Management of hemolytic-uremic syndrome

Haemolytic-uremic syndrome due to infection with adenovirus: A case report and literature review

RATIONALE

Haemolytic-uremic syndrome is a rare but serious complication of bacterial and viral infections, which is characterized by the triad of: acute renal failure, microangiopathic haemolytic anemia and thrombocytopenia, sometimes severe, requiring peritoneal dialysis. In Europe, hemolytic-uremic syndrome (HUS) in paediatric pathology is primarily caused by Shiga toxin-producing Escherichia coli (STEC) O157, followed by O26. Beside these etiologies, there are other bacterial and viral infections, and also noninfectious ones that have been associated to lead to HUS as well: in the progression of neoplasia, medication-related, post-transplantation, during pregnancy or associated with the antiphospholipid syndrome, systemic lupus erythematosus or family causes with autosomal dominant or recessive inheritance. In terms of pathogenesis, HUS is the result of endothelial injury, most commonly being a result of the action of Shiga toxin. The unfavorable prognosis factors being represented by the age of more than 5 years old, different etiologies from STEC, persistent oligoanuria, central nervous system and glomerular impairment, the association of fever with leukocytosis. HUS is responsible for 7% of cases of hypertension in infants, and an important cause of significant kidney damage in adults.

PATIENT CONCERNS

We present one case of HUS caused by adenovirus in a boy of 1 year and 7 months old with severe evolution, which required peritoneal dialysis.

DIAGNOSE

Stool sample repeated examination for adenovirus antigen was positive in 2 samples.

INTERVENTION

During hospitalization, the patient required 8 peritoneal dialysis sessions.

OUTCOME

The renal function was corrected on discharge, the patient required cardiovascular monitoring 1 month after discharge.

LESSON

Although the most common cause that leads to HUS remains STEC, other etiologies like viral ones that may be responsible for severe enteric infection with progression into HUS should not be neglected.

Anaemia in pregnancy

Anaemia in pregnancy, defined as a haemoglobin concentration (Hb) < 110 g/L, affects more than 56 million women globally, two thirds of them being from Asia. Multiple factors lead to anaemia in pregnancy, nutritional iron deficiency anaemia (IDA) being the commonest. Underlying inflammatory conditions, physiological haemodilution and several factors affecting Hb and iron status in pregnancy lead to difficulties in establishing a definitive diagnosis. IDA is associated with increased maternal and perinatal morbidity and mortality, and long-term adverse effects in the new born. Strategies to prevent anaemia in pregnancy and its adverse effects include treatment of underlying conditions, iron and folate supplementation given weekly for all menstruating women including adolescents and daily for women during pregnancy and the post partum period, and delayed clamping of the umbilical cord at delivery. Oral iron is preferable to intravenous therapy for treatment of IDA. B12 and folate deficiencies in pregnancy are rare and may be due to inadequate dietary intake with the latter being more common. These vitamins play an important role in embryo genesis and hence any relative deficiencies may result in congenital abnormalities. Finding the underlying cause are crucial to the management of these deficiencies. Haemolytic anaemias rare also rare in pregnancy, but may have life-threatening complications if the diagnosis is not made in good time and acted upon appropriately.

Cardiac failure in hemolytic uremic syndrome and rescue with extracorporeal life support

Extrarenal involvement manifesting in the cardiovascular system is a rare but potentially fatal complication of hemolytic uremic syndrome (HUS). Current treatment is aimed at cardiovascular supportive measures while awaiting organ recovery. However, there are cases in which this recovery never occurs, and patients succumb secondary to heart failure. We report two cases of severe cardiac failure in children in the acute phase of HUS and the use of extracorporeal membrane oxygenation (ECMO) to support one patient to cardiac recovery. Clinicians should be aware of this potentially life-threatening cardiac involvement and should consider the use of ECMO for potentially salvageable children with HUS.

Haemolytic uraemic syndrome

Diarrhoea-associated haemolytic uraemic syndrome develops in about 5 to 10% of children with haemorrhagic colitis due to Escherichia coli (E. coli) O157:H7 and is a common cause of acute renal failure in childhood. Endothelial cell damage, white blood cell activation and platelet-endothelial cell interactions are important in the pathogenesis. Meticulous supportive care, with attention to nutrition and fluid, and electrolyte balance, is important. Dialysis is necessary in many children. Public health follow-up is important to minimise the spread of E. coli O157:H7, which is transmitted by person-to-person, as well as through contaminated food products. 20-year follow-up studies report that 75% of children recover without any clinically significant long term sequelae. Chronic renal failure is reported in about 5% of children.

