Oesophageal and severe gut involvement in the haemolytic uraemic syndrome

Factors affecting dialysis duration in children with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome

BACKGROUND

Predicting disease severity can be informative for management of HUS. Dialysis requirement, volume depletion, elevated white blood cell counts, very young age, and use of antimotility agents are known factors associated with severe HUS.

METHODS

A retrospective cohort analysis was performed to identify factors associated with dialysis duration using electronic medical record and chart review of 76 children ≤ 18 years of age at presentation with STEC-HUS identified through billing data from July 2008 to April 2020 at James Whitcomb Riley Hospital for Children, Indiana University, Indiana.

RESULTS

Novel findings associated with prolonged dialysis duration were age ≥ 6 years old at presentation (p = 0.041) and lack of drop in platelets below 60,000/mm3 anytime during the illness (p = 0.015). In addition, children with NSAID exposure trended longer on dialysis: 15 days with vs. 10 days without (p = 0.117). Known risk factors for severe disease including elevated peak white blood cell (WBC) count and higher hematocrit at presentation were also associated with longer dialysis duration: children with peak WBC > 20,000/mm3 were on dialysis for 15 vs. 9.5 days (p = 0.002) and in children on dialysis ≥ 14 days hematocrit at presentation was 29.6% vs. 24.2% (p = 0.03). Children requiring dialysis for 20 days or longer were more likely to be on anti-hypertensive medications (p = 0.025) and have chronic kidney disease at 12-month follow up (p = 0.044).

CONCLUSIONS

Age ≥ 6, elevated WBC count > 20,000/mm3, higher hematocrit at presentation, lack of drop in platelets to < 60,000/mm3, and possibly NSAID exposure during illness are associated with longer dialysis duration in STEC-HUS. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Shiga toxin-associated hemolytic uremic syndrome complicated by intestinal perforation in a child with typical hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is one of the most common causes of acute renal failure in childhood and is primarily diagnosed in up to 4.5% of children who undergo chronic renal replacement therapy. Escherichia coli serotype O157:H7 is the predominant bacterial strain identified in patients with HUS; more than 100 types of Shiga toxin-producing enterohemorrhagic E. coli (EHEC) subtypes have also been isolated. The typical HUS manifestations are microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency. In typical HUS cases, more serious EHEC manifestations include severe hemorrhagic colitis, bowel necrosis and perforation, rectal prolapse, peritonitis, and intussusceptions. Colonic perforation, which has an incidence of 1%-2%, can be a fatal complication. In this study, we report a typical Shiga toxin-associated HUS case complicated by small intestinal perforation with refractory peritonitis that was possibly because of ischemic enteritis. Although the degree of renal damage is the main concern in HUS, extrarenal complications should also be considered in severe cases, as presented in our case.

Acute appendicitis in a patient with hemolytic uremic syndrome: an unusual clinical scenario

Gastroenteritis due to Escherichia coli O157:H7 occurs in young children and is associated with consumption of under cooked beef. Approximately 5-10% of patients will develop hemolytic uremic syndrome (HUS): renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. A 6-year-old boy was admitted with abdominal pain, guaiac positive stool, decreased urine output and elevated creatinine levels. Hemodialysis was initiated upon rapid progression to anuria. On hospital day # 5 he developed acute abdominal pain, which was different from his initial assessment. Exam revealed focal tenderness in the right lower quadrant with localized guarding and rebound. Ultrasound demonstrated a dilated, fluid filled tubular structure in the RLQ concerning for appendicitis. Based on these findings the patient was taken to the operating room for a laparoscopic appendectomy. The patient had undergone dialysis the previous day and was preoperatively treated with DDAVP to minimize the risk of bleeding. The procedure occurred without complication and final pathology confirmed acute appendicitis. This case highlights the unique clinical scenario in which patients with HUS require operative intervention. Surgical procedures can be performed on these patients, however, all precautions should be taken to minimize the risk of bleeding, including the use of preoperative DDAVP.

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.

Current concepts in the diagnosis and management of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura is a multisystem disease characterized by thrombocytopenia, hemolytic anemia, renal failure, fever, and neurologic abnormalities. Plasma exchange has revolutionized the outcome of this entity from a once fatal disease to a disease that potentially is cured or has prolonged remission. The understanding of the pathophysiology of TTP continues to evolve. Recently, investigators showed that a deficiency in a specific plasma protease responsible for cleaving vWf plays a crucial role in the familial form of TTP. This explains in part why patients usually respond to plasma exchange therapy. The identification of a mutation in a specific gene that belongs to the metalloproteinase family located at chromosome 9q34 could have important therapeutic implications. TTP can be induced by certain drugs, especially immunosuppressants, in the setting of bone marrow and solid organ transplantation. This disease also has been described in association with HIV, pregnancy, cancer, and chemotherapy. TTP remains an ideal example of how knowledge about the etiology of a disease can improve therapeutic interventions.

