Objective: To determine the prevalence of IgG antiendothelial cell antibodies (AECA) in patients with scleroderma (systemic sclerosis, SSc) and to correlate it with clinical spectrum and autoantibody profile.
Methods: Seventy-six patients with SSc and 50 matched healthy controls were studied. Immunological variables were antinuclear antibody (ANA), rheumatoid factor (RF), and Scl-70. IgG-AECA was measured by cellular ELISA.
Results: The prevalence of IgG-AECA was 27.6% in patients with SSc compared to 6% in controls (p < 0.01). Forty percent of patients with diffuse disease had this antibody, versus 13.5% of those with limited cutaneous involvement (p < 0.05). Patients with AECA had significantly higher incidence of digital infarcts and gangrene (p < 0.01) and pulmonary arterial hypertension (p < 0.001) than those without. In the AECA positive group, mean IgG-AECA levels (measured by absorbance values) were significantly higher in patients with digital infarcts (0.91+/-0.31 vs 0.60+/-0.05; p < 0.01) and pulmonary arterial hypertension (1.14+/-0.37 vs 0.68+/-0.13; p < 0.001) compared to those without these features.
Conclusion: IgG-AECA appears to be an important marker for disease severity in scleroderma.