Cardiac tamponade in diarrhoea-positive haemolytic uraemic syndrome

Cardiovascular impairment in Shiga-toxin-2-induced experimental hemolytic-uremic syndrome: a pilot study

Introduction

Hemolytic-uremic syndrome (HUS) can occur as a systemic complication of infection with Shiga toxin (Stx)-producing Escherichia coli (STEC). Most well-known aspects of the pathophysiology are secondary to microthrombotic kidney disease including hemolytic anemia and thrombocytopenia. However, extrarenal manifestations, such as cardiac impairment, have also been reported. We have investigated whether these cardiac abnormalities can be reproduced in a murine animal model, in which administration of Stx, the main virulence factor of STEC, is used to induce HUS.

Methods

Mice received either one high or multiple low doses of Stx to simulate the (clinically well-known) different disease courses. Cardiac function was evaluated by echocardiography and analyses of biomarkers in the plasma (troponin I and brain natriuretic peptide).

Results

All Stx-challenged mice showed reduced cardiac output and depletion of intravascular volume indicated by a reduced end-diastolic volume and a higher hematocrit. Some mice exhibited myocardial injury (measured as increases in cTNI levels). A subset of mice challenged with either dosage regimen showed hyperkalemia with typical electrocardiographic abnormalities.

Discussion

Myocardial injury, intravascular volume depletion, reduced cardiac output, and arrhythmias as a consequence of hyperkalemia may be prognosis-relevant disease manifestations of HUS, the significance of which should be further investigated in future preclinical and clinical studies.

Extracorporeal Membrane Oxygenation and Hemolytic Uremic Syndrome in Children: Outcome Review of a Multicenter National Database

Hemolytic uremic syndrome (HUS) is a triad of hemolytic anemia, thrombocytopenia, and acute renal failure. In critically ill children with HUS, extrarenal manifestations may require intensive care unit admission and extracorporeal membrane oxygenation (ECMO) support. Outcomes specific to HUS and ECMO in children have not been well investigated. The primary aim of this project was to query a multicenter database to identify risk factors associated with mortality in HUS patients supported on ECMO. A secondary aim was to identify factors associated with ECMO utilization in children with HUS. Utilizing the Pediatric Health Information System database (January 2004 and September 2018), this retrospective, multicenter cohort study identified the index HUS hospitalization among children aged 0 to 18 years. Univariate analysis was used to compare demographics, clinical characteristics, and procedures to identify risk factors associated with adverse outcomes. Among 4,144 subjects, 37 were supported on ECMO. Survival for those on ECMO support was 54%. Among nonsurvivors, 59% of deaths occurred within 14 days of hospitalization. The mean hospital LOS was 15.9 days in nonsurvivors versus 53.9 days for survivors (p < 0.001). When comparing subjects supported on ECMO to those who were not, patients with ECMO support had statistically longer hospital LOS and higher rates of extrarenal involvement (p < 0.001). This study found a mortality rate of 46% among HUS patients requiring ECMO. The investigated clinical risk factors were not associated with mortality among the ECMO population. The study identifies risk factors associated with ECMO utilization in children with HUS.

Cardiac Manifestation among Children with Hemolytic Uremic Syndrome

OBJECTIVE

The primary objectives of the study were to describe the association between cardiac manifestations and in-hospital mortality among children with hemolytic uremic syndrome.

STUDY DESIGN

Using the Pediatric Health Information System database, this retrospective, multicenter, cohort study identified the first hemolytic uremic syndrome-related inpatient visit among children ≤18 years (years 2004-2018). The frequency of selected cardiac manifestations and mortality rates were calculated. Multivariate analysis identified the association of specific cardiac manifestations and the risk of in-hospital mortality.

