High prevalence of antithyroid antibodies in anti-glomerular basement membrane antibody-mediated disease

Anti-glomerular basement membrane antibody (anti-GBM Ab)-mediated disease a nd autoimmune thyroiditis are characterized by the presence of organ-specif ic antibodies. The diagnosis of autoimmune thyroiditis is usually based on the presence of serum antithyroid antibodies. Few studies have adressed the relationship between anti GBM-Ab mediated disease and autoimmune thyroid p athology. Given that this disorder is often asymptomatic, associations of t he two pathologies may be under-diagnosed. This study investigated the prev alence of serum antithyroid antibodies (antithyroglobuin (anti-TG) and anti -thyroid peroxidase (anti-TPO)) in patients with anti-GEM Ab-mediated disea se. Antithyroid antibodies presence was investigated in sera from 35 patien ts in whom anti-GEM Ah-mediated disease had been diagnosed. Anti-glomerular basement membrane antibodies and anti-thyroid antibodies (anti-TG and anti -TPO) were assayed using an enzyme-linked immunosorbent assay. Forty-five p ercent of patients with anti-GEM Ab-mediated disease (16/35) had positive a ntithyroid antibody titers. Eighteen percent (3/16) suffered from subclinic al hypothyroidism. In conclusion, the high prevalence of antithyroid antibo dies in these patients suggests a possible pathogenic link between autoimmu ne thyroiditis and anti GBM Ab-mediated disease.