Performance of Platelin LS and dilute Russell's viper venom for the screening of lupus anticoagulant in patients with venous thromboembolism.
Lupus anticoagulant is associated with thrombosis and pregnancy morbidity, and its detection is of major clinical importance. The nature and concentration of phospholipids strongly influence the sensitivity of activated partial thromboplastin time (aPTT) reagents to lupus anticoagulant. We investigated the ability of Platelin LS, an aPTT reagent, to screen lupus anticoagulant among 94 patients with venous thromboembolism by comparing its performance with the dilute Russell viper venom time (dRVVT). Twenty-four patients had an abnormal aPTT and dRVVT, whereas 37 only had a prolonged dRVVT. In users of oral anticoagulants (n = 56), the dRVVT prolonged more frequently than the aPTT (98.2 vs 39.3%, P < 0.0001). After the mixing study, seven patients maintained abnormal aPTT and dRVVT ratios, five of whom had prolonged mixture with both tests. The agreement in the mixing study between aPTT and dRVVT was substantial (kappa = 0.78, 95% confidence interval = 0.48-1.00). Except for one patient, the aPTT screened all cases that demonstrated phospholipid dependency of their inhibitor during the confirmatory procedure with the dRVVT. In conclusion, the aPTT using Platelin LS was highly associated with the presence of lupus anticoagulant detected by the dRVVT among patients with venous thromboembolism, and could be reliably employed as a screening assay for lupus anticoagulant.
Morelli
Vânia Maris
VM
Division of Hematology and Transfusion Medicine, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil. vmorelli@hemato.epm.br
Rodrigues
Celso Arrais
CA
Noguti
Maria Aparecida Eiko
MA
Matos
Marinez Farana
MF
da Silveira
Raniely Casimiro
RC
Ribeiro
Aline Amorim Martinez
AA
Lourenço
Dayse Maria
DM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time / Q000592:standards; D011517:Prothrombin Time / Q000592:standards; D011933:Reagent Kits, Diagnostic / Q000592:standards; D054556:Venous Thromboembolism / Q000097:blood*; D014757:Viper Venoms / Q000737:chemistry
D016682:Lupus Coagulation Inhibitor; D011933:Reagent Kits, Diagnostic; D014757:Viper Venoms