Scielo RSS http://scielo.pt/rss.php?pid=0872-016920230002&lang=en vol. 37 num. 2 lang. en http://scielo.pt/img/en/fbpelogp.gif http://scielo.pt http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200057&lng=en&nrm=iso&tlng=en ABSTRACT Vancomycin and aminoglycosides are potentially nephrotoxic broad-spectrum antibiotics, which can be used both in the treatment of severe infections and in surgical prophylaxis, in pediatric patients. Prolonged antibiotic therapy and high trough concentrations are associated with toxicity. Additionally, several individual factors contribute to nephrotoxicity increasing the risk of acute kidney injury (AKI) and consequente chronic kidney disease in the future. We developed a retrospective and observational study in the Pediatrics Department of a tertiary hospital in Portugal, to analyze clinical practice regarding monitoring and surveillance of vancomycin and aminoglycosides. The results showed low rates of monitoring, which reinforces the importance of raising awareness about this issue, recognizing its importance, and adopting preventive measures that may mitigate the risk of toxicity and improve children’s renal prognosis in adult life. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200060&lng=en&nrm=iso&tlng=en ABSTRACT Introduction: Acute kidney injury is frequent in patients with COVID-19 and is associated with a higher mortality than in patients without acute kidney injury. Therefore we aimed to compare the creatinine and cystatin C initial values and trend in COVID-19 patients admitted to the Intensive Care Unit (ICU), in order to understand how renal dysfunction affects the prognosis. Methods: Longitudinal retrospective, single-center study of COVID-19 patients admitted to a tertiary care hospital ICU, between April 2020 and April of 2021. Demographic variables comorbidities, serum urea, creatinine, cystatin C values, as well as outcome were studied. Statistical analysis performed in SPSS 27. Results: The sample consists of 207 ICU patients, with mean age of 68 years, 68.6% male. Had chronic kidney disease, 11.5% (n=25) and the most prevalent comorbidities were hypertension, dyslipidemia and obesity. The median (interquartile range) length of stay at the ICU was 11 (6 - 19) days. The values of creatinine, cystatin C, urea adjusted for age and sex, at the time of hospital admission, were not significant for mortality. However, the variation in marker values between the first and second evaluation moments showed that a 5% increase in creatinine values increased, on average, the risk of death by about 2.3 times and a 5% increase in cystatin C values, increased, on average, the risk of death by about 2 times. Conclusion: The decline in renal function has a significant prognostic impact in patients with COVID-19. Therefore, an early detection of renal dysfunction in these patients is essential. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200068&lng=en&nrm=iso&tlng=en ABSTRACT Rituximab, a monoclonal antibody with the ability to bind itself to CD20, leads to a rapid depletion of B-cells (in around 24-72 hours), limiting antibody formation. The marker CD20 does not exist in any other cell type, which makes the action of rituximab specific. This antibody has been used in autoimmune entities such as rheumatoid arthritis and in hematological malignancies, but recently it has gained popularity as an important immunosuppressor in selected kidney diseases. In nephrology, this anti-CD20 antibody had its first indication in anti-neutrophil cytoplasmic antibody-associated vasculitis, but can now be used in primary membranous nephropathy, minimal change disease, lupus nephritis and others. There is also some data that indicates rituximab might have a promising role in other glomerular diseases in the future, but to date evidence is still lacking to recommend its widespread use. The aim of this document is to compile the most recent scientific evidence as to when rituximab should be used in the treatment of various glomerular diseases, and which other may come to benefit from it in the future. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200076&lng=en&nrm=iso&tlng=en ABSTRACT Chronic kidney disease (CKD) affects more than 10% of the general population worldwide, amounting to more than 800 million individuals. Some important conditions associated with CKD are hypertension, diabetes, dyslipidemia, sedentary lifestyle, and smoking. According to World Health Organization (WHO), regular physical activity helps to prevent and manage non-communicable diseases such as diabetes and hypertension, associated with weight reduction. It is known that a decrease in systolic blood pressure is associated with significant reduction in all causes of mortality and major cardiovascular events. As far as diabetes concerned, beyond first-line medication, healthy lifestyle behaviours should be considered, in which physical activity is included. Training leads to improved skeletal muscle response with increased expression and activity of proteins involved in glucose metabolism and insulin sensitivity. Concerning dyslipidemia, one of the recommended interventions encompasses lifestyle, noting that in patients with low, moderate, or high cardiovascular risk, depending on the LDL value, the treatment involves physical activity and weight loss or its association with pharmacotherapy. CKD patients have some particularities that condition the exercise prescription and the interpretation of its benefits. This review is intended to systematize the importance of exercise in CKD and its determinants. