MERCURY-SPECIFIC LYMPHOCYTES - AN INDICATION OF MERCURY ALLERGY IN MAN

In this study, 18 patients with oral lichen planus (OLP), adjacent to amalgam fillings, were tested in vitro with an optimized lymphocyte pr oliferation test, MELISA (memory lymphocyte immunostimulation assay) a nd with a patch test. Twenty subjects with amalgam fillings but withou t oral discomfort and 12 amalgam-free subjects served as controls. The results show that patients with OLP have significantly higher lymphoc yte reactivity to inorganic mercury, a corrosion product of amalgam, c ompared to control groups. Removal of amalgam fillings resulted in the disappearance of oral mucosal changes, thus indicating a causal relat ionship. Positive responses to phenylmercury (phenyl-Hg), a bactericid al agent in rootfillings and in pharmaceutical preparations, were also noted in the oral lichen group but not in the control groups. Thus, l ow-grade chronic exposure to mercury may induce a state of systemic se nsitization as verified by Hg-specific lymphocyte reactivity in vitro.