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

An Outbreak of Shiga Toxin-Positive Enteroaggregative Escherichia coli O104:H4 Related Hemolytic Uremic Syndrome in Turkey: A Multicenter Study

INTRODUCTION

Serious outbreaks of Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) have been reported globally. In 2011, Germany experienced a significant outbreak of HUS caused by enteroaggregative E. coli (EAEC) O104:H4 strain. Since then, no other outbreaks of this strain have been reported. This study aims to evaluate pediatric patients affected by the second documented worldwide outbreak of STEC-HUS (EAEC O104:H4 serotype) contaminating local drinking water.

METHODS

Medical records of patients hospitalized in five pediatric intensive care units (PICUs) diagnosed with STEC-HUS between July and September 2022 were evaluated retrospectively.

RESULTS

Eighteen patients (14 girls and 4 boys) were enrolled in the study. The median age was 7.4 (Interquartile range [IQR] 1.3-17) years. Abdominal pain was the most common symptom (100%). The mean duration between symptom onset and development of STEC-HUS was 3 days (IQ 1-9). EAEC O104:H4 serotype was detected in the stool samples of 8 patients. Neurological involvement was observed in 3 patients, cardiac involvement in 2 patients, and both in 1 patient. Two patients required respiratory support and dialysis was performed in 16 (88.8%) patients. Plasmapheresis was administered to 2 patients, and eculizumab was given to four. No mortality was reported during follow-up; the mean durations of PICU and hospital stays were 11.3 and 31.6 days, respectively.

CONCLUSION

Outbreaks of HUS can have serious impacts on both mortality and morbidity. However, timely diagnosis and implementation of appropriate supportive care, including dialysis, respiratory support, and medical treatment for eligible patients, can lead to favorable outcomes.

Shiga toxin-producing Escherichia coli infection as a precipitating factor for atypical hemolytic-uremic syndrome

BACKGROUND

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy characterized by intravascular hemolysis. It can be classified as either typical, primarily caused by Shiga toxin-producing Escherichia coli (STEC) infection, or as atypical HUS (aHUS), which results from uncontrolled complement activation.

METHODS

We report the case of a 9-year-old boy with aHUS due to compound heterozygous complement factor H-related genes (CFHR) 1/3 and CFHR1-CFHR4 deletions, leading to the development of anti-complement factor H (CFH) autoantibodies. The patient presented nephrological and neurological thrombotic microangiopathy with STEC positivity. Additionally, we provide an extensive literature review of aHUS cases initially classified as typical.

RESULTS

A total of 11 patients were included, 73% of whom were pediatric. Kidney replacement therapy was required in 73% of patients. The recurrence rate was 55%. All cases were found positive for pathological variants of the complement system genes. The most commonly implicated gene was CFH, while the CFHR genes were involved in 36% of cases, although none exhibited anti-CFH autoantibodies. Anti-complement therapy was administered in 54% of cases, and none of the patients who received it early progressed to kidney failure.

CONCLUSIONS

STEC infection does not exclude aHUS diagnosis, and early use of anti-complement therapy might be reasonable in life-threatening conditions. Genetic testing can be helpful in patients with atypical presentations and can confirm the necessity of prolonged anti-complement therapy.

Eculizumab in Shiga toxin-producing Escherichia coli hemolytic uremic syndrome: a systematic review

BACKGROUND

Infection-associated hemolytic uremic syndrome (IA-HUS), most often due to infection with Shiga toxin-producing bacteria, mainly affects young children. It can be acutely life-threatening, as well as cause long-term kidney and neurological morbidity. Specific treatment with proven efficacy is lacking. Since activation of the alternative complement pathway occurs in HUS, the monoclonal C5 antibody eculizumab is often used off-label once complications, e.g., seizures, occur. Eculizumab is prohibitively expensive and carries risk of infection. Its utility in IA-HUS has not been systematically studied. This systematic review aims to present, summarize, and evaluate all currently available data regarding the effect of eculizumab administration on medium- to long-term outcomes (i.e., outcomes after the acute phase, with a permanent character) in IA-HUS.

METHODS

PubMed, Embase, and Web of Science were systematically searched for studies reporting the impact of eculizumab on medium- to long-term outcomes in IA-HUS. The final search occurred on March 2, 2022. Studies providing original data regarding medium- to long-term outcomes in at least 5 patients with IA-HUS, treated with at least one dose of eculizumab during the acute illness, were included. No other restrictions were imposed regarding patient population. Studies were excluded if data overlapped substantially with other studies, or if outcomes of IA-HUS patients were not reported separately. Study quality was assessed using the ROBINS-I tool for risk of bias in non-randomized studies of interventions. Data were analyzed descriptively.

RESULTS

A total of 2944 studies were identified. Of these, 14 studies including 386 eculizumab-treated patients met inclusion criteria. All studies were observational. Shiga toxin-producing E. coli (STEC) was identified as the infectious agent in 381 of 386 patients (98.7%), effectively limiting the interpretation of the data to STEC-HUS patients. Pooling of data across studies was not possible. No study reported a statistically significant positive effect of eculizumab on any medium- to long-term outcome. Most studies were, however, subject to critical risk of bias due to confounding, as more severely ill patients received eculizumab. Three studies attempted to control for confounding through patient matching, although residual bias persisted due to matching limitations.

DISCUSSION

Current observational evidence does not permit any conclusion regarding the impact of eculizumab in IA-HUS given critical risk of bias. Results of randomized clinical trials are eagerly awaited, as new therapeutic strategies are urgently needed to prevent long-term morbidity in these severely ill patients.

SYSTEMATIC REVIEW REGISTRATION NUMBER

OSF Registries, MSZY4, Registration DOI https://doi.org/10.17605/OSF.IO/MSZY4 .

Eculizumab in STEC-HUS: a paradigm shift in the management of pediatric patients with neurological involvement

BACKGROUND

Eculizumab for the treatment of atypical hemolytic uremic syndrome (HUS) is a standard of care. Central nervous system (CNS) involvement in Shiga toxin-producing Escherichia coli (STEC)-HUS is associated with increased morbidity and mortality. There is no consensus on the use of plasma exchange and/or eculizumab. We report a series (n = 4) of children with CNS involvement in STEC-HUS with excellent outcomes after treatment with eculizumab only and supportive therapies.

