Anticardiolipin and anti-beta2GPI antibodies in a large series of European patients with systemic lupus erythematosus. Prevalence and clinical associations. European Concerted Action on the Immunogenetics of SLE.
OBJECTIVE
To test the prevalences and the clinical associations of anticardiolipin (aCL) and anti-beta2GPI (abeta2GPI) antibodies in a large series of European patients with systemic lupus erythematosus (SLE).


METHODS
574 SLE patients from 7 European countries were tested for aCL and abeta2GPI by ELISA methods.


RESULTS
aCL of IgG, IgM, and IgA isotypes were detected in 22.8%, 14%, and 13.9% of the patients, respectively. IgG and IgM abeta2GPI were detected in 20% of the patients. The presence of aCL was highly associated with the presence of abeta2GPI. Medium-high titer IgG aCL and abeta2GPI were associated with thrombosis, with similar sensitivity, specificity, and positive predictive value. When present at medium-high titer, IgG aCL were associated with thrombocytopenia, IgM aCL with hemolytic anemia, and cerebrovascular accidents. IgA aCL with livedo reticularis and Raynaud's phenomenon.


CONCLUSIONS
aCL, when present at medium-high titer, are as important as abeta2GPI, as a risk factor for thrombosis. Medium-high titer aCL, but not abeta2GPI, are associated with other clinical features of the antiphospholipid syndrome.
Sebastiani
G D
GD
Divisione di Reumatologia, Ospedale San Camillo, Roma Italy.
Galeazzi
M
M
Tincani
A
A
Piette
J C
JC
Font
J
J
Allegri
F
F
Mathieu
A
A
Smolen
J
J
de Ramon Garrido
E
E
Fernandez-Nebro
A
A
Jedryka-Goral
A
A
Papasteriades
C
C
Morozzi
G
G
Bellisai
F
F
De Pitá
O
O
Marcolongo
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D005060:Europe / Q000453:epidemiology; D005260:Female; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007518:Isoantibodies / Q000145:classification; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D016036:Seroepidemiologic Studies; D053482:beta 2-Glycoprotein I
D017153:Antibodies, Anticardiolipin; D006023:Glycoproteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007518:Isoantibodies; D053482:beta 2-Glycoprotein I