RESULTS

Among 3915 patients in the analysis, 238 (6.1%) had cardiac manifestations. A majority of patients (82.8%; n = 197) had 1 cardiac condition and 17.2% (n = 41) had ≥2 cardiac conditions. The most common cardiac conditions was pericardial disease (n = 102), followed by congestive heart failure (n = 46) and cardiomyopathy/myocarditis (n = 34). The percent mortality for patients with 0, 1, or ≥2 cardiac conditions was 2.1%, 17.3%, and 19.5%, respectively. Patients with any cardiac condition had an increased odds of mortality (OR, 9.74; P = .0001). In additional models, the presence of ≥2 cardiac conditions (OR, 9.90; P < .001), cardiac arrest (OR, 38.25; P < .001), or extracorporeal membrane oxygenation deployment (OR, 11.61; P < .001) were associated with increased risk of in-hospital mortality.

CONCLUSIONS

This study identified differences in in-hospital mortality based on the type of cardiac manifestations, with increased risk observed for patients with multiple cardiac involvement, cardiac arrest, and extracorporeal membrane oxygenation deployments.

Hemolytic uremic syndrome related to Shiga-like toxin-producing Escherichia coli with encephalitis hiding a human herpesvirus-6 infection: a case report

BACKGROUND

Cardiac and neurological involvement in hemolytic uremic syndrome are life-threatening complications. The most frequent complications of cardiac involvement in hemolytic uremic syndrome are myocarditis and cardiac dysfunction due to fluid overload. Pericarditis remains very rare in hemolytic uremic syndrome. To our knowledge, only five cases of cardiac tamponade associated with hemolytic uremic syndrome have been described in literature. A 27-month-old Caucasian girl presented with symptoms of nonbloody diarrhea and tonic-clonic seizures. The diagnosis of Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome with central nervous system involvement was made, and stool examination revealed infection with a Shiga-like toxin-producing Escherichia coli. She did not need renal replacement therapy but had severe neurological impairment. The patient's course was complicated by pericardial effusion. A pericardiocentesis was performed via an apical approach because the pericardial effusion was predominantly surrounding the left ventricle. Effusion analysis showed an exudate and positivity for human herpesvirus-6B on polymerase chain reaction with viremia. This finding was consistent with primary human herpesvirus-6 infection with encephalitis.

CONCLUSION

We report this uncommon case of Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome associated with a severe human herpesvirus-6 infection. Secondary isolated pericardial effusion and atypical neurological involvement are uncommon in Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome and should lead the physician to perform additional investigations.

Pericardial effusion in anti-complement factor H antibody-associated atypical hemolytic uremic syndrome: two case reports

Hemolytic uremic syndrome (HUS), a cause of pediatric acute kidney injury (AKI), has a spectrum of extra-renal manifestations. While neurological and gastrointestinal system involvement is common, cardiac involvement is rare. This is more so with pericardial involvement, though it has been reported in a handful of HUS cases associated with shiga toxin-producing Escherichia coli (STEC HUS). However, this complication has scarcely been reported in atypical HUS (aHUS) where there is alternate complement abnormality or DKGE (diacylglycerol kinase epsilon) mutation. We describe two children diagnosed with anti-complement factor H (CFH) antibody-associated aHUS who had pericardial involvement. Two boys, one 10-year-old and another 8-year-old, presented with pallor, oliguria and hypertension. They both had microangiopathic haemolytic anemia, thrombocytopenia and AKI suggestive of HUS. Complement workup revealed elevated anti-CFH antibody titres. With a diagnosis of anti-CFH antibody aHUS, they were started on plasmapheresis, pulse methylprednisolone and cyclophosphamide. The first case developed cardiac tamponade during the second week of hospital stay for which he needed pigtail drainage and further immunosuppression with rituximab. He gradually improved and pigtail was removed. The second case presented with pericardial effusion which subsequently resolved during the course of treatment. Thus, our patients developed pericardial effusion, with one of them progressing to life-threatening cardiac tamponade. Therefore, it is prudent that we are aware of this complication while treating children with aHUS.

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.

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.

