Contributions to Nephrology

In this chapter, anticoagulation treatments for adsorption techniques in continuous renal replacement therapy (CKRT) will be reviewed. Anticoagulation used with adsorption techniques is quite different than anticoagulation in classical CKRT with nonadsorptive therapies. Regional citrate anticoagulation (RCA) and unfractionated heparin (UFH) are the most common anticoagulation modalities for both nonselective adsorptive membranes - such as surface-treated acrylonitrile 69 membranes (AN69ST) and polymethylmethacrylate membranes - and selective adsorptive membranes such as AN69-oXiris...

Despite recent technical advances in dialysis care over the past decades, the mortality rate of critically ill patients with acute kidney injury (AKI) requiring dialysis and of chronic kidney disease (CKD) remains unacceptably high. Several preclinical studies have increased our knowledge of the principal mechanisms involved in the pathophysiology of AKI and CKD. Additionally, the development of efficient and specific compensatory sorbent systems in renal replacement therapy to remove unwanted compounds has created the possibility to treat renal diseases and their underlying pathological triggers...

Direct hemoperfusion with the CytoSorb® adsorbent has experienced widespread use in several critical care settings including sepsis and multiorgan failure. The reported conditions of clinical usage and resulting outcomes vary considerably. The aim of the study was to provide an overview on current treatment recommendations based on the available clinical evidence. We performed a literature analysis using PubMed/MEDLINE and ClinicalTrials.gov to identify clinical data describing parameters of clinical usage of CytoSorb® in patients with septic shock (inclusion and exclusion criteria, starting, and dosing of treatment) and their impact on outcome...

Leptospirosis is the most common zoonosis frequently seen in the tropics and subtropics especially during the rainy season when humans wade in floods contaminated by the urine of infected rats in urban areas. Aside from direct toxicity of the leptospires, the role of an exuberant immune response to the pathogen leading to secondary organ damage has been recognized. Thus, our treatment protocol for patients with severe leptospirosis characterized by renal failure, acute liver injury, and lung hemorrhage now includes a short course of methylprednisolone and intravenous cyclophosphamide...

The Jafron series of sorbent cartridges provides a comprehensive array of coated, highly biocompatible sorbent beads made of styrene-divinylbenzene copolymers. Such beads carry a mean diameter of 0.8 mm with a range from 0.60 to 1.18 mm. The maximal pore size of these coated beads and the volume of the cartridge vary according to the type of cartridge ranging between 50 Da and 60 kDa. The sorbents, the size of the cartridge, the volume of sorbent, and the pore size (which reaches 60 kDa with the HA330 cartridge) aim to take advantage of the principles of molecular adsorption in a variety of diseases from uremic toxin retention to poisoning and drug overdose, from kidney disease to liver failure, from acute respiratory distress syndrome to sepsis, from toxic skin injury to COVID-19...

Acute liver failure and acute-on-chronic liver failure are conditions in which the loss of metabolic function of the liver leads to the accumulation of several toxins such as bilirubin. Patients with sepsis or multiple organ dysfunction syndrome have a greater risk of developing liver failure, and hyperbilirubinemia is associated with poor prognosis. Bilirubin removal may not only alleviate signs and symptoms of liver dysfunction but also act as an index of removal of albumin-bound toxins. Conjugated and unconjugated bilirubin, due to their molecular weight and albumin-binding capacity, respectively, cannot be removed by classic dialysis; therefore, different extracorporeal techniques have been developed to remove bilirubin from the blood...

The history of sorbents is about 2 centuries long. It is important to analyze and report the progress of science in this field, understand how modern hemoadsorption takes place, and appreciate how new devices have been designed and manufactured. It is also important to describe the nature, the structure, and the composition of sorbent materials and characterize the mechanisms of the adsorption process. Progressive improvements have been obtained from the original aluminosilicates and porous carbons with the use of new synthetic polymeric materials...

Sepsis and multiple organ failure (MOF) are characterized by multiple hemodynamic changes and imbalanced immune response of the patient. Oxiris is a highly adsorptive membrane with the ability to remove cytokines and endotoxins, as well as to perform renal replacement therapy. Here we describe the evolution from previous AN69 to the 3-in-1 Oxiris membrane, and review its characteristics and performance. In clinical practice, Oxiris showed consistent effects in mean arterial pressure recovery, a decrease in vasopressor needs, and reduction of the Sequential Organ Failure Assessment score...

Sorbents have been utilized in the past for intoxication and poisoning, but their spectrum of clinical application is now expanding. Hemoadsorption (HA) is still indicated for toxin and poison removal, but other molecules are considered appropriate targets for this blood purification modality. HA combined with hemodialysis (HA + HD) has been proposed for end-stage kidney disease patients to remove molecules that are not easily removed by classic HD or hemodiafiltration. More recently, a rationale for the use of sorbents in critical illness, sepsis, and acute kidney injury has emerged due to the proposed humoral theory behind these disorders...

Recent advances in the development of sorbent materials have enabled the development of hemoperfusion (HP). However, HP dose and prescription are not standardized and there is no consensus in clinical practice guidelines. Adequate prescription and modality are of utmost importance to ensure HP effectiveness. Although the main indication of CytoSorb®, HA330/380, polymyxin B, and Seraph® is sepsis, these devices may be beneficial in many other situations such as liver failure, rhabdomyolysis, pancreatitis, cardiopulmonary bypass, extensive burns, and trauma or to ensure antiplatelet therapy drug removal...

