Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inorganic mercury (iHg) is known to induce autoimmune disease in susceptible rodent strains. Additionally, in inbred strains of mice prone to autoimmune disease, iHg can accelerate and exacerbate disease manifestations. Despite these well-known links between iHg and autoimmunity in animal models, no association between iHg alone and autoimmune disease in humans has been documented. However, it is possible that low-level iHg exposure can interact with disease triggers to enhance disease expression or susceptibility. To address whether exposure to iHg can alter the course of subsequent acquired autoimmune disease, we used a murine model of acquired autoimmunity, lupus-like chronic graft-versus-host disease (GVHD), in which autoimmunity is induced using normal, nonautoimmune prone donor and F1 recipient mice resistant to Hg-induced autoimmunity. Our results indicate that a 2-week exposure to low-dose iHg (20 or 200 micro g/kg every other day) to donor and host mice ending 1 week before GVHD induction can significantly worsen parameters of disease severity, resulting in premature mortality. iHg pretreatment clearly worsened chronic lupus-like disease, rather than GVHD worsening iHg immunotoxicity. These results are consistent with the hypothesis that low-level, nontoxic iHg preexposure may interact with other risk factors, genetic or acquired, to promote subsequent autoimmune disease development.
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PMID:Low-dose exposure to inorganic mercury accelerates disease and mortality in acquired murine lupus. 1289 45

Mercury (Hg) has long been recognized as a neurotoxicant; however, recent work in animal models has implicated Hg as an immunotoxicant. In particular, Hg has been shown to induce autoimmune disease in susceptible animals with effects including overproduction of specific autoantibodies and pathophysiologic signs of lupus-like disease. However, these effects are only observed at high doses of Hg that are above the levels to which humans would be exposed through contaminated fish consumption. While there is presently no evidence to suggest that Hg induces frank autoimmune disease in humans, a recent epidemiological study has demonstrated a link between occupational Hg exposure and lupus. In our studies, we have tested the hypothesis that Hg does not cause autoimmune disease directly, but rather that it may interact with triggering events, such as genetic predisposition, exposure to antigens, or infection, to exacerbate disease. Treatment of mice that are not susceptible to Hg-induced autoimmune disease with very low doses and short term exposures of inorganic Hg (20-200 microg/kg) exacerbates disease and accelerates mortality in the graft versus host disease model of chronic lupus in C57Bl/6 x DBA/2 mice. Furthermore, low dose Hg exposure increases the severity and prevalence of experimental autoimmune myocarditis (induced by immunization with cardiac myosin peptide in adjuvant) in A/J mice. To test our hypothesis further, we examined sera from Amazonian populations exposed to Hg through small-scale gold mining, with and without current or past malaria infection. We found significantly increased prevalence of antinuclear and antinucleolar antibodies and a positive interaction between Hg and malaria. These results suggest a new model for Hg immunotoxicity, as a co-factor in autoimmune disease, increasing the risks and severity of clinical disease in the presence of other triggering events, either genetic or acquired.
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PMID:Mercury and autoimmunity: implications for occupational and environmental health. 1602 90