H. Ihn et al., Characterization of autoantibodies to endothelial cells in systemic sclerosis (SSc): association with pulmonary fibrosis, CLIN EXP IM, 119(1), 2000, pp. 203-209
To determine the prevalence and the characterization of antibodies to endot
helial cells in patients with SSc, serum samples from 80 patients with SSc,
20 patients with systemic lupus erythematosus (SLE), and 20 healthy contro
l subjects were examined by ELISA using cultured human umbilical vein endot
helial cells (HUVEC), indirect immunofluorescence analysis (IIF), and immun
oblotting using cytoplasmic extract of HUVEC. IgG and/or IgM isotype anti-e
ndothelial cell antibodies (AECA) were demonstrated by ELISA in 43 of 80 pa
tients with SSc (54%), in 15 of 20 patients with SLE (75%), and in none of
20 healthy control subjects. Immunofluorescence analysis on HUVEC substrate
showed homogeneous cytoplasmic staining. Immunoblotting demonstrated that
these patients had antibodies directed to one or several antigens of approx
imately 60, 90, 110 and 140 kD, and the most common responses were to the 9
0-kD antigen. By the immunofluorescence method using HUVEC, affinity-purifi
ed anti-90-kD antibodies showed identical cytoplasmic staining to that prod
uced by sera positive for AECA. Furthermore, AECA were closely correlated w
ith pulmonary fibrosis in patients with SSc. These findings suggest that pa
tients with SSc have abnormal antibodies to endothelial cell antigens, and
support the hypothesis that endothelial dysfunction is involved in the deve
lopment of this disease.