Comparison of the Level of DNA-Hydrolyzing Polyclonal IgG Antibodies in Sera of Patients with Hashimoto's Thyroiditis and Nontoxic Nodal Goiter.

Various catalytically active IgG antibodies or abzymes have been recently detected in the sera of patients with several autoimmune pathologies, where their presence is most probably associated with autoimmunization. Here we show for the first time that IgG from peripheral blood of patients with Hashimoto's thyroiditis and nontoxic nodal goiter possesses DNase activity. The properties of the DNase IgGs distinguished them from other known human DNases.

Catalytic diversity of polyclonal RNA-hydrolyzing IgG antibodies from the sera of patients with systemic lupus erythematosus.

Various catalytic antibodies or abzymes have been detected in the sera of patients with several autoimmune pathologies, and recently we have shown that RNase activity is associated with IgGs and IgMs from the sera of patients with systemic lupus erythematosus (SLE) but not with those from the sera of normal humans. Here we present for the first time convincing evidence showing that highly purified SLE IgG, its F(ab) fragments and separated L-chains catalyze RNA hydrolysis. These IgGs hydrolyze RNA about one to three orders of magnitude faster than DNA.