Sequelae of haemolytic uraemic syndrome

Postdiarrheal hemolytic uremic syndrome in Egyptian children: An 11-year single-center experience

Hemolytic-uremic syndrome (HUS) is a leading cause of childhood acute kidney injury (AKI) worldwide, with its postdiarrheal (D+HUS) form being the most common. Scarce data are available regarding D+HUS epidemiology from developing countries. This study aims to reveal the characterization of D+ HUS in Egyptian children. This is a retrospective study of all children with D+HUS admitted to a tertiary pediatric hospital in Egypt between 2007 and 2017. The study included epidemiological, clinical and laboratory data; management details; and outcomes. A cohort of 132 children aged 4months to 12 years was analyzed. Yearly incidence peaked in 2017, and spring showed the highest peak. All cases had a diarrheal prodrome that was bloody in 83% of the cases. Edema and decreased urine output were the most frequent presentations (50.3% and 42.4%, respectively). Escherichia coli was detected in 56 cases. Dialysis was performed in 102 cases. Eight patients died during acute illness, while five patients experienced long-term sequels. Lactate dehydrogenase (LDH) positively correlated with serum creatinine and negatively correlated with reticulocytic count. Univariate analysis showed that longer anuria duration, short duration between diarrheal illness and development of AKI (P = 0.001), leukocyte count above 20 × 10⁹ cells/L (P ≤ 0.001), platelet count below 30 × 10⁹ cells/L (P = 0.02), high LDH levels (P = 0.02) and hematocrit above 30% (P = 0.0001), need for dialysis (P = 0.03), and neurological involvement (P ≤ 0.001) were associated with unfavorable outcomes. This is the first report with a detailed insight into the epidemiology of D+HUS in Egyptian children. The incidence of D+HUS is increasing in our country due to increased awareness of the disease and the poor public health measures. Anuria duration, leukocyte count, and neurological involvement are predictors of poor outcome in the current work, and LDH is introduced as a marker of disease severity.

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.

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.

Intermediate Follow-up of Pediatric Patients With Hemolytic Uremic Syndrome During the 2011 Outbreak Caused by E. coli O104:H4

Background.

In 2011 Escherichia coli O104:H4 caused an outbreak with >800 cases of hemolytic uremic syndrome (HUS) in Germany, including 90 children. Data on the intermediate outcome in children after HUS due to E. coli O104:H4 have been lacking.

Methods.

Follow-up data were gathered retrospectively from the medical records of patients who had been included in the German Pediatric HUS Registry during the 2011 outbreak.

Results.

Seventy-two of the 89 (81%) patients were included after a median follow-up of 3.0 (0.9-4.7) years. Hypertension and proteinuria were present in 19% and 28% of these patients, respectively. Of 4 patients with chronic kidney disease (CKD) > stage 2 at short-term follow-up, 1 had a normalized estimated glomerular filtration rate, and 3 (4%) had persistent CKD > stage 2. In 1 of these patients, CKD improved from stage 4 to 3; 1 who had CKD stage 5 at presentation received kidney transplantation; and 1 patient required further hemodialysis during follow-up. One patient (1.4%) still had major neurological symptoms at the latest follow-up. Dialysis during the acute phase (P = .01), dialysis duration (P = .01), and the duration of oligo-/anuria (P = .005) were associated with the development of renal sequelae. Patients treated with eculizumab (n = 11) and/or plasmapheresis (n = 13) during the acute phase of HUS had comparable outcomes.

Conclusions.

The overall outcome of pediatric patients after HUS due to E. coli O104:H4 was equivalent to previous reports on HUS due to other types of Shiga toxin-producing E. coli (STEC). Regular follow-up visits in patients are recommended after STEC-HUS.

Long-term health-related quality of life and psychological adjustment in children after haemolytic-uraemic syndrome

BACKGROUND

In children after haemolytic-uraemic syndrome (HUS), little is known about long-term health-related quality of life (HRQoL) and psychological adjustment as defined by behavioural problems, depressive symptoms and post-traumatic stress symptoms.

METHODS

Sixty-two paediatric patients with a history of HUS were included in this study. Medical data of the acute HUS episode were retrieved retrospectively from hospital records. Data on the clinical course at study investigation were assessed by clinical examination and laboratory evaluation. HRQoL and psychological adjustment data were measured by standardised, parent- and self-reported questionnaires.

RESULTS

Haemolytic-uraemic syndrome was diagnosed at a mean of 6.5 years before the initiation of the study (standard deviation 2.9, range 0.1-15.7) years. Among the preschool children, parents reported that their child was less lively and energetic (HRQoL emotional dimension), while no increased behavioural problems were reported. In the school-age children, self- and proxy-reported HRQoL was well within or even above the norms, while increased total behavioural problems were found. The school-age children reported no increased depression scores. Also none of the children met the criteria for full or partial HUS-associated posttraumatic stress disorder.

CONCLUSIONS

Healthcare providers should be particularly alert to behavioural problems in school-age children with a history of HUS and to lower HRQoL in preschool children.