METHODS

A retrospective chart review of patients with CNS involvement in STEC-HUS is managed with supportive therapies and eculizumab only.

RESULTS

Four patients (75% female) with a median age of 5 years and 11 months (IQR: 23.5-105.5 months) were admitted to a tertiary pediatric nephrology center with CNS involvement in STEC-HUS. Neurological symptoms presented between days 2 and 7 of illness and included ataxia, altered mental status, visual symptoms, and seizures. All had an abnormal MRI brain. All received two doses of eculizumab, 1 week apart (dosing according to weight). Resolution of neurological symptoms was evident at a mean of 60 h post-administration (range: 24-72 h). All patients have complete kidney and neurological recovery at 12-month follow-up.

CONCLUSION

We present a case series of four children with STEC-HUS and CNS involvement, managed with eculizumab only, in lieu of plasma exchange (as per our previous policy). The marked improvement in symptoms in our cohort supports the use of eculizumab, rather than plasma exchange in the CNS involvement of STEC-HUS.

Efficacy and Safety of Eculizumab in Pediatric Patients Affected by Shiga Toxin-Related Hemolytic and Uremic Syndrome: A Randomized, Placebo-Controlled Trial

SIGNIFICANCE STATEMENT

Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) is a serious condition, characterized by multiorgan thrombotic microangiopathy, mainly affecting children. Renal involvement is severe, with approximately half of patients requiring dialysis. So far, no specific treatment has been proven efficient in STEC-HUS. The use of eculizumab, a monoclonal antibody inhibiting terminal complement complex, has demonstrated remarkable success in atypical hemolytic uremic syndrome, but its use in uncontrolled studies to treat STEC-HUS has yielded inconsistent results. In this Phase 3 randomized, placebo-controlled trial in 100 pediatric patients with STEC-HUS, the findings did not show efficacy of eculizumab during the acute phase of the disease. However, the results indicated a reduction of renal sequelae in eculizumab-treated patients at 1-year follow-up. Larger prospective studies would be needed to further explore eculizumab as a potential treatment.

BACKGROUND

Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) in children is a severe condition, resulting in approximately 50% of patients requiring RRT. Furthermore, at least 30% of survivors experience kidney sequelae. Recently, activation of the complement alternative pathway has been postulated as a factor in STEC-HUS pathophysiology, leading to compassionate use of eculizumab, a monoclonal antibody inhibiting the terminal complement complex, in affected patients. Given the lack of therapy for STEC-HUS, a controlled study of eculizumab efficacy in treating this condition is a priority.

METHODS

We conducted a Phase 3 randomized trial of eculizumab in children with STEC-HUS. Patients were randomly assigned in a 1:1 ratio to receive either eculizumab or placebo during 4 weeks. Follow-up lasted for 1 year. The primary end point was RRT duration <48 hours after randomization. Secondary endpoints included hematologic and extrarenal involvement.

RESULTS

Baseline characteristics were similar among the 100 patients who underwent randomization. The rate of RRT <48 hours did not differ significantly between the two groups (48% in the placebo versus 38% in the eculizumab group; P = 0.31) or in the course of ARF. The two groups also exhibited similar hematologic evolution and extrarenal manifestations of STEC-HUS. The proportion of patients experiencing renal sequelae at 1 year was lower in the eculizumab group than in the placebo group (43.48% and 64.44%, respectively, P = 0.04). No safety concern was reported.

CONCLUSIONS

In pediatric patients with STEC-HUS, eculizumab treatment does not appear to be associated with improved renal outcome during acute phase of the disease but may reduce long-term kidney sequelae.

CLINICAL TRIALS REGISTRATIONS

EUDRACT (2014-001169-28) ClinicalTrials.gov ( NCT02205541 ).

HUS with mutations in CFH and STEC infection treated with eculizumab in a 4-year-old girl

BACKGROUND

Hemolytic uremic syndrome secondary to Shiga-toxin-producing Escherichia coli infection (STEC-HUS) generally shows a favorable outcome. Few cases develop extra-renal complications, since neurological involvement is an important cause of morbidity and mortality. The role of complement in STEC-HUS has been recently highlighted, and the use of eculizumab in severe cases has been communicated. HUS results from environmental and genetic factors, but the simultaneous occurrence of STEC and complement mutations remains undetermined.

METHODS

A pediatric case with severe STEC-HUS carrying CFH mutations, with favorable response to eculizumab is analyzed.

RESULTS

STEC-HUS was diagnosed in a 4-year-old girl with classic HUS, including low C3. Peritoneal dialysis was started due to hypertension, oligoanuria, and pleural effusion. She evolved with generalized tonic-clonic seizures and required mechanical ventilation. MRI reported multiple supra- and infratentorial ischemic lesions with laminar/striatal cortical necrosis and leukoencephalopathy. After two eculizumab doses, a significative stabilization in diuresis, blood pressure, creatinine, and C3 was achieved. At the third week, episodes of massive digestive bleeding and a life-threatening condition required a colectomy thus preserving the ileocecal valve. Due to atypical evolution, a genetic study was considered, identifying two heterozygous variants (CFH S1191L/V1197A).

