Relation of antivimentin antibodies to anticardiolipin antibodies in systemic lupus erythematosus

Tests for antivimentin antibodies (AVA) were performed on 50 systemic lupus erythematosus (SLE) and 63 control sera by indirect immunofluorescence and enzyme linked immunosorbent assay (ELISA). The prevalence was significantly raised in SLE (38% and 50% of sera positive for IgM-AVA and IgG-AVA, respectively, by immunofluorescence; 36% and 64% of sera positive for IgM-AVA and IgG-AVA, respectively, by ELISA) in comparison with the control sera. A significant correlation existed between IgM-AVA, on the one hand, and anticardiolipin antibodies (ACA) and anti-single-stranded DNA (ssDNA), on the other. A stepwise principal component analysis demonstrated that IgM-AVA and IgG-AVA accounted for 71% of the total variance in SLE (50 patients x 5 parameters = total variance). Twenty ACA positive serum samples from patients with syphilis were therefore tested for the presence of AVA, but hardly any were found to be positive. IgM-AVA from patients with SLE were inhibited by cardiolipin and absorbed with ssDNA. An association between AVA positivity and arthralgia was also shown in SLE.