Shigella and Shiga toxin-producing Escherichia coli causing bloody diarrhea in Latin America

In Latin America, Shigella and shiga toxin-producing Escherichia coli are the two leading agents in the cause of bloody diarrhea. The already high and increasing antimicrobial resistance of Shigella also is a significant problem. Shiga toxin-producing E. coli is an emerging disease with life-threatening complications: hemolytic uremic syndrome. Although E. coli O157:H7 remains the most commonly recognized serotype, recently emerging, non-O157 bacteria may be the cause of a similar spectrum of disease in humans.

Current Clinical Practice: Current Management of Thrombotic Thrombocytopenic Purpura

Historically, the mortality rate of thrombotic thrombocytopenic purpura (TTP) approached 100%. However, by the 1980's, new therapy was instituted with a vast improvement in survival to 90%. The exact pathogenesis of TTP remains elusive. Yet, despite incomplete understanding of the pathophysiology, outcome has improved due to increased awareness of the symptomatology leading to earlier diagnosis and better supportive care, in addition to effective therapy with plasma exchange. TTP represents a disease in which prompt diagnosis and treatment can lead to a critical difference in clinical outcome.

Neurotoxicity of intrathecal Shiga toxin 2 and protection by intrathecal injection of anti-Shiga toxin 2 antiserum in rabbits

The initial brain lesions in rabbits given intravenous Shiga toxin 2 (Stx2) were noted at 24 h in an area around the third ventricle (Fujii et al., Infect Immun 1996, 64: 5053-60). This result implied that Stx2 is present in the cerebrospinal fluid (CSF) despite the fact that the toxin was administered intravenously. We measured Stx2 activity in CSF by using a Vero cell cytotoxicity assay at various times after an intravenous injection of Stx2. Stx2 was detected from 2 h after the injection, and its concentration in CSF remained at a high level for a further 6 h. Fifty percent lethal doses (LD 50) of Stx2 were measured in rabbits after intravenous and intrathecal Stx2 injections; The LD 50 after an intrathecal injection of Stx2 was 0. 36 microg/kg, which was 9.2-fold lower than that of an intravenous injection of Stx2 (3.4 microg/kg). Magnetic resonance images obtained after an intrathecal Stx2 injection (5 microg/kg) were compared with those obtained after an intravenous Stx2 injection (5 microg/kg). At 48 h, the cerebellar lesions had spread from the area in contact with the CSF on a T2-weighted image, which suggests that the intrathecal Stx2 may invade the cerebellum directly. We then examined whether anti-Stx2 antiserum injected intrathecally protects rabbits against brain damage. Eighty percent of the rabbits infected with Stx2 at 5 microg/kg died within 8 days from brain damage. Rabbit anti-Stx2 sera (with titres of x16 and x64 by the Ouchterlony precipitation method) were administered into the CSF space through the cisterna magna. All the rabbits ( n=10) survived when they were given an intrathecal injection of rabbit anti-Stx2 antiserum 2 h before the intravenous injection of Stx2. Our results suggest that a leakage of Stx2 into the CSF from the choroid plexus causes brain damage, and that an intrathecal injection of anti-Stx2 antiserum could be a therapy for acute encephalopathy caused by Stx2-producing Escherichia coli.

Management of patients with hemolytic uremic syndrome demonstrating severe azotemia but not anuria

There are no specific indications for dialysis in a patient with typical hemolytic uremic syndrome (D + HUS) who does not have anuria, hyperkalemia, volume overload, or severe acidemia. We managed five patients with D + HUS, aged 1.5-14 years, without dialysis despite marked azotemia, because they were not anuric and because they had none of the acid-base, fluid, or electrolyte perturbations that may have been indications for dialysis. Each had markedly elevated blood urea nitrogen (range 137-234 mg/dl) and serum creatinine concentrations (range 5.4-15.4 mg/dl). None was anuric and one was oliguric for 4 days. There were no complications and each recovered. We have reviewed the published literature on the use of dialysis in patients with D + HUS and have not found any guidelines that relate to the management of similar cases. It is our view that management of D + HUS patients without dialysis is appropriate when the patient is passing urine and the acid-base, serum electrolyte concentrations and fluid balances can be managed without dialysis.