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200081&lng=en&nrm=iso&tlng=en ABSTRACT Introduction: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have shown positive renal outcomes in diabetic patients. There is also emerging evidence in non-diabetic patients. This review was conducted to analyse the renal outcomes of SGLT2i in patients without diabetes mellitus (DM). Methods: A systematic review was performed in a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) compliant manner. We included only randomized trials that examined the effect of SGLT2i on renal outcomes in non-diabetic patients. Results: A total of ten randomized trials were included with a combined cohort of 26 298 patients. There was a tendency for lesser risk of adverse renal outcomes in heart failure (HF) patients with reduced ejection fraction (EF) (hazard ratio (HR) 0.50-0.71). Lesser effect on adverse renal outcomes was seen in HF patients with preserved EF (HR 0.95). For both preserved and reduced EF HF, there was a statistically significant reduction in the rate of decline in estimated glomerular filtration rate (eGFR) (p<0.001). On a short follow-up, there was a significant reversible reduction in GFR. In the long term, chronic kidney disease (CKD) proteinuric patients had a statistically significant lesser risk of adverse renal outcomes (p<0.001) and a significant reduction in albuminuria (p=0.0016). CKD patients, including non-proteinuric, had a significant reduction in the rate of kidney disease progression (HR = 0.71). Conclusion: Treatment with SGLT2i significantly reduces the rate of kidney disease progression in CKD non-diabetic patients with eGFR ≥ 20 mL/min/1.73 m2. Benefit seems greater in proteinuric patients. Benefit for eGFR < 20 mL/min/1.73 m2, dialysis and kidney transplant patients is yet to be defined. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200089&lng=en&nrm=iso&tlng=en ABSTRACT The diagnosis of antibody-mediated rejection has become more common and represents a major cause of kidney graft loss. The ideal treatment remains unknown, with little evidence supporting the use of a specific therapy. The definition of antibody-mediated rejection is based on serologic (presence and/or development of donor-specific antibodies) and histologic (evidence of acute tissue injury with C4d deposition or other signs of antibody interaction with the vascular endothelium) criteria. Antibody-mediated rejection without donor‐specific antibodies is a subcategory with a defying diagnosis. This particularly entity is increasingly being reported as an important cause of allograft dysfunction in kidney transplantation. We describe the case of a kidney transplant recipient with a low immunological risk and delayed graft function due to an antibody-mediated rejection with negative donor-specific antibodies. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200093&lng=en&nrm=iso&tlng=en ABSTRACT Primary hyperoxaluria type 1 is a rare genetic disease caused by mutations in AGXT, leading to an excessive hepatic production of oxalate, resulting in urolithiasis, nephrocalcinosis and chronic kidney disease. The authors present the case of a young female with PH1 who is the first patient treated with lumasiran in Portugal, and currently has a follow-up of 18 months. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200097&lng=en&nrm=iso&tlng=en ABSTRACT Pembrolizumab is an immune checkpoint inhibitor used as a cancer therapy. The incidence of immune related adverse events in patients receiving immune checkpoint inhibitors can be as high as 59%-85. Renal adverse effects are uncommon, but the incidence of kidney toxicity related to pembrolizumab is rising as the use of this agent becomes more frequent. We present an uncommon case of biopsy-proven acute interstitial nephritis secondary to pembrolizumab in a patient with metastatic squamous cell carcinoma at the time of his fourth scheduled cycle. Despite the good initial tumor response, pembrolizumab had to be suspended and the patient started on corticosteroids with an initial good response. On his own initiative, the patient stopped prednisolone early, leading to a rebound acute kidney injury. Pembrolizumab was not reintroduced for the risk of further renal function worsening. His clinical status declined due to the progression of the neoplastic disease, and he was referred for palliative care. This case illustrates the importance of systematizing some key points in the approach to acute interstitial nephritis secondary to pembrolizumab: the role of the differential diagnosis of acute kidney injury in a patient under an immune checkpoint inhibitor, the role of glucocorticoids and the controversy about rechallenging this drug after a related acute interstitial nephritis. