Shiga Toxin-Producing Escherichia Coli Hemolytic-Uremic Syndrome


Epidemiology


Etiology

1) Post-viral infection: in young children
2) Familial HUS:
3) Post-Mitomycin-C therapy: in adults
4) Enterohemorrhagic E. Coli gastroenteritis:
5) Post-BMT: usually occurs 4-12 months after BMT


Diagnosis

Intravascular Hemolysis
-Normal or increased retic count
-Elevated LDH
-Indirect hyperbili-rubinemia
-Decreased hapto-globin
-Urine Hb-pos (only when hemolysis is severe)

-Urine bili-neg
-Urine hemosiderin-pos (only when hemolysis is chronic)
-Urine urobilinogen-variable

Smear: polychro-matophilia/ RBC fragments (schisto-cytes), helmet cells/ nucleated RBC

Thrombocytopenia (range = 5-100k)

Near normal PT/ PTT/ fibrinogen/ D-dimers (these findings exclude DIC)

BM Bx: erythroid hyperplasia/ increased megakaryocytes
Renal: proteinuria/ moderate uremia
Liver: conjugated hyperbilirubin-emia
ANA: positive in 20% of cases
LP: normal
Head CT: normal


Clinical

Multisystem Disease (similar to TTP, except more frequent renal failure and uncommon neuro findings):
-Acute hemolysis with thrombocytopenic purpura
-Acute oliguric renal failure
-Neurologic manifes-tations are uncommon


Treatment


Prognosis


References