Antiendothelial cell antibodies in scleroderma correlate with severe digital ischemia and pulmonary arterial hypertension.

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. 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. 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. IgG-AECA appears to be an important marker for disease severity in scleroderma.