Acute Kidney Injury: Medical Causes and Pathogenesis.

Acute kidney injury (AKI) is a common clinical syndrome characterized by a sudden decline in or loss of kidney function. AKI is not only associated with substantial morbidity and mortality but also with increased risk of chronic kidney disease (CKD). AKI is classically defined and staged based on serum creatinine concentration and urine output rates. The etiology of AKI is conceptually classified into three general categories: prerenal, intrarenal, and postrenal. Although this classification may be useful for establishing a differential diagnosis, AKI has mostly multifactorial, and pathophysiologic features that can be divided into different categories. Acute tubular necrosis, caused by either ischemia or nephrotoxicity, is common in the setting of AKI. The timely and accurate identification of AKI and a better understanding of the pathophysiological mechanisms that cause kidney dysfunction are essential. In this review, we consider various medical causes of AKI and summarize the most recent updates in the pathogenesis of AKI.

SARS-CoV2 Infection and Acute Kidney Injury - A Rare Presentation

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2) is one of the most devastating and lethal pandemics in human history. The disease initially affected adults much more than children, but now pediatric patients are being more commonly affected. Symptoms are often mild in pediatric age and characterized by the occurrence of fever and gastroenteritis. Respiratory involvement is generally benign in this age group and improves with symptomatic treatment. Kidneys can be a target of the disease and several factors have been incriminated. We report the case of a 5-year-old patient hospitalized for acute kidney injury following an asymptomatic SARS-CoV2 infection. We aim to focus practitioners' attention on a different aspect of renal involvement in this disease.Copyright © 2023, Pakistan Pediatric Journal. All rights reserved.

Rapid deterioration of renal function following coronavirus disease 2019 in a renal transplant recipient.

Introduction: The coronavirus disease 2019 pandemic emerged in December 2019. Renal transplant recipients receiving chronic immunosuppression are considered to be at a high risk of infection. Aside from upper respiratory tract symptoms, coronavirus disease 2019 has also been reported to cause acute kidney injury in 20-50% of infected cases. Case presentation: A 62-year-old male renal transplant recipient presented with high fever, diarrhea, and cough, concurrent with rapid deterioration of graft function. The patient tested positive for coronavirus disease 2019. The pathological findings of the graft biopsy revealed diffuse flattening of tubular epithelial cells and extensive loss of the brush border in proximal tubular cells. Mycophenolate mofetil was discontinued and sotrovimab, remdesivir, intravenous immunoglobulin, and intravenous methylprednisolone were administered, resulting in gradual improvements in clinical symptoms and renal function. Conclusion: We describe a case of a coronavirus disease 2019-infected kidney transplant recipient who developed severe acute kidney injury caused by severe acute tubular necrosis.

SARS-CoV-2 infection of kidney tissues in some severe and fatal cases of COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to diverse clinical manifestations and pathologies that involve multiple organs. Even though the disease severity is manifested mainly in the respiratory tract, which is the primary target of SARS-CoV-2 infection, acute kidney injury in the form of acute tubular necrosis has also been noted in some COVID-19 cases. It is not entirely clear whether renal cells can be infected by the virus that might be involved in acute kidney disorder. In a recent publication by Radovic and colleagues, that has been selected as the editor's choice paper published in the Journal of Medical Virology, the authors provided strong histopathological and immunofluorescence evidence of SARS-CoV-2 infection and tissue injury of renal parenchymal and tubular epithelial cells, which strongly suggest an active viral replication in the kidney of some severe and fatal COVID-19 cases, and to a lesser extent, a potential role for innate immune cells in viral infection and renal disease pathogenesis.

SARS-CoV-2 infection of kidney tissues from severe COVID-19 patients.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manifests diverse clinical pathologies involving multiple organs. While the respiratory tract is the primary SARS-CoV-2 target, acute kidney injury is common in COVID-19 patients, displaying as acute tubular necrosis (ATN) resulting from focal epithelial necrosis and eosinophilia, glomerulosclerosis, and autolysis of renal tubular cells. However, whether any renal cells are infected by SARS-CoV-2 and the mechanism involved in the COVID-19 kidney pathology remain unclear. METHODS: Kidney tissues obtained at autopsy from four severe COVID-19 patients and one healthy subject were examined by hematoxylin and eosin staining. Indirect immunofluorescent antibody assay was performed to detect SARS-CoV-2 spike protein S1 and nonstructural protein 8 (NSP8) together with markers of different kidney cell types and immune cells to identify the infected cells. RESULTS: Renal parenchyma showed tissue injury comprised of ATN and glomerulosclerosis. Positive staining of S1 protein was observed in renal parenchymal and tubular epithelial cells. Evidence of viral infection was also observed in innate monocytes/macrophages and NK cells. Positive staining of NSP8, which is essential for viral RNA synthesis and replication, was confirmed in renal parenchymal cells, indicating the presence of active viral replication in the kidney. CONCLUSIONS: In fatal COVID-19 kidneys, there are SARS-CoV-2 infection, minimally infiltrated innate immune cells, and evidence of viral replication, which could contribute to tissue damage in the form of ATN and glomerulosclerosis.

