Veripath Test Directory

Description The panel includes whole blood platelet aggregation in response to various concentrations of Ristocetin, including standard and the lowest concentration. The Ristocetin response curve aids in diagnosing von Willebrand disease type 2B, in which there is a rare "gain of function" form of von Willebrand disease that results in von Willebrand factor avidly binding platelets. As a result platelet counts are usually reduced in patients with von Willebrand disease type 2B.
Specimen Requirements 
Container Light blue (3.2% sodium citrate) and 1 purple (EDTA) collection tubes
Specimen Type Blood
Preferred Collection Volume 3mL Sodium citrate and 4mL EDTA
Minimum Collection Volume Adult: 2mL (Sodium Citrate and 2mL EDTA), Neonates: 2mL (Sodium citrate and 2mL EDTA)
Collection Instructions When drawing specimens for coagulation testing, always draw a "pilot" tube (7-10ml plain red top tube), completely filled. This removes tissue fluid contamination. Samples should be obtained from peripheral vein whenever possible. If drawn from indwelling catheter, the line should be flushed with 15mL of saline. After irrigation, a "pilot" tube should be drawn and discarded.
Specimen Handling In-house patients, transport specimens by hand at room temperature. Specimen must not be transported by automatic tube station.
Outside clients, follow collection instructions and the steps below:
1. Specimen must remain at room temperature.
2. Specimen must arrive within 1 hour after collection.
Rejection Criteria Refrigerated, frozen, or centrifuged specimens, >4 hours old, clotted.
Methodology Aggregometry.
Reference Range See interpretive report.
CPT Code(s) 85576 X 3, 85390
Department Hemostasis/Coagulation
Contact Information Hemostasis Lab; 214-633-4959 Customer Service: 214-633-0400, Toll Free 1-877-887-8136.
Turn Around Time1-3 days
Performed Monday - Friday 7am-5pm
Performed by Hemostasis Lab
Notes 1. Platelet count must be greater than or equal to 100,000.
Updated/Reviewed 07/25/2016