Lipopolysaccharide promotes and augments metal allergies in mice, dependent on innate immunity and histidine decarboxylase

BACKGROUND

Few adequate murine models exist for metal allergies, it being especially difficult to induce Ni allergy in mice.

OBJECTIVE

We examined the effect of lipopolysaccharide (LPS) on allergies to Ni and other metals in mice.

METHODS

Ten days after sensitization with a metal salt and LPS, the ears were challenged with the same metal salt.

RESULTS

LPS+NiCl(2) (1 mM) was effective at sensitizing mice to Ni, LPS being effective at very low concentrations whether injected intradermally or intraperitoneally. The ear-swelling response to Ni was more severe and more rapid in C57BL/6 mice than in BALB/c mice. In mast-cell-deficient mice, TNF-alpha-deficient mice, and interestingly even in nude (T cell deficient) mice, NiCl(2)+LPS induced a Ni allergy similar in degree to that in the respective control mice, but it induced Ni allergy only weakly in TLR4-mutant mice, macrophage-depleted mice, and IL-1-deficient mice. The activity of the histamine-forming enzyme histidine decarboxylase (HDC) in the ears increased in parallel with ear swelling, and HDC-deficient mice were resistant to ear swelling. Challenge with NiCl(2)+LPS augmented ear swelling (vs. NiCl(2) alone). LPS induced effective sensitization to other metals (Cr, Co, Pd, or Ag).

CONCLUSIONS

These results indicate that in mice, LPS is a very important inducer of metal allergies, and potently promotes them (dependent on both innate immunity and HDC induction in cells other than mast cells). We discussed the idea that the bacterial environment is important for the establishment of metal allergies and for their provocation, and that the current thinking (including the contribution of T cells) should be reappraised in future studies.

Allergy to metals as a cause of orthopedic implant failure

BACKGROUND

A constantly growing social demand for orthopedic implants has been observed in Poland. It is estimated that about 5% of patients experience post-operation complications. It is suspected that in this group of patients an allergic reaction contributes to rejection of metal implants.

MATERIALS AND METHODS

The aim of our study was to assess contact allergy to metals in 14 people (9 women and 5 men) suffering from poor implant tolerance. In some of them, recurrent skin eruptions, generalized or nearby implants, have occurred and in 3 patients skin fistula was observed. These complaints appeared one year after operation. The patients underwent patch tests with allergens from the Chemotechnique Diagnostics (Malmö, Sweden), including nickel, chromium, cobalt, palladium, copper, aluminum. In addition, allergens, such as titanium, vanadium and molybdenum prepared by chemical laboratory in the Nofer Institute of Occupational Medicine, Lódiź, Poland, were introduced.

RESULTS AND CONCLUSIONS

Of the 14 patients, 8 persons (5 women and 3 men) were sensitized to at least one metal, mostly to nickel (7/14) and chromium (6/14). Of the 8 sensitized patients, 3 were reoperated. Owing to the exchange of prosthesis the complaints subsided, including healing up skin fibulas. These facts weight in favor of the primeval sensitizing effect of metal prosthesis and the relation between allergy and clinical symptoms of poor tolerance to orthopedic implants.

Nickel, cobalt, chromium, palladium and gold induce a mixed Th1- and Th2-type cytokine response in vitro in subjects with contact allergy to the respective metals

Nickel (Ni), the main cause of contact allergy to metals, induces in vitro production of both Th1- and Th2-type cytokines in peripheral blood mononuclear cells (PBMC) from allergic subjects. Because the knowledge of the cellular immune response to other metals involved in contact allergy has been limited, we investigated the cytokine profile induced by Ni, cobalt (Co), chromium (Cr), palladium (Pd) and gold (Au) in PBMC from patients with patch test reactivity to the respective metals. PBMC from patients with patch test reactivity to Ni, Co, Cr, Au and/or Pd (n = 31) and non-allergic controls (n = 5) were stimulated in vitro with corresponding metal salts. Th1- [interleukin (IL)-2 and interferon (IFN)-gamma] and Th2- (IL-4 and IL-13) type cytokine responses were measured by enzyme-linked immunospot (ELISpot) and/or enzyme-linked immunosorbent assay (ELISA). All metals induced a mixed Th1- and Th2-type cytokine production in PBMC from individual patients with patch test reactivity to the corresponding metal, but not in control PBMC. Significantly higher responses in the patient versus controls were found for Cr (IL-2 and IL-13), Pd (IL-2 and IL-4), Au (IL-13 and IFN-gamma) (all P < 0.05) and Ni (all four cytokines; P < 0.01) but not Co. Overall, 71% (37/52) and 89% (81/91) of the positive and negative patch test reactivities to metals, respectively, were matched by the in vitro reactivity. In conclusion, our data suggest that sensitization to Co, Cr, Pd and Au results in a cellular immune response of a character similar to the mixed Th1- and Th2-type cytokine profile shown previously to be induced by Ni.

