The immunopathology of siliconosis. History, clinical presentation, and relation to silicosis and the chemistry of silicon and silicone

A Prospective Observational Clinical Cohort of Women with Suspected Breast Implant Illness

Background: This study aims to describe a prospective clinical cohort of patients with silicone breast implants and suspected Breast Implant Illness (BII). Methods: Women were included in a specialized silicone outpatient clinic at Amsterdam UMC, the Netherlands. Baseline characteristics were collected including medical history, implant details, and symptoms. Experienced physicians categorized BII suspicion as high, moderate, or low, based on symptoms and after exclusion of other probable causes. Additionally, participants completed questionnaires assessing symptoms and daily life impact at baseline, 6 months, 1, 2, and 5 years. For this initial analysis, the results from the first three years of inclusions were collected. Results: Data from 353 women were collected from December 2020-December 2023. At baseline, the most reported symptoms were fatigue, arthralgia, myalgia, and morning stiffness, accompanied by local symptoms in 83.3% of patients. At the clinic, 112 women were categorized as having high suspicion of BII, 147 women as moderate, and 94 women as low. At follow-up, 182 women (51.6%) opted for explantation. Following explantation, women with a high or moderate suspicion of BII experienced more significant symptom improvement, accompanied by a decrease in anxiety and a greater sense of control over their illness, compared to women with a low suspicion of BII. Conclusions: Our study highlights a distinct interplay of systemic and local symptoms among women with suspicion of BII. Women with a high or moderate BII suspicion benefit significantly more from explantation than women with low suspicion. Experienced physicians are pivotal in effectively assessing and guiding this patient group, highlighting the need for tailored clinical approaches.

Pulmonary adverse events of breast silicone implants and silicone injection

The incidence of breast implants and silicone injections has continuously increased since their FDA approval for use in the 1960's. The prevalence of overall adverse events is approximately 20%. The actual incidence of pulmonary adverse events is unknown. This review focuses on the pulmonary adverse events of breast implants and silicone injections. Vascular complications are represented by acute and chronic embolisation syndromes with a clinico-radiological presentation of alveolar hemorrhage. Inflammatory complications are numerous, including siliconoma, which is a granulomatous reaction mimicking a mesothelioma. On the other hand, there are some reports arguing a link between the development of auto-immune diseases and breast implants, such as scleroderma, rheumatoid arthritis, Sjögren's syndrome, and dermatomyositis. Finally, for patients with asthma, breast implants may contribute to poor disease control. Cases of eosinophilic granulomatosis with polyangeitis have been described. Thus, it is of interest to decipherate mechanisms and incidence of these effects in prospective studies to better manage pulmonary diseases in patients wearing breast implants in order to understand their role as culprits or bystanders. In addition, characterization of subpopulations with increased risk of adverse events is needed as we highlighted that some subpopulations seem to be at greater risk of developing them, notably asthmatics.

[Siliconosis with rheumatoid polyarthritis following a breast implant rupture: Case report and literature review]

Breast implant rupture is a common complication in plastic surgery, with various clinical presentations, due to silicone migration. In this article, we present the case of a patient with ruptured silicone implants, who developed siliconosis with rheumatoid polyarthritis, and evolved favourably after explantation surgery. The physiopathology of this disease, and the implication of silicone migration are still controversial, and yet to be confirmed.

Dust Deposition Impacts at a Liquidated Gold Mine Village: Gauteng Province in South Africa

The windy season brings numerous community complaints for gold mining companies situated in the Witwatersrand due to windblown dust from partially rehabilitated tailings storage facilities (TSFs). For communities encroaching onto TSFs, windblown dust is perceived as a health hazard and an environmental challenge. In a study conducted in 2017 by the Lawyers for Human Rights, the community of a gold mine village perceived tailings storage facility 6 (TSF6) and other surrounding tailings storage facilities which are partially rehabilitated to be a health and socio-economic threat. Since 2013, when a nearby gold mining company was liquidated, this community has been complaining about dust fallout. To validate the claims made by the community this paper reports on the dust deposition impacts, and respiratory illnesses risk posed by wind-blown generated dust. The study conducts an air quality assessment using dispersion modelling of windblown dust. Surface material from the TSFs was sampled, analysed for silica and heavy metal content using X-ray fluorescence (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) respectively. This study finds that PM₁₀ dust fallout, high in silica and uranium content, could potentially pose health threats to the surrounding community. The study further shows that dust deposition is the highest in July-October, with TSF6 posing a nuisance while TSF1 represents a potential health threat owing to its particle size distribution for the surrounding gold mine village community. Potential receptors of the air pollution by dust in this study area include neighbouring property owners, business owners of the nearby shopping centre, the school and the clinic. This study further finds that sudden mine closure due to mine liquidation results in unrehabilitated tailings storage facilities which exacerbates dust deposition.

