[Digestive manifestations in hemolytic uremic syndrome in children]

Hemolytic uremic syndrome: differential diagnosis with the onset of inflammatory bowel diseases

BACKGROUND

Shiga-toxin Escherichia coli productor (STEC) provokes frequently an important intestinal damage that may be considered in differential diagnosis with the onset of Inflammatory Bowel Disease (IBD). The aim of this work is to review in the current literature about Hemolytic Uremic Syndrome (HUS) and IBD symptoms at the onset, comparing the clinical presentation and symptoms, as the timing of diagnosis and of the correct treatment of both these conditions is a fundamental prognostic factor. A focus is made about the association between typical or atypical HUS and IBD and a possible renal involvement in patient with IBD (IgA-nephropathy).

METHODS

A systematic review of scientific articles was performed consulting the databases PubMed, Medline, Google Scholar, and consulting most recent textbooks of Pediatric Nephrology.

RESULTS

In STEC-associated HUS, that accounts for 90% of cases of HUS in children, the microangiopathic manifestations are usually preceded by gastrointestinal symptoms. Initial presentation may be considered in differential diagnosis with IBD onset. The transverse and ascending colon are the segments most commonly affected, but any area from the esophagus to the perianal area can be involved. The more serious manifestations include severe hemorrhagic colitis, bowel necrosis and perforation, rectal prolapse, peritonitis and intussusception. Severe gastrointestinal involvement may result in life-threatening complications as toxic megacolon and transmural necrosis of the colon with perforation, as in Ulcerative Colitis (UC). Transmural necrosis of the colon may lead to subsequent colonic stricture, as in Crohn Disease (CD). Perianal lesions and strictures are described. In some studies, intestinal biopsies were performed to exclude IBD. Elevation of pancreatic enzymes is common. Liver damage and cholecystitis are other described complications. There is no specific form of therapy for STEC HUS, but appropriate fluid and electrolyte management (better hyperhydration when possible), avoiding antidiarrheal drugs, and possibly avoiding antibiotic therapy, are recommended as the best practice. In atypical HUS (aHUS) gastrointestinal manifestation are rare, but recently a study evidenced that gastrointestinal complications are common in aHUS in presence of factor-H autoantibodies. Some report of patients with IBD and contemporary atypical-HUS were found, both for CD and UC. The authors conclude that deregulation of the alternative complement pathway may manifest in other organs besides the kidney. Finally, searching for STEC-infection, or broadly for Escherichia coli (E. coli) infection, and IBD onset, some reviews suggest a possible role of adherent invasive E. coli (AIEC) on the pathogenesis of IBD.

CONCLUSIONS

The current literature shows that gastrointestinal complications of HUS are quite exclusive of STEC-associated HUS, whereas aHUS have usually mild or absent intestinal involvement. Severe presentation as toxic megacolon, perforation, ulcerative colitis, peritonitis is similar to IBD at the onset. Moreover, some types of E. coli (AIEC) have been considered a risk factor for IBD. Recent literature on aHUS shows that intestinal complications are more common than described before, particularly for patients with anti-H factor antibodies. Moreover, we found some report of patient with both aHUS and IBD, who benefit from anti-C5 antibodies injection (Eculizumab).

[Hemolytic-uremic syndrome (HUS) in children at the University Hospital Center in Dakar: about four cases]

Le syndrome hémolytique et urémique (SHU) est une cause fréquente d'insuffisance rénale aiguë (IRA) organique chez l'enfant. C'est une complication évolutive des gastroentérites aiguës (GEA) en particulier à Escherichia coli de l'enfant. Notre objectif était de décrire les aspects cliniques, thérapeutiques et évolutifs de cette affection chez quatre enfants. Nous avions colligé quatre cas de SHU. L’âge moyen était de 10,5 mois (5-15mois) exclusivement des garçons. L'examen clinique retrouvait une anémie de type hémolytique (pâleur et ictére), un syndrome oedémateux avec oligo-anurie (2 cas), une hypertension artérielle (1 patient), une GEA avec déshydratation sévère et choc hypovolémique (2 patients), des troubles de conscience. L'IRA était notée chez tous les patients de même que la thrombopénie et les schizocytes au frottis. Le Coombs direct était négatif. Il y avait une hyperkaliémie (3patients) dont 1 patient supérieure à 9,2 mmol/l, une hyponatrémie à 129mmol/l(1 patient) et une hypernatrémie à 153mmol/l (1 patient). Le shu était secondaire à une pneumonie à pneumocoque (1 patient), une GEA à E. coli (1 patient). Le traitement était essentiellement symptomatique et comprenait la restriction hydrique, la transfusion de concentrés érythrocytaires, les diurétiques, la dialyse péritonéale et l'hémodialyse. L’évolution était marquée par la survenue d'une insuffisance rénale chronique (1 patient) après 6 mois de suivi et la guérison (1 cas). Nous avions noté 3décés. Le SHU est la cause la plus fréquente d'IRA organique du nourrisson. Le diagnostic est essentiellement biologique, le traitement est surtout symptomatique.