Diagnostic relevance of the determination of lymphocyte subpopulations in environmental medicine

Earlier hopes that determination of lymphocyte subpopulations might become a strong diagnostic tool in environmental medicine have not been fulfilled in recent years. Analysis of the scientific literature rather shows that there are only few examples for environmental exposures causing reproducible shifts of lymphocyte subpopulations. Moreover, current knowledge suggests that "environmental diseases" are not associated with characteristic changes of subpopulation patterns. If lymphocyte subpopulations are analyzed, each diagnostic step, including indication, sample handling, analytic procedure and data-interpretation, should adhere to good quality criteria. Taking all together, the determination of lymphocyte subpopulations in the context of environmental medicine comes under category IV of the criteria of the Commission for Methods and Quality Assurance in Environmental Medicine of the German federal health authority (Robert Koch-Institute; RKI): "A procedure cannot be recommended because there is not sufficient information to justify it" (here: no solid trends in epidemiological examinations), "and because theoretical considerations speak against an application" (here: high physiological variability and missing exposure or substance specificity).

Micro analysis of metals in dental restorations as part of a diagnostic approach in metal allergies

In dentistry, a variety of potentially allergenic metals are used, such as mercury, palladium, nickel, gold, chromium, cobalt and other metals. This paper describes a diagnostic approach from a dentist's point of view, which enables analysis of metals in a patient's oral cavity. If metal allergy is suspected, a micro analysis can be used to determine which metals are present in the restorations. When the exact composition of the dental materials is known, the patient can be tested in vivo (patch test) and/or in vitro (lymphocyte proliferation test) to reveal sensitization. Two patients with nickel allergy are described where removal of nickel-containing materials (bridge and orthodontic wire) resulted in the marked alleviation of symptoms and improvement of health. Finally, if allergy to specific metals has been established, the restorations containing the implicated metals should be removed to discontinue the exposure and thus facilitate the patient's health.

[Immunotoxicity of metals and protective function of pineal factors]

Analysis of the literature data shows that different metals has immunotoxical properties. Biological active compounds of the pineal gland and especially its main hormone, melatonin decreased of toxic shifts through normalization of immune state.

[Autoimmune thyroiditis--selected etiopathogenic mechanisms]

Autoimmune thyroiditis occurs as organ specific autoimmune disease not only as an isolated impairment of thyroid gland, but also linked to many autoimmune endocrinopathies. Genetic predisposition in the area of HLA antigens was followed up by patients with autoimmune thyroiditis diagnosed in this way and it appeared that genetic predisposition in isolated autoimmune thyroiditis is different when compared to the occurrence linked to endocrine polyglandular disease. In selected groups of patients with autoimmune disease also the influence of extraneous factors on the development of the autoimmune process was followed up, namely the influence of heavy metals and the influence of infectious agent--Helicobacter pylori. These factors have a different character of activation of autoimmune thyroiditis too, depending on the character of its manifestation as isolated disorder or in link to autoimmune polyglandular syndrome type II, or in link to the group of polyglandular activation of autoimmunity. To conclude, this study leads to the assumption, that autoimmune thyroiditis is a set of clinical syndromes that depends on the activation of the autoimmune process, rather than a strictly genetically and epigenetically characterized nosological unit.