Neurological involvement in children with E. coli O104:H4-induced hemolytic uremic syndrome

BACKGROUND

The aim of this study was to analyze the neurological involvement and outcome in pediatric patients with hemolytic uremic syndrome (HUS) during the 2011 epidemic caused by Escherichia coli O104:H4.

METHODS

Clinical data and data from magnetic resonance imaging (MRI) scans and electroencephalography (EEG) during the acute phase of the disease and during follow-up at 3 and 6 months were analyzed in 50 patients. Twenty-five of these patients underwent neuropsychological testing (WISC IV) during follow-up.

RESULTS

Neurological involvement (stupor or coma, seizures, visual disturbances, paresis, myocloni) was initially observed in 14/50 (28%) patients. One patient died. EEG abnormalities were more frequent in patients with neurological involvement than in those without (12/14 vs. 13/25, respectively). Cranial MRI scans were analyzed in nine patients with neurological involvement, of whom five showed abnormal findings. At the 3- and 6-month follow-ups, EEG abnormalities were found in 14/40 (35%) and 7/36 (19%) patients, respectively, whereas 28/42 (67%) and 17/39 (44%) patients, respectively, complained about on-going reduced performance. Neuropsychological testing showed a slightly lower global intelligence quotient in patients with neurological involvement versus those without (113.4 ± 2.8 vs. 119.4 ± 1.8, respectively).

CONCLUSIONS

Neurological involvement was frequent in our cohort. Accordingly, the incidence of pathological EEG findings was high, even in patients without clinical signs of neurological involvement. Nevertheless, major neurological sequelae were rare, and neuropsychological outcome was favorable after 6 months.

Neuropsychological outcome after complicated Shiga toxin-producing Escherichia coli infection

Background

The diarrhea associated hemolytic uremic syndrome (HUS) is a major cause of acute uremic failure in children, but not very common in adults. The enterohaemorrhagic Escherichia coli -epidemic in Germany in 2011 affected mostly young and healthy adults. While their immediate deficits have been published, not much is known about the time course and degree of recovery concerning cognitive and behavioral impairment.

Methods and Findings

Twenty patients with Shiga toxin –producing Escherichia coli infection and neurological symptoms underwent comprehensive neuropsychological assessment 3 months and 1 year after the acute disease. Overall, there was an excellent recovery of cognitive functions. In a detailed neuropsychological analysis no significant deficits could be noticed 1 year after the infection in terms of cognitive function, alertness, executive functions and speech. Interestingly there were no correlations between different indicators for severity of disease (hemoglobin and creatinin levels, days of hospitalization, neurological symptoms and MRI changes) and neuropsychological outcome. However, there were a small number of patients with limitations in every day and professional life even one year after the acute disease.

Conclusions

Our study does not provide definitive answers regarding risk factors for these limitations. Still since Shiga toxin –producing Escherichia coli infection is a rare condition in adults, the information this study provides is important for the clinical practice. On one hand for consulting patients and on the other to raise the awareness of the physicians to possible long term complains and the consideration of neuropsychological assessment and supportive psychological treatment.

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).

Thrombotic stroke in a child with diarrhea-associated hemolytic-uremic syndrome with a good recovery

A boy aged 3.5 years with post-diarrheal hemolytic-uremic syndrome (HUS) was referred to our hospital because of convulsion and stupor. He had been admitted to a regional hospital with a 3-day history of bloody diarrhea, colic abdominal pain and fever. Two days later, he had complained of generalized seizures and oliguria. On admission, he developed anuria, and serum blood nitrogen and creatinine increased to 56 mg/100 ml and 2.8 mg/100 ml, respectively. Platelets decreased to 42,000/microl. Under the diagnosis of HUS, a continuous hemodiafiltration treatment had to be instituted. Computed tomography of his head at hospital day 5 revealed abnormal low density area of infarction with edema in both the basal ganglia involving with the posterior limb of internal capsule. Serum titer of IgM antibody to Escherichia coli O157 showed positive value. Although his anuria and stupor persisted over 10 days, he recovered without serious complications. These clinical observations may indicate that patients with similar lesions do not necessarily have serious morbidity.

Neuropsychological sequelae of haemolytic uraemic syndrome. Investigators of the HUS Cognitive Study

BACKGROUND

Severe haemolytic uraemic syndrome (HUS) in childhood can cause stroke, hemiplegia, cortical blindness, and psychomotor retardation. These outcomes are evident at the time of discharge immediately after the acute illness. Less is known about the neuropsychological outcomes of less severely affected children who recover from acute HUS.

AIMS

This multicentre case control study investigated the hypothesis that children who survive an acute episode of HUS without recognizable neurological injuries have greater impairment of cognitive, academic, and behavioural functions than controls.

DESIGN

Children with HUS were eligible if they had no evidence of severe neurological dysfunction when discharged from one of six Canadian hospitals. Controls had been admitted to hospital for a non-HUS illness and were matched by age, sex, first language, and socioeconomic status. All subjects underwent evaluation of behaviour, academic achievement, cognitive function, and verbal abilities using standardised tests administered by a psychometrist blinded to the case or control status.