Extrarenal manifestations of the hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC HUS)

Hemolytic uremic syndrome is commonly caused by Shiga toxin-producing Escherichia coli (STEC). Up to 15% of individuals with STEC-associated hemorrhagic diarrhea develop hemolytic uremic syndrome (STEC HUS). Hemolytic uremic syndrome (HUS) is a disorder comprising of thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury. The kidney is the most commonly affected organ and approximately half of the affected patients require dialysis. Other organ systems can also be affected including the central nervous system and the gastrointestinal, cardiac, and musculoskeletal systems. Neurological complications include altered mental status, seizures, stroke, and coma. Gastrointestinal manifestations may present as hemorrhagic colitis, bowel ischemia/necrosis, and perforation. Pancreatitis and pancreatic beta cell dysfunction resulting in both acute and chronic insulin dependant diabetes mellitus can occur. Thrombotic microangiopathy (TMA) in cardiac microvasculature and troponin elevation has been reported, and musculoskeletal involvement manifesting as rhabdomyolysis has also been described. Extrarenal complications occur not only in the acute setting but may also be seen well after recovery from the acute phase of HUS. This review will focus on the extrarenal complications of STEC HUS. To date, management remains mainly supportive, and while there is no specific therapy for STEC HUS, supportive therapy has significantly reduced the mortality rate.

Typical or Atypical Hemolytic Uremic Syndrome and the Use of Eculizumab: 4 Illustrative Cases

Typical hemolytic uremic syndrome (HUS) in children is caused mostly by Escherichia coli 0157:H7 in our country. Atypical HUS (aHUS) causes include Streptococcus pneumoniae, methyl malonic aciduria, deficiency of ADAMST 13, and genetic or acquired disorder of the complement. Treatment of HUS relies on supportive measures while treatment of aHUS includes plasmapheresis and specific treatments. Recently, eculizumab has been proposed for the treatment of aHUS and many clinicians now believe that eculizumab should be the first-line standard of care. The purpose of this article is to illustrate the difficulties in the diagnostic process of HUS and therefore the subsequent problem to promptly choose the appropriate treatment. To date, workup of HUS continues to take many days leaving the clinicians with a choice between several therapeutic options. With the emergence of eculizumab, it becomes crucial to find faster diagnostic tools and to adapt HUS treatment protocols. We reported here clinical cases where eculizumab use was probably not appropriate once the correct diagnosis of typical HUS was made and cases where it would have been useful because of the late diagnosis of aHUS.

An outbreak of hemolytic uremic syndrome in southern Romania during 2015-2016: Epidemiologic, clinical, laboratory, microbiologic, therapeutic and outcome characteristics

BACKGROUND AND AIMS

To describe the epidemiologic, clinical, microbiological, therapeutic and outcome characteristics of a HUS outbreak occurring in southern Romania from 2015 to 2016.

METHODS

We retrospectively collected data from the medical records of all HUS cases hospitalized at the pediatric nephrology department of Marie Curie Children's Hospital of Bucharest, Romania.

RESULTS

There were 32 HUS cases (19 girls/13 boys, 87.6% <2 years), all associated with diarrhea (bloody in 13, 40.6%). Thirteen (40.6%) and 4 (12.5%) patients had oliguria and anuria at admission. Extreme pallor, generalized edema, vomiting, dehydration, fever and seizures were found in 100%, 56.3%, 31.3%, 31.3%, 25% and 9.4% of patients, respectively. E. coli and STEC were identified in the stools of 6 and 8 patients, respectively; E. coli O₂₆ and O₁₅₇ infection were documented serologically in 10 and 3 children, respectively. There were 15/32 (46.9%) patients with confirmed HUS. Eighteen (56.3%) patients were hypertensive; other complications included infections, left ventricular hypertrophy, cardiopulmonary arrest, seizures and encephalopathy in 62.5%, 37.5%, 28.3%, 18.8% and 12.5%, respectively. Peritoneal dialysis and hemodialysis were performed in 23 (72%) and 2 patients, respectively. Three patients (9.4%) died early during hospitalization. A 6-12-month follow-up of 26 patients revealed that 65.4% had post-HUS sequelae (persistent hypertension and chronic renal failure in 34.6% and 30.8%, respectively).

CONCLUSIONS

The principal STEC serotype involved was O₂₆:H₁₁ and the number of confirmed HUS cases reached half of the patients. Compared with the medical literature, this outbreak had a higher rate of complications and renal sequelae and was associated with a high fatality rate.

