title: Abnormal optical waveform profiles in coagulation assays from patients with antiphospholipid antibodies.
abstract: Transmittance waveforms are the optical data generated during clot formation on photo-optical coagulation analyzers and are used to define specific events of the clotting reactions. Thus, a prothrombin time (PT) or an activated partial thromboplastin time (aPTT) can be divided into a pre-coagulation phase, a coagulation phase, and a post-coagulation phase. These phases are further characterized by parameters that define the timing, the rate, the 'slope', and the magnitude of the signal change of the reactions. We investigated the transmittance waveform parameters obtained during PT and aPTT of patients with antiphospholipid antibodies (APLA) who were or were not taking warfarin, normal donors, and non-APLA patients taking warfarin. An abnormal deflection in the pre-coagulation phase of the PT (called slope 1) was observed in 61.5% of the patients with APLA, in contrast to 5.9% of non-APLA patients taking warfarin (P= 0.0015). The presence of an abnormal PT slope 1 was reagent specific and was inversely correlated with the anticardiolipin antibody immunoglobulin G (IgG) level, which suggests that the abnormal PT slope 1 may reflect interactions between patient IgG and components from the thromboplastin, possibly phospholipids. The abnormal PT slope 1 values may be of diagnostic utility in the identification of patients with antiphospholipid syndromes.
authors: Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors: Z
authors: Z
authors: Su
authors: P J
authors: PJ
authors: Braun
authors: K F
authors: KF
authors: Klemp
authors: K R
authors: KR
authors: Baker
authors: E H
authors: EH
authors: Thames
authors: T L
authors: TL
authors: Ortel
mesh_terms: D017153:Antibodies, Anticardiolipin / Q000097:blood; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy; D001780:Blood Coagulation Tests / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D016022:Case-Control Studies; D006801:Humans; D007202:Indicators and Reagents; D007700:Kinetics; D014859:Warfarin / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D000925:Anticoagulants; D007202:Indicators and Reagents; D014859:Warfarin