CONCLUSION

STEC-HUS in patients with a genetic predisposition has been previously reported, but the low frequency of occurrence makes it a rare disease. As in the present case, patients with atypical course might benefit from genetic analysis to evaluate early eculizumab initiation and to better understand its phenotype. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Neurological involvement in children with hemolytic uremic syndrome

Our objective was to establish the rate of neurological involvement in Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome (STEC-HUS) and describe the clinical presentation, management and outcome. A retrospective chart review of children aged ≤ 16 years with STEC-HUS in Children's Health Ireland from 2005 to 2018 was conducted. Laboratory confirmation of STEC infection was required for inclusion. Neurological involvement was defined as encephalopathy, focal neurological deficit, and/or seizure activity. Data on clinical presentation, management, and outcome were collected. We identified 240 children with HUS; 202 had confirmed STEC infection. Neurological involvement occurred in 22 (11%). The most common presentation was seizures (73%). In the neurological group, 19 (86%) were treated with plasma exchange and/or eculizumab. Of the 21 surviving children with neurological involvement, 19 (91%) achieved a complete neurological recovery. A higher proportion of children in the neurological group had renal sequelae (27% vs. 12%, P = .031). One patient died from multi-organ failure.Conclusion: We have identified the rate of neurological involvement in a large cohort of children with STEC-HUS as 11%. Neurological involvement in STEC-HUS is associated with good long-term outcome (complete neurological recovery in 91%) and a low case-fatality rate (4.5%) in our cohort. What is Known: • HUS is associated with neurological involvement in up to 30% of cases. • Neurological involvement has been reported as predictor of poor outcome, with associated increased morbidity and mortality. What is New: • The incidence of neurological involvement in STEC-HUS is 11%. • Neurological involvement is associated with predominantly good long-term outcome (90%) and a reduced case-fatality rate (4.5%) compared to older reports.

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.

Renal diseases and the role of complement: Linking complement to immune effector pathways and therapeutics

The complement system is an ancient and phylogenetically conserved key danger sensing system that is critical for host defense against pathogens. Activation of the complement system is a vital component of innate immunity required for the detection and removal of pathogens. It is also a central orchestrator of adaptive immune responses and a constituent of normal tissue homeostasis. Once complement activation occurs, this system deposits indiscriminately on any cell surface in the vicinity and has the potential to cause unwanted and excessive tissue injury. Deposition of complement components is recognized as a hallmark of a variety of kidney diseases, where it is indeed associated with damage to the self. The provenance and the pathophysiological role(s) played by complement in each kidney disease is not fully understood. However, in recent years there has been a renaissance in the study of complement, with greater appreciation of its intracellular roles as a cell-intrinsic system and its interplay with immune effector pathways. This has been paired with a profusion of novel therapeutic agents antagonizing complement components, including approved inhibitors against complement components (C)1, C3, C5 and C5aR1. A number of clinical trials have investigated the use of these more targeted approaches for the management of kidney diseases. In this review we present and summarize the evidence for the roles of complement in kidney diseases and discuss the available clinical evidence for complement inhibition.

Peripheral nervous system manifestations of Shiga toxin-producing E. coli-induced haemolytic uremic syndrome in children

Background

The Neurological involvement is the most common extra-renal complication of Shiga toxin-producing E. coli-hemolytic uremic syndrome (HUS) or typical HUS. On brain magnetic resonance examination, main neurological signs encompass acute lesions of the basal ganglia and the white matter, which could usually regress after Eculizumab infusion. In contrast, peripheral nervous system (PNS) manifestations in typical HUS are very rare and, when occurring, they require a careful management of neurological sequelae and an intensive multidisciplinary neuro-rehabilitation program.

Case presentation

Here, we present two pediatric cases of severe and complicated typical HUS with PNS manifestations who required therapeutic treatment and an intensive multidisciplinary neuro-rehabilitation program.

In both cases, PNS manifestations were followed by the recovery from typical HUS-related severe central neurological damage and manifested mainly with marked bilateral motor deficit and hyporeflexia/areflexia in the lower limbs. The peripheral polyneuropathy was treated with immunosuppressive therapy (methylprednisolone boluses, i.v. immunoglobulins, plasma exchange), followed by a prolonged intensive neuro-rehabilitation program. After 8 months of rehabilitation, both patients gained complete functional recovery.

Conclusions

PNS manifestations during typical HUS are a rare event and potentially leading to severe disability. A timely clinical assessment is mandatory to set up a prompt therapeutic and rehabilitation program and to obtain a complete clinical and functional recovery.

Eculizumab exposure in children and young adults: indications, practice patterns, and outcomes-a Pediatric Nephrology Research Consortium study

BACKGROUND

Eculizumab is approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Its use off-label is frequently reported. The aim of this study was to describe the broader use and outcomes of a cohort of pediatric patients exposed to eculizumab.

METHODS

A retrospective, cohort analysis was performed on the clinical and biomarker characteristics of eculizumab-exposed patients < 25 years of age seen across 21 centers of the Pediatric Nephrology Research Consortium. Patients were included if they received at least one dose of eculizumab between 2008 and 2015. Traditional summary statistics were applied to demographic and clinical data.

RESULTS

A total of 152 patients were identified, mean age 9.1 (+/-6.8) years. Eculizumab was used "off-label" in 44% of cases. The most common diagnoses were aHUS (47.4%), Shiga toxin-producing Escherichia coli HUS (12%), unspecified thrombotic microangiopathies (9%), and glomerulonephritis (9%). Genetic testing was available for 60% of patients; 20% had gene variants. Dosing regimens were variable. Kidney outcomes tended to vary according to diagnosis. Infectious adverse events were the most common adverse event (33.5%). No cases of meningitis were reported. Nine patients died of noninfectious causes while on therapy.

CONCLUSIONS

This multi-center retrospective cohort analysis indicates that a significant number of children and young adults are being exposed to C5 blockade for off-label indications. Dosing schedules were highly variable, limiting outcome conclusions. Attributable adverse events appeared to be low. Cohort mortality (6.6%) was not insignificant. Prospective studies in homogenous disease cohorts are needed to support the role of C5 blockade in kidney outcomes.

The Benefits of Complement Measurements for the Clinical Practice

The complement cascade is an evolutionary ancient innate immune defense system, playing a major role in the defense against infections. Its function in maintaining host homeostasis on activated cells has been emphasized by the crucial role of its overactivation in ever growing number of diseases, such as atypical hemolytic uremic syndrome (aHUS), autoimmune diseases as systemic lupus erythematosus (SLE), C3 glomerulopathies (C3GN), age-related macular degeneration (AMD), graft rejection, Alzheimer disease, and cancer, to name just a few. The last decade of research on complement has extended its implication in many pathological processes, offering new insights to potential therapeutic targets and asserting the necessity of reliable, sensitive, specific, accurate, and reproducible biomarkers to decipher complement role in pathology. We need to evaluate accurately which pathway or role should be targeted pharmacologically, and optimize treatment efficacy versus toxicity. This chapter is an introduction to the role of complement in human diseases and the use of complement-related biomarkers in the clinical practice. It is a part of a book intending to give reliable and standardized methods to evaluate complement according to nowadays needs and knowledge.

