Treatment of severe neurological deficits with IgG depletion through immunoadsorption in patients with Escherichia coli O104:H4-associated haemolytic uraemic syndrome: a prospective trial

Hemolytic-Uremic Syndrome in Children

Hemolytic uremic syndrome is characterized by a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. Most cases are caused by Shiga-toxin-producing bacteria, especially Escherichia coli. Transmission occurs through ground beef and unpasteurized milk. STEC-HUS is the main cause of acute renal failure in children. Management remains supportive. Immediate outcome is most often. Atypical HUS represents about 5% of cases, has a relapsing course with more than half of the patients progressing to end-stage kidney failure. Most cases are due to variants in complement regulators of the alternative pathway. Complement inhibitors, such as eculizumab, have considerably improved the prognosis.

Therapeutic apheresis in kidney diseases: an updated review

Besides conventional medical therapies, therapeutic apheresis has become an important adjunctive or alternative therapeutic option to immunosuppressive agents for primary or secondary kidney diseases and kidney transplantation. The available therapeutic apheresis techniques used in kidney diseases, including plasma exchange, double-filtration plasmapheresis, immunoadsorption, and low-density lipoprotein apheresis. Plasma exchange is still the leading extracorporeal therapy. Recently, growing evidence supports the potential benefits of double-filtration plasmapheresis and immunoadsorption for more specific and effective clearance of pathogenic antibodies with fewer side effects. However, more randomized controlled trials are still needed. Low-density lipoprotein apheresis is also an important supplementary therapy used in patients with recurrent focal segmental glomerulosclerosis. This review collects the latest evidence from recent studies, focuses on the specific advantages and disadvantages of these techniques, and compares the discrepancy among them to determine the optimal therapeutic regimens for certain kidney diseases.

Treatment of Shiga-Toxin Hus with Severe Neurologic Features with Eculizumab

Hemolytic Uremic Syndrome (HUS) is a constellation of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Shiga toxin-producing Escherichia coli- (STEC-) mediated HUS is a common cause of acute renal failure in children and can rarely result in severe neurological complications such as encephalopathy, seizures, cerebrovascular accidents, and coma. Current literature supports use of eculizumab, a monoclonal antibody that blocks complement activation, in atypical HUS (aHUS). However, those with neurologic complications from STEC-HUS have complement activation and deposition of aggregates in microvasculature and may be treated with eculizumab. In this case report, we describe a 3-year-old boy with diarrhea-positive STEC-HUS who developed severe neurologic involvement in addition to acute renal failure requiring renal replacement therapy. He was initiated on eculizumab therapy, with clinical improvement and organ recovery. This case highlights systemic complications of STEC-HUS in a pediatric patient. The current literature is limited but has suggested a role for complement mediation in cases with severe complications. We review the importance of early recognition of complications, use of eculizumab, and current data available.

Steroid Pulse Therapy for Severe Central Nervous System Involvement in Shiga Toxin-Producing Escherichia coli-Related Hemolytic Uremic Syndrome

We report on the case of a 7-year-old boy with Shiga toxin-producing Escherichia coli-related hemolytic uremic syndrome (STEC-HUS), initially presenting with abdominal pain as the only clinical feature and thus requiring differential diagnosis with a surgical emergency. Diagnosis of STEC-HUS was made with the appearance of bloody diarrhea and renal function impairment, and the clinical picture rapidly progressed to multiorgan failure. Relatively late and severe central nervous system (CNS) involvement was present, characterized by subacute encephalitis progressing to coma, which became apparent when the acute phase of thrombotic microangiopathy was resolving. Therefore, neurologic manifestations were thought to be related to reperfusion damage to the CNS and high-dose IV steroid pulse therapy was empirically administered. Following this therapeutic scheme, neurologic involvement resolved with no sequelae. This case offers several points of discussion on the clinical presentation and the diagnostic approach to STEC-HUS, on the related neurologic complications, and on a novel approach to their management.

Shiga Toxin-Associated Hemolytic Uremic Syndrome: Specificities of Adult Patients and Implications for Critical Care Management

Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is a form of thrombotic microangiopathy secondary to an infection by an enterohemorrhagic E. coli. Historically considered a pediatric disease, its presentation has been described as typical, with bloody diarrhea at the forefront. However, in adults, the clinical presentation is more diverse and makes the early diagnosis hazardous. In this review, we review the epidemiology, most important outbreaks, physiopathology, clinical presentation and prognosis of STEC-HUS, focusing on the differential features between pediatric and adult disease. We show that the clinical presentation of STEC-HUS in adults is far from typical and marked by the prevalence of neurological symptoms and a poorer prognosis. Of note, we highlight knowledge gaps and the need for studies dedicated to adult patients. The differences between pediatric and adult patients have implications for the treatment of this disease, which remains a public health threat and lack a specific treatment.

