Post-Diarrheal Hemolytic Uremic Syndrome (D HUS)

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Post-Diarrheal Hemolytic Uremic Syndrome (DHUS)

• Richard L. Siegler M.D.
• Professor Emeritus
• University of Utah School of Medicine

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What is Post-Diarrheal Hemolytic Uremic
Syndrome (DHUS) and where did it come from ?

• The syndrome includes
• Acute kidney failure
• Hemolytic anemia
• Thrombocytopenia (low platelet count)
• Most common cause of acute renal (kidney) failure
  in young children also occurs in older children
  and adults

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How did these otherwise harmless E. coli become
such killers?

• DNA from a Stx producing bacterium (Shigella
  dysenteriae type 1) transferred by bacteriophage
  to E. coli
• This provided E. coli with genes to produce Shiga
  toxin (Stx), one of the most potent toxins known
  to man  

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Pathogenic Cascadefrom diarrhea to dialysis

• Chain of events
• ingestion of Stx producing E. coli
• multiplication in bowel
• absorption of Stx into circulation

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pathogenic cascade, cont.

• Chain of events, cont.
• attachment of Stx to receptors in kidney, and
  occasionally other organs
• movement of toxin into cells
• cell injury or death

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pathogenic cascade, cont.the end result is

• hemorrhagic colitis (bloody diarrhea)
• kidney injury, causing acute renal failure
• damage of red blood cells causing anemia
• trapping and destruction of platelets causing
  bleeding
• occasional damage to other organs (brain,
  pancreas, heart, lungs, eyes)

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Signs and Symptoms

• diarrhea (usually bloody) with severe pain can
  be mistaken for appendicitis
• pallor
• bruises
• seizures and/or coma (occasionally)
• little (oliguria) or no (anuria) urine
• high blood pressure
• pancreatic damage (diabetes)

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Hospital course and Treatment

• meticulous attention to salt and water balance
• dialysis for kidney failure
• blood transfusions for anemia
• Platelet transfusions for bleeding
• aggressive nutritional support (e.g., total
  parenteral nutrition TPN)
• treatment of high blood pressure
• treatment of seizures

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Outcomes

• Death in 3-5, due to
• brain damage (stroke and/or brain swelling)
• bowel necrosis and perforation
• heart damage
• lung injury
• multiorgan injury (seen in most fatal cases)

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outcomes, cont.

• Those who survive may be left with
• permanent kidney damage
• brain damage
• hypertension
• diabetes

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Monitoring

• Chronic kidney failure may occur decades later
  (due to hyperfiltration injury)
• most common in those who had prolonged kidney
  failure (oligoanuria) gt10 days
• proteinurea (protein in the urine) is an early
  sign

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monitoring, cont.

• Hypertension may begin years later (in those with
  chronic kidney damage)
• Diabetes can latter occur (in those with
  pancreatic injury)

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Summary

• D HUS is a life threatening complication of Stx
  producing E. coli
• It occurs primarily in infants and young
  children, but also affects adults
• Is fatal 3-5 of victims
• Survivors (30-50) are left with chronic kidney
  damage that can be progressive later in life
• Life long monitoring is necessary