Clinical Background: Automobile accidents constitute one of the main causes of morbidity and mortality worldwide. Kidney injury related to automobile accidents occurs through several mechanisms. Among the mechanisms are direct traumatic injury, rhabdomyolysis, acute renal failure, hypovolemic shock, and others. Kidney injuries after traffic accidents can have different forms of clinical presentation, which can include morphological and functional changes of the organ. Epidemiology: Annually, approximately 1...

Clinical Background: The heart can cause kidney disease, and the kidney can cause heart disease. As an example of the first situation, we can mention dilated cardiomyopathies, which can lead to renal failure of the pre-renal type due to the state of renal hypoflow. As an example of the second situation, we can remember that renal failure is a risk factor for cardiovascular diseases, such as coronary heart disease, due to the acceleration in the process of atherosclerosis that it promotes. Epidemiology: In this chapter, we will address what we consider to be the two main aspects of the interrelationships between heart and kidney disease that are "cardiorenal syndrome (CRS)" and "chronic kidney disease (CKD) and coronary heart disease (CHD)...

Obstetric-related acute kidney injury (obstetric AKI) is an important and complex public health problem; its early recognition and proper treatment are key in preventing maternal and fetal adverse outcomes. While the incidence of obstetric AKI has drastically declined in some developing countries due to reduction of sepsis-related causes, the opposite has been observed in other developed nations in the last decade due to advanced maternal age and the presence of comorbidities. The diagnosis of obstetric AKI has been made difficult by the physiologic decrease in serum creatinine of pregnancy as well as the absence of a uniform definition for AKI in this population...

Clinical Background: Cancer therapeutics (for both solid and hematological malignancies) have evolved over the last two decades, from traditional chemotherapies to novel treatments. A better supportive care, older patients with comorbidities who receive multiple chemotherapeutic and pharmacological regimens, multiple CT scans with contrast agents, and new therapeutic options are also increasing the number of cancer patients who can develop acute kidney injury (AKI) or chronic kidney disease (CKD). Challenges: Targeted therapies and immunotherapies, which harness the body's own immune system to fight cancer cells have led to improved survival in cancer patients, yet all are associated with many organ toxicities...

Clinical Background: Hydration status, which is influenced by environment and self-behavior is associated with kidney health and disease. Epidemiology: Lack of safe water, sanitation, and high temperatures are environmental issues that affect a significant part of the worldwide population. Occupational factors that discourage proper hydration, as well as low water intake in favorable environment conditions, are also highly prevalent. As a consequence, inadequate water intake can lead to several kidney problems ranging from uncomplicated urinary tract infections to kidney stones, acute kidney injury, and chronic disorders with high mortality rates...

Snakebite-related acute kidney injury (AKI) is mainly caused by bites from the Viperidae family which are common snakes worldwide. It is a frequent and potentially fatal clinical complication. Coagulation abnormalities are usually present and are most likely to contribute to AKI development. A better comprehension of AKI pathogenesis following the toxicsyndrome may improve patient management by primary healthcare providers, allowing earlier diagnosis and treatment. This chapter highlights the main studies about snakevenom-related AKI, the most common snakes around the world, and the respective mechanisms of AKI...

Clinical Background: Cigarette smoking is one of the leading causes of preventable deaths, including cardiovascular diseases and cancer. However, the effects of tobacco use on chronic kidney disease (CKD) are less widespread. Epidemiology: Smoking tobacco is associated with proteinuria and attenuation of glomerular filtration rate in the general population of different ethnicities. Smoking also accelerates the progression of established CKD and aggravates proteinuria along the wide spectrum of causes determining kidney disease...

Clinical Background: Poly- and perfluorinated compound (PFCS) pollution has been found to be the driver of different diseases, including glucose intolerance, hyperlipidemia, thyroid diseases, gestational diabetes mellitus and hypertension, testicular and genitourinary cancer, as well as impaired kidney function. This review focuses on the renal effects of PFCS, intending to clarify their occurrence and pathogenetic mechanisms. Epidemiology: Between October 31st, 2017, and March 31st, 2020, most frequently analyzed PFCS were perfluorooctane sulfonate, perfluorooctanoic acid, sodium perfluoro-1-hexanesulfonate, perfluoro-n-nonanoic acid, and perfluoro-n-decanoic acid...

Clinical Background: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread globally from late 2019, reaching pandemic proportions. Epidemiology: The related disease, COVID-19, exacerbates and progresses due to patients' abnormal inflammatory/immune responses, widespread endothelial damage, and complement-induced blood clotting with microangiopathy. COVID-19 manifests mainly as a respiratory illness. In cases of severe viral pneumonia, it may lead to acute respiratory distress syndrome, respiratory failure, and death...

Clinical Background: Nephrotoxic acute kidney injury or toxin-related acute kidney injury (ToxAKI) is a relevant and relatively common category of kidney damage. Exogenous toxins and venomous animals with epidemiologic variations across the world are some nephrotoxic agents. Epidemiology: The epidemiologic features of the toxic agent-related acute kidney injury are associated with different culture, biodiversity of the tropics, and economic status. It seems economic status is the major factor which defines the etiology of ToxAKI...