HUS-induced cardiac and circulatory failure is reversible using cardiopulmonary bypass as rescue

BACKGROUND

Extra-renal involvement in hemolytic uremic syndrome (HUS) includes gastrointestinal, pancreatic, hepatic, neurological and cardiac manifestations. The current 3-5% mortality rate in HUS patients is primarily attributed to complications related to the central nervous system and the heart. In this brief report, we illustrate that severe cardiac involvement in a patient with HUS is potentially reversible using cardiopulmonary bypass as rescue.

CASE-DIAGNOSIS/TREATMENT

A 12-year-old boy was diagnosed with enterohemorrhagic Escherichia coli-induced HUS related to E. coli serotypes O55:H7 and O121:H19. The patient developed anuria and hypertension of 150/105 mmHg and had neurological symptoms, with lethargy, confusion and later a tonic-clonic seizure successfully treated with midazolam. Laboratory tests on blood samples revealed acute renal failure, with a creatinine level of 3.98 mg/dL, thrombocytopenia of 47 × 10⁹/L, lactate dehydrogenase level of 3620 IU/L, low haptoglobin (<20 mg/dL), anemia (10.0 g/dL) and schistocytes on blood smears. Peritoneal dialysis was initiated without complications. Serum potassium level was normal. At day 3, the patient suffered cardiac arrest on two separate occasions. Troponin-T, creatine kinase and creatine kinase-MB levels were significantly increased. The second episode of cardiac arrest could not be reversed with advanced cardiopulmonary resuscitation, and a cardiopulmonary bypass circuit was established. Declining cardiac pump function to a near non-contractile state with an ejection fraction of <10% was observed on echocardiography. This persisted during the following days. After the patient had been on the cardiopulmonary bypass (CPB) circuit for 7 days, the myocardium slowly recovered function. Three days later, the CPB was successfully discontinued; the echocardiography showed near-normal ejection fraction, and electrocardiography (ECG) showed sinus rhythm.

CONCLUSIONS

Fatal outcome in patients with HUS may be the result of severe cardiac involvement. The present case illustrates the need for intensive supportive care, including the use of CPB, as the cardiac symptoms in HUS patients may be reversible. We suggest the monitoring of cardiac-specific enzymes, ECG and echocardiography in high-risk patients.

Direct cardiac involvement in childhood hemolytic-uremic syndrome: case report and review of the literature

Overhydration, hypertension, anemia, or dyselectrolytemias sometimes cause cardiovascular impairment in childhood hemolytic-uremic syndrome. Here, we report the case of a 4.5-year-old boy with hemolytic-uremic syndrome and sudden onset, 6 h later, of hemodynamic compromise secondary to a cardiac thrombotic micro-angiopathy. The child died. In the literature, we found 18 further cases with cardiac compromise ≤25 days after diagnosis. The following causes were found: micro-angiopathy, pericardial blood causing tamponade, and myocarditis.

CONCLUSION

We were able to document only 19 cases of childhood hemolytic-uremic syndrome complicated by a direct cardiac compromise. Nonetheless, we speculate that a direct cardiac compromise accounts for many cases of childhood hemolytic-uremic syndrome complicated by sudden death during the initial hospitalization. Hence, we propose to always measure troponin in children with hemolytic-uremic syndrome to detect a latent myocardial damage. What is Known: • Overhydration, hypertension, anemia, or dyselectrolytemias sometimes cause cardiovascular impairment in childhood hemolytic-uremic syndrome. What is New: • This study documents 19 cases of childhood hemolytic-uremic syndrome complicated by a direct cardiac compromise ≤ 25 days after diagnosis. • The Following causes were found: micro-angiopathy, pericardial blood causing tamponade, and myocarditis.

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.

Biomarkers detect involvement of acute myocardial injury in a paediatric haemolytic-uraemic syndrome patient

Although extrarenal manifestations of haemolytic-uraemic syndrome are not frequent, myocardial dysfunction should be given special consideration because of the importance of proper early haemodynamic management and potential complications. We report the case of a 21-month-old child with haemolytic-uraemic syndrome who developed clinical signs of poor myocardial function with depressed myocardial function noted by bedside echocardiography and significant elevation of biomarkers. Early intervention and supportive treatment for the patient were crucial during the acute phase of cardiac failure, and repeated monitoring of biomarkers and ecocardiography were useful diagnostic tools that provided relevant information throughout the patient's evolution.