Severely ill pediatric patients with Shiga toxin-associated hemolytic uremic syndrome (STEC-HUS) who suffered from multiple organ involvement in the early stage

BACKGROUND

Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is the main cause of pediatric acute kidney injury (AKI) in Argentina. Endothelial injury is the trigger event in the microangiopathic process. The host inflammatory response to toxin and E. coli lipopolysaccharide (LPS) is involved in disease pathophysiology.

METHODS

This retrospective study describes pediatric STEC-HUS patients with multiorgan involvement at the initial phase of disease. A retrospective study of critically ill HUS patients with evidence of E. coli infection was conducted through a period of 15 years.

RESULTS

Forty-four patients 35.4 ± 4.1 months were admitted to the intensive care unit for 21 ± 2 days. Mechanical ventilation was required in 41 patients, early inotropic support in 37, and 28 developed septic shock. Forty-one patients required kidney replacement therapy for 12 ± 1 days. Forty-one patients showed neurological dysfunction. Dilated cardiomyopathy was demonstrated in 3 patients, left ventricular systolic dysfunction in 4, and hypertension in 17. Four patients had pulmonary hemorrhage, and acute respiratory distress syndrome in 2. Colectomy for transmural colonic necrosis was performed in 3 patients. Thirty-seven patients were treated with therapeutic plasma exchange, and 28 patients received methylprednisolone (10 mg/kg for 3 days). Of the surviving 32 patients, neurological sequelae were seen in 11 and chronic kidney failure in 5.

CONCLUSIONS

Severe clinical outcome at onset suggests an amplified inflammatory response after exposure to Shiga toxin and/or E. coli LPS. STEC-HUS associated with severe neurological involvement, hemodynamic instability, and AKI requires intensive care and focused therapy.

Therapeutic Uses of Bacterial Subunit Toxins

The B subunit pentamer verotoxin (VT aka Shiga toxin-Stx) binding to its cellular glycosphingolipid (GSL) receptor, globotriaosyl ceramide (Gb₃) mediates internalization and the subsequent receptor mediated retrograde intracellular traffic of the AB5 subunit holotoxin to the endoplasmic reticulum. Subunit separation and cytosolic A subunit transit via the ER retrotranslocon as a misfolded protein mimic, then inhibits protein synthesis to kill cells, which can cause hemolytic uremic syndrome clinically. This represents one of the most studied systems of prokaryotic hijacking of eukaryotic biology. Similarly, the interaction of cholera AB5 toxin with its GSL receptor, GM1 ganglioside, is the key component of the gastrointestinal pathogenesis of cholera and follows the same retrograde transport pathway for A subunit cytosol access. Although both VT and CT are the cause of major pathology worldwide, the toxin–receptor interaction is itself being manipulated to generate new approaches to control, rather than cause, disease. This arena comprises two areas: anti neoplasia, and protein misfolding diseases. CT/CTB subunit immunomodulatory function and anti-cancer toxin immunoconjugates will not be considered here. In the verotoxin case, it is clear that Gb₃ (and VT targeting) is upregulated in many human cancers and that there is a relationship between GSL expression and cancer drug resistance. While both verotoxin and cholera toxin similarly hijack the intracellular ERAD quality control system of nascent protein folding, the more widespread cell expression of GM1 makes cholera the toxin of choice as the means to more widely utilise ERAD targeting to ameliorate genetic diseases of protein misfolding. Gb₃ is primarily expressed in human renal tissue. Glomerular endothelial cells are the primary VT target but Gb₃ is expressed in other endothelial beds, notably brain endothelial cells which can mediate the encephalopathy primarily associated with VT2-producing E. coli infection. The Gb₃ levels can be regulated by cytokines released during EHEC infection, which complicate pathogenesis. Significantly Gb₃ is upregulated in the neovasculature of many tumours, irrespective of tumour Gb₃ status. Gb₃ is markedly increased in pancreatic, ovarian, breast, testicular, renal, astrocytic, gastric, colorectal, cervical, sarcoma and meningeal cancer relative to the normal tissue. VT has been shown to be effective in mouse xenograft models of renal, astrocytoma, ovarian, colorectal, meningioma, and breast cancer. These studies are herein reviewed. Both CT and VT (and several other bacterial toxins) access the cell cytosol via cell surface ->ER transport. Once in the ER they interface with the protein folding homeostatic quality control pathway of the cell -ERAD, (ER associated degradation), which ensures that only correctly folded nascent proteins are allowed to progress to their cellular destinations. Misfolded proteins are translocated through the ER membrane and degraded by cytosolic proteosome. VT and CT A subunits have a C terminal misfolded protein mimic sequence to hijack this transporter to enter the cytosol. This interface between exogenous toxin and genetically encoded endogenous mutant misfolded proteins, provides a new therapeutic basis for the treatment of such genetic diseases, e.g., Cystic fibrosis, Gaucher disease, Krabbe disease, Fabry disease, Tay-Sachs disease and many more. Studies showing the efficacy of this approach in animal models of such diseases are presented.

Outcome of children with Shiga toxin-associated haemolytic uraemic syndrome treated with eculizumab: a matched cohort study

BACKGROUND

Treatment with eculizumab in Shiga toxin-associated haemolytic and uraemic syndrome (STEC-HUS) remains controversial despite its increasing utilization. The aim of our study was to evaluate the outcomes of children treated with eculizumab for STEC-HUS in a single-centre matched cohort study.