Irreversibly binding anti-metal chelate antibodies: Artificial receptors for pretargeting

Antibodies against metal chelates may potentially be used in biomedical applications such as targeted imaging and therapy of cancer. Highly specific monoclonal antibodies can be developed, but their binding strength needs to be maximized for them to be of practical use. In general, the half-life for dissociation of an antibody-ligand complex is more than an order of magnitude lower than the half-lifetimes for decay of medically useful radiometal ions. Practically speaking, the metal chelate-based ligand will not be bound to its receptor long enough for all of the bound radiometal to decay. A novel approach to this problem is a combination of synthetic chemistry and site-directed mutagenesis, to position a mildly reactive group on the metal chelate adjacent to a complementary reactive group on the antibody when the complex is formed. The partners are chosen to be sufficiently unreactive so that they coexist with other molecules in living systems without undergoing reaction. When the antibody-chelate complex is formed the effective local concentrations of the two groups can be non-physically large, so that a permanent link is formed in the complex even though no reaction occurs when the partners are free in solution.

Periprosthetic osteolysis: an immunologist's update

PURPOSE OF REVIEW

Inflammation-induced osteolysis is a problem in both inflammatory arthritis and total joint arthroplasty. New drug therapies have been shown to slow, halt, or even reverse the osteolysis associated with inflammatory arthritis. Unfortunately, similar advances in the medical treatment of periprosthetic osteolysis have not occurred. This review will update the state of periprosthetic osteolysis.

RECENT FINDINGS

Preliminary results with phase I and II clinical trials with AMG-162, a human IgG2 that binds receptor activator of nuclear factor kappaB (RANK) ligand, have been reported. Based on these results AMG-162 appears to be safe and to have a potent effect on osteoclast function. Based on animal studies, it is expected that regents such as AMG-162 that block RANK-ligand/RANK interaction will have activity in inflammation-induced osteolysis. Volumetric three-dimensional and magnetic resonance imaging scans for detecting and quantifying periprosthetic osteolysis have been validated in cadaver studies. Lymphocytic infiltrates and positive skin tests to cobalt have been found in patients with periprosthetic osteolysis after second generation metal-on-metal prostheses. These findings again raise the question of whether metal allergy may contribute to implant failure in these patients. A new subset of T helper cells that are neither Th1 nor Th2, but secrete a unique pattern of cytokines including IL-17, has recently been discovered. The importance of these cells in modifying particle-induced osteolysis remains to be determined.

SUMMARY

There have been significant advances in our understanding of periprosthetic osteolysis, imaging technology to quantify osteolysis, and drug development. The time now seems ripe to translate these advances in clinical trials.

Interactions of Chemicals and Metal Ions with Proteins and Role for Immune Responses

Chemicals and metal ions often induce allergic contact dermatitis. We review here recent advances in the development of in vitro assays for prediction of skin sensitizing potency based on chemical and biological reactivity as well as in the identification of physiological binding partners and immunological pathomechanisms of chemical and metal ion induced disease.

Metal-specific lymphocyte reactivity is downregulated after dental metal replacement

OBJECTIVES

This study was done to evaluate the results and clinical relevance of an optimized lymphocyte proliferation test, MELISA, for metal-induced inflammation in patients with CFS-like symptoms. The treatment of patients consisted of the replacement of incompatible dental materials (RID) together with supportive anti-oxidant therapy.

DESIGN OF THE STUDY

513 patients were tested by MELISA at the beginning of the study. Out of this group, 248 patients were available for follow-up MELISA after RID.

METHODS

In MELISA, lymphocytes are isolated from the blood and cultivated with different metal salts in tissue culture medium containing 10% inactivated human AB+ serum or autologous serum. After 5 days, the presence of metal-reactive lymphocytes are measured by isotope labelling of newly formed DNA in growing lymphoblasts and evaluated by calculating the Stimulation Index.

RESULTS

Nickel was the most common sensitizer, followed by inorganic mercury, thimerosal, lead, cadmium, palladium and gold. After RID treatment, a decrease of metal-specific lymphocyte responses in patients who reacted to metals at the beginning of the study could be observed. The cultivation of lymphocytes in autologous and homologous serum did not significantly affect the results. Simultaneous, the health status of patients improved as well.

CONCLUSIONS

Replacement of incompatible dental materials resulted in down-regulation of metal-induced lymphocyte sensitivity in vitro, as well as in the improvement of health status of majority of patients with unspecific CFS-like symptoms.