Therapeutic Plasma Exchange in the Critically Ill Patient: Technology and Indications

Therapeutic plasma exchange (TPE) is frequently the most common Apheresis Medicine technique used for extracorporeal therapy of a wide variety of renal, neurological, hematological, and other clinical indications. Many of these clinical indications require intensive care during critical illness. Conventional TPE uses one of two main technical methods to achieve the goal of removing known disease mediators from the plasma: using centrifugal forces to separate and remove components of blood, or a membrane filtration method that separates plasma from the cellular components of blood. The following review discusses the basic principles of TPE, the technological aspects, and relevant clinical scenarios encountered in the intensive care unit, including relevant guidelines and recommendations from the American Society for Apheresis.

Plasma exchange and thrombotic microangiopathies: From pathophysiology to clinical practice

Thrombotic microangiopathy (TMA) brings together many diseases that have a commonality in the apparition of mechanical hemolysis with consuming thrombopenia. In all cases, these diseases can be life threatening, thereby justifying the implementation of treatment as an emergency. First-line treatment represents plasma exchange. This treatment has proven efficiency in improving the vital patient's and functional prognosis. However, the administration methods of plasma exchange can be redefined in light of the understanding of the pathophysiology of TMA. The aim of this review is to try to define, from pathophysiology, the place of plasma exchanges in the modern therapeutic arsenal of TMA.

Shiga Toxin-Associated Hemolytic Uremic Syndrome: A Narrative Review

The severity of human infection by one of the many Shiga toxin-producing Escherichia coli (STEC) is determined by a number of factors: the bacterial genome, the capacity of human societies to prevent foodborne epidemics, the medical condition of infected patients (in particular their hydration status, often compromised by severe diarrhea), and by our capacity to devise new therapeutic approaches, most specifically to combat the bacterial virulence factors, as opposed to our current strategies that essentially aim to palliate organ deficiencies. The last major outbreak in 2011 in Germany, which killed more than 50 people in Europe, was evidence that an effective treatment was still lacking. Herein, we review the current knowledge of STEC virulence, how societies organize the prevention of human disease, and how physicians treat (and, hopefully, will treat) its potentially fatal complications. In particular, we focus on STEC-induced hemolytic and uremic syndrome (HUS), where the intrusion of toxins inside endothelial cells results in massive cell death, activation of the coagulation within capillaries, and eventually organ failure.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 10⁹ colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 10⁴ Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.

Haemolytic uraemic syndrome - a rare case report of bloody diarrhoea in adults

BACKGROUND

Haemolytic uraemic syndrome is a rarely seen in adults often leading to critical illness. This case highlights how difficult it can be to establish a diagnosis and treat when a patient presents with bloody diarrhoea.

CASE PRESENTATION

A 17-year-old Iraqi man presented to the emergency department with abdominal pain and bloody diarrhoea. He was initially treated as acute appendicitis, undergoing an appendectomy but following a recurrence in his symptoms a colonoscopy was performed. A diagnosis of shiga toxin-producing Escherichia coli leading to HUS was suspected following histology obtained at colonoscopy and this was confirmed on antibody testing. Despite intravenous fluids and supportive therapy the patient's symptoms and condition deteriorated. He developed seizures and acute renal failure requiring intubation and plasma exchange in the intensive care setting. He eventually required treatment with ecluzimab therapy; a monoclonal antibody and subsequently made a full recovery.

CONCLUSIONS

Haemolytic uraemic syndrome is a triad of progressive renal failure, thrombocytopenia and haemolytic anaemia which is a condition rarely seen in adults. It is usually associated with an E. coli infection and supportive therapy remains the mainstay of treatment.

An Atypical Case of Shiga Toxin Producing-Escherichia Coli Hemolytic and Uremic Syndrome (STEC-HUS) in a Lung Transplant Recipient

We herein describe the first case of thrombotic microangiopathy (TMA) which was related to Shiga toxin producing-Escherichia Coli Hemolytic and Uremic Syndrome (STEC-HUS) after lung transplantation. His maintenance immunosuppression relied on tacrolimus plus mycophenolic acid. TMA was treated with plasma exchanges (PE) (fresh frozen plasma substitution). After five days of PE, platelets count and lactate dehydrogenase level normalized, whereas hemoglobin continued to gradually decrease and no improvement in kidney function was observed. After seven PE sessions, all TMA biological signs resolved. However, kidney function did not improve, and the patient still required chronic dialysis.

A pediatric neurologic assessment score may drive the eculizumab-based treatment of Escherichia coli-related hemolytic uremic syndrome with neurological involvement

BACKGROUND

Thrombotic microangiopathy (TMA) is a clinical syndrome encompassing a large group of rare but severe disorders including thrombotic thrombocytopenic purpura (TTP) and both typical and atypical forms of hemolytic uremic syndrome (HUS). The key role of the complement system is well known in TTP and atypical HUS, but recent reports describe its involvement in the pathogenesis of HUS secondary to gastrointestinal infections due to Shiga toxin-producing Escherichia coli (STEC).

