High Titers of Antibodies to Single-stranded DNA in Linear Scleroderma

Seven patients with severe linear scleroderma were initially found to have antibodies to double-stranded DNA (dsDNA) in higher titers, using the Farr technique. These patients, however, lacked the systemic involvement normally accompanying such antibodies. A detailed investigation of their sera using Crithidia luciliae assay and single-stranded DNA (ssDNA) labeled with iodine 131 disclosed high titers of antibodies to ssDNA and absent dsDNA antibodies. The ssDNA antibody titer was considerably higher than the mean for unselected patients with systemic lupus erythematosus. It is possible that these antibodies define a subgroup of patients with linear scleroderma who have more severe and extensive involvement of skin and underlying tissues.