Hardware removal: indications and expectations

Although hardware removal is commonly done, it should not be considered a routine procedure. The decision to remove hardware has significant economic implications, including the costs of the procedure as well as possible work time lost for postoperative recovery. The clinical indications for implant removal are not well established. There are few definitive data to guide whether implant removal is appropriate. Implant removal may be challenging and lead to complications, such as neurovascular injury, refracture, or recurrence of deformity. When implants are removed for pain relief alone, the results are unpredictable and depend on both the implant type and its anatomic location. Current literature does not support the routine removal of implants to protect against allergy, carcinogenesis, or metal detection. Surgeons and patients should be aware of appropriate indications and have realistic expectations of the risks and benefits of implant removal.

Time course of release of inflammatory markers after coronary stenting: comparison between bare metal stent and sirolimus-eluting stent

BACKGROUND

High levels of release of inflammatory markers after coronary angioplasty are predictors of late restenosis. Sirolimus-eluting stent reduces the risk of restenosis.

AIM OF THE STUDY

To compare the release of inflammatory markers after coronary angioplasty with sirolimus-eluting stent and bare metal stent.

METHODS

Sixteen patients with a proximal left anterior descending coronery artery stenosis were randomly assigned to receive either bare metal stent (n = 8) or sirolimus-eluting stent (n = 8). We measured simultaneously aortic and coronary sinus concentrations of the von Willebrand factor antigen, tumor necrosis factor-alpha and interleukin-6 before, immediately and after 2 h after stenting. High-sensitivity C-reactive protein and troponin-I circulating levels were measured before and 6 and 24 h after coronary angioplasty.

RESULTS

Before stenting, all values were similar in both groups. The coronary sinus change of the von Willebrand factor antigen level between baseline and 2 h after stenting was + 20.1 +/- 26.9% in the bare metal stent group and -5.7 +/- 23.02% in the sirolimus-eluting stent group (P < 0.05). We observed a significant increase in the von Willebrand factor antigen (from 132.8+/-58.8 to 169 +/- 40.7%, P < 0.05) systemic concentrations 24 h after stenting in the bare metal stent group but not in the sirolimus-eluting stent group (from 140.6+/-84% to 136 +/- 39.5%), P = NS).

CONCLUSION

The present study shows that a difference in the release of inflammatory markers can be detected after coronary stenting with bare metal stent or sirolimus-eluting stent. The lower release of the von Willebrand factor antigen in the coronary sinus 2 h after the procedure and the lower systemic concentrations of the von Willebrand factor antigen 24 h after stenting in the sirolimus-eluting stent group are likely to reflect a reduced production of the von Willebrand factor antigen at the site of the vascular injury.

T cell receptor (TCR) interaction with haptens: metal ions as non-classical haptens

Haptens are classified as low molecular chemicals with an intrinsic potential to covalently modify proteins, and many of them are strong inducers of contact hypersensitivity (CHS). CHS is T cell mediated, and hapten-specific T cells have been shown to interact with hapten-modified, MHC-associated peptides. However, the most common contact sensitizer in the industrialized world is nickel. In contrast to classical haptens, nickel ions do not form covalent bonds to proteins, but rather become caught in reversible coordination complexes. We here review work demonstrating that some T cells, indeed, may react to such Ni complexes on the MHC/peptide-surface absolutely comparable to other haptens. In other cases, Ni ions unlike classical haptens, may activate T cells by crosslinking their receptors to MHC molecules, independent of the nature of the associated peptide. Moreover, Ni-interacting proteins appear to make use of the reversibility of Ni-binding, and to mediate the transfer of Ni-ions to the receptor-MHC interphase. We have demonstrated such properties for human serum albumin (HSA) as well as for transferrin and identified numerous new Ni-binding proteins in human B-cell lines or dendritic cells by affinity purification and mass spectroscopy. These proteins include a notable number of known heat shock proteins and chaperones, implying that Ni may functionally interfere with these stress proteins.

