ISSN 2997-1036
International Journal of Hematology | Vol. 6, No. 5, May 2015 | pp. 33–40
DOI: 10.46882/2015/IJH/000065
Original Article
Title: Screening for lupus anticoagulant using a simplified kaolin clotting time mixing assay in patients with unexplained arterial thrombosis
Names of Authors: Y. Z. Ibrahim¹, A. B. Okafor², C. D. Danjuma³
Authors’ Affiliations: ¹Department of Haematology, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria; ²Department of Pathology, University of Ibadan, Ibadan, Nigeria; ³Department of Haematology, University of Maiduguri, Maiduguri, Nigeria
Abstract: Lupus anticoagulant is an important acquired thrombophilic marker linked to arterial strokes and peripheral vascular occlusions. This study evaluated the diagnostic accuracy of a simplified kaolin clotting time (KCT) mixing assay for identifying lupus anticoagulant in 64 adult patients presenting with unexplained, unprovoked arterial thrombosis. Standardized 1:1 and 4:1 mixtures of patient plasma with normal pooled plasma were performed without automated phospholipid reagents, and results were compared with reference diluted Russell’s viper venom time guidelines. Lupus anticoagulant was confirmed in 21.8% (14 of 64) of the patients using reference indexes. The simplified kaolin clotting time mixing protocol demonstrated a sensitivity of 85.7% and a specificity of 88.0% for identifying lupus anticoagulant presence. Kaolin clotting time prolongation indices correlated with the severity of thrombotic recurrence rates (r = 0.42, P < 0.05). While less sensitive than Russell's venom test for heparin-containing matrices, the simplified kaolin clotting method provides an inexpensive, reproducible diagnostic alternative for baseline thrombophilia screening in resource-limited settings.
Keywords: Lupus anticoagulant, kaolin clotting time, mixing studies, arterial thrombosis, antiphospholipid antibodies
Manuscript Timeline: Received: February 12, 2015; Revised: March 20, 2015; Accepted: April 05, 2015; Published: May 15, 2015