Reactivity profiles of autoantibodies to different phospholipids and the phospholipid-binding protein beta2-glycoprotein I in patients with clinical symptoms related to thromboembolic and/or vasculopathic events with or without connective tissue diseases.
To study the antigenic and epitope specificities of anti-phospholipid Ab in detail, we investigated 177 patients without (62 with APS-related systemic clinical symptoms, 115 with microangiopathies) and 164 patients with connective tissue diseases (CTD). Ab associated with primary APS (pAPS) seem to show a restricted specificity (phospholipid/beta2-GPI-complexes), whereas those in secondary APS (sAPS) react additionaly with pure beta2-GPI. Simultaneously, beta2-GPI-independent Ab were also frequently present in both conditions (50% of all Ab-positive sera). In CTD patients, the reactivity profile "pure beta2-GPI + phospholipid/beta2-GPI-complexes" is significantly associated with clinically manifest sAPS. Comparing cardiolipin and phosphatidylserine as antigenic target, the overall concordance (crossreactivity?) between both assays was lower than expected (52%), being highest in pAPS (87%) and sAPS (65%). Based on these results, a two-step procedure for reliable serological diagnosis of APS could be recommended: Ab-screening using a mix of phospholipids complexed with beta2-GPI (sensitivity > 90% for Ab concentrations above 20 U/ml) followed by an assay allowing the simultaneous detection of all relevant antigenic and epitope specificities.
Jaekel
H P
HP
Institute of Laboratory Diagnostics, Microbiology and Transfusion Medicine, Dietrich Bonhoeffer Clinical Centre, Neubrandenburg, Germany. LAB@dbk-nb.de
Schmid
D
D
Müller
E W
EW
Ziutelis
V
V
Trabandt
A
A
Grobe
N
N
Kaskel-Paul
S
S
Höh
H
H
Bauer
B
B
Sudik
R
R
Baldauf
A
A
Werle
E
E
D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000276:immunology; D017152:Antibodies, Antiphospholipid / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000276:immunology*; D002308:Cardiolipins / Q000276:immunology; D003240:Connective Tissue Diseases / Q000150:complications / Q000276:immunology*; D003429:Cross Reactions; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010718:Phosphatidylserines / Q000276:immunology; D011247:Pregnancy; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013923:Thromboembolism / Q000209:etiology / Q000276:immunology*; D014652:Vascular Diseases / Q000209:etiology / Q000276:immunology*; D053482:beta 2-Glycoprotein I
D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D002308:Cardiolipins; D006023:Glycoproteins; D010718:Phosphatidylserines; D053482:beta 2-Glycoprotein I