The role of metals as a risk factor of civilization diseases - a follow-up study
Institute of Clinical and Experimental Dental Medicine, First Faculty of Medicine and GUH,
Charles University, Prague, Czech Republic
Annotation
To assess the health status of patients examined and treated in the context of their proven
intolerance to metals, looking at them 5 to 10 years after the therapeutic intervention, and the
verification of continuing adverse effects of metals in the mouth on the health of patients with
metal intolerance using anamnestic, clinical (dental and cardiologic) and laboratory tests
(MELISA ® test and a test for cancer markers).
Introduction
Metals in the form of salts or alloys are included in the environment and are used for therapeutic
purposes in many areas of medicine (Bigazzi 2000). Most of all in dentistry, because the normal
restoration of teeth can not be done without them. Metals in the body bind to proteins, enzymes,
coenzymes and cell membranes and thus create compounds, haptens, recognited by the immune
system. They interfere with the immune system not only with toxic effects, but more often they
provoke the hapten-specific immune response, which may lead to inflammatory, allergic or
autoimmune responses (Gardner et al. 2009, Zheng et al. 2005, Schiraldi and Monestier 2009). Some
heavy metals (lead, mercury) cause an autoimmune response by the Th1 and Th2 clones imbalance
and thus increase the production of autoantibodies (Heo et al. 1996). Even at low doses mercury
damages the cardiac autonomic activity by parasympathetic dysfunction (Lim et al. 2010) and can also
influence the procoagulant activity of red blood cells (Lim and kol.2010b), thus increasing the risk of
the cardiovascular disease. Its role in carcerogenesis was also repeatedly discussed (Godfrey 2007,
Flora et al. 2008, Ortiz and Yamauchi 2009).
Metals also have an impact on the pathological changes in the oral cavity - the metallic pigmentation
of the gingiva, mucosa or hard dental tissues (Venclíková et al. 2007), as well as on inflammatory and
lichenoid changes on the soft tissues in the oral cavity. The dominant role is played by the dental
amalgam (Ditrichova et al. 2007 Ditrichová and Kaprálová 2009). It constitutes a major source of
mercury exposure - 50 to 75% of the average daily intake (Tucek 2006, Urban 2006).
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Project´s Objective
The project aims to assess the health status of patients examined and treated in the context of proven
intolerance to metals, looked at 5 to 10 years after the therapeutic intervention.
In the short term the health of patients sensitive to metals will be monitored, in the long-term the
effectiveness of the therapy (the removal of undesirable metals from the mouth) will be verified and
above all the impact of metal exposure from dental materials on the presence of systemic disease will
be studied in patients, where no therapeutic intervention has been performed, focusing on the
occurrence and development of cardiovascular, cancer and autoimmune diseases. The state of the oral
cavity and the presence of inflammation, lichenoid or pigmentary changes on the soft tissues in the
oral cavity will also be controlled.
Working hypothesi
The impact of metals from dental materials on the body of susceptible individuals is still a
controversial topic. On one side there are proponents of the theory of adverse effects of metals
released in minimal amounts from dental alloys in the mouth on the organism and on the other hand,
there are proponents of biocompatibility of these materials. The project is to determine the health
impacts of removing metals to which are patients sensitive from their mouth and to examine the
effects of long-term chronic exposure to small amounts of metals on the body of sensitive patients
without a therapeutic intervention.
Metodology
Patients who during the years 1996-2005 participated in research studies dealing with the reactions of
the organism to metals, will get a questionnaire focused on historical data from the period after the last
visit to our workplace. They will be divided into groups according to their answers: the patients who
responded to the MELISA ® test for mercury and / or other metals, who underwent removal of
undesirable metals from their mouth (A), and those with metals remining in their oral cavity, to which
there was the reaction in the MELISA ® test found (B).
Based on the evaluation of the returned questionnaires, selected patients will be invited for an
examination to determine their health status.