METHODS

Data were retrospectively collected from medical records of children diagnosed with STEC-HUS. The outcomes of patients treated with eculizumab for STEC-HUS were compared with those of a control group of untreated patients matched for age, sex and severity of acute kidney injury with a 1:2 matching scheme.

RESULTS

Eighteen children (median age 40.6 months) with STEC-HUS treated with eculizumab were compared with 36 matched control patients (median age 36.4 months) who did not receive eculizumab. All patients survived in the two groups. Within 1 month of HUS onset, the evolution of haematological and renal parameters did not differ between the two groups. At 12 months of follow-up, renal outcome was not significantly different between the two groups. At the last follow-up, the prevalence of decreased glomerular filtration rate in the eculizumab group (27%) was not statistically different from that in controls (38%), as was the prevalence of proteinuria and high blood pressure. Children who received eculizumab more often had extrarenal sequelae during follow-up. Eculizumab treatment appeared to be safe in children with STEC-HUS.

CONCLUSION

The benefit of eculizumab on renal and extrarenal outcomes in STEC-HUS could not be established based on our findings. However, efficacy and safety are not best assessed by the observational design and small sample size of our study. Randomized controlled trials are thus required to determine the efficacy of eculizumab in this indication.

Rasburicase improves the outcome of acute kidney injury from typical hemolytic uremic syndrome

BACKGROUND

Typical hemolytic uremic syndrome (HUS) causes acute kidney injury (AKI) and serious sequelae of chronic kidney disease (CKD) in some. Hyperuricemia is a common finding in typical HUS that may contribute to kidney damage. We explored whether aggressive management of hyperuricemia with rasburicase could improve outcomes in AKI patients with typical HUS.

METHODS

We retrospectively analyzed medical records of children with typical HUS admitted to a tertiary center between 2005 and 2017. We compared clinical outcomes of hospitalization and 1-year post-discharge between those with rasburicase treatment (n = 13) and those without (controls, n = 29).

RESULTS

With rasburicase treatment, hyperuricemia corrected more rapidly (median 36 vs. 120 h, p < 0.001), and hospital stays were shorter (median 9 vs. 12 days, p = 0.003) than in the controls. There was no difference in dialysis requirement. At 1-year post-discharge, the proportion of patients with impaired kidney function (estimated glomerular filtration rate < 90 mL/min/1.73 m²) was lower in the rasburicase group (7.7% vs. 41.4%, p = 0.036) than in the controls. Hypertension and proteinuria tended to be more common in the controls than in the rasburicase group. Collectively, long-term renal sequelae of impaired kidney function, proteinuria, or hypertension at a 1-year follow-up was less common in the rasburicase group than in the controls (7.7% vs. 62.1%; p = 0.001).

CONCLUSIONS

Children with typical HUS treated with rasburicase had shorter hospital stays and less long-term sequelae at 1-year post-discharge than those who were not treated with rasburicase. These results support the use of rasburicase to prevent CKD in pediatric patients with typical HUS-associated AKI. Graphical Abstract.

Microvascular thrombosis: experimental and clinical implications

A significant amount of clinical and research interest in thrombosis is focused on large vessels (eg, stroke, myocardial infarction, deep venous thrombosis, etc.); however, thrombosis is often present in the microcirculation in a variety of significant human diseases, such as disseminated intravascular coagulation, thrombotic microangiopathy, sickle cell disease, and others. Further, microvascular thrombosis has recently been demonstrated in patients with COVID-19, and has been proposed to mediate the pathogenesis of organ injury in this disease. In many of these conditions, microvascular thrombosis is accompanied by inflammation, an association referred to as thromboinflammation. In this review, we discuss endogenous regulatory mechanisms that prevent thrombosis in the microcirculation, experimental approaches to induce microvascular thrombi, and clinical conditions associated with microvascular thrombosis. A greater understanding of the links between inflammation and thrombosis in the microcirculation is anticipated to provide optimal therapeutic targets for patients with diseases accompanied by microvascular thrombosis.

Acute Myocarditis and Eculizumab Caused Severe Cholestasis in a 17-Month-Old Child Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli

Cardiovascular involvement is uncommon in pediatric patients with hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). In this case report we presented a case of 17-month-old toddler who had a sporadic type of STEC-HUS complicated by acute myocarditis. The patient was successfully treated by a single dose of eculizumab after six doses of therapeutic plasma exchange (TPE) were inefficient to prevent the cardiac complication. Hepatotoxicity was observed after a single dose of eculizumab. Hepatic and cholestatic enzyme levels slowly returned to normal within 6 months. To the best of our knowledge, this is the first case of myocarditis/cardiomyopathy treated with eculizumab in STEC-HUS. This case illustrates the need for vigilance regarding myocardial involvement and eculizumab-induced hepatotoxicity in STEC-HUS.

Low C3 Serum Levels Predict Severe Forms of STEC-HUS With Neurologic Involvement

Background: The correlation between the severity of hemolytic uremic syndrome related to Shiga toxin–producing Escherichia coli (STEC-HUS) and involvement of the complement system has been examined in a small number of studies, with conflicting results. In the present study, we investigated whether serum C3 levels on admission are associated with neurologic involvement.

Methods: To this purpose, 68 consecutive STEC-HUS patients were recruited and main clinical and laboratory variables ad hospital admission were compared between those with or without neurologic involvement.

Results: STEC-HUS patients who developed neurologic involvement (NI) showed significant higher leukocyte count, C-reactive protein and hemoglobin, and lower sodium levels as compared with those without. Interestingly, baseline serum levels of C3 were significantly lower in patients with NI as compared with those without (p < 0.001). Moreover, when stratified according to need of Eculizumab rescue therapy due to severe NI, patients treated with this drug showed baseline C3 serum levels significantly lower than those who were not (p < 0.001).

Low C3 was independent risk factor for NI in our patients' population when entered as covariate in a multivariate logistic regression analysis including other major variables previously proposed as possible predictors of poor prognosis in STEC-HUS (for instance, leukocyte count, c-reactive protein, sodium levels) (HR 6.401, 95%CI 1.617–25.334, p = 0.008 for C3).