Hemolytic disorders associated with cancer

Three principal environmental causes of hemolytic anemia in malignancy have been identified: (1) hemolysis mediated by auto-antibodies to red cells; (2) hemolysis due to microangiopathic disorders; and (3) chemotherapy-induced red cell destruction. These three environmental stressors occur rarely in cancer patients, and they form the subject of this review.

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.

Haemolytic uraemic syndrome: prognostic factors in children over 3 years of age

Previous studies have shown that age at onset of primary haemolytic uraemic syndrome (HUS) is a feature of prognostic significance, the disease being of much better outcome in paediatric patients younger than 3 years than in older children. In an attempt to find an explanation for such a difference, we analysed the clinical and pathological features of 42 children over 3 years of age who presented with HUS between 1955 and 1990 in our department. On the basis of the presence of a prodromal diarrhoea, we divided our patients into two groups: 21 children presented with the diarrhoea-associated (typical or D+) form of HUS, whereas 21 had the non-diarrhoea-associated (atypical or D-) form. Of the 42 children, 20 (47.5%) progressed to end-stage renal failure. However, our study shows that age at onset of HUS is not a prognostic feature per se. The difference in outcome between children and infants is most likely related to the high incidence of the atypical subset of HUS in children over 3 years, a subset that is very uncommon in infants. The ominous features which characterise this form of the disease are: (1) the absence of a diarrhoeal prodrome, (2) normal urine output, (3) marked proteinuria, (4) hypertension, (5) the occurrence of relapses or recurrences and (6) the presence of widespread and severe arteriolar changes on renal biopsy. The poor prognosis of the atypical form of HUS warrants the use of fresh-frozen plasma infusions and/or plasma exchange as early as possible in the course of the disease.

Cisplatin-associated hemolytic uremic syndrome

BACKGROUND

Hemolytic uremic syndrome (HUS) is an acquired disorder largely affecting infants and young children. It is characterized by the triad of microangiopathic hemolytic anemia, acute renal failure, and thrombocytopenia. Although its etiology is unknown, viral and bacterial infections, disseminated malignancies in adults, and a variety of chemotherapeutic agents including cisplatin, have been implicated in its occurrence. The association of HUS with chemotherapeutic agents after its detection in a pediatric patient treated with cisplatin is reviewed.

METHODS

A 16-year-old male with osteosarcoma was treated with cisplatin as part of a chemotherapy protocol. After the fourth course, his renal function deteriorated and necessitated cessation of cisplatin. Nine months after the initiation of cisplatin, HUS developed. There was no evidence of residual tumor or metastatic disease. He received numerous packed erythrocyte and platelet transfusions for persistent hemolysis and underwent several episodes of hemodialysis. Utilizing this patient as an example, the authors reviewed the incidence of HUS developing subsequent to the use of other chemotherapeutic agents.

RESULTS

In the publishing literature, chemotherapy-associated HUS has been described to occur 54 days to 14 months after the initiation of chemotherapeutic regimens. A variety of agents was associated with the phenomenon.

CONCLUSION

Hemolytic uremic syndrome may be a complication of cisplatin, as evidenced by the condition that occurred in a 16-year-old patient with osteosarcoma after cisplatin therapy.

Hemolytic uremic syndrome in dogs

A disease syndrome similar to the hemolytic uremic syndrome of people is described in three dogs with acute renal failure. In each dog, hemorrhagic gastroenteritis preceded the onset of anuric acute renal failure. Evidence of microangiopathic hemolytic anemia (schizocytes, thrombocytopenia, and increased concentrations of fibrin split products) was present in the three dogs. Serum chemistry results showed increased concentrations of blood urea nitrogen, creatinine, and phosphorus. Ultrasound examination performed in one dog revealed increased echogenicity of the renal cortices. Treatment for anuric acute renal failure using a continuous dopamine and furosemide infusion established urine production in one of three dogs. Microscopic examination of tissue from the two dogs that underwent necropsy showed occlusion of the renal vasculature by fibrin thrombi consistent with microangiopathic arteriolar thrombosis. The pathophysiology and current knowledge of human hemolytic uremic syndrome is compared with hemolytic uremic syndrome in these dogs.