Clinical features, therapeutic interventions and long-term aspects of hemolytic-uremic syndrome in Norwegian children: a nationwide retrospective study from 1999-2008

Background

Hemolytic-uremic syndrome (HUS) is a clinical triad of microangiopathic hemolytic anemia, impaired renal function and thrombocytopenia, primarily affecting pre-school-aged children. HUS can be classified into diarrhea-associated HUS (D⁺HUS), usually caused by Shiga toxin-producing Escherichia coli (STEC), and non-diarrhea-associated HUS (D⁻HUS), both with potentially serious acute and long-term complications. Few data exists on the clinical features and long-term outcome of HUS in Norway. The aim of this paper was to describe these aspects of HUS in children over a 10-year period.

Methods

We retrospectively collected data on clinical features, therapeutic interventions and long-term aspects directly from medical records of all identified HUS cases <16 years of age admitted to Norwegian pediatric departments from 1999 to 2008. Cases of D⁺HUS and D⁻HUS are described separately, but no comparative analyses were possible due to small numbers. Descriptive statistics are presented in proportions and median values with ranges, and/or summarized in text.

Results

Forty seven HUS cases were identified; 38 D⁺HUS and nine D⁻HUS. Renal complications were common; in the D⁺HUS and D⁻HUS group, 29/38 and 5/9 developed oligoanuria, 22/38 and 3/9 needed dialysis, with hemodialysis used most often in both groups, and plasma infusion(s) were utilized in 6/38 and 4/9 patients, respectively. Of extra-renal complications, neurological complications occurred in 9/38 and 2/9, serious gastrointestinal complications in 6/38 and 1/9, respiratory complications in 10/38 and 2/9, and sepsis in 11/38 and 3/9 cases, respectively. Cardiac complications were seen in two D⁺HUS cases. In patients where data on follow up ≥1 year after admittance were available, 8/21 and 4/7 had persistent proteinuria and 5/19 and 4/5 had persistent hypertension in the D⁺HUS and D⁻HUS group, respectively. Two D⁺HUS and one D⁻HUS patient were diagnosed with chronic kidney disease and one D⁺HUS patient required a renal transplantation. Two D⁺HUS patients died in the acute phase (death rate; 5 %).

Conclusions

The HUS cases had a high rate of complications and sequelae, including renal, CNS-related, cardiac, respiratory, serious gastrointestinal complications and sepsis, consistent with other studies. This underlines the importance of attention to extra-renal manifestations in the acute phase and in renal long-term follow-up of HUS patients.

Diabetes during diarrhea-associated hemolytic uremic syndrome: a systematic review and meta-analysis

OBJECTIVE

To quantify the incidence of diabetes during the acute phase of diarrhea-associated hemolytic uremic syndrome (D + HUS) and to identify features associated with its development.

RESEARCH DESIGN AND METHODS

A systematic review and meta-analysis of articles assessing diabetes during D + HUS was conducted. Relevant citations were identified from Medline, Embase, and Institute for Scientific Information Citation Index databases. Bibliographies of relevant articles were hand searched. All articles were independently reviewed for inclusion and data abstraction by two authors.

RESULTS

Twenty-one studies from six countries were included. Only 2 studies reported a standard definition of diabetes; 14 defined diabetes as hyperglycemia requiring insulin. The incidence of diabetes during the acute phase of D + HUS could be quantified in a subset of 1,139 children from 13 studies (1966-1998, age 0.2-16 years) and ranged from 0 to 15%, with a pooled incidence of 3.2% (95% CI 1.3-5.1, random-effects model, significant heterogeneity among studies, P = 0.007). Children who developed diabetes were more likely to have severe disease (e.g., presence of coma or seizures, need for dialysis) and had higher mortality than those without diabetes. Twenty-three percent of those who developed diabetes acutely died, and 38% of survivors required long-term insulin (median follow-up 12 months). Recurrence of diabetes was possible up to 60 months after initial recovery.

CONCLUSIONS

Children with D + HUS should be observed for diabetes during their acute illness. Consideration should be given to long-term screening of D + HUS survivors for diabetes.