To underline the role of complement in the worsening of STEC-HUS patients' clinical conditions and outcomes, all patients were divided into two groups according to the baseline lower vs. normal serum levels of C3 and the main data on care needs were assessed. Interestingly more patients with lower C3 serum levels required renal replacement therapy (p = 0.024), anti-hypertensive therapy (p = 0.011), Intensive Care Unit admission (p = 0.009), and longer hospitalization (p = 0.003), thus displaying significantly more severe disease features as compared with those with normal C3 serum levels.

Conclusions: Our data suggests that children with STEC-HUS with decreased C3 concentrations at admission are more likely to develop neurologic involvement and are at increased risk of having severe clinical complications.

Sudden Cardiac Arrest and Malignant Ventricular Tachycardia in an 8-Year-Old Pediatric Patient Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli

Gastrointestinal, neurological, pancreatic, hepatic, and cardiac dysfunction are extrarenal manifestations of hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). The most frequent cause of death for STEC-HUS is related to the central nervous system and cardiovascular system. Cardiac-origin deaths are predominantly related to thrombotic microangiopathy-induced ischemia and the immediate development of circulatory collapse. STEC-HUS cardiac related deaths in children are rare with only sporadic cases reported. In our literature search, we did not come across any pediatric case report about STEC-HUS causing sudden cardiac arrest and malignant ventricular tachycardia (VT). Herein, we report the case of an 8-year-old female child with a typical clinical manifestation of STEC-HUS. On the seventh day of pediatric intensive care unit admission, the patient had a sudden cardiac arrest, requiring resuscitation for 10 minutes. The patient had return of spontaneous circulation with severe monomorphic pulsed malignant VT. Intravenous treatment with lidocaine, amiodarone and magnesium sulfate were promptly initiated, and we administered multiple synchronized cardioversions, but VT persisted. Furthermore, we were not able to ameliorate her refractory circulation insufficiency by advanced cardiopulmonary resuscitation. Thus, inevitably, the patient lost her life. This case illustrates the need for aggressive management and the dilemma that pediatric critical care specialists, cardiologists, and nephrologists have to face when dealing with STEC-HUS that is worsened by a sudden cardiac arrest accompanied with VT.

Follow-up of children with infection-associated haemolytic uraemic syndrome 1979-1995: Would eculizumab have improved prognosis?

The late outcome in 55 children with infection-mediated haemolytic uremic syndrome (Shiga Toxin E Coli (STEC)-HUS and pneumococcal HUS) observed in 1979-1995 was followed up 23 years after disease onset. Of these, two were later confirmed to have atypical HUS (aHUS). Furthermore, of this population, five children had impaired kidney function at 3-months follow-up, which continued to deteriorate. These children had significant oliguria/anuria and hypertension during their illness requiring early dialysis and antihypertensive therapy. At 23 years post-disease onset, all five (100%) of these children have developed end-stage kidney disease or chronic kidney disease. Eculizumab is a monoclonal antibody that binds with high affinity to the C5 protein of the complement pathway, a major component of the pathophysiology of infection-mediated HUS. There are no long-term randomised controlled trials in the literature to support its use in such cases. Our 23-year follow-up of a population of severely affected children with infection-mediated HUS demonstrates a high percentage of chronic kidney disease and end-stage kidney disease (19%). Randomised controlled trials with eculizumab are now being conducted in this affected cohort.

Verotoxin Receptor-Based Pathology and Therapies

Verotoxin, VT (aka Shiga toxin,Stx) is produced by enterohemorrhagic E. coli (EHEC) and is the key pathogenic factor in EHEC-induced hemolytic uremic syndrome (eHUS-hemolytic anemia/thrombocytopenia/glomerular infarct) which can follow gastrointestinal EHEC infection, particularly in children. This AB5 subunit toxin family bind target cell globotriaosyl ceramide (Gb₃), a glycosphingolipid (GSL) (aka CD77, pk blood group antigen) of the globoseries of neutral GSLs, initiating lipid raft-dependent plasma membrane Gb₃ clustering, membrane curvature, invagination, scission, endosomal trafficking, and retrograde traffic via the TGN to the Golgi, and ER. In the ER, A/B subunits separate and the A subunit hijacks the ER reverse translocon (dislocon-used to eliminate misfolded proteins-ER associated degradation-ERAD) for cytosolic access. This property has been used to devise toxoid-based therapy to temporarily block ERAD and rescue the mutant phenotype of several genetic protein misfolding diseases. The A subunit avoids cytosolic proteosomal degradation, to block protein synthesis via its RNA glycanase activity. In humans, Gb₃ is primarily expressed in the kidney, particularly in the glomerular endothelial cells. Here, Gb₃ is in lipid rafts (more ordered membrane domains which accumulate GSLs/cholesterol) whereas renal tubular Gb₃ is in the non-raft membrane fraction, explaining the basic pathology of eHUS (glomerular endothelial infarct). Females are more susceptible and this correlates with higher renal Gb₃ expression. HUS can be associated with encephalopathy, more commonly following verotoxin 2 exposure. Gb₃ is expressed in the microvasculature of the brain. All members of the VT family bind Gb₃, but with varying affinity. VT2e (pig edema toxin) binds Gb₄ preferentially. Verotoxin-specific therapeutics based on chemical analogs of Gb₃, though effective in vitro, have failed in vivo. While some analogs are effective in animal models, there are no good rodent models of eHUS since Gb₃ is not expressed in rodent glomeruli. However, the mouse mimics the neurological symptoms more closely and provides an excellent tool to assess therapeutics. In addition to direct cytotoxicity, other factors including VT–induced cytokine release and aberrant complement cascade, are now appreciated as important in eHUS. Based on atypical HUS therapy, treatment of eHUS patients with anticomplement antibodies has proven effective in some cases. A recent switch using stem cells to try to reverse, rather than prevent VT induced pathology may prove a more effective methodology.

C3 levels and acute outcomes in Shiga toxin-related hemolytic uremic syndrome

BACKGROUND

The correlation between complement activation and severity of hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS) has been examined in few studies, with conflicting results. We investigated whether C3 levels on admission are associated with worse acute outcomes.