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200102&lng=en&nrm=iso&tlng=en ABSTRACT Renal hypouricemia (RHUC) is an autosomal recessive disease caused by the dysfunction of uric acid (UA) transporters in the proximal tubule causing increased fractional excretion of uric acid (FEUA). It is associated with mutations of SLC22A12 that codifies for URAT1, involved in RHUC type 1, or SLC2A9 which codifies for GLUT9 and is involved in RHUC type 2. We present the case of a man diagnosed with RHUC type 2 following hospitalization for acute kidney injury (AKI). A 43-year-old was hospitalized due to AKI after a 20 km walk at an outdoor temperature of 30°C. On the objective examination, he was dehydrated. Blood tests presented severe azotemia (creatininemia 16.43 mg/dL, uremia 254 mg/dL), UA 3.6 mg/dL, fosfatemia 6 mg/dL, Na 138 mEq/L, K 4.2 mEq/L, Cl 102 mEq/l, arterial gasometry with pH 7.35, pCO2 36 mmHg, HCO3 20 mmol/L, lactates 1.4 mmol/L. Urine test with proteinuria and unremarkable sediment. His kidneys had foci of microlithiasis. He started vigorous fluid therapy and sustained improvement in renal function was seen, with no need for renal function replacement therapy. The subsequent evaluation showed hypouricemia <1.5 mg/dL and FEUA of 32.5% (normal range 5.5%-8.5%). The molecular study identified the variant c.1221del p.(His407Glnfs*8) in the SLC2A9 gene in homozygosis, which established the diagnosis of RHUC type 2. This case highlights the importance of recognizing hereditary RHUC to prevent its manifestations, including exercise-induced AKI, nephrolithiasis, nephrocalcinosis, and more rarely, progression to stage 5 CKD. Its diagnosis should be considered in individuals with serum UA <2 mg/dL and elevated FEUA. Additionally, it should be confirmed by the identification of mutations in homozygous or compound heterozygous in SLC22A12 or SCL2A9. Treatment includes xanthine oxidoreductase inhibitors and adequacy of physical activity. The use of uricosuric antihypertensive drugs whose mechanism of action involves blocking the URAT1 transporter should be avoided. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200106&lng=en&nrm=iso&tlng=en ABSTRACT Wunderlich syndrome is a rare condition characterized by atraumatic spontaneous renal hemorrhage that can have serious associated complications, especially in chronic kidney disease and end-stage kidney disease patients due to their complexity. Diagnosis requires a high index of suspicion, since its classical presentation with Lenk’s triad is only seen in less than a quarter of patients. Early detection is of outmost importance because of this syndrome potential for causing hemodynamic instability and shock. Spontaneous renal hemorrhage has been reported much less frequently in peritoneal dialysis as compared to hemodialysis. To our knowledge, only 3 single-cases involving peritoneal dialysis patients were published since the year 2000. We describe an uncommon case report of a 68-year-old male undergoing continuous ambulatory peritoneal dialysis for 5 years and taking warfarin for permanent atrial fibrillation who developed Wunderlich syndrome presenting with Lenk’s triad. The patient was managed with percutaneous drainage of the renal hemorrhage and was able to continue peritoneal dialysis in the acute phase of disease. Unfortunately, he subsequently developed peritoneal membrane failure having to transition to hemodialysis 2.5 months after the WS episode. The authors will review literature on Wunderlich syndrome on end-stage kidney disease patients, discuss oral anticoagulation on peritoneal dialysis patients, maintenance of the technique, and finally, address the consequences of Wunderlich syndrome on peritoneal membrane diffusion capacity. http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-01692023000200112&lng=en&nrm=iso&tlng=en ABSTRACT Waldenstrom’s macroglobulinemia (WM) is an IgM associated lymphoplasmacytic lymphoma and kidney disease is a rare complication. We report a case of a 41-year-old male with a history of WM diagnosed 16 years ago, currently with no indication for treatment. The patient presented with nephrotic syndrome and acute kidney injury, hypertension, and multiple lymphadenopathies. A kidney biopsy was performed, showing minimal change disease with lymphomatous infiltration of B-lymphocytes CD20+. Therapy with bortezomib, dexametahasone and rituximab was started and after 6 months of follow-up he presented progressive recovery of renal function and remission of proteinuria. This case illustrates the importance of screening renal disease in WM patients. A kidney biopsy should be performed in those presenting with otherwise unexplained renal failure and/or nephrotic syndrome.