Table 3.

Differentiating features between the three types of TMA.

Laboratory parameter	TTP	STEC-HUS	aHUS
Anemia	+	+	+
Thrombocytopenia	+	+	+
Schistocytes	+	+	+
Elevated creatinine	+/−	+	+
Activity of ADAMTS13	<10%	>10%	>10%
Shiga toxin	–	+	–
Complement level	Normal	Normal	Low/Normal

+: positive; −: negative.

TMA: thrombotic microangiopathy; TTP: thrombotic thrombocytopenic purpura; STEC-HUS: Shiga toxin-related hemolytic uremic syndrome; aHUS: atypical hemolytic uremic syndrome.