Hemolytic-uremic syndrome

HUS is one of the most common causes of acute renal failure in childhood. D+ HUS is the most common form and usually follows an episode of hemorrhagic colitis due to VTEC or S. dysenteriae type 1. The SLT elaborated by these organisms is responsible for the endothelial damage that is the initial insult in the pathogenesis of the acute renal failure. Excellent supportive care is necessary to reduce the mortality and morbidity due to HUS.

Post-transplantation outcome of patients with hemolytic-uremic syndrome: update

The outcome of renal transplantation in patients with hemolytic-uremic syndrome (HUS) is variable in reported cases. An update of the previously published series of patients from the University of Minnesota is reported. Seventeen patients with HUS received a renal transplant. Seven patients had recurrent HUS based on strict clinical and histological features and in 4 of these patients grafts were loss from recurrent HUS, with 1 patient losing three successive grafts. Three patients had histological features consistent with HUS but lacked some of the clinical features. Seven patients had no evidence of recurrent HUS post transplantation. The incidence of recurrence of HUS post transplantation in this updated report remains high (7/17 patients). There was no difference in the allografts used (living-related donor grafts were more common in all groups) or in the immunosuppression in the different groups of patients; only 1 patient with recurrent HUS received cyclosporine. The published cases of transplantation in patients with HUS show a variable recurrence rate of 0-25% in different centers with a poor graft outcome in patients with recurrence; a higher incidence of early chronic vascular rejection with decreased graft survival is also reported in patients without recurrence. Patients with HUS post renal transplant are at a variable risk of recurrence of HUS or decreased graft survival, and the factors responsible for this outcome are not known.

Surgical complications of the hemolytic-uremic syndrome

Hemolytic-uremic syndrome (HUS) of childhood is a triad of acute hemolytic anemia, thrombocytopenia, and acute renal failure associated with a gastrointestinal prodrome. From 1977 to 1988, 134 patients with HUS were admitted to this institution. All patients presented with abdominal pain and diarrhea, which was virtually always bloody. Seventy-eight patients (60%) required dialysis. Five patients died (4%). One patient died as a result of colon perforation, the other four patients died of other nonsurgical complications of HUS. Three patients underwent exploratory laparotomy. One patient had a hemoperitoneum from mesenteric and transmural bleeding of the entire intraabdominal colon. Another patient had undergone surgery elsewhere for presumed intussusception with pancolitis found at exploration. Fourteen days postoperatively, he had a spontaneous perforation of the transverse colon. The third patient presented with pancolitis and perforation of the transverse colon. Despite surgical intervention he died on the sixth postoperative day. One other patient was treated conservatively for pancreatitis, which developed 3 weeks after her presentation with HUS. Complications requiring surgical intervention in HUS are rare, potentially lethal, and usually involve the colon.

Anticytotoxin-neutralizing antibodies in immune globulin preparations: potential use in hemolytic-uremic syndrome

The pathogenesis of primary (classic) hemolytic-uremic syndrome (HUS) is thought to be related to cytotoxin-producing enteric pathogens such as Shigella dysenteriae serotype 1 and Escherichia coli serotypes O157:H7 and 026:H11. The relevant cytotoxins include Shiga toxin and the closely related Shiga-like toxins (SLTs) produced by some E. coli strains. Intravenously administered immune globulin (IVIG) therapy has been reported to be beneficial in a few children with HUS. We therefore examined commercially available immune globulin preparations for the presence of anticytotoxin-neutralizing antibodies. Cytotoxicity and neutralization of the HUS-associated cytotoxins were quantitatively determined by means of a (3H)thymidine-labeled HeLa cell assay. The immune globulin preparations tested almost completely neutralized Shiga toxin (produced by S. dysenteriae 1) and SLT-I (produced by E. coli serotype 026:H11). Twofold dilutions of the preparations showed significant (p less than 0.01) neutralizing titers of 1:64 to 1:128. No significant neutralization (greater than 20%) of SLT-II (produced by E. coli strain C600 (933W] was noted. The IVIG preparation lost its inhibitory activity when passed through a protein A-Sepharose column, which bound immune globulin, indicating that its neutralizing effect is related to the antibody content. We also examined sera from 30 children without diarrhea or HUS; only one child had neutralizing titers against Shiga toxin (1:64) and SLT-I (1:128). Immune globulin preparations contain anticytotoxin-neutralizing antibodies, a finding that warrants further investigation of the therapeutic role of these preparations in early treatment of children with HUS related to Shiga toxin and SLT-I.