- Paper Report
- Open Access
IgA anti-?2-glycoprotein I antibodies
- Carrock Sewell1
© Current Science Ltd 1999
- Published: 3 November 1999
- anti phospholipid antibody syndrome
- ?2-glycoprotein I
The anti phospholipid syndrome (APS) is characterised by clinical manifestations of thromboembolic phenomena, intra-uterine fetal loss and thrombocytopenia. APS is also associated with anti-phospholipid antibodies, which are autoantibodies directed against a modified ?2-glycoprotein I (?2-GPI). The modified structure is a result of interaction with anionic phospholipids. Although IgG, and to some extent IgM anti phospholipid antibodies are recognised as being of diagnostic significance, the role of IgA autoantibodies is not clear. This study examined the role of IgG, IgM and IgA isotype anti-?2-GPI in APS. To evaluate the prevalance of IgG, IgA and IgM anti-?2-GPI antibodies in APS, and to establish the clinical significance of IgA type antibodies compared with other isotypes.
As expected, anti-?2-GPI antibodies were detected at higher titre in patients with APS than normal controls. Subgroup analysis showed that APS patients with high IgG anti-?2-GPI titres were associated with venous thrombosis (P = 0.003), thrombocytopenia (P = 0.01), fetal loss (P = 0.01) or heart valve disease (P < 0.03). High IgM anti-?2-GPI was associated with only thrombocytopenia (P < 0.04) or heart valve disease (P = 0.01). Elevated IgA anti-?2-GPI titres were linked to venous thrombosis (P = 0.007), thrombocytopenia (P < 0.02), or heart valve disease (P < 0.02) (all also associated with other isotypes) and also livido reticularis (P = 0.01) or epilepsy (P = 0.01) (IgA isotype only).
30 patients with symptoms of APS secondary to systemic lupus erythematosus (SLE), three patients with primary APS and 30 normal controls had anti-cardiolipin and anti-?2-GPI antibodies measured by ELISA.