BACKGROUND: Patients with certain autoimmune and allergic diseases, such as systemic lupus, multiple sclerosis, autoimmune thyroiditis or atopic eczema, often show increased lymphocyte stimulation by low doses of inorganic mercury in vitro. The patients often report clinical metal hypersensitivity, especially to nickel.
OBJECTIVE AND METHODS: In this study we examined the health impact of amalgam replacement in mercury-allergic patients with autoimmunity. The suitability of MELISA, an optimized lymphocyte stimulation test, for the selection of susceptible patients and monitoring of sensitization was also examined. Amalgam fillings were replaced with composites and ceramic materials. Follow-up health status and lymphocyte reactivity were assessed and evaluated half a year or later following amalgam removal.
RESULTS: Results of lymphocyte reactivity measured with MELISA indicate that in vitro reactivity after the replacement of dental amalgam decreased significantly to inorganic mercury, silver, organic mercury and lead. Out of 35 patients, 25 patients (71%) showed improvement of health. The remaining patients exhibited either unchanged health (6 patients, 17%) or worsening of symptoms (4 patients, 11%). The highest rate of improvement was observed in patients with multiple sclerosis, the lowest rate was noted in patients with eczema. The initial mercury-specific lymphocyte reactivity was significantly higher in the responder group, than in the non-responders, whose health was not improved by amalgam removal. All patients with health improvement after amalgam replacement showed reduced proliferation to inorganic mercury in follow-up MELISA. In vitro responses to phenylmercury and nickel did not differ between the groups.
CONCLUSIONS: Mercury-containing amalgam may be an important risk factor for patients with autoimmune diseases. MELISA is a valuable tool for selection of patients for amalgam replacement and also for monitoring of metal allergies.