Ristocetin-induced platelet aggregation (RIPA) and RIPA mixing studies

Juan Pablo Frontroth, Emmanuel J Favaloro

Research output: Book chapter/Published conference paperChapter (peer-reviewed)

39 Citations (Scopus)


Ristocetin-induced platelet aggregation (RIPA) is used as an in vitro test to determine the presence and integrity of the platelet glycoprotein (GP) Ibα-V-IX complex and von Willebrand factor (VWF) interaction and is usually performed using platelet-rich plasma (PRP). Impairment in the response of VWF/GPIbα-V-IX is measured with reference to several established concentrations of ristocetin and may indicate defects in VWF or in GPIbα-V-IX function. RIPA-based mixing studies comprise an additional approach to testing this interaction to help define whether defects identified by RIPA lie in VWF or in GPIbα-V-IX. For example, the correction of an abnormal RIPA trace after mixing PRP with normal plasma and rechallenging with ristocetin at 1.0 mg/mL suggests VWF function/quantity defect. RIPA mixing studies at lower doses of ristocetin (0.5 mg/mL) are recommended for discrimination of von Willebrand disease type 2B (VWD2B) from the rarer platelet-type (PT) VWD and for the phenotypic laboratory diagnosis of VWD2B. The demonstration of a plasma factor capable of inducing platelet aggregation at such low doses of ristocetin represents the hallmark for the phenotypic laboratory diagnosis of VWD2B. Moreover, since both VWD2B and PT-VWD may present with thrombocytopenia, RIPA-based mixing studies are also useful in thrombocytopenic patients in whom RIPA testing is difficult to assess.

Original languageEnglish
Title of host publicationHemostasis and thrombosis
Subtitle of host publicationMethods and protocols
EditorsEmmanuel J. Favaloro , Giuseppe Lippi
Place of PublicationNew York
PublisherHumana Press
Number of pages22
ISBN (Electronic)9781493971961
ISBN (Print)9781493971947
Publication statusPublished - 14 Aug 2017

Publication series

NameMethods in Molecular Biology
PublisherHumana Press
ISSN (Print)1064-3745


Dive into the research topics of 'Ristocetin-induced platelet aggregation (RIPA) and RIPA mixing studies'. Together they form a unique fingerprint.

Cite this