title: A unique antiphospholipid assay recognizing phospholipid mixture compared with criteria antiphospholipid immunoassays in lupus patients.
abstract: Background While essential for the classification of antiphospholipid syndrome (APS), anticardiolipin (aCL) assays lack specificity and anti-β2glycoproteinI (anti-β2GPI) assays lack sensitivity in this regard. Our aim was to perform a comparative analysis of the APhL ELISA assay (IgG/IgM) and criteria antiphospholipid (aPL) immunoassays in identifying APS-related clinical manifestations in a large group of patients with systemic lupus erythematosus (SLE). Methods Serum samples from 1178 patients from the Hopkins ( n = 543), LUMINA ( n = 588) and Jamaican SLE cohorts ( n = 47) were examined for IgG/IgM positivity in aCL (in-house), anti-β2GPI (two commercial kits) and APhL (Louisville APL) ELISA assays. Correlation of assay positivity with clinical manifestations and sensitivity, specificity, positive and negative predictive values and likelihood ratios were evaluated. A case series analysis was also performed in patients for whom there was isolated positivity in the specific aPL assays. Results The prevalence of aCL positivity was 34.9%, anti-β2GPI kit A was 22.6%, APhL was 11.5% and anti-β2GPI kit B was 7.6% in the study population. Anti-β2GPI kit B, aCL and APhL assays were correlated with venous thrombosis, while only APhL was significantly correlated with arterial thrombosis and consistently correlated with pregnancy-related morbidity. No significant correlations were noted for anti-β2GPI kit A. Sensitivity was greatest for aCL assays followed by anti-β2GPI kit A, APhL and anti-β2GPI kit B, while specificity was greatest and equal for anti-β2GPI kit B and APhL assays. Conclusions Overall, APhL antibodies, especially IgG, represent a promising biomarker for the classification of APS patients in the context of autoimmunity and in risk assessment with regards to pregnancy morbidity and thrombotic manifestations.
authors.affiliation: 1 University of Texas Southwestern Medical Center, Texas, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: 2 University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: R
authors.initials: R
authors.lastname: Willis
authors.affiliation: 2 University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: E
authors.initials: E
authors.lastname: Papalardo
authors.affiliation: 3 John Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: M
authors.initials: M
authors.lastname: Petri
authors.affiliation: 4 University of the West Indies, Mona Campus, Kingston, Jamaica.
authors.forename: E N
authors.initials: EN
authors.lastname: Harris
authors.affiliation: 2 University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: A
authors.initials: A
authors.lastname: Schleh
authors.affiliation: 4 University of the West Indies, Mona Campus, Kingston, Jamaica.
authors.forename: K
authors.initials: K
authors.lastname: DeCeulaer
authors.affiliation: 4 University of the West Indies, Mona Campus, Kingston, Jamaica.
authors.forename: M
authors.initials: M
authors.lastname: Smikle
authors.affiliation: 5 Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico.
authors.forename: L M
authors.initials: LM
authors.lastname: Vilá
authors.affiliation: 6 University of Texas School of Medicine at Houston, Texas, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Reveille
authors.affiliation: 7 University of Alabama at Birmingham, Alabama, USA.
authors.forename: G S
authors.initials: GS
authors.lastname: Alarcón
authors.affiliation: 2 University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: E B
authors.initials: EB
authors.lastname: Gonzalez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016736:Antiphospholipid Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult; D053482:beta 2-Glycoprotein I / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D053482:beta 2-Glycoprotein I
keywords: Anticardiolipin antibodies; antiphospholipid syndrome; classification; pregnancy morbidity; thrombosis