Ristocetin-induced platelet aggregation

Specimen:

5-10 mL blood in citrate (usually after prior arrangement with the laboratory).

Method:

See Platelet aggregometry.

Reference Interval:

Consult laboratory.

Application:

Investigation of patients with a history suggestive of an inherited bleeding disorder.

Interpretation:

An insensitive test for reduced levels of von Willebrand factor (classical von Willebrand disease). However, the test is useful for the detection of variant von Willebrand disease (especially Type 2 VWD and pseudo [platelet-type] VWD).

Ristocetin-induced platelet aggregation (RIPA) is absent in Bernard-Soulier syndrome, a rare autosomal recessive bleeding disorder. This is due to the absence of the receptor for ristocetin on the platelet surface.

Reference:

Favaloro EJ. Clin Haematol 2001; 14: 299-319.

Rodeghiero F et al. Thromb Haemost 1990; 64: 349-352.