T Lymphocyte-Mediated Immune Responses to Chemical Haptens and Metal Ions: Implications for Allergic and Autoimmune Disease

Chemical haptens and metal ions interact with proteins and thereby become recognizable by T and B lymphocytes. They induce the production of proinflammatory cytokines and chemokines by various cell types due to triggering of innate immune responses. This is an important prerequisite for the activation of the adaptive immune system and the development of diseases like allergic contact dermatitis and adverse drug and autoimmune reactions. Our increasing knowledge about the molecular basis of hapten and metal ion recognition by T cells and about the pathomechanisms of contact hypersensitivity and chemical-induced autoimmune reactions allows concomitant progress in the development of modern strategies for immunotherapy and will hopefully enable more specific intervention in hapten- and metal ion-induced human diseases in the future.

Sarcoidal-Type Allergic Contact Granuloma

As body piercing is increasingly en vogue, complications are on the rise as well. Biopsies of such lesions can impose special problems to the reviewing dermatopathologist. We present two patients who developed papulonodular lesions at the sites of ear piercings. Unexpectedly, the findings included prominent sarcoidal granuloma formation with confluent areas of fibrinoid necrosis. An infectious etiology was excluded. However, patch testing revealed contact allergy to palladium, platinum, and nickel. Interestingly, histopathologic examination of the patch test sites also demonstrated granuloma formation. These findings suggest that the lesions represent allergic contact granulomas. When confronted with this special type of tissue reaction in skin biopsies of piercing sites, the reviewing dermatopathologist should consider the possibility of an allergic reaction. Careful history and thorough diagnostic procedures, including biopsy of the patch test site can establish the diagnosis of contact allergic granuloma.

[Allergies in orthodontics]

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

Environmentally relevant metal and transition metal ions enhance Fc epsilon RI-mediated mast cell activation

Upon contact with allergen, sensitized mast cells release highly active proinflammatory mediators. Allergen-mediated mast cell activation is an important mechanism in the pathogenesis of atopic asthma. Asthmatic patients are especially susceptible to air pollution. Epidemiologic studies found a positive correlation between severity of symptoms among asthmatic patients and the level of particulate matter (PM) in the air. Among the constituents of PM are metals and transition metals, which could mediate some of its adverse effects on human health. We sought to determine the effect of metal and transition metal ions on allergen-mediated mast cell activation. We observed that several metal and transition metal ions activated mast cells and enhanced allergen-mediated mast cell activation. Thus, Al(3+), Cd(2+), and Sr(2+) induced release of granule-associated N-acetyl-ss-d-hexosaminidase, and Al(3+) and Ni(2+) enhanced antigen-mediated release. Metal and transition metal ions also induced significant secretion of interleukin (IL)-4 and increased antigen-mediated IL-4 secretion in mast cells. These effects of metal and transition metal ions on mast cells were observed at concentrations that do not result in direct cytotoxicity and might be relevant for environmental exposure. Thus, metals and transition metals could increase the level of allergen-mediated mast cell activation, which might be one of the mechanisms mediating exacerbation of allergen-driven asthma symptoms by air pollution.

[Sperm antibodies and immunologic intolerance to metals in infertile couples]

OBJECTIVE

Verification of the hypothesis of a relationship between the presence of antibodies against sperm cells and immunological reactivity to some metals in infertile couples by the MELISA test.

SETTING

Department of Obstetrics and Gynecology, Medical Faculty, Charles University and Faculty Hospital, Plzen.

METHOD

From 23 female patients and 21 men (a total of 44 subjects treated for infertility) with confirmed serum antibodies against sperm cells the authors isolated lymphocytyes from the peripheral blood stream, divided them into individual cultures and investigated them by the MELISA test using different metal compounds.

RESULTS

The outcome of the MELISA test are values of the stimulation index (SI) by means of which the authors investigated the reactivity of the organism to the given metal. Special attention was devoted to compounds of organic and inorganic mercury. The SI values were subsequently compared with different data obtained from a detailed anamnestic questionnaire which was focused specially on contact with metals and on allergic reactions. In the investigated group of patients the authors detected a positive immune reactivity to inorganic mercury, Ag, Al, Fe. In some subjects they found a very high positive immune reactivity to inorganic mercury, Ni, Al, Cd and Ti. The control groups were formed by healthy fertile subjects without antibodies against sperm cells and with physiological SI values.

CONCLUSION

The authors did not prove a direct relationship between the intensity of the laboratory reactivity to metals and the presence of antibodies against sperm cells which cause deterioration of fertility. An exogenous load of metals could in case of genetic predisposition be only one of the factors which participate in the formation of antibodies against sperm cells. The investigation proved that its is not essential, contrary to the view of many stomatologists, to eliminate metal compounds completely from dental practice.