METHODS

TMA mainly affects the kidney, but extra-renal complications are frequently described. The involvement of the central nervous system (CNS) represents often a life-threatening condition and it can result in serious long-term disability in HUS patients who overcome the acute phase of illness. In the present study, we retrospectively analyzed a pediatric cohort of a single tertiary pediatric hospital in Southern Italy, in which this complication occurred in 12/54 children (22% of cases), of whom five with severe neurological involvement had been successfully treated with eculizumab.

RESULTS

The great clinical variability of brain injury in our cohort has led us to retrospectively build a "neurological score" useful to assess the clinical severity of neurologic involvement. Subjects with higher neurologic score due to the most severe CNS involvement resulted in the group of patients early treated with eculizumab, obtaining a good clinical response (four out five patients). In conclusion, the early treatment with eculizumab in children with severe neurological involvement during STEC-HUS was associated with complete regression of both acute kidney injury (AKI) and neurological lesions observed at magnetic resonance imaging (MRI).

CONCLUSIONS

A "neurological score" may be a useful tool to drive the early treatment of CNS complications in STEC-HUS with eculizumab, although future perspective controlled studies are urgently needed to validate this therapeutic approach.

Hemolytic Uremic Syndrome

Hemolytic uremic syndrome (HUS) is the clinical triad of thrombocytopenia, anemia, and acute kidney injury. Classically associated with enterocolitis from Shiga toxin-producing Escherichia coli, HUS is also associated with Streptococcus pneumoniae infections; genetic dysregulation of the alternative complement pathway or coagulation cascade; and, rarely, a hereditary disorder of cobalamin C metabolism. These share a common final pathway of a prothrombotic and proinflammatory state on the endothelial cell surface, with fibrin and platelet deposition. Much work has been done to distinguish between the different mechanisms of disease, thereby informing the optimal therapeutic interventions for each entity.

Eculizumab treatment in severe pediatric STEC-HUS: a multicenter retrospective study

BACKGROUND

Hemolytic uremic syndrome related to Shiga-toxin-secreting Escherichia coli infection (STEC-HUS) remains a common cause of acute kidney injury in young children. No specific treatment has been validated for this severe disease. Recently, experimental studies highlight the potential role of complement in STEC-HUS pathophysiology. Eculizumab (EC), a monoclonal antibody against terminal complement complex, has been used in severe STEC-HUS patients, mostly during the 2011 German outbreak, with conflicting results.

METHODS

On behalf of the French Society of Pediatric Nephrology, we retrospectively studied 33 children from 15 centers treated with EC for severe STEC-HUS. Indication for EC was neurologic involvement in 20 patients, cardiac and neurologic involvement in 8, cardiac involvement in 2, and digestive involvement in 3. Based on medical status at last follow-up, patients were divided into two groups: favorable (n = 15) and unfavorable outcomes (n = 18).

RESULTS

Among patients with favorable outcome, 11/14 patients (79%) displayed persistent blockade of complement activity before each EC reinjection. Conversely, in patients with unfavorable outcome, only 9/15 (53%) had persistent blockade (p = n.s.). Among 28 patients presenting neurological symptoms, 19 had favorable neurological outcome including 17 with prompt recovery following first EC injection. Only two adverse effects potentially related to EC treatment were reported.

CONCLUSIONS

Taken together, these results may support EC use in severe STEC-HUS patients, especially those presenting severe neurological symptoms. The study, however, is limited by absence of a control group and use of multiple therapeutic interventions in treatment groups. Thus, prospective, controlled trials should be undertaken.

The shaping, making and baking of a pancreatologist

The European Pancreatic Club Lifetime Achievement award is a distinction awarded for research on the pancreas. It comes with the obligation to submit a review article to the society's journal, Pancreatology. Since the research topics of my group have recently been covered in reviews and book chapters I want to use this opportunity to appraise the stations of my clinical and research education, the projects that I pursued and abandoned, the lessons I have learned from them, and the women and men who influenced my training and development as a physician scientist. Some crossed my path, some become collaborators and friends, and some turned into role models and had a lasting impact on my life.

A devastating case of diarrhea-associated hemolytic uremic syndrome associated with extensive cerebral infarction; why we need to do better

A 4-year-old girl with diarrhea-associated hemolytic uremic syndrome (D+HUS) was transferred to the PICU of our center due to deteriorating renal function and neurological involvement. On admission, a comatous child was seen with hypoventilation and she was placed on mechanical ventilation. Hemodialysis was commenced but plasma exchange was discontinued due to repeated hypersensitivity reactions. A trial of eculizumab was given in light of the worsening of her neurologic condition with development of a pyramidal syndrome and deepening of the coma. Hematological and renal improvement were noted but severe neurologic involvement persisted. MRI revealed extensive bilateral zones of corticocerebral infarction and neurological damage proved to be irreversible. Diarrhea-associated hemolytic uremic syndrome is a common cause of Acute Kidney Injury associated with severe short- and long-term complications. Neurologic involvement is frequent but often reversible. Currently, no effective treatment strategies are available and a paucity of data exists concerning the efficacy of potential treatment options such as early plasma exchange, eculizumab, and high dose corticosteroids. A concerted effort is needed to early identify patients at risk for poor outcome with trials aimed at evaluating the efficacy of potential treatment options for this subgroup.

