Detection of IgG anti-Domain I beta2 Glycoprotein I antibodies by chemiluminescence immunoassay in primary antiphospholipid syndrome.
BACKGROUND
IgG anti-Domain I (anti-DI) β2 Glycoprotein I (β2GPI) antibodies are associated to thrombotic risk in antiphospholipid syndrome (APS), but their detection is technically difficult. In this study, a chemiluminescent immunoassay (CLIA) was used to evaluate the clinical significance of IgG anti-DI in a large cohort of patients with primary APS (PAPS).


METHODS
The study population included 88 patients with PAPS, 63 ELISA-negative subjects and 166 controls. IgG anti-DI, IgG anticardiolipin (aCL) and IgG anti-β2GPI antibodies were assayed using CLIA (HemosIL AcuStar®).


RESULTS
The sensitivity and specificity of IgG anti-DI antibodies were comparable to those of IgG aCL and IgG anti-β2GPI antibodies. There was a significant agreement, association and titre correlation between IgG anti-DI and IgG aCL as well as IgG anti-β2GPI antibodies (p<0.001 for all). IgG anti-DI antibody showed lesser prevalence and mean titres in the pregnancy morbidity than in thrombotic and PAPS patients with both involvements (p<0.001). Regarding the conventional aPL antibody profiles, the triple positivity group had higher prevalence and mean titres than single and double positivity ones (p<0.001).


CONCLUSIONS
This study provides further evidence that anti-DI antibodies can be considered a promising biomarker for risk assessment particularly in patients having vascular thrombosis and triple conventional aPL positivity.
Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy. Electronic address: lauro.meneghel@studenti.unipd.it.
Lauro
L
Meneghel
Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Amelia
A
Ruffatti
Chair of Internal Medicine, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Sabrina
S
Gavasso
Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Marta
M
Tonello
Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Elena
E
Mattia
Chair of Internal Medicine, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Luca
L
Spiezia
Chair of Internal Medicine, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Daniela
D
Tormene
Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Ariela
A
Hoxha
Chair of Cardiovascular Pathology, Department of Cardiological, Thoracic and Vascular Sciences, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Marny
M
Fedrigo
Chair of Internal Medicine, Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy.
Paolo
P
Simioni
D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood*; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000097:blood*; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D017434:Protein Structure, Tertiary; D012680:Sensitivity and Specificity; D013927:Thrombosis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D053482:beta 2-Glycoprotein I / Q000037:antagonists & inhibitors / Q000097:blood / Q000276:immunology
D017153:Antibodies, Anticardiolipin; D007074:Immunoglobulin G; D053482:beta 2-Glycoprotein I
Anti-Domain I antibodies; Anti-β2 Glycoprotein I antibodies; Anticardiolipin antibodies; Antiphospholipid syndrome; Chemiluminescence immunoassay