A new paradigm: Diagnosis and management of HSCT-associated thrombotic microangiopathy as multi-system endothelial injury

Hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is now a well-recognized and potentially severe complication of HSCT that carries a high risk of death. In those who survive, TA-TMA may be associated with long-term morbidity and chronic organ injury. Recently, there have been new insights into the incidence, pathophysiology, and management of TA-TMA. Specifically, TA-TMA can manifest as a multi-system disease occurring after various triggers of small vessel endothelial injury, leading to subsequent tissue damage in different organs. While the kidney is most commonly affected, TA-TMA involving organs such as the lung, bowel, heart, and brain is now known to have specific clinical presentations. We now review the most up-to-date research on TA-TMA, focusing on the pathogenesis of endothelial injury, the diagnosis of TA-TMA affecting the kidney and other organs, and new clinical approaches to the management of this complication after HSCT.

Extra-renal manifestations of complement-mediated thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are rare but severe disorders, characterized by endothelial cell activation and thrombus formation leading to hemolytic anemia, thrombocytopenia, and organ failure. Complement over activation in combination with defects in its regulation is described in an increasing number of TMA and if primary for the disease denominated as atypical hemolytic-uremic syndrome. Although TMA predominantly affects the renal microvasculature, extra-renal manifestations are observed in 20% of patients including involvement of the central nerve system, cardiovascular system, lungs, skin, skeletal muscle, and gastrointestinal tract. Prompt diagnosis and treatment initiation are therefore crucial for the prognosis of disease acute phase and the long-term outcome. This review summarizes the available evidence on extra-renal TMA manifestations and discusses the role of acute and chronic complement activation by highlighting its complex interaction with inflammation, coagulation, and endothelial homeostasis.

Long-term outcomes of Shiga toxin hemolytic uremic syndrome

Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome (HUS) is an important cause of acute kidney injury (AKI). The outcomes of STEC HUS have improved, and the acute mortality rate in children is 1-4%. About 70% of patients recover completely from the acute episode and the remainder have varying degrees of sequelae. Only a few retrospective studies have reviewed these patients over long periods. Methodological flaws include a lack of strict definitions, changing modes of treatment, ascertainment bias and loss of subjects to follow-up. The kidneys bear the brunt of the long-term damage: proteinuria (15-30% of cases); hypertension (5-15%); chronic kidney disease (CKD; 9-18%); and end-stage kidney disease (ESKD; 3%). A smaller number have extra-renal sequelae: colonic strictures, cholelithiasis, diabetes mellitus or brain injury. Most renal sequelae are minor abnormalities, such as treatable hypertension and/or variable proteinuria. Most of the patients who progress to ESKD do not recover normal renal function after the acute episode. Length of anuria (more than 10 days) and prolonged dialysis are the most important risk factors for a poor acute and long-term renal outcome. After the acute episode all patients must be followed for at least 5 years, and severely affected patients should be followed indefinitely if there is proteinuria, hypertension or a reduced glomerular filtration rate (GFR).

Myocardial infarction is a complication of factor H-associated atypical HUS

Cardiac complications are frequently seen in thrombotic thrombocytopaenic purpura related to ADAMTS13 deficiency. We describe the case of a 43-year-old woman who was diagnosed with an atypical haemolytic-uraemic syndrome (aHUS) associated with a pathogenic mutation in the factor H gene (C623S). After 15 days of treatment, she suffered a sudden cardiac arrest and died despite intensive resuscitation attempts. She showed only one cardiovascular risk factor, hypercholesterolaemia. Her sudden death was secondary to cardiac infarction related to a coronary thrombotic microangiopathy. This is the first case of aHUS related to a mutation in the factor H gene associated with cardiac microangiopathy. This case emphasizes the need to screen for cardiac complication during the treatment of aHUS.