METHODS

Demographic, clinical, and laboratory variables were compared between dialyzed and non-dialyzed patients and between those with or without extrarenal complications. Univariate and multivariate analyses were performed; odds ratio (OR) and 95% confidence interval (95%CI) were calculated. C3 concentrations were correlated with dialysis length (Spearman test) and ROC curves with area under the curves (AUC) were calculated to identify C3 concentrations able to discriminate patients with dialysis requirements and complicated course.

RESULTS

Among 49 children, 33 had normal and 16 had decreased C3 concentrations. Higher hemoglobin, lactic dehydrogenase, urea and creatinine and lower albumin, sodium, and C3 and C4 concentrations at admission were associated with dialysis requirement; only creatinine remained significant (p = 0.03, OR 2.1, 95%CI 1.34-2.7) by multivariate analysis. Patients with a complicated course presented higher leukocyte count, hemoglobin and lactic dehydrogenase and lower albumin, sodium, and C3 and C4. In the multivariate analysis, leukocyte count (p = 0.02, OR 2.6, 95%CI 1.4-4.3) and C3 concentration (p = 0.039, OR 1.7, 95%CI 1.1-2.73) were independently associated with a complicated disease. C3 levels correlated with dialysis length (r = - 0.42, p = 0.002); nevertheless, they were unable to discriminate dialysis requirement (AUC = 0.25, 95%CI 0.11-0.38) and extrarenal complications (AUC = 0.24, 95%CI 0.11-0.4).

CONCLUSIONS

Our study suggests that decreased C3 levels at admission are associated with a more complicated STEC-HUS episode.

Shiga-Toxin E. coli Hemolytic Uremic Syndrome: Review of Management and Long-term Outcome

Purpose of Review

We review the pathophysiology of Shiga-Toxin Enteropathogenic–Hemolytic Uremic Syndrome (STEC-HUS), strategies to ameliorate or prevent evolution of STEC-HUS, management and the improved recognition of long-term adverse outcomes.

Recent Findings

Following on from the preclinical evidence of a role for the complement system in STEC-HUS, the use of complement blocking agents has been the major focus of most recent clinical research. Novel therapies to prevent or lessen HUS have yet to enter the clinical arena. The long-term outcomes of STEC-HUS, similarly to other causes of AKI, are not as benign as previously thought.

Summary

Optimizing supportive care in STEC-HUS is the only current recommended treatment. The administration of early isotonic fluids may reduce the severity and duration of STEC-HUS. The role of complement blockade in the management of STEC-HUS remains unclear. The long-term sequelae from STEC-HUS are significant and patients with apparent full renal recovery remain at risk.

Pediatric NMOSD: A Review and Position Statement on Approach to Work-Up and Diagnosis

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) primarily affecting the optic nerves and spinal cord, but also involving other regions of the CNS including the area postrema, periaqueductal gray matter, and hypothalamus. Knowledge related to pediatric manifestations of NMOSD has grown in recent years, particularly in light of newer information regarding the importance of not only antibodies to aquaporin 4 (AQP4-IgG) but also myelin oligodendrocyte glycoprotein (MOG-IgG) in children manifesting clinically with this syndrome. In this review, we describe the current state of the knowledge related to clinical manifestations, diagnosis, and chronic therapies for children with NMOSD, with emphasis on literature that has been published in the last 5 years. Following the review, we propose recommendations for the assessment/follow up clinical care, and treatment of this population.

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.

Use of complement monoclonal antibody eculizumab in Shiga toxin producing Escherichia coli associated hemolytic uremic syndrome: A review of current evidence

Complement activation plays an important role in the pathogenesis of atypical hemolytic uremic syndrome. Eculizumab is a monoclonal antibody that blocks complement activity and has been approved for use in the treatment of atypical hemolytic uremic syndrome (HUS). Less well appreciated is the role of complement in Shiga toxin-induced HUS (Shiga toxin producing Escherichia coli [STEC]-HUS). To a limited extent, eculizumab has been used off label in patients with severe STEC-HUS with neurological involvement. Through a systematic search of available databases, we identified 16 reports describing the use of eculizumab in STEC-HUS (eight case reports/series, seven retrospective studies, and one prospective cohort study). All studies described its use in severe STEC-HUS with neurological or multiorgan dysfunction; none were randomized or blinded. Four studies used the control groups. Although the overall quality of evidence is low, some published studies showed positive clinical improvement after treatment with eculizumab in severe STEC-HUS with progressive neurological involvement.

Hemolytic uremic syndrome in a developing country: Consensus guidelines

BACKGROUND

Hemolytic uremic syndrome (HUS) is a leading cause of acute kidney injury in children. Although international guidelines emphasize comprehensive evaluation and treatment with eculizumab, access to diagnostic and therapeutic facilities is limited in most developing countries. The burden of Shiga toxin-associated HUS in India is unclear; school-going children show high prevalence of anti-factor H (FH) antibodies. The aim of the consensus meeting was to formulate guidelines for the diagnosis and management of HUS in children, specific to the needs of the country.

METHODS

Four workgroups performed literature review and graded research studies addressing (i) investigations, biopsy, genetics, and differential diagnosis; (ii) Shiga toxin, pneumococcal, and infection-associated HUS; (iii) atypical HUS; and (iv) complement blockade. Consensus statements developed by the workgroups were discussed during a consensus meeting in March 2017.

RESULTS

An algorithm for classification and evaluation was developed. The management of Shiga toxin-associated HUS is supportive; prompt plasma exchanges (PEX) is the chief therapy in patients with atypical HUS. Experts recommend that patients with anti-FH-associated HUS be managed with a combination of PEX and immunosuppressive medications. Indications for eculizumab include incomplete remission with plasma therapy, life-threatening features, complications of PEX or vascular access, inherited defects in complement regulation, and recurrence of HUS in allografts. Priorities for capacity building in regional and national laboratories are highlighted.

CONCLUSIONS

Limited diagnostic capabilities and lack of access to eculizumab prevent the implementation of international guidelines for HUS in most developing countries. We propose practice guidelines for India, which will perhaps be applicable to other developing countries.