Treatment and management of children with haemolytic uraemic syndrome

Haemolytic uraemic syndrome (HUS), comprising microangiopathic haemolytic anaemia, thrombocytopaenia and acute kidney injury, remains the leading cause of paediatric intrinsic acute kidney injury, with peak incidence in children aged under 5 years. HUS most commonly occurs following infection with Shiga toxin-producing Escherichia coli (STEC-HUS). Additionally, HUS can occur as a result of inherited or acquired dysregulation of the alternative complement cascade (atypical HUS or aHUS) and in the setting of invasive pneumococcal infection. The field of HUS has been transformed by the discovery of the central role of complement in aHUS and the dawn of therapeutic complement inhibition. Herein, we address these three major forms of HUS in children, review the latest evidence for their treatment and discuss the management of STEC infection from presentation with bloody diarrhoea, through to development of fulminant HUS.

Treatment of thrombotic microangiopathy with a focus on new treatment options

The thrombotic microangiopathies (TMA) are a heterogeneous group of disorders, characterized by microangiopathic haemolytic anaemia with red cell fragmentation, thrombocytopenia and signs of organ dysfunction due to disturbed microcirculation. Current laboratory methods can be used to better distinguish some of these entities. Organ dysfunction can be severe and life-threatening, and immediate start of sufficient therapy is necessary to avoid permanent damage or death. The therapeutic options, however, are often limited to symptomatic measures, and are not standardized or based on high scientific evidence. During the preceding years, not only considerable progress has been made in better diagnosis of TMA, but also new therapeutic strategies have been established. Initial treatment still is based on plasma exchange and symptomatic measures to protect organ function. New concepts (immunosuppression, targeted anti-von Willebrand factor or anti-complement therapy, replacement with recombinant enzymes) are discussed in this article.

Postdiarrheal hemolytic and uremic syndrome with severe multiorgan involvement and associated early risk factors

AIM

Identifying early clinical and biological factors associated with severe forms of postdiarrheal hemolytic uremic syndrome (D+HUS) that may help practitioners determine appropriate treatment.

METHODS

This retrospective study was conducted in 49 children with D+HUS between 2001 and 2011. Severe forms were defined as occurrence of one of the following conditions: death, major neurological involvement, cardiovascular involvement, and/or the presence of sequelae (neurological, cardiovascular, pancreatic, or renal).

RESULTS

During the acute phase, 35 children exhibited at least one type of extrarenal involvement including 13 severe forms with a median delayed occurrence after admission of 4.5 days (range: 1-8) for comatose children and 5 days (range: 2-6) for cardiovascular involvement; 32 children required dialysis and three died. In multivariate analysis, (i) major neurological involvement (n=13), (ii) dialysis (n=32), and (iii) sequelae (n=12) were associated with (i) fever during the prodromal phase requiring dialysis at admission, (ii) C-reactive protein level (CRP) >22mg/L at admission, and (iii) major neurological involvement and a white blood cell count (WBC)>20×10³/mm³ during the acute stage, respectively.

CONCLUSIONS

D+HUS is a multiorgan disease with a delayed occurrence of life-threatening extrarenal organ involvement. Severe forms appear to be associated with early biological and clinical inflammatory parameters.

The 2011 German Enterohemorrhagic Escherichia Coli O104:H4 Outbreak-The Danger Is Still Out There

Enterohemorrhagic Escherichia coli (EHEC) are Shiga toxin (Stx) producing bacteria causing a disease characterized by bloody (or non-bloody) diarrhea, which might progress to hemolytic uremic syndrome (HUS). EHEC O104:H4 caused the largest ever recorded EHEC outbreak in Germany in 2011, which in addition showed the so far highest incidence rate of EHEC-related HUS worldwide. The aggressive outbreak strain carries an unusual combination of virulence traits characteristic to both EHEC-a chromosomally integrated Stx-encoding bacteriophage, and enteroaggregative Escherichia coli-pAA plasmid-encoded aggregative adherence fimbriae mediating its tight adhesion to epithelia cells. There are currently still open questions regarding the 2011 EHEC outbreak, e.g., with respect to the exact molecular mechanisms resulting in the hypervirulence of the strain, the natural reservoir of EHEC O104:H4, and suitable therapeutic strategies. Nevertheless, our knowledge on these issues has substantially expanded since 2011. Here, we present an overview of the epidemiological, clinical, microbiological, and molecular biological data available on the 2011 German EHEC O104:H4 outbreak.

