ALLERGIC DISEASE, IMMUNOGLOBULINS, EXPOSURE TO MERCURY AND DENTAL AMALGAM IN SWEDISH ADOLESCENTS

High-dose exposure to inorganic mercury in man can influence the immun e system and in rare cases cause immune-related disease. Some experime ntal animals also react with autoimmunity after low doses of inorganic mercury. Glomerulonephritis and an increased formation of immunoglobu lin type E (IgE) are characteristic of these reactions. A recent study of 15-year-old adolescents demonstrated an association between immuno globulin type A (IgA) and mercury concentration in plasma (P-Hg). Ther e was also an association between allergic disease and IgA levels. The present study included 54 male and 23 female 19-year-old students who were recruited from a cohort that had been previously defined in a su rvey of allergic disease. Of the students, 39 (51%) had asthma, allerg ic rhinoconjunctivitis or eczema. Similar amalgam burden and P-Hg leve ls were observed in students with (n = 39) and without (n = 38) allerg ic disease (P = 0.48 and P = 0.98, respectively). As expected, IgE lev els were significantly higher in the group with allergic disease (P = 0.006), but there was no association between P-Hg and IgE. The P-Hg le vels were very low (median 1.50 nmol/l) and correlated significantly ( r = 0.31) with the small number of amalgam surfaces (P = 0.007). Thirt y-seven students had no amalgam fillings. P-Hg levels did not associat e significantly with IgA, but did so with IgC(2) (r = 0.33; P = 0.003) . No conclusive correlation was observed between IgG(2) and-amalgam fi llings. The findings of this study in 19-year-old subjects differ from earlier data obtained in a sample 4 years younger. The possibility of chance in the association between P-Hg levels and IgG(2) must, howeve r, be considered.