Chrono-log Whole Blood Lumi-Aggregation Systems improve detection of abnormal platelet function by measuring platelet aggregation and dense granule secretion simultaneously in a physiologic whole blood environment. Efficient and economic, the simplicity and heightened sensitivity of whole blood testing allows clinicians to establish a therapeutic monitoring program.

Rapid and Simple Diagnostic Capability
Patients with histories suggestive of hemorrhagic are often investigated for coagulation defects rather than platelet dysfunction, because optical aggregation studies are time-consuming and ambiguous.

Now, with less than 5mL of blood and in less time than it takes to prepare plasma for tests of coagulation, you can detect platelet dysfunction due to:

	von Willebrand disease
	Secrection Defects
	Storage pool deficiency
	Membrane receptor site defects
	Non-sterodial anti-inflammatories

For detecting vW disease, ristocetin aggregation by the impedance method in whole blood is more reflective of in-vivo conditions than tie-consuming ristocetin co-factor assays in fixed platelets. It is a highly sensitive and time efficient method of screening persons at risk of the disease.

Direct luminescent measurement of ATP secretion in blood provides unequivocal evidence of normal dense granule release and is quantitative measure of platelet activation. In contrast, repetitive dose response optical aggregation tests in platelet rich plasma failed to diagnose 67% of patients with storage pool deficiency and a prolonged bleeding time. Simultaneous measurements of the release reaction provides further insight into the mechanisms of platelet response.

Because impedance aggregometry in whole blood is a more adequate tool for detection of platelet hyperaggregability than the optical method, patients at risk for thromoboembolic complications can be identified. This greater sensitivity results from performing tests in the presence of red cells and leukocytes.
 

Chrono-Log Aggregation Systems

Patients with a previous history of thrombosis show a high prevalence of platelet hyperactivity. Where the goal of therapy is inhibiting platelet aggregation, Chrono-log Whole Blood Aggregometers can routinely identify patients at risk for thromobosis or bleeding and can verify effective treatment.

Aspirin (ASA) is used therapeutically to inhibit thromboxane production of circulating platelets. Monitoring of effective dosage levels of ASA alone, or in combination with dipyridamole, can be easily performed by measuring platelet aggregation with arachidonic acid or with a low collagen concentration (1ug/mL) and the simultaneous measurement of thromboxane-dependent ATP release.

The coronary vasodilator, anti-thrombotic drug, Dipyridamole, significantly inhibits aggregation in whole blood; this inhibition is not seen in platelet-rich plasma. Interaction between platelets and red blood cells plays an important role in the anti-platelet activity of Dipyridamole.

Sensitive Luminescence Technique

A wide variety of luminescent reactions (ATP release, total adenine nucleotides, ionized calcium mobilization, superoxide generation and others) can be measured by the sensitive photomultipler tube int eh Chrono-log Lumi-Aggregation Systems, which provides a voltage output proportional to the luminescence intensity. In addition to detecting Storage Pool and Secretion defects, luminescence is also a rapid and sensitive method for detecting Heparin-Induced Thrombocytopenia (HIT).

  GMI, Inc.
  6511 Bunker Lake Blvd.  
  Ramsey, Minnesota, 55303   USA
  Tel. 763-712-8717          Fax 763-712-8724 
  Send electronic mail to richard@gmi-inc.com