosis, chronically dialyzed using a tunneled catheter placed through the left femoral vein. With use of the Surfacer® device it was possible to recreate, with an inside-out technique, a tract through the fibrous tissue of the completely occluded right brachiocephalic and right internal jugular veins, subsequently placing a tunneled catheter into the right atrium through this later vein. Conclusion: We report the first successful use in Portugal of a new vascular access device that allows us to rescue a previous unusable right central venous axis for the placement of a central venous catheter, thus avoiding the use of less advantageous options such as the femoral veins and preserving venous vascular capital.

Daratumumab: A new future for AL-Amyloidosis and Multiple Myeloma

Concomitant development of symptomatic amyloid light-chain (AL) amyloidosis and multiple myeloma (MM) is rare and has a poor survival rate. Introduction of thalidomide and bortezomib, a proteasome inhibitor, has improved the survival of patients with MM; however, it has not cured the disease. Nevertheless, monoclonal antibodies may treat the disease using an immunotherapeutic approach. This report describes the case of a 39-year-old man with MM IgG lambda, heavily treated with multiple QT cycles and two hematopoietic stem cell transplants, who developed light chain amyloidosis. After an interdisciplinary discussion, daratumumab was initiated. Approximately 24 months later, he presents complete remission of the disease, normal renal function and no associated symptoms.

Simultaneous pancreas-kidney transplantation after liver transplantation: first Portuguese case report

Simultaneous kidney pancreas transplantation, if feasible, is the treatment of choice for the management of end-stage renal disease in patients with type 1 diabetes. This intervention can offer glycemic control and might also stabilize or even reverse some of the metabolic complications of diabetes. Chronic kidney disease has become a critical problem in orthotopic liver transplantation due to multiple risk factors, including post-transplant diabetes mellitus and immunosuppression. This has a major impact on graft and patient survival. In this paper we present the case of a 42-year-old man submitted to a simultaneous pancreas kidney transplant after a successful liver transplantation 18 years earlier. The surgical procedure was uneventful, and the patient was discharged 18 days after admission. The case findings support that simultaneous pancreas and kidney transplantation is an effective method for the treatment of chronic kidney disease in patients with diabetes and a previous liver transplant.

Rituximab-induced hypersensitivity pneumonitis in a kidney transplant patient

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.

The importance of graft kidney biopsy: A case of proteinuria one week after transplantation

Failure to thrive in a pediatric patient

Impact of COVID 19, an Indian nephrologist’s perspective