Public Health Research Resulting from One of the World's Largest Outbreaks Caused by Entero-Hemorrhagic Escherichia coli in Germany 2011: A Review

In 2011, Germany experienced one of the largest outbreaks of entero-hemorrhagic Escherichia coli (EHEC) ever reported. Four years thereafter, we systematically searched for scientific publications in PubMed and MEDPILOT relating to this outbreak in order to assess the pattern of respective research activities and to assess the main findings and recommendations in the field of public health. Following PRISMA guidelines, we selected 133 publications, half of which were published within 17 months after outbreak onset. Clinical medicine was covered by 71, microbiology by 60, epidemiology by 46, outbreak reporting by 11, and food safety by 9 papers. Those on the last three topics drew conclusions on methods in surveillance, diagnosis, and outbreak investigation, on resources in public health, as well as on inter-agency collaboration, and public communication. Although the outbreak primarily affected Germany, most publications were conducted by multinational cooperations. Our findings document how soon and in which fields research was conducted with respect to this outbreak.

Hemolytic uremic syndrome due to Shiga toxin-producing Escherichia coli infection

The leading cause of hemolytic uremic syndrome (HUS) in children is Shiga toxin-producing Escherichia coli (STEC) infection, which has a major outbreak potential. Since the early 2010s, STEC epidemiology is characterized by a decline of the historically predominant O157 serogroup and the emergence of non-O157 STEC, especially O26 and O80 in France. STEC contamination occurs through the ingestion of contaminated food or water, person-to-person transmission, or contact with ruminants or their contaminated environment. The main symptom is diarrhea, which is bloody in about 60% of patients and occurs after a median incubation period of three days. Shiga toxins released by STEC induce a cascade of thrombogenic and inflammatory changes of microvascular endothelial cells. HUS is observed in 5-15% of STEC infection cases, defined by the triad of mechanical hemolytic anemia, thrombocytopenia, and acute renal injury. The diagnosis of STEC infection relies on biological screening for Shiga toxins and STEC in stools and serology. Treatment of STEC-HUS is mainly symptomatic, as no specific drug has proved effective. The effect of antibiotics in STEC infection and STEC-HUS remains debated; however, some bacteriostatic antibiotics might have a beneficial effect. Proofs of evidence of a benefit from complement blockade therapy in STEC-HUS are also lacking. Clinical and bacteriological STEC-HUS surveillance needs to be continued. Ongoing prospective studies will document the role of bacteriostatic antibiotics in STEC infection and STEC-HUS, and of complement blockade therapy in STEC-HUS.

Complement C5-inhibiting therapy for the thrombotic microangiopathies: accumulating evidence, but not a panacea

Thrombotic microangiopathy (TMA), characterized by organ injury occurring consequent to severe endothelial damage, can manifest in a diverse range of diseases. In complement-mediated atypical haemolytic uraemic syndrome (aHUS) a primary defect in complement, such as a mutation or autoantibody leading to over activation of the alternative pathway, predisposes to the development of disease, usually following exposure to an environmental trigger. The elucidation of the pathogenesis of aHUS resulted in the successful introduction of the complement inhibitor eculizumab into clinical practice. In other TMAs, although complement activation may be seen, its role in the pathogenesis remains to be confirmed by an interventional trial. Although many case reports in TMAs other than complement-mediated aHUS hint at efficacy, publication bias, concurrent therapies and in some cases the self-limiting nature of disease make broader interpretation difficult. In this article, we will review the evidence for the role of complement inhibition in complement-mediated aHUS and other TMAs.

Haemolytic uraemic syndrome

Haemolytic uraemic syndrome is a form of thrombotic microangiopathy affecting predominantly the kidney and characterised by a triad of thrombocytopenia, mechanical haemolytic anaemia, and acute kidney injury. The term encompasses several disorders: shiga toxin-induced and pneumococcus-induced haemolytic uraemic syndrome, haemolytic uraemic syndrome associated with complement dysregulation or mutation of diacylglycerol kinase ɛ, haemolytic uraemic syndrome related to cobalamin C defect, and haemolytic uraemic syndrome secondary to a heterogeneous group of causes (infections, drugs, cancer, and systemic diseases). In the past two decades, experimental, genetic, and clinical studies have helped to decipher the pathophysiology of these various forms of haemolytic uraemic syndrome and undoubtedly improved diagnostic approaches. Moreover, a specific mechanism-based treatment has been made available for patients affected by atypical haemolytic uraemic syndrome due to complement dysregulation. Such treatment is, however, still absent for several other disease types, including shiga toxin-induced haemolytic uraemic syndrome.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Postinfectious Hemolytic Uremic Syndrome