The clinical follow-up examination of the oral cavity, accompanied by OPG x-ray, MELISA ® test
with a limited number of metals (due to initial patient response) will be performed, laboratory tests for
oncogenic markers and autoantibodies will be carried out, and an cardiologic assessment will be
performed (physical, echocardiography, endothelial function and genetic characteristics of the
atherosclerotic process - Monto et al. 2009). As the cardiovascular disease is not just a result of an
environmental but also genetic predisposition, patients are classified according to to five genetic
markers [CELSR2, 9p21.9, CETP, ApoF, F2 (PT)] into groups with different levels of risk (Anderson
et al. 2010). This will allow more precise analysis of other risk factors controlled.
If autoantibodies are detected in the laboratory tests, if test is positive for oncogenic markers and the
diagnosis of cardiovascular disease is at this satge identified, patients will get a recommendation to
visit a specialized department for a further treatment.
MELISA® method
The principle of this method is a lymphocyte proliferation test (LTT - lymphocyte transformation test)
stimulated with metal antigens (Stejskal et al. 1994, 1996 and Valentine-Thon and Schiwara 2003).
Timetable
In the first year of the project, anamnestic data questionnaire will be developed (Dr.Procházková and
Dr.Himmlová) and sent to patients, diagnosed using the MELISA ® metod 1996-2006 (a graduate G). There will be a methodology for evaluating the questionnaire formed (Dr.Tomka), data from
questionnaires returned by patients will be digitalized (G) and evaluated (Dr.Podzimek).
In the second year of the project the evaluation of questionnaires will be completed (Dr.Podzimek) and
patients for health status determination will be selected (Dr.Procházková). The patients will be invited
for a clinical examination of the oral cavity (Dr.Himmlová and Dr.Tomka), to undergo the MELISA ®
test (Dr.Podzimek) and for other laboratory testing: testing for oncogenic markers (ICEM - Ing.
Hubacek, the collection of biological material and preparation of laboratory analysis will be carried
out by the high school-leaver - HSL) and autoantibodies (Dr.Podzimek) and for a cardiologic
examination (ICEM - Doc.Adámková, the G will participate in the functional examination of
cardiovascular system). A continuous evaluation of the results will be carried out and presented at
Czech and foreign conferences.
In the third year of the project clinical and laboratory tests will be completed and evaluation of the
results for the entire duration of the project will be carried out (all involved members of the research
team). These results will be published at international conferences and in professional journals. All
members of the team will participate in the presentation of results. A future direction of our research
will be outlined .
The method of data collection, their analysis and design of statistical processing
Patients who were examined by MELISA ® test in the period of 1996-2006 for suspected metal
intolerance (about 600 persons) will be sent questionnaires focused on the development of their health
and establishing whether the recommendations emerged from the test results were accepted and
implemented or not. Stamped envelopes for a return of questionnaires will be included.
Data obtained from the returned questionnaires during the first year of the project will be evaluated to
anable to form two groups of patients with proven intolerance to metals in the MELISA ® test - one
group with metal removed from their mouth (about 150 persons) and the other without having
undesirable metals removed from the mouth (150 people). These groupes of patients, sufficiently
numerous for statistical analysis, will be called for clinical examination to perform health
objectification during the second and at the beginning of the third year. Results of the tests and the
questionnaire data will be digitized for computer processing during the second and third year of the
project to enable the comparison of the two groups. In the second year a continuous evaluation will
continue. Statistical processing is done by routine methods in the third year of the project as it was
done in previous projects. Quantitative parameters will be compared by the Student t-test and the
Pearson test c2 will be used for qualitative parameters.
Cooperation
The Institute of Clinical and Experimental Medicine is the co-proposer of the project.
