“New” Antigenic Targets and Methodological Approaches for Refining Laboratory Diagnosis of Antiphospholipid Syndrome

Table 2

Different antibody specificities in APS.

Autoantibody	Clinical associations	Prevalence	References
Anti-CL/β2-GPI	IgG isotype related to thrombotic events and mainly associate with cerebrovascular accidents and myocardial infarction; IgG titers correlate with brain thrombosis	80–90%	[10, 117]
Anti-β2-GPI	May inhibit protein C and annexin V anticoagulant activity and boost platelets adhesion and may play a role in development of thromboembolic phenomena	60–90%	[10, 118]
Anti-β2-GPI-DI	Associate with thrombosis and obstetric manifestations (more than antibodies directed to other domains)	27–85%	[31–33, 38, 107]
IgA anti-β2-GPI	May be related to miscarriages, thrombocytopenia, livedo reticularis, pulmonary hypertension, and seizure; present in association with SLE	20–25%	[40–42, 107, 119]
Anti-protein S/protein C	Associate with a severe thrombotic phenotype	14%/49%	[14]
Anti-PT/PS	Strongly associate with thrombosis and pregnancy complications	50–90%	[11, 49, 63]
Anti-vimentin/CL	May be related to recurrent thrombosis and pregnancy morbidity	88–92.5%	[12, 50]
Anti-AnnA5	Clinical correlation with pregnancy-related morbidity is still controversial	30.4%	[41, 120]
Anti-AnnA2	Alter profibrinolytic activity and correlate with thrombotic events	25.0%	[58]
Anti-PE	May affect protein C pathway and bind coagulation factor XI, may correlate with thrombotic events, and may be present in patients with unexplained thrombosis or early fetal loss	73–95%	[69–72]
Anti-LBPA	Associate with aCL, anti-β2-GPI, and LA and do not provide yet a real advantage for diagnosis and/or identification of different clinical subsets	67%	[73–76]

aPL: anti-phospholipid antibodies; anti-CL: anti-cardiolipin antibodies; anti-β2-GPI: anti-beta2-glycoprotein I antibodies; anti-β2-GPI-DI: anti-beta2-glycoprotein I antibodies domain I antibodies; anti-PT/PS: anti-prothrombin/phosphatidylserine antibodies; anti-vimentin/CL: anti-vimentin/cardiolipin antibodies; anti-AnnA5: anti-annexin A5 antibodies; anti-AnnA2: anti-annexin A2 antibodies; anti-PE: anti-phosphatidylethanolamine antibodies, anti-LBPA: anti-lyso-bis-phosphatidic acid antibodies; SLE: systemic lupus erythematosus.