Post-infectious hemolytic uremic syndrome (HUS) is caused by specific pathogens in patients with no identifiable HUS-associated genetic mutation or autoantibody. The majority of episodes is due to infections by Shiga toxin (Stx) producing Escherichia coli (STEC). This chapter reviews the epidemiology and pathogenesis of STEC-HUS, including bacterial-derived factors and host responses. STEC disease is characterized by hematological (microangiopathic hemolytic anemia), renal (acute kidney injury) and extrarenal organ involvement. Clinicians should always strive for an etiological diagnosis through the microbiological or molecular identification of Stx-producing bacteria and Stx or, if negative, serological assays. Treatment of STEC-HUS is supportive; more investigations are needed to evaluate the efficacy of putative preventive and therapeutic measures, such as non-phage-inducing antibiotics, volume expansion and anti-complement agents. The outcome of STEC-HUS is generally favorable, but chronic kidney disease, permanent extrarenal, mainly cerebral complication and death (in less than 5 %) occur and long-term follow-up is recommended. The remainder of this chapter highlights rarer forms of (post-infectious) HUS due to S. dysenteriae, S. pneumoniae, influenza A and HIV and discusses potential interactions between these pathogens and the complement system.

The alternative pathway of complement and the thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are disorders defined by microangiopathic hemolytic anemia, non-immune thrombocytopenia and have multi-organ involvement including the kidneys, brain, gastrointestinal, respiratory tract and skin. Emerging evidence points to the central role of complement dysregulation in leading to microvascular endothelial injury which is crucial for the development of TMAs. This key insight has led to the development of complement-targeted therapy. Eculizumab is an anti-C5 monoclonal antibody, which has revolutionized the treatment of atypical hemolytic uremic syndrome. Several other anti-complement therapeutic agents are currently in development, offering a potential armamentarium of therapies available to treat complement-mediated TMAs. The development of sensitive, reliable and easy to perform assays to monitor complement activity and therapeutic efficacy will be key to devising an individualized treatment regime with the potential of safely weaning or discontinuing treatment in the appropriate clinical setting.

Complement and the kidney in the setting of Shiga-toxin hemolytic uremic syndrome, organ transplantation, and C3 glomerulonephritis

OBJECTIVES

To review the role of complement in glomerular pathologies focusing on thrombotic microangiopathies (TMA) caused by Shiga toxin (Stx) and organ transplantation associated hemolytic uremic syndrome (HUS) as well as C3 glomerulopathy (C3G).

METHODS

Examination of literature discussing TMA associated with Stx HUS, transplantation related HUS and C3G.

RESULTS

There is an emerging role for complement biology in the renal glomerulus where its inappropriate over-activation is integral to several diseases. Stx HUS patients show evidence of complement activation and the toxin itself can activate complement and inhibit its normal regulation. However, therapeutic complement blockade has not yet proven effective in all circumstances. This may be partly related to late use and a clinical trial could be warranted. Organ transplantation associated HUS has carried a poor prognosis. While case reports supporting the use of complement inhibition exist, there has not been a formal trial. Complement activation in C3G is established but again treatment with complement inhibition has failed to be uniformly beneficial. Here, too, a clinical trial may help determine which subgroup of patients should be treated with these agents.

CONCLUSION

Complement plays an important role in the glomerulus but more work is needed to fully understand how it contributes to normal function and pathology. This will help direct appropriate therapy in these diseases.

Diarrhea-associated hemolytic uremic syndrome with severe neurological manifestations treated with IgG depletion through immunoadsorption

BACKGROUND

Diarrhea-associated hemolytic uremic syndrome (HUS) is characterized by acute kidney injury with microangiopathic hemolytic anemia and thrombocytopenia with a diarrhea prodrome, typically caused by Shiga-like toxin-producing Escherichia coli. Supportive management is generally recommended.

CASE REPORT

A 58-year-old female with diarrhea-associated HUS developed delayed-onset severe neurological manifestations including coma, status epilepticus, and subcortical magnetic resonance imaging signal alterations. Rescue treatment with immunoglobulin (Ig)G depletion through immunoadsorption was followed by significant improvement in neurological and renal function. The patient recovered with only minimal sequelae.

CONCLUSION

Delayed-onset neurological abnormalities may occur in diarrhea-associated HUS. Novel specific treatment options include IgG depletion through immunoadsorption. Severe clinical and imaging findings do not preclude a good outcome.