Complement in Thrombotic Microangiopathies: Unraveling Ariadne's Thread Into the Labyrinth of Complement Therapeutics

Thrombotic microangiopathies (TMAs) are a heterogeneous group of syndromes presenting with a distinct clinical triad: microangiopathic hemolytic anemia, thrombocytopenia, and organ damage. We currently recognize two major entities with distinct pathophysiology: thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). Beyond them, differential diagnosis also includes TMAs associated with underlying conditions, such as drugs, malignancy, infections, scleroderma-associated renal crisis, systemic lupus erythematosus (SLE), malignant hypertension, transplantation, HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets), and disseminated intravascular coagulation (DIC). Since clinical presentation alone is not sufficient to differentiate between these entities, robust pathophysiological features need to be used for early diagnosis and appropriate treatment. Over the last decades, our understanding of the complement system has evolved rapidly leading to the characterization of diseases which are fueled by complement dysregulation. Among TMAs, complement-mediated HUS (CM-HUS) has long served as a disease model, in which mutations of complement-related genes represent the first hit of the disease and complement inhibition is an effective and safe strategy. Based on this knowledge, clinical conditions resembling CM-HUS in terms of phenotype and genotype have been recognized. As a result, the role of complement in TMAs is rapidly expanding in recent years based on genetic and functional studies. Herein we provide an updated overview of key pathophysiological processes underpinning complement activation and dysregulation in TMAs. We also discuss emerging clinical challenges in streamlining diagnostic algorithms and stratifying TMA patients that could benefit more from complement modulation. With the advent of next-generation complement therapeutics and suitable disease models, these translational perspectives could guide a more comprehensive, disease- and target-tailored complement intervention in these disorders.

Outbreak of Shiga toxin-producing Escherichia-coli-associated hemolytic uremic syndrome in Istanbul in 2015: outcome and experience with eculizumab

BACKGROUND

This study aims to identify epidemiological and clinical characteristics of patients and report our experience with eculizumab treatment during an outbreak of hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC) in Istanbul in 2015.

METHODS

Thirty-two children (21 females, median age 3.25 years) were included in this study. Demographic, clinical and laboratory data, and treatment details were retrospectively collected. Renal outcomes were assessed at last follow-up visit. To assess the effect of eculizumab on prognosis of STEC-HUS, subgroup analysis was performed on patients who required dialysis.

RESULTS

A high number of cases occurred within a certain region of Istanbul. Stool samples were cultured from 21 patients (65%), and enteroaggregative E. coli (EAEC; n = 7) and enterohemorrhagic E. coli (EHEC; n = 3) strains were detected. Rates of dialysis treatment, neurological manifestations, and death were 59%, 25%, and 3%, respectively. Mean follow-up duration was 8.6 ± 2.6 months (range 3-12 months). None of the patients (n = 25) was on dialysis at the final visit. The complete renal recovery rate was 54%. Nine patients were treated with eculizumab. At final follow-up visit, no differences in estimated glomerular filtration rate, proteinuria level, or hypertension incidence were observed between patients treated with eculizumab and those not treated with eculizumab.

CONCLUSIONS

An outbreak of EAEC occurred in a specific region of Istanbul. Livestock markets were suspected as the source. Evidence for beneficial effects of eculizumab on renal outcome was not clear in this cohort.

Eculizumab in STEC-HUS: need for a proper randomized controlled trial

Hemolytic uremic syndrome caused by Shiga toxin-producing E. coli (STEC-HUS) is often associated with a severe morbidity including neurological involvement and a mortality of 1-5%. Although STEC-HUS is often self-limited, improvement of treatment strategies is needed for cases with complications and, among others, plasma exchange/plasmapheresis and use of antibiotics have been advocated. With the availability of the complement blocker eculizumab, now a standard treatment of atypical HUS, several series have addressed its use in STEC-HUS, with variable response; randomized controlled trials are lacking.In this issue of Pediatric Nephrology, Pecheron et al. present a cohort of 33 pediatric patients with severe HUS treated with eculizumab. Neurological involvement was observed in 85% of the patients and 94% required dialysis. Most patients (55%) did not benefit from eculizumab and renal dysfunction as well as neurological sequelae did not resolve. In a subgroup of patients, however, rapid neurological improvement was described. In the post-hoc-defined group of patients with favorable outcome, there was a trend towards more sustained complement inhibition, although this finding was not significant compared to patients with an unfavorable outcome.Because multiple interventions were used and the study did not include any control group, future controlled studies are urgently needed to resolve the debate as to whether eculizumab can be an effective treatment for both prevention and treatment of complications in STEC-HUS.

Short- and Long-Term Renal Outcome of Hemolytic-Uremic Syndrome in Childhood

Introduction: Hemolytic-uremic syndrome (HUS) is a common cause for intrarenal acute kidney injury in childhood. More than 90% of HUS cases are associated with an infection by Shigatoxin-producing Escherichia coli (STEC) whereas the reminder comprises a heterogeneous group (here classified as Non-STEC-HUS). Renal impairment can persist in patients with HUS. This study presents data from four decades investigating the short- and long-term outcome of HUS in childhood. Materials and Methods: In a retrospective single-center-study clinical and laboratory data of the acute phase and of 1- to 10-year follow-up visits of children with HUS were analyzed. Results: 92 HUS-patients were identified from 1996 to 2014 (STEC-HUS-group: n = 76; Non-STEC-HUS-group: n = 16) and 220 HUS-patients between 1976 and 1995. STEC-HUS was increasingly caused by Non-O157 strains and mortality rate declined over the past decades (1.3 vs. 9.5%). Renal sequelae persisted more often in the group 1976-1995 (39.3%) than in the group 1996-2014 (28.3%), but more than 50% of all patients were lost to follow-up. Conclusion: Although renal outcome has improved over the investigated last decades, patients with HUS still face a high risk of permanent renal damage. These findings underline the importance of a consequent long-term follow-up in HUS-patients.