Dongmei Yin1,2, Philip G de Groot2, Marisa Ninivaggi2, Katrien M J Devreese3,4, Bas de Laat1,2. 1. Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands. 2. Department of Functional Coagulation, Synapse Research Institute, Maastricht, The Netherlands. 3. Coagulation Laboratory, Department of Laboratory Medicine, Ghent University Hospital, Ghent, Belgium. 4. Department of Diagnostic Sciences, Ghent University, Ghent, Belgium.
Abstract
BACKGROUND: Patients positive for all three types of antiphospholipid antibodies (aPLs; triple positivity) have been identified for having a high risk for thrombotic events. However, the clinical significance of isolated lupus anticoagulant (LAC) positivity is debated. OBJECTIVES: To investigate the clinical relevance of isolated LAC. METHODS: A total of 456 patients were enrolled in this study; 66 antiphospholipid syndrome patients and 390 control patients. The control group consisted of autoimmune patients (n = 91), patients with thrombosis but without aPLs (n = 127), and normal controls (n = 172). LAC, anticardiolipin (anti-CL), and anti-β2 glycoprotein I (anti-β2GPI) immunoglobulin G (IgG) and immunoglobulin M (IgM) were determined according to the International Society on Thrombosis and Haemostasis (ISTH) guidelines. Anti-CL and anti-β2GPI were measured by four different solid-phase platforms to overcome variability between test systems. The noncriteria IgA anti-CL and anti-β2GPI, antidomain I of β2GPI IgG, and antiphosphatidylserine/prothrombin antibodies (anti-PS/PT) IgG and IgM were detected according to the ISTH guidelines for solid-phase assays. RESULTS: In total, 70 patients were positive for LAC, of which 44 were negative for both anti-β2GPI and anti-CL antibodies. We found that isolated LAC proved to be strongly associated with vascular thrombosis (odds ratio [OR]: 7.3; 95% confidence interval [CI]: 3.3-16.1), even better than triple-positive samples (OR: 4.3; 95% CI: 1.6-12.2). The titers of the anti-PS/PT IgG and IgM were significantly higher in triple-positivity samples compared with samples with isolated LAC positivity. The majority of single LAC positives were anti-PS/PT-negative. We observed that LAC positivity was weaker in isolated LAC-positive patients compared with LAC activity in triple-positive patients. CONCLUSION: Isolated LAC was highly associated with thrombosis. The presence of anti-PS/PT antibodies could not explain LAC positivity in isolated LAC. Isolated LAC showed a weaker LAC activity compared with triple-positive patients. Thieme. All rights reserved.
BACKGROUND: Patients positive for all three types of antiphospholipid antibodies (aPLs; triple positivity) have been identified for having a high risk for thrombotic events. However, the clinical significance of isolated lupus anticoagulant (LAC) positivity is debated. OBJECTIVES: To investigate the clinical relevance of isolated LAC. METHODS: A total of 456 patients were enrolled in this study; 66 antiphospholipid syndrome patients and 390 control patients. The control group consisted of autoimmune patients (n = 91), patients with thrombosis but without aPLs (n = 127), and normal controls (n = 172). LAC, anticardiolipin (anti-CL), and anti-β2 glycoprotein I (anti-β2GPI) immunoglobulin G (IgG) and immunoglobulin M (IgM) were determined according to the International Society on Thrombosis and Haemostasis (ISTH) guidelines. Anti-CL and anti-β2GPI were measured by four different solid-phase platforms to overcome variability between test systems. The noncriteria IgA anti-CL and anti-β2GPI, antidomain I of β2GPI IgG, and antiphosphatidylserine/prothrombin antibodies (anti-PS/PT) IgG and IgM were detected according to the ISTH guidelines for solid-phase assays. RESULTS: In total, 70 patients were positive for LAC, of which 44 were negative for both anti-β2GPI and anti-CL antibodies. We found that isolated LAC proved to be strongly associated with vascular thrombosis (odds ratio [OR]: 7.3; 95% confidence interval [CI]: 3.3-16.1), even better than triple-positive samples (OR: 4.3; 95% CI: 1.6-12.2). The titers of the anti-PS/PT IgG and IgM were significantly higher in triple-positivity samples compared with samples with isolated LAC positivity. The majority of single LAC positives were anti-PS/PT-negative. We observed that LAC positivity was weaker in isolated LAC-positive patients compared with LAC activity in triple-positive patients. CONCLUSION: Isolated LAC was highly associated with thrombosis. The presence of anti-PS/PT antibodies could not explain LAC positivity in isolated LAC. Isolated LAC showed a weaker LAC activity compared with triple-positive patients. Thieme. All rights reserved.
Authors: Erivelton de Azevedo Lopes; Gustavo Guimarães Moreira Balbi; Maria G Tektonidou; Vittorio Pengo; Savino Sciascia; Amaia Ugarte; H Michael Belmont; Maria Gerosa; Paul R Fortin; Chary Lopez-Pedrera; Lanlan Ji; Hannah Cohen; Guilherme Ramires de Jesús; D Ware Branch; Cecilia Nalli; Michelle Petri; Esther Rodriguez; Nina Kello; Roberto Ríos-Garcés; Jason S Knight; Tatsuya Atsumi; Rohan Willis; Maria Laura Bertolaccini; Doruk Erkan; Danieli Andrade Journal: Adv Rheumatol Date: 2021-10-28