Figure 2.

Relationship between anti‐native β₂glycoprotein I (β₂GPI) and anti‐glucose‐modified GPI (G‐β₂GPI) antibodies in primary anti‐phospholipid antibody syndrome (PAPS) and APS associated with systemic lupus erythematosus (SLE) (SAPS) patients. Sera from patients with PAPS and SAPS were analysed by enzyme‐linked immunosorbent assay (ELISA) for the detection of anti‐native‐β₂GPI and anti‐G‐β₂GPI immunoglobulin (Ig)G. The arrows indicate the sera from patients (PAPS or SAPS) positive for anti‐G‐β₂GPI but negative for anti‐native‐β₂GPI. The horizontal line shows the cut‐off level calculated as mean optical density (OD) value in control healthy subjects’ sera ± 3 standard deviations (s.d.).