Discussion
The study builds on the projects carried out within the grants IGA MZ CR in the period of 19962010, especially on the Project No NJ 6775-3 "The presence of heavy metals in dental materials as a
risk factor for the development of autoimmune disease", in which a correlation between metal action
and increased autoantibody formation in sensitive individuals was demonstrated . The negative impact
of heavy metals on the development of cancer and diseases of the cardiovascular system has been very
recent discussed (Godfrey 2007, Flora et al. 2008, Ortiz and Yamauchi, 2009, Lim et al. 2010, Lim et
al. 2010b). Therefore we determine in our study the impact of the metals from dental materials on
patients sensitive to these metals, in the longer term.
Information on the readiness of participating departments
The main proposer - assistent professor Jarmila Procházková, MD, PhD - is a principal investigator of
seven research projects IGA MZ CR (five projects rated as "A", one of the "B" and one to be
completed in 2011) and a co-investigator of 11 research projects, of which 8 projects were rated as
"A", three, " B "and one to be completed in 2010).
Lucie Himmlová, MD, PhD is a repeatedly successful applicant and the head investigator of research
projects supported by the IGA Ministry of Health, and deals with similar issues as the main
investigator concerned with" side effects of metals on the human body from the dental,
histopathological, therapeutic and diagnostic points of view.
Stepan Podzimek, NSciD, Ph.D. working on the above research projects dealing with MELISA® test
and will implement appropriate immunological methods for the project.
Milan Tomka MD. has been handling the clinical investigations of patients with metal intolerance
during his academic training and within the research projects.
The clinical examination of patients will be carried out at the Institute of the Dental Research, General
University Hospital and 1st Faculty of Medicine, Charles University.
The MELISA ® test has already been implemented since 1996 in the Laboratory for Oral Biology in
the Institute of the Dental Research, General University Hospital and 1st Faculty of Medicine,
Charles University where the assessment of the autoantibodies has routinely been performed in recent
years.
The Institute of the Dental Research, General University Hospital and 1st Faculty of Medicine,
Charles University has the staff and equipment for the above methodology.
The examination of oncogenic markers, and cardiological examinations will be carried out at the
Department of Preventive Cardiology of the Institute of Clinical and Experimental Medicine in
Prague, which has the staff and equipment for this type of testing as well.
The project´s benefits
Our project will identify health risks resulting from the contact with the metals contained in dental
materials in the oral cavity and it will formulate preventive recommendations for practice. This will
contribute mainly to the following objectives of the Departmental research and development program
of the Ministry of Health III:
a) ensuring the development of applied clinical research in Czech Republic as the essential source of
new clinical practice in diagnostics, treatment and prevention in health care
b) improving of research on the nutrition and environment effects on the occurrence of the gravest and
most common disorders (eating disorders, the effects of external environment and nutrition) to the
emergence of cardiovascular diseases, the emergence of cancer, immune system disorders and
resistance to infectious diseases.
The outcome is expected to benefit dentists, general practitioners and internists.
Expected results and purpose of the project
The project´s results will demonstrate a possible association of some serious systemic illness with the
presence of certain metals in the oral cavity of susceptible individuals . The identification of health
risks and the objectification of possible algorithms of treatment of patients with metal intolerance will
thus become more exact in the future. This will be reflected both on the medico-legal level(possible
iatrogenic disability of patients), and on socio-economic levels, avoiding long-term treatment of
symptoms and the deterioration of overall health in individual patients.
The project results will be published in domestic and foreign impacted or refereed journals.
The expected outcome will be an introduction of metal intolerance diagnosis as an important step to
identify health risks in intolerant patients. From this will ensue implications for metal exposure
alteration in the oral cavity for dentistry and in the surgical specializations - especially for
implantology. The result should correspond to the expected benefits of the 09 subprogramme (the
relationship between health and the environment, preventive approaches in health care) - "Better and
more effective monitoring of health determinants and risk factors as the basis for an objective
assessment of the epidemiological situation and the effectiveness of prevention and treatment in order
to improve population health status and quality of life. "