Antibodies to beta 2-glycoprotein I and clinical manifestations in patients with systemic lupus erythematosus.
OBJECTIVE
To investigate whether anticardiolipin antibodies (aCL) in patients with systemic lupus erythematosus (SLE) bind to beta 2-glycoprotein I (beta 2GPI), and to search for a relationship between the presence of IgG and/or IgM anti-beta 2GPI antibody and clinical manifestations in SLE patients.


METHODS
IgG and IgM anti-beta 2GPI in 308 Japanese SLE patients were measured using phospholipid-independent enzyme immunoassays. Relationships to clinical histories and to various laboratory data were examined.


RESULTS
The values of anti-beta 2GPI and aCL, as measured by conventional enzyme immunoassay, showed a strong correlation, but the anti-beta 2GPI assay was more useful in distinguishing beta 2GPI-dependent aCL from beta 2GPI-independent aCL. The presence of IgG anti-beta 2GPI was associated with an increased frequency of a history of thrombosis. Comparisons of various laboratory data suggested that the titer of anti-beta 2GPI may fluctuate with disease activity.


CONCLUSIONS
The results suggest that pathogenic aCL is directed against structurally altered beta 2GPI and that enzyme immunoassay for anti-beta 2GPI may prove useful in evaluating the risk of thrombosis and monitoring the clinical course in patients with SLE.
Tsutsumi
A
A
Department of Medicine II, Hokkaido University School of Medicine, Sapporo, Japan.
Matsuura
E
E
Ichikawa
K
K
Fujisaku
A
A
Mukai
M
M
Kobayashi
S
S
Koike
T
T
D000026:Abortion, Habitual / Q000276:immunology; D000906:Antibodies / Q000097:blood*; D017153:Antibodies, Anticardiolipin / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D016682:Lupus Coagulation Inhibitor / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000150:complications / Q000276:immunology*; D011247:Pregnancy; D012189:Retrospective Studies; D013588:Syphilis Serodiagnosis; D013927:Thrombosis / Q000276:immunology*; D053482:beta 2-Glycoprotein I
D000906:Antibodies; D017153:Antibodies, Anticardiolipin; D006023:Glycoproteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor; D053482:beta 2-Glycoprotein I