TABLE 3

Thrombotic thrombocytopenic purpura vs hemolytic uremic syndrome

Thrombotic thrombocytopenic purpuraHemolytic-uremic syndrome
Ischemia, tissue injuryMultiorganRenal
Presentation in childrenFew cases (early onset of congenital TTP)Most cases; usually accompanied by bloody diarrhea (except in atypical hemolytic-uremic syndrome)
ADAMTS13 activityMarkedly reducedNormal or mildly reduced in almost all cases
RecurrenceCommonRare
Therapeutic plasma exchangeGood responsePoor response when associated with Escherichia coli infection
May help in atypical hemolytic uremic syndrome
SequelaeApproximately 80% of patients showing complete response without sequelaePermanent renal damage in 30% (rate higher in atypical hemolytic uremic syndrome)