Jerome Tonog*, Gabriella Iacovetti**

* Hawthorne-Effect Inc., Lafayette CA

** Sandstone Diagnostics, Inc., Pleasanton CA

Abstract

Background: Ensuring high quality specimens is a critical challenge in performing at-home clinical trial patient follow-up visits in which blood draws are conducted outside of a conventional draw center or laboratory. Our mobile healthcare professionals’ (HEROs) existing options for prompt plasma stabilization have been limited to either transporting plasma separation tubes (PSTs) to a nearby laboratory, or using a portable, fixed angle centrifuge either in the patient’s home or the phlebotomist’s vehicle. Such limitations hinder the laboratory acceptance rate for assays susceptible to sample degradation (e.g. high hemolysis), lead to repeat patient visits for redraws, reduce the HERO’s daily visit throughput, and constrain our geographic footprint for providing mobile patient follow-up services.

The Torq™ Zero Delay Centrifuge System from Sandstone Diagnostics is a lightweight, hand-portable device for immediately separating and stabilizing plasma at the point of collection. The Torq system is comprised of the ZDrive™ – a 4” diameter, battery-powered centrifuge – and ZDiscs™ – evacuated and anticoagulated cartridges designed to collect whole blood and isolate liquid plasma from cells following a brief (4 minute) spin upon collection.

The objective of this study was to evaluate the Torq System’s usability by HEROs performing cardiology patient follow-up visits in ongoing trials measuring BNP and proBNP levels – two plasma-based analytes susceptible to whole blood degradation. A secondary objective was to assess difference in the centralized laboratory sample acceptance rate between Torq samples and PSTs.

Methods: Torq ZDrives and 4mL EDTA ZDiscs were deployed to n= 7 HEROs, who used the device with n=21 patients participating in the clinical trials. HERO training included written instructions and a 5-minute online training video. During the visits, ZDiscs were loaded directly after draw via syringe and immediately spun in the ZDrive. Plasma was then extracted from the ZDisc by pipette and transferred to plasma transport tube for shipment to the centralized laboratory. HEROs were also asked to complete a brief usability survey assessing the system materials/supplies, training, and ease-of-use for each process step.

Results: 7 out of 7 (100%) HEROs agreed that the Torq System performed as expected, and 7 out of 7 (100%) reported they liked using the Torq System. In addition, 21 out of 21 (100%) samples collected and processed with the Torq System were accepted by the laboratory.

Conclusions:  The Torq System provides a rapid, effective, and easy-to-use method for collecting and stabilizing plasma samples in at-home clinical trial at-home patient follow-up visits. Torq has been well-received by our mobile healthcare professionals, decreases our need for repeat patient visits, reduces our personnel’s equipment burden, and has dramatically improved the laboratory specimen acceptance rate in pilot evaluation.