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NASCOLA News - Bulletin Item
  

Posted: Wednesday, January 19, 2011

New Products from r2 Diagnostics

 

r2 Diagnostics has announced the introduction of new venom screen and confirm reagents for detection of lupus anticoagulants.

 

LupoTek DetecTin VL and CorrecTin VL test kits are qualitative tests intended to aid in the detection of lupus anticoagulants (LA) in citrated plasma.  LupoTek DetecTin VL and LupoTek CorrecTin VL use Vipera lebetina venom (VLV) rather than Vipera russelli (Russell’s Viper) venom (RVV). Using VLV is more eco-friendly than using RVV, as the VL viper is less endangered than the VR viper.

 

Vipera lebetina venom (VLV), like Russell's viper venom (RVV), will directly activate Factor X without requiring Factor VII. The activated Factor X in conjunction with Factors V, II, calcium ions and phospholipid will generate thrombin which converts fibrinogen to fibrin, producing a clot in the test system.

 

LupoTek DetecTin VL, the low phospholipid reagent, is designed as the screening reagent to detect a prolongation of the clotting time. LupoTek CorrecTin VL is the high phospholipid reagent that neutralizes the LA and corrects the clotting time to normal, confirming the presence of a Lupus Anticoagulant.

 

LupoTek DetecTin VL and CorrecTin VL demonstrated sensitivity of 100% and specificity of 100% with a normalized ratio of 1.30 in a 122 patient cutoff study.

 This reagent combination also demonstrated 98% positive agreement, 96% negative agreement, and 97% overall agreement with dRVV reagents in a 155 patient, multisite study.

 

 

LupoTek KCT - Kaolin Clotting Time - is also intended to assist in the detection of lupus anticoagulants in citrated plasma, and recently gained FDA 510(K) clearance. The LupoTek KCT is a modified activated partial thromboplastin time (APTT) reagent without any added phospholipids.  The KCT is exquisitely sensitive to LA, and has been reported as the most sensitive test for LA. (Lesperance B, David M, Rauch J, Infante-Rivard C, Rivard GE: Relative sensitivity of different tests in the detection of low titer lupus anticoagulants. Thromb Haemost 1988 Oct 31;60(2):217-219)

 

In a study of 180 patients, the KCT demonstrated 100% agreement in previously diagnosed LA patients and  59% agreement in those patients who were determined to have no evidence of  LA as compared to an APTT using a LA-sensitive reagent,  which demonstrated  87% agreement in the LA- positive group and 15% agreement in the LA-negative group.

 

The LupoTek KCT is suitable for use on most semiautomated and automated coagulation analyzers.