Clinical presentation, complications and treatment of infection with verocytotoxin-producing Escherichia coli. Challenges for the clinician

Seventeen years after its recognition, outbreaks and sporadic infections attributed to Escherichia coli O157 continue to increase. Acute gastrointestinal, and the systemic complications haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP), are frequent and severe. Current challenges that face clinicians are the early recognition of infection, identification of risk factors for poor prognosis, determination of appropriate monitoring for the development of complications, establishment of a therapeutic strategy and, finally, advice for patients about their long-term prognosis. Clinical features which, in combination, have been shown to distinguish E. coli O157 infection from other enteric pathogens are a history of bloody diarrhoea, visibly bloody stools, absence of fever, a leucocyte count greater than 10 x 10(9) l(-1) and abdominal tenderness on physical examination. The most consistent risk factors for the development of HUS/TTP are the extremes of age and a raised leucocyte count. Bloody diarrhoea and 'antimotility' drugs are also likely to be important risk factors. Recent evidence from the central Scotland outbreak suggests that individuals who are taking drugs that reduce gastric acidity or antibiotics at the time of infection with E. coli O157, or who have a short incubation period, may also be at increased risk of progression to HUS/TTP. Clinical management, in particular the role of antibiotics in gastrointestinal infection, remains controversial, and retrospective assessment of the 1996 outbreaks from central Scotland and Japan only adds to this controversy. Therapeutic plasma exchange is a promising treatment for adults who develop HUS/TTP, but its role has yet to be determined definitively, either in a randomized controlled trial or by an international register of cases. Significant chronic sequelae of infection occur, particularly irritable bowel syndrome after uncomplicated gastrointestinal infection, and renal failure after HUS/TTP. Their frequency and severity are likely to become evident over the next decade.

Effectiveness of therapeutic plasma exchange in the 1996 Lanarkshire Escherichia coli O157:H7 outbreak

BACKGROUND

The largest number of adult cases of haemolytic uraemic syndrome (HUS)/thrombotic thrombocytopenic purpura (TTP) during an Escherichia coli O157 outbreak occurred in 1996 in central Scotland. Adults who develop HUS/TTP induced by E. coli O157 tend to be elderly and have a historical mortality rate of almost 90% when treated conservatively. Therefore the decision was made to treat adults who developed HUS/TTP during this outbreak with therapeutic plasma exchange (TPE). We report our outcome with this controversial treatment.

METHODS

A case definition for HUS/TTP was developed at the beginning of the outbreak. All cases meeting this definition were considered for TPE. Information on demographics, clinical features, treatment and outcome of patients was obtained by retrospective case note review.

FINDINGS

22 adults developed HUS/TTP. They had a mean age of 71 years. 16 cases received TPE. Six cases had contraindications to TPE or died before the procedure could be done. Ten of the 22 (45%) adults with HUS/TTP died. Five of the 16 (31%) TPE-treated cases died, four of eight aged over 70 years compared with one of eight aged less than 70 years. Premorbid illness, neurological features, treatment with ciprofloxacin or prostacyclin, and the laboratory severity of HUS/TTP were not associated with death; the number of cases, however, was too small to allow statistical conclusion.

INTERPRETATION

The mortality rate is high in adults who develop HUS/TTP induced by E. coli O157. TPE appears to be a promising treatment that was well tolerated in our elderly patients. A national register of adult cases of HUS/TTP induced by E. coli O157 should be established.

Surgical complications of the haemolytic uraemic syndrome

During the first outbreak of haemolytic uraemic syndrome (HUS) to be reported in Australia, 22 children were admitted to the Women's and Children's Hospital, Adelaide. The outbreak was caused by an entero-haemorrhagic Escherichia coli strain (EHEC) of serotype 011:H-, a strain rarely implicated as a cause for HUS. In all 22 patients, the onset of HUS was preceded by a gastrointestinal (GI) prodrome. All patients had diarrhoea. In 17 (73%), the diarrhoea became bloody; in 20 (86%) there was vomiting; in 15 (65%) there was abdominal pain; and in 12 (50%) all three symptoms were present. Abdominal symptoms continued to complicate the course of 4 patients. Two of these underwent exploratory laparotomy, both had gangrenous colon excised, and both survived. The 2 remaining patients were successfully treated non-operatively. One further patient underwent appendicectomy before the diagnosis of HUS was made. There was 1 death during this epidemic. In patients with HUS and GI involvement, optimal surgical management requires careful consideration of the indications for, and the timing of, surgical intervention.

[Digestive manifestations in hemolytic uremic syndrome in children]

BACKGROUND

Gastro-intestinal manifestations are relatively frequent during the course of hemolytic uremic syndrome (HUS), some of them requiring special supportive care. This work was aimed at retrospectively studing gastrointestinal manifestations of HUS and determining their place in the prognosis.

PATIENTS

Thirty-seven children aged 4 months to 11 years (22 girls and 15 boys) were included in the study.

RESULTS

All children but one had gastrointestinal prodromes. During the course of HUS, various manifestations were seen: bloody diarrhea in 32% of patients, ileo-ileal intussusception in 3%, rectal prolapse in 8% and hepatic cytolysis in 38%. Seven patients with bloody diarrhea had a complicated course, lethal in one. Comparison between these seven children and the 30 others revealed some indicators of severe gut involvement: female sex, short duration of gastrointestinal prodromes, hemorrhagic colitis with rectal prolapse, high WBC count, high neutrophils count and less important degree of anemia at admission. Severity of the gastrointestinal lesions was correlated with that of the outcome of the renal disease.

CONCLUSION

Gastrointestinal tract is frequently affected in HUS and severe complications can appear, potentially leading to death. Total parenteral nutrition could prevent occurrence of gastrointestinal complications. Severe gastrointestinal lesions are associated with a poor renal outcome.

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.