Dental amalgam, mercury toxicity, and renal autoimmunity

Chronic exposure to elemental metallic mercury may induce an immunological glomerular disease. Since humans are exposed to mercury vapor (Hg0) from dental amalgam restorations and kidney is an important target organ of mercury vapor and mercury deposition in kidney increases proportionally with the dose, our aim was to test the occurrence of specific antibodies to antiglomerular basement membrane (anti-GBM-IgG) among individuals with adverse effects to mercury from dental amalgam fillings. We selected a group of patients (n=24) with a history of long-term exposure to mercury vapor from mercury-containing amalgam fillings and showing adverse effects that were laboratory confirmed. Enzyme-linked immunosorbent assays (ELISAs) were used to evaluate serum levels of antibodies to anti-GBM-IgG. None of the patients showed evidence of anti-GBM autoimmunity, either in subgroups with strong allergy to mercury or its compounds (i.e., organic mercury) or in those patients who had past thimerosal-containing vaccines coverage (7 of 24). There was no evidence of the presence of circulating anti-GBM antibodies in subjects suffering from adverse events due to long-term exposure to mercury from dental amalgams, even in individuals who presented allergy to mercury.