Neurological Sequelae in Adults After E coli O104: H4 Infection-Induced Hemolytic-Uremic Syndrome

In an outbreak of shiga toxin-producing Escherichia coli infections and associated hemolytic-uremic syndrome (STEC O104:H4) in Germany in the year 2011 neurological complications in adult patients occurred unexpectedly frequent, ranging between 48% and 100% in different patient groups. Few is known about the long-term effects of such complications and so we performed follow-up exams on 44 of the patients treated for STEC-HUS at Hannover Medical Scool in this observational study. Standardized follow-up exams including neurological and neuropsychological assessments, laboratory testing, magnetic resonance imaging (MRI), and EEG were carried out. Subgroups were examined 2 (n = 34), 7 (n = 22), and 19 (n = 23) months after disease onset. Additionally, at the 19-month follow-up, quality of life, sleep quality, and possible fatigue were assessed.Nineteen months after disease onset 31 patients were reassessed, 22 of whom still suffered from symptoms such as fatigue, headache, and attention deficits. In the neuropsychological assessments only 39% of the patients performed normal, whereas 61% scored borderline pathological or lower. Upon reviewal, the follow-up data most prominently showed a secondary decline of cognitive function in about one-quarter of the patients. Outcome was not related to treatment or laboratory data in the acute phase of the disease nor length of hospitalization. Prognosis of STEC-HUS associated brain dysfunction in adults with regard to severity of symptoms is mostly good; some patients however still have not made a full recovery. Patients' caretakers have to be aware of possible secondary decline of brain function as was observed in this study.

Complement Component 5 Mediates Development of Fibrosis, via Activation of Stellate Cells, in 2 Mouse Models of Chronic Pancreatitis

BACKGROUND & AIMS

Little is known about the pathogenic mechanisms of chronic pancreatitis. We investigated the roles of complement component 5 (C5) in pancreatic fibrogenesis in mice and patients.

METHODS

Chronic pancreatitis was induced by ligation of the midpancreatic duct, followed by a single supramaximal intraperitoneal injection of cerulein, in C57Bl6 (control) and C5-deficient mice. Some mice were given injections of 2 different antagonists of the receptor for C5a over 21 days. In a separate model, mice were given injections of cerulein for 10 weeks to induce chronic pancreatitis. Direct effects of C5 were studied in cultured primary cells. We performed genotype analysis for the single-nucleotide polymorphisms rs 17611 and rs 2300929 in C5 in patients with pancreatitis and healthy individuals (controls). Blood cells from 976 subjects were analyzed by transcriptional profiling.

RESULTS

During the initial phase of pancreatitis, levels of pancreatic damage were similar between C5-deficient and control mice. During later stages of pancreatitis, C5-deficient mice and mice given injections of C5a-receptor antagonists developed significantly less pancreatic fibrosis than control mice. Primary pancreatic stellate cells were activated in vitro by C5a. There were no differences in the rs 2300929 SNP between subjects with or without pancreatitis, but the minor allele rs17611 was associated with a significant increase in levels of C5 in whole blood.

CONCLUSIONS

In mice, loss of C5 or injection of a C5a-receptor antagonist significantly reduced the level of fibrosis of chronic pancreatitis, but this was not a consequence of milder disease in early stages of pancreatitis. C5 might be a therapeutic target for chronic pancreatitis.

Hypertension and mild chronic kidney disease persist following severe haemolytic uraemic syndrome caused by Shiga toxin-producing Escherichia coli O104:H4 in adults

BACKGROUND

Shiga toxin-producing, enteroaggregative Escherichia coli was responsible for the 2011 outbreak of haemolytic uraemic syndrome (HUS). The present single-centre, observational study describes the 1-year course of the disease with an emphasis on kidney function. Outcome data after 1 year are associated with treatment and patient characteristics at onset of HUS.

METHODS

Patients were treated according to a standardized approach of supportive care, including a limited number of plasmapheresis. On top of this treatment, patients with severe HUS (n = 35) received eculizumab, a humanized anti-C5 monoclonal antibody inhibiting terminal complement activation. The per-protocol decision--to start or omit an extended therapy with eculizumab accompanied by azithromycin--separated the patients into two groups and marked Day 0 of the prospective study. Standardized visits assessed the patients' well-being, kidney function, neurological symptoms, haematological changes and blood pressure.

RESULTS

Fifty-six patients were regularly seen during the follow-up. All patients had survived without end-stage renal disease. Young(er) age alleviated restoring kidney function after acute kidney injury even in severe HUS. After 1 year, kidney function was affected with proteinuria [26.7%; 95% confidence interval (CI) 13.8-39.6], increased serum creatinine (4.4%, CI 0.0-10.4), increased cystatin C (46.7%, CI 32.1-61.3) and reduced (<90 mL/min) estimated glomerular filtration rate (46.7%, CI 32.1-61.3). Nine of the 36 patients without previous hypertension developed de novo hypertension (25%, CI 10.9-39.1). All these patients had severe HUS.

CONCLUSIONS

Although shiga toxin-producing Escherichia coli (STEC)-HUS induced by O104:H4 was a life-threatening acute disease, follow-up showed a good recovery of organ function in all patients. Whereas kidney function recovered even after longer duration of dialysis, chronic hypertension developed after severe HUS with neurological symptoms and could not be prevented by the extended therapy.

