Indeterminate lupus anticoagulant results: Prevalence and clinical significance.
10.5045/kjh.2011.46.4.239
- Author:
Khaldoun ALKAYED
1
;
Kandice KOTTKE-MARCHANT
Author Information
1. Department of Pediatrics, King Hussein Cancer Center, Amman, Jordan.
- Publication Type:Original Article
- Keywords:
Antiphospholipid antibodies;
Antiphospholipid syndrome;
Indeterminate lupus anticoagulant
- MeSH:
Antibodies, Antiphospholipid;
Antiphospholipid Syndrome;
Autoimmune Diseases;
Cohort Studies;
Follow-Up Studies;
Humans;
Lupus Coagulation Inhibitor;
Male;
Multivariate Analysis;
Myocardial Infarction;
Partial Thromboplastin Time;
Prevalence;
Pulmonary Embolism;
Retrospective Studies;
Stroke;
Thrombosis;
Venous Thrombosis;
Warfarin
- From:Korean Journal of Hematology
2011;46(4):239-243
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Reports of indeterminate lupus anticoagulant (LAC) results are common; however, no published data on their prevalence or clinical significance are available. We investigated the prevalence and clinical characteristics of patients with indeterminate LAC. METHODS: We retrospectively reviewed the clinical and serologic characteristics of 256 unselected patients with LAC results. RESULTS: Indeterminate results were observed in 32.7% of LAC profiles that were least frequent (25.4%) when activated partial thromboplastin time (aPTT) was normal, most frequent (39.8%) when aPTT was elevated, and were observed in 35% of patients taking warfarin. The final indeterminate LAC cohort included 65 patients with a mean follow-up of 18 months. Malignancy and autoimmune disease were present in 29% and 25% of patients, respectively. The most common thrombotic events were deep vein thrombosis (DVT) (28%), cerebral ischemic stroke (14%) and pulmonary embolism (14%). Patients with indeterminate results were more likely to be men, older, and with a history of DVT, superficial thrombosis, or myocardial infarction than patients with negative tests (N=106). Concurrent warfarin therapy was more prevalent in the indeterminate group, but was not statistically significant. In the multivariate analysis, none of the variables showed statistical significance. During follow-up, 10 of 16 patients with indeterminate results showed change in classification upon retesting. CONCLUSION: Patients with indeterminate LAC results were common, and their clinical characteristics differed from those with negative results. There is a need for a prospective study of the clinical history of patients with indeterminate LAC results.
