Figure 1

Anti-endothelial-cell antibody serum levels in systemic lupus erythematosus (SLE) patients, systemic sclerosis (SSc) patients, and normal healthy donors. Box–whisker plot of anti-endothelial-cell antibodies (AECA) IgG binding index (BI) in SLE patients with psychosis and mood disorders (group A, n = 17), in SLE patients without psychiatric involvement other than anxiety (group B, n = 34), in SSc patients (n = 34), and in 66 normal healthy donors. AECA were expressed as a BI, equal to 100 × (S-A)/(B-A), where S is the optical density (OD) of the sample tested, A is the OD of a negative control, and B that of a positive reference serum. AECA were considered positive when the BI was higher than the cutoff value (mean + 2 SD for 66 healthy controls), corresponding to 50% of a positive reference serum from an SLE patient. Median, quartiles, range, and possibly extreme values are indicated. The broken line represents the cutoff. †, group A vs Group B, P = 0.03; ‡, group A vs SSc, P = 0.0002; *, group A vs normal healthy donors, P < 0.0001; ¶ group B vs SSc, P = 0.01; Φ, group B vs normal healthy donors, P < 0.0001; §, SSc vs normal healthy donors, P = 0.002.