129 Hemolytic Uremic Syndrome Flashcards
Other names for Shiga toxin–producing Escherichia coli (STEC) HUS
Diarrhea-associated HUS (D+HUS) and “typical” HUS
Two types of Shiga toxin in STEC
Similar in structure and function to ricin
Stx1: identical to Shigella dysenteriae serotype 1 toxin
Stx2: strongly associated with hemorrhagic colitis and HUS
The pentameric B subunit responsible for binding to the
Glycosphingolipid globotriaosylceramide (Gb3) or CD77 or Pk blood group antigen
The predilection for renal injury is a result of the relatively high expression of Gb3 on renal tubular epithelial, mesangial, and glomerular endothelial cells.
TRUE OR FALSE
STEC-HUS can occur at any age but affects mainly children younger than age 5 years and is rare before age 6 months.
TRUE
STEC-HUS can occur at any age but affects mainly children younger than age 5 years and is rare before age 6 months.
E.coli strain that accounts for at least 80% of STEC-HUS
E. coli O157:H7
O104:H4 serotype: one of the most virulent strains that is responsible for SETE-HUS in during a German outbreak in 2011
O26:H11 serotype: most common non-O157 serotype causing human disease in Europe and North America.
Patients develop abdominal pain, tenderness, and diarrhea between ____and ____ days after ingesting STEC
2 and 12 days
Mean incubation period of 3–7 days and a median of 3 days
The diarrhea usually becomes bloody within 1–3 days, at which time patients are typically afebrile.
Of children younger than 10 years of age with bloody diarrhea and E. coli O157:H7 infection, approximately ____ % develop STEC-HUS
15%
The acute onset of microangiopathic hemolytic anemia, thrombocytopenia, and renal injury an average of 7 days (range, 5–13 days) after the start of diarrhea.
Treatment for STEC-HUS
Early IV hydration
Antibiotics
Antimotility agents and narcotics increase the risk of HUS and neurologic complications.
Nonsteroidal antiinflammatory drugs and antihypertensives that reduce renal perfusion such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers should be avoided.
TRUE OR FALSE
Antibiotics should not be used early in the course of acute diarrheal illness caused by E. coli O157:H7 because antibiotics increase the risk of HUS.
TRUE
Antibiotics should not be used early in the course of acute diarrheal illness caused by E. coli O157:H7 because antibiotics increase the risk of HUS.
However, retrospective analysis of a 2011 outbreak of E. coli O104:H4 infection indicates that treatment with multiple antibiotics after the development of HUS may have reduced the incidence of seizures and death.
May be considered to prevent the development of end stage renal disease in children who have persistent impaired renal function at 3-months after onset
Eculizumab
HUS not commonly associated with diarrhea or STEC infection and occurs in patients without an obvious predisposing condition
Complement-associated HUS or aHUS
Mutation that causes familial type of HUS
Complement factor H (CFH)
The dysregulation of the ________________ pathway drives the pathogenesis of aHUS.
Aternative complement pathway
Homozygous or compound heterozygous mutations in _____________ cause aHUS with high penetrance that presents before 1 year of age with hypertension, hematuria, and proteinuria.
Diacylglycerol kinase ε (DGKE)
After excluding severe ADAMTS13 deficiency, STEC-HUS, and secondary causes of thrombotic microangiopathy, plasma exchange can be stopped, and _____________ should be administered for the presumptive diagnosis of aHUS
Eculizumab
900 mg intravenously every week for 4 weeks followed by 1200 mg in week 5 and every other week thereafter