COVID-19 and kidney failure, a mini-review to recent evidence

In COVID-19 infection, most of the renal disturbances are due to acute tubular necrosis. Renal dysfunction occurs in severe COVID-19 infection and is usually secondary to sepsis, cytokine storm, and hypotension. Other conditions, such as exacerbated inflammatory responses, dehydration, hypoxia, hypercoagulability, endothelial damage, pneumonia, septicemia, drug nephrotoxicity, and myocardial dysfunction also contribute to renal failure. © 2022 The Author(s);Published by Nickan Research Institute. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A Case of Adult Multisystem Inflammatory Syndrome Following COVID-19 Vaccine.

Multisystem inflammatory syndrome is a life-threatening condition associated with elevated inflammatory markers and multiple organ injury. A diagnosis of exclusion, it has been reported after severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2) in children and adults; recently it has been described in some post-COVID-19 vaccinated individuals. The prognosis with supportive care and immunomodulatory therapy is good, although some individuals may require treatment in the intensive care unit (ICU). Here we report a case of a 58-year-old man who developed multi-organ failure after receiving the second dose of the Moderna mRNA-1273 COVID-19 vaccine. He required critical organ support in the ICU. An extensive workup was done to rule out alternative infectious and inflammatory processes. Following a period of gradual in-hospital convalescence, our patient made a full recovery. To our knowledge, this is the first comprehensively described case of multisystem inflammatory syndrome associated with Moderna mRNA-1273 COVID-19 vaccine in an adult over 50 years of age.

Spectrum of Kidney Injury Following COVID-19 Disease: Renal Biopsy Findings in a Single Italian Pathology Service.

The onset of coronavirus disease (COVID-19) as a pandemic infection, has led to increasing insights on its pathophysiology and clinical features being revealed, such as a noticeable kidney involvement. In this study, we describe the histopathological, immunofluorescence, and ultrastructural features of biopsy-proven kidney injury observed in a series of SARS-CoV-2 positive cases in our institution from April 2020 to November 2021. We retrieved and retrospectively reviewed nine cases (two pediatric and seven adults) that experienced nephrotic syndrome (six cases), acute kidney injury (two cases), and a clinically silent microhematuria and leukocyturia. Kidney biopsies were investigated by means of light microscopy, direct immunofluorescence, and electron microscopy. The primary diagnoses were minimal change disease (four cases), acute tubular necrosis (two cases), collapsing glomerulopathy (two cases), and C3 glomerulopathy (one case). None of the cases showed viral or viral-like particles on ultrastructural analysis. Novel and specific histologic features on kidney biopsy related to SARS-CoV-2 infection have been gradually disclosed and reported, harboring relevant clinical and therapeutic implications. Recognizing and properly diagnosing renal involvement in patients experiencing COVID-19 could be challenging (due to the lack of direct proof of viral infection, e.g., viral particles) and requires a proper integration of clinical and pathological data.

[Kidney damage in COVID-19]. / Les atteintes rénales de la COVID-19.

COVID-19 is a disease caused by the RNA virus SARS-CoV-2. It is characterised by an attack mainly affecting the respiratory system. There is renal involvement which is characterised by three main types of damage, acute tubular necrosis occurring in the most severe cases, proximal tubulopathy which is a prognostic marker of the disease and segmental and focal hyalinosis occurring in a genetically predisposed terrain. The pathophysiology of SARS-CoV-2 renal involvement is not yet defined. The direct role of the virus is debated, whereas the cytokine storm and the hypoxic and thrombotic complications seem more important. The long-term outcome of the renal damage appears to be quite good. Long-term follow-up will allow us to say whether the renal damage is part of the long COVID.