How sex and age affect immune responses, susceptibility to infections, and response to vaccination

Do men die young and sick, or do women live long and healthy? By trying to explain the sexual dimorphism in life expectancy, both biological and environmental aspects are presently being addressed. Besides age-related changes, both the immune and the endocrine system exhibit significant sex-specific differences. This review deals with the aging immune system and its interplay with sex steroid hormones. Together, they impact on the etiopathology of many infectious diseases, which are still the major causes of morbidity and mortality in people at old age. Among men, susceptibilities toward many infectious diseases and the corresponding mortality rates are higher. Responses to various types of vaccination are often higher among women thereby also mounting stronger humoral responses. Women appear immune-privileged. The major sex steroid hormones exhibit opposing effects on cells of both the adaptive and the innate immune system: estradiol being mainly enhancing, testosterone by and large suppressive. However, levels of sex hormones change with age. At menopause transition, dropping estradiol potentially enhances immunosenescence effects posing postmenopausal women at additional, yet specific risks. Conclusively during aging, interventions, which distinctively consider the changing level of individual hormones, shall provide potent options in maintaining optimal immune functions.

Serum tau protein as a marker of disease activity in enterohemorrhagic Escherichia coli O111-induced hemolytic uremic syndrome

Tau protein levels in cerebrospinal fluid (CSF) and serum are elevated in patients with various central nervous system diseases. We investigated whether serum tau protein levels are useful for predicting and assessing disease activity of acute encephalopathy (AE) in enterohemorrhagic Escherichia coli (EHEC) O111-induced hemolytic uremic syndrome (HUS; EHEC encephalopathy). Serum samples were obtained from 14 patients with EHEC O111/HUS, 20 patients with non-EHEC-related AE, and 20 age- and sex-matched healthy controls. CSF samples were obtained from 2 patients with EHEC encephalopathy and 20 patients with non-EHEC-related AE. Tau protein levels and levels of several proinflammatory cytokines were quantified by enzyme-linked immunosorbent assays. Results were compared with the clinical features of EHEC encephalopathy, including magnetic resonance image (MRI) findings. Serum tau levels in patients with EHEC encephalopathy were significantly elevated compared with those in patients with EHEC O111/HUS without encephalopathy, patients with non-EHEC-related AE, and healthy controls. The ratio of CSF tau levels to serum tau levels was >1.0 in all patients with non-EHEC-related AE but <1.0 in 2 patients with EHEC encephalopathy. Serum tau protein levels increased rapidly and markedly in patients with severe EHEC 0111/HUS and encephalopathy when HUS occurred, but were not elevated in mild patients, even in the HUS phase. Furthermore, changes in serum tau protein levels in patients with EHEC encephalopathy were consistent with abnormalities on brain MRI and were positively correlated with proinflammatory cytokine levels. Our results indicate that serum tau protein might be useful to predict and assess disease activity of EHEC encephalopathy.

Quality of life one year post-Shiga toxin-producing Escherichia coli O104 infection--a prospective cohort study

BACKGROUND

In 2011, a major outbreak of hemolytic-uremic syndrome (HUS) and bloody diarrhea related to infections from Shiga toxin-producing Escherichia coli O104 (STEC) occurred in Germany. While previous research has focused on the medical components of this disease, we aimed to investigate the course of health-related quality of life (HrQoL) over 12 months including somatic and psychosocial risk factors. Furthermore, the influence of chronic fatigue (CF) on HrQoL was examined.

METHODS

A prospective cohort study with n = 389 patients completing self-report scales at baseline, after 6 months (participation rate: 79%) and after 12 months (participation rate: 77%). The courses of physical and mental HrQoL over the 12 month period were calculated by employing general linear mixed models.

KEY RESULTS

While the physical component score of HrQoL reached a score comparable to the general population, the mental component score remained below average 12 months after STEC infection. Female gender, prior psychiatric disorder, and prior traumatic events were risk factors for a worse HrQoL course after 12 months, while social support was identified to be protective. CF was associated with low HrQoL. In addition, the somatic symptom burden remained persistently high.

CONCLUSIONS & INFERENCES

Our results show high somatic and psychosocial burden in patients 12 months after STEC infection. We recommend considering the risk factors and protective factors of poor HrQoL early in the treatment of STEC or similar diseases. Patients who are suffering from persisting somatic symptoms, CF, and impaired HrQoL may require specific aftercare.

STEC:O111-HUS complicated by acute encephalopathy in a young girl was successfully treated with a set of hemodiafiltration, steroid pulse, and soluble thrombomodulin under plasma exchange

We report a 14-year-old girl, who developed shigatoxin-producing E. coli (STEC)-HUS complicated by encephalopathy. She was successfully treated with hemodiafiltration, high-dose methylprednisolone pulse therapy, and soluble recombinant thrombomodulin under plasma exchange. von Willebrand factor multimers analysis provides potential insights into how the administered therapies might facilitate successful treatment of STEC-HUS.