Is explantation of silicone breast implants useful in patients with complaints?

In this review, we present a critical review of the existing literature reflecting the results of explantation of silicone breast implants in patients with silicone-related complaints and/or autoimmune diseases. A literature search was performed to discuss the following issues: which clinical manifestations and autoimmune diseases improve after explantation, and what is the course of these complaints after explantation. Next, we reviewed studies in which the effect of explantation on laboratory findings observed in patients with silicone breast implants was studied, and lastly, we reviewed studies that described the effect of reconstruction of the breast with a new implant or autologous tissue after explantation. We calculated from the literature that explantation of the silicone breast improved silicone-related complaints in 75 % of the patients (469 of 622). In patients with autoimmune diseases, however, improvement was only infrequently observed without additional therapy with immunosuppressive therapy, i.e., in 16 % of the patients (3 of 18). The effect of explantation did not influence autoantibody testing such as ANA. We discuss several possibilities which could clarify why patients improve after explantation. Firstly, the inflammatory response could be reduced after explantation. Secondly, explantation of the implants may remove a nociceptive stimulus, which may be the causative factor for many complaints. Options for reconstruction of the explanted breast are autologous tissue and/or water-/hydrocellulose-filled breast implant. Unfortunately, in very few studies attention was paid to reconstructive possibilities. Therefore, no adequate conclusion regarding this issue could be drawn. In conclusion, explantation is useful for improvement of silicone-related complaints in 75 % of the patients, whereas in patients who developed autoimmune diseases improvement is only observed when explantation is combined with immunosuppressive therapy. In a patient with silicone-related complaints in which explantation is considered, the patient should be counseled for the different options of reconstruction after explantation.

Evolution of consciousness of exposure to siloxanes-review of publications

The purpose of this description is to review scientific literature from 1944 to 2017 as a source of information on the reasons for the increased interest in siloxanes (silicones). Not only the research area, but first, the changes in the tendency of research aims are important issues in the evaluation. On the one hand, the authors emphasize the unique properties of linear and cyclic siloxanes, providing many examples of beneficial applications, and on the other hand, there are some warnings of overcoming of the safety barrier of their presence in human environment. Analyzing the results from the SCOPUS database, it can be argued that the increased interest of scientists and government agencies particularly relates to the analysis of siloxanes in biological and environmental samples. This is caused not only by the widespread use of various siloxanes in the pharmaceutical, medical, cosmetic and food industries, but also by the direct contact of these compounds with tissues, as well as an increased access to knowledge and modern research tools that have developed the awareness of hazards. The development of research methods enables not only constant monitoring of progressively lower siloxanes concentrations in various samples, but because of the specificity of these methods, it also enables an identification of specific siloxane compounds and evaluation of their effects on humans and environment. This paper discusses the issues of the evolution of consciousness of exposure to siloxanes due to their increased synthesis and widespread use in many areas of human life, which contributes to environmental pollution.

Destiny rides again: the reappearance of silicone gel-filled breast implant toxicity

Background Twenty-five years ago attorneys representing ailing women in class action litigation against silicone breast implant manufacturers made the procedural error of defining silicone-induced toxicity in the courtroom before it was properly studied in the exam room. This aberrant methodology perverted the proper research process, rendered verification of any real disease elusive, and cemented the groundwork for a repeat public health crisis potentially affecting two million women in the USA who possess new silicone gel devices inserted over the past 10 years. Patients and methods Six women, previously well, aged 27 to 53 (mean 42), were recipients of the new generations of cohesive silicone gel-filled breast implants approved for general use by the Food and Drug Administration (FDA) since December of 2006. They averaged seven years of total implantation time, and none experienced implant rupture. Results All six became ill on average 3.5 years from the time of implantation. By seven years the women manifested multiple types of skin rashes, polyarthritis, fatigue, protracted AM stiffness, myalgias, headaches, photosensitivity, hair loss, paresthesias, tinnitus, lymphadenopathy, chest pain, cognitive dysfunction, dry eyes, skin pigment changes, itching, muscle twitching, dizziness, nausea, easy bruising, and odor and smell sensitivity. Three of the four who were explanted noted improvement and/or resolution of at least 50% of their total disease manifestations. Conclusions These six women are representative of over 70,000 other breast implant recipients who, over the past three years, have had their new silicone devices permanently removed because of alleged gel-induced toxicity. The recurrence of this public health crisis has been fueled by manufacturers' research fraud, FDA ineptness, faulty informed consent, patient abandonment, proprietary manufacturing secrecy, misleading advertising, physician indifference, aberrant research methodology, and lax Congressional oversight.