[Allergic reactions to implant materials]

The extent of the immune response upon implantation of metallic devices depends on the individual reactivity and on material characteristics. If specific T-cellular sensitization occurs or an allergy to metal preexists, hypersensitive reactions to implant components may develop. They include eczema, impaired wound healing, and sterile osteomyelitis. The existence of allergy-induced implant loosening is still an open question. Further improvement of clinical allergological diagnostics, better understanding of peri-implantar immune reactions, and interdisciplinary collection of epidemiological data concerning allergy to implants will contribute to a better knowledge about tolerance of implant material in humans.

Immunomodulation by metals

Occupational or environmental exposure to metals is believed to affect human health adversely. One mechanism whereby metals can alter health is through modulation of immune homeostasis. Imbalances in immune regulation by metals can lead to inadequate or excessive production of inflammatory cytokines. Alternatively, metals can lead to inappropriate activation of lymphoid subsets involved in acquired immunity to specific antigens. Some resultant pathologies may include chronic inflammatory processes and autoimmune diseases. Metals may change the response repertoire by direct and indirect means by influencing expression of new antigens, new peptides, and/or antigen presentation by modifying the antigen-presenting complex. The differences in metal-induced immune responses between humans and the mechanisms of metal immunomodulation are discussed.

Metalloantibodies: mercury(II)-dependent acyl transferases

A new approach for the elicitation of metal-dependent catalytic antibodies for ester hydrolysis is described. A coordinatively unsaturated mercury complex 1-(Hg), has been utilized as a hapten to elicit antibodies that incorporate mercury(II) as a Lewis acid cofactor. From a panel of monoclonal antibodies generated to 1-(Hg), antibody 38G2 was found to hydrolyze the ester 3 in the presence of HgCl(2) [K(m)app(3)=345 microM; K(m)app(Hg(2+))=87 microM; k(cat)app/k(uncat)=3 x 10(2)]. This is the first example of a biocatalyst that enlists mercuric ion as a cofactor and it is anticipated that this approach will open new avenues for exploitation of metals thought previously beyond the scope of protein catalysts.

Metal sensitivity in patients with orthopaedic implants

All metals in contact with biological systems undergo corrosion. This electrochemical process leads to the formation of metal ions, which may activate the immune system by forming complexes with endogenous proteins. Implant degradation products have been shown to be associated with dermatitis, urticaria, and vasculitis. If cutaneous signs of an allergic response appear after implantation of a metal device, metal sensitivity should be considered. Currently, there is no generally accepted test for the clinical determination of metal hypersensitivity to implanted devices. The prevalence of dermal sensitivity in patients with a joint replacement device, particularly those with a failed implant, is substantially higher than that in the general population. Until the roles of delayed hypersensitivity and humoral immune responses to metallic orthopaedic implants are more clearly defined, the risk to patients may be considered minimal. It is currently unclear whether metal sensitivity is a contributing factor to implant failure.

Environmental immunogens and T-cell-mediated responses in fibromyalgia: evidence for immune dysregulation and determinants of granuloma formation

Thirty-nine patients with fibromyalgia syndrome (FMS) according to American College of Rheumatology criteria were studied for cell-mediated sensitivity to environmental chemicals. Lymphocytes were tested by standard [(3)H]thymidine incorporation in vitro for T cell memory to 11 chemical substances. Concanavalin A (Con A) was used to demonstrate T cell proliferation. Controls were 25 contemporaneous healthy adults and 252 other concurrent standard controls without any aspect of FMS. Significantly higher (P < 0.01) stimulation indexes (SI) were found in FMS for aluminum, lead, and platinum; borderline higher (0.05 > P > 0.02) SI were found for cadmium and silicon. FMS patients showed sporadic responses to the specific substances tested, with no high-frequency result (>50%) and no obvious pattern. Mitogenic responses to Con A indicated some suppression of T cell functionality in FMS. Possible links between mitogenicity and immunogenic T cell proliferation, certain electrochemical specifics of granuloma formation, maintenance of connective tissue, and the fundamental nature of FMS are considered.