RESULTS

Ninety-one case control pairs were enrolled. No important differences between patients with HUS and paired controls were evident on tests of IQ, behaviour, verbal abilities, or academic achievement. There was no increased risk of attention deficit disorder among patients with HUS. There was no correlation between the severity of acute renal failure and neuropsychological measures, although scores on some verbal ability tests were lower in those with the highest serum creatinine concentrations during illness.

CONCLUSIONS

Children discharged from hospital without apparent neurological injury after an episode of acute HUS do not have an increased risk of subclinical problems with learning, behaviour, or attention.

Escherichia coli O157:H7

Escherichia coli O157 was first identified as a human pathogen in 1982. One of several Shiga toxin-producing serotypes known to cause human illness, the organism probably evolved through horizontal acquisition of genes for Shiga toxins and other virulence factors. E. coli O157 is found regularly in the faeces of healthy cattle, and is transmitted to humans through contaminated food, water, and direct contact with infected people or animals. Human infection is associated with a wide range of clinical illness, including asymptomatic shedding, non-bloody diarrhoea, haemorrhagic colitis, haemolytic uraemic syndrome, and death. Since laboratory practices vary, physicians need to know whether laboratories in their area routinely test for E. coli O157 in stool specimens. Treatment with antimicrobial agents remains controversial: some studies suggest that treatment may precipitate haemolytic uraemic syndrome, and other studies suggest no effect or even a protective effect. Physicians can help to prevent E. coli O157 infections by counselling patients about the hazards of consuming undercooked ground meat or unpasteurised milk products and juices, and about the importance of handwashing to prevent the spread of diarrhoeal illness, and by informing public-health authorities when they see unusual numbers of cases of bloody diarrhoea or haemolytic uraemic syndrome.

The hemolytic uremic syndrome

HUS is the most common cause of acute renal failure in infants and young children and follows a diarrheal prodrome about 90% of the time. Persuasive evidence shows that virtually all of postdiarrheal cases are caused by EHEC infections, and that the great majority of cases in the United States are caused by the EHEC serotype O157:H7. Mortality is approximately 5%, and approximately 10% of survivors are left with severe sequelae. A much larger number (30%-50%) experience mild chronic renal damage. Public health strategies, including zero tolerance for fecal contamination in slaughter houses and additional public education on proper food handling and cooking, does much to decrease the prevalence of the syndrome. Efforts to further dissect the postdiarrheal pathogenic cascade should continue, and an animal model needs to be developed. Only then will researchers be positioned to develop effective intervention strategies. Preventing life-threatening extrarenal complications, especially of the CNS, is a major challenge. Idiopathic nondiarrheal HUS accounts for approximately 10% of cases and comprises a poorly understood composite of HUS subsets. Research directed toward a better understanding of these mysterious variants also is a priority for the years ahead.

Hemolytic uremic syndrome - clinical aspects and outcome of an outbreak: Report of 28 cases

Hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. There are two main subgroups: the typical form of HUS follows a diarrheal prodrome (D+HUS) and the atypical form is without the diarrheal prodrome (D-HUS). We have studied 28 children with HUS over a period of 15 months between 1992 and 1993. The median age was 2.2 years (range from six months to six years). All children had prodromal diarrhea. Hypertension was present in 71% and neurological complications in 39%. All the patients had oliguria or anuria (16 oliguric and 12 anuric). The mean duration of anuria was 16 days (range seven to 42 days). Serum creatinine on admission ranged between 112 and 1064 Amicromol/L (mean 453 Amicromol/L). The lowest hemoglobin level and platelet count during hospitalization ranged between 38 and 87 g/L and 7 to 147x109/L respectively. Leukocytosis on admission was present in 22 patients, low C3 was documented in 11 patients (34%), and four patients had low C4. All patients received fresh frozen plasma transfusion, a total of 25 patients received dialysis therapy, 19 patients were treated with peritoneal dialysis (PD), one patient had hemodialysis (HD), and five patients had both HD and PD. The mean duration of dialysis was 18 days (range three to 56 days). Only one patient died (mortality rate 3%). The median duration of hospital stay was 28 days (range eight to 90 days). We conclude that HUS is emerging as an important clinical and public health problem and that early comprehensive management including dialysis therapy, aggressive management of hypertension, fresh frozen plasma transfusion, and nutritional support all improve the outcome and decrease the mortality and morbidity in patients with HUS.

Extrarenal involvement in diarrhoea-associated haemolytic-uraemic syndrome

A review of extrarenal involvement in diarrhoea-associated haemolytic-uraemic syndrome (HUS) is based on 64 of our autopsied patients and an update of the literature. Large bowel pathology was the commonest (29 cases), followed by the central nervous system (21 cases), the heart (19 cases) and the pancreas (19 cases). The severity of systemic involvement was associated with the magnitude of renal compromise and the prognosis of the acute phase. Diarrhoea-associated HUS is described as a multiorgan entity, due to extensive microvascular damage and thrombosis. At present mortality during the acute phase is not confined to renal failure; systemic involvement can also lead to death.