Table 2.

Comparison between EDTA-associated and vWD type 2B-associated platelet clumping.

Distinguishable features	EDTA-associated	vWD type 2B-associated
Clumping	Due to in vitro process	Due to in vivo process
Bleeding tendency	None	Characteristic
MPV	Normal	Increased due to left shift
Further work-up to confirm platelet clumping	Testing citrate or heparin anticoagulated sample, others	(1) Platelet aggregation studies using low ristocetin concentration (2) Molecular testing (Exon 28 sequencing)