Objective: To determine the prevalence and clinical significance of anti-pyruvate dehydrogenase complex (anti-PDC) antibodies in systemic sclerosis (SSc).
Methods: Serum samples from patients with limited cutaneous SSc (n = 81) or diffuse cutaneous SSc (n = 63) were examined for anti-PDC antibodies by enzyme-linked immunosorbent assay (ELISA) and immunoblotting.
Results: IgG- and/or IgM-isotype anti-PDC antibodies were demonstrated by ELISA in 26 of 144 patients with SSc (18%). By immunoblotting, 19 patients had IgG anti-PDC antibodies. Among these patients with IgG anti-PDC antibodies, antibody to the E1 alpha subunit was significantly associated with the presence of laboratory abnormalities typical of primary biliary cirrhosis (PBC).
Conclusion: Antibody to the E1 alpha subunit of PDC may be a serologic indicator for the development of PBC in patients with SSc.