Alterations of Fas and Fas-Related Molecules in Patients with Silicosis

Persons with silicosis have not only respiratory disorders but also autoimmune diseases. To clarify the mechanisms involved in the dysregulation of autoimmunity found in patients with silicosis, we have been focusing on Fas and Fas-related molecules in the Fas-mediated apoptotic pathway, because Fas is one of the most important molecules regulating autoimmunity involving T cells. Our findings showed that patients with silicosis exhibited elevated serum soluble Fas levels, an increased relative expression of the soluble fas and dcr3 genes in peripheral blood mononuclear cells, high levels of other variant messages of the fas transcript, relatively decreased expression of genes encoding several physiological inhibitors (such as survivin and toso), and dominancy of lower-membrane Fas expressers in lymphocytes, which transcribe soluble fas dominantly, compared with soluble fas transcription in healthy donors. These findings are consistent with known features regarding immunological factors, such as serum immunogulobulin G levels and the titer of anti-nuclear autoantibodies in silicosis. In addition, anti-caspase 8 autoantibody and anti-Fas autoantibody were detected in serum specimens from patients with silicosis, and a functional assay showed that anti-Fas antibody stimulated Fas-mediated apoptosis. We hypothesize that there are two subpopulations of silicosis lymphocytes. One is a long-term surviving fraction that includes self-recognizing clones showing lower levels of membrane Fas and inhibition of Fas/Fas ligand binding in extracellular spaces. The other subpopulation exhibits apoptosis caused by silica and silicates, is recruited from bone marrow, shows higher levels of membrane Fas, and is sensitive to anti-Fas autoantibody. Further investigation should be performed to confirm the effects of silica and silicates on the human immune system.

Breast implant-associated anaplastic large cell lymphoma: two distinct clinicopathological variants with different outcomes

BACKGROUND

ALK-negative anaplastic large cell lymphoma associated with breast implant (i-ALCL) has been recently recognized as a distinct entity. Among 43 830 lymphomas registered in the French Lymphopath network since 2010, 300 breast lymphomas comprising 25 peripheral T-cell lymphomas (PTCL) were reviewed. Among PTCL, ALK-negative ALCL was the most frequent and all of them were associated with breast implants.

PATIENTS AND METHODS

Since 2010, all i-ALCL cases were collected from different institutions through Lymphopath. Immuno-morphologic features, molecular data and clinical outcome of 19 i-ALCLs have been retrospectively analyzed.

RESULTS

The median age of the patients was 61 years and the median length between breast implant and i-ALCL was 9 years. Most implants were silicone-filled and textured. Implant removal was performed in 17 out of 19 patients with additional treatment based on mostly CHOP or CHOP-like chemotherapy regimens (n = 10/19) or irradiation (n = 1/19). CHOP alone or ABVD following radiation without implant removal have been given in two patients. The two clinical presentations, i.e. effusion and less frequently tumor mass correlated with distinct histopathologic features: in situ i-ALCL (anaplastic cell proliferation confined to the fibrous capsule) and infiltrative i-ALCL (pleomorphic cells massively infiltrating adjacent tissue with eosinophils and sometimes Reed-Sternberg-like cells mimicking Hodgkin lymphoma). Malignant cells were CD30-positive, showed a variable staining for EMA and were ALK negative. Most cases had a cytotoxic T-cell immunophenotype with variable T-cell antigen loss and pSTAT3 nuclear expression. T-cell receptor genes were clonally rearranged in 13 out of 13 tested cases. After 18 months of median follow-up, the 2-year overall survival for in situ and infiltrative i-ALCL was 100% and 52.5%, respectively.

CONCLUSIONS

In situ i-ALCLs have an indolent clinical course and generally remain free of disease after implant removal. However, infiltrative i-ALCLs could have a more aggressive clinical course that might require additional therapy to implant removal.

Anaplastic large cell lymphoma (ALCL) and breast implants: breaking down the evidence

Systemic anaplastic large cell lymphoma (ALCL) is a distinct disease classification provisionally sub-divided into ALCL, Anaplastic Lymphoma Kinase (ALK)(+) and ALCL, ALK(-) entities. More recently, another category of ALCL has been increasingly reported in the literature and is associated with the presence of breast implants. A comprehensive review of the 71 reported cases of breast implant associated ALCL (iALCL) is presented indicating the apparent risk factors and main characteristics of this rare cancer. The average patient is 50 years of age and most cases present in the capsule surrounding the implant as part of the periprosthetic fluid or the capsule itself on average at 10 years post-surgery suggesting that iALCL is a late complication. The absolute risk is low ranging from 1:500,000 to 1:3,000,000 patients with breast implants per year. The majority of cases are ALK-negative, yet are associated with silicone-coated implants suggestive of the mechanism of tumorigenesis which is discussed in relation to chronic inflammation, immunogenicity of the implants and sub-clinical infection. In particular, capsulotomy alone seems to be sufficient for the treatment of many cases suggesting the implants provide the biological stimulus whereas others require further treatment including chemo- and radiotherapy although reported cases remain too low to recommend a therapeutic approach. However, CD30-based therapeutics might be a future option.

The monobloc hydrogel breast implant, experiences and ideas

This study is focused on the properties of the monobloc hydrogel (MH) breast implant, which has been around for more than 30 years, and to see how it behaves with regard to health complaints as sometimes seen in some patients who had received silicone gel (SG) breast implants. Patients responded to a questionnaire examining their experience with breast implants. Three groups were included. First, the control group (n = 34) of women without breast implants. Second, a C group of women (n = 42) who began and remained on the MH implant. Third, the B group of women who had their silicone gel implant replaced by the MH implant. In the B1 subgroup (n = 22), a capsulectomy was also performed. In the B2 subgroup (n = 13), the replacement was carried out without a capsulectomy. The C group behaved very much like the control group. The women of the B group experienced an improvement of their complaints and the improvement was even better after a capsulectomy. The only difference between the MH and SG implants is the content of the implant. The satisfaction of women with MH implants is generally high and not or hardly associated with health complaints. In women with SG implants and health complaints, these complaints can be relieved by replacement of the implants by MH implants.

ALK-1-negative anaplastic large cell lymphoma associated with breast implants: a new clinical entity

Concerns have been raised recently regarding the increasing number of reports of non-Hodgkin lymphoma (NHL) that developed in close proximity to silicone or saline breast implants. In particular, an increased risk of anaplastic large cell lymphoma (ALCL) in patients with breast prostheses has been proposed. We reviewed clinical and pathologic findings in 40 women who received a diagnosis of breast NHL arising in association with breast implants and of 27 patients who had a diagnosis of ALCL with breast involvement reported in the published literature. Among the 40 reported cases of prosthesis-associated breast lymphomas, 28 were anaplastic lymphoma kinase-1-negative (ALK-1(-)) ALCLs, whereas of 27 ALCLs in patients without implants found in the literature, only 10 were ALK-1(-). The finding of 28 cases of breast ALK-1(-) ALCL occurring in patients with implants compared with 10 cases in women without implants is in favor of an association between silicone breast prostheses and ALK-1(-) ALCL. Although the incidence of this type of lymphoma remains remarkably low given that breast prostheses have been widely used for decades, clinical and pathologic evidence for a causative role is becoming dramatically strong. The histologic, phenomenologic, and clinical similarities of the majority of implant-related ALK-1(-) ALCLs suggest a common mechanism, especially when compared with the counterpart of patients without implants in which very few and highly dishomogeneous cases of the same malignancy were detected. There is convincing evidence that primary implant-related ALK-1(-) ALCL represents a distinct clinicopathologic entity that has been inappropriately fitted into the category of systemic ALK-1(-) ALCL. Thus it should be recognized as a separate category and classified on its own.

Osteogenic potential of biosilica on human osteoblast-like (SaOS-2) cells

Biosilica is a natural polymer, synthesized by the poriferan enzyme silicatein from monomeric silicate substrates. Biosilica stimulates mineralizing activity and gene expression of SaOS-2 cells. To study its effect on the formation of hydroxyapatite (HA), SaOS-2 cells were grown on different silicatein/biosilica-modified substrates (bone slices, Ca-P-coated coverslips, glass coverslips). Growth on these substrates induced the formation of HA nodules, organized in longitudinal arrays or spherical spots. Nodules of sizes above 1 μm were composed of irregularly arranged HA prism-like nanorods, formed by aggregates of three to eight SaOS-2 cells. Moreover, growth on silicatein/biosilica-modified substrates elicited increased [(3)H]dT incorporation into DNA, indicative of enhanced cell proliferation. Consequently, an in vitro-based bioassay was established to determine the ratio between [(3)H]dT incorporation and HA formation. This ratio was significantly higher for cells that grew on silicatein/biosilica-modified substrates than for cells on Ca-P-coated coverslips or plain glass slips. Hence, we propose that this ratio of in vitro-determined parameters reflects the osteogenic effect of different substrates on bone-forming cells. Finally, qRT-PCR analyses demonstrated that growth of SaOS-2 cells on a silicatein/biosilica matrix upregulated BMP2 (bone morphogenetic protein 2, inducer of bone formation) expression. In contrast, TRAP (tartrate-resistant acid phosphatase, modulator of bone resorption) expression remained unaffected. We conclude that biosilica shows pronounced osteogenicity in vitro, qualifying this material for studies of bone replacement also in vivo.

Dysregulation of the immune system caused by silica and asbestos

Silica and asbestos cause pneumoconioses known as silicosis and asbestosis, respectively, that are each characterized by progressive pulmonary fibrosis. While local effects of inhaled silica particles alter the function of alveolar macrophages and sequential cellular and molecular biological events, general systemic immunological effects may also evolve. One well-known health outcome associated with silica exposure/silicosis is an increase in the incidence of autoimmune disorders. In addition, while exposure to silica--in the crystalline form--has also been seen to be associated with the development of lung cancers, it remains unclear as to whether or not silicosis is a necessary condition for the elevation of silica-associated lung cancer risks. Since asbestos is a mineral silicate, it would be expected to also possess generalized immunotoxicological effects similar to those associated with silica particles. However, asbestos-exposed patients are far better known than silicotic patients for development of malignant diseases such as lung cancer and mesothelioma, and less so for the development of autoimmune disorders. With both asbestos and crystalline silica, one important dysregulatory outcome that needs to be considered is an alteration in tumor immunity that allows for silica- or asbestos- (or asbestos-associated agent)-induced tumors to survive and thrive in situ. In this review, the immunotoxicological effects of both silica and asbestos are presented and contrasted in terms of their abilities to induce immune system dysregulation that then are manifest by the onset of autoimmunity or by alterations in host-tumor immunity.

In vitro interactions between splenocytes and dansylamide dye-embedded nanoparticles detected by flow cytometry

Engineered nanoparticles (NPs) possess a range of biological activity. In vitro methods for assessing toxicity and efficacy would be enhanced by simultaneous quantitative information on the behavior of NPs in culture systems and signals of cell response. We have developed a method for visualizing NPs within cells using standard flow-cytometric techniques and uniquely designed spherical siloxane NPs with an embedded (covalently bound) dansylamide dye. This method allowed NP visualization without obscuring detection of relevant biomarkers of cell subtype, activation state, and other events relevant to assessing bioactivity. We determined that NPs penetrated cells and induced a range of biological signals consistent with activation and costimulation. These results indicate that NPs may affect cell function at concentrations below those inducing cytotoxicity or apoptosis and demonstrate a novel method to image both localization of NPs and cell-level effects.

FROM THE CLINICAL EDITOR

A method for visualizing NPs within cells using standard flow-cytometric techniques is reported in this paper. The novel method allowed NP visualization without obscuring detection of relevant biomarkers of cell subtype, activation state, and other events relevant to assessing bioactivity. NPs also induced a range of biological signals consistent with activation and costimulation.

Cytokine alteration and speculated immunological pathophysiology in silicosis and asbestos-related diseases

This review is partly composed of the presentation "Cytokine alteration and speculated immunological pathophysiology in silicosis and asbestos-related diseases" delivered during the symposium "Biological effects of fibrous and particulate substances and related areas" organized by the Study Group of Fibrous and Particulate Studies of the Japanese Society of Hygiene and held at the 78th Annual Meeting in Kumamoto, Japan. In this review, we briefly introduce the results of recent immunological analysis using the plasma of silica and asbestos-exposed patients diagnosed with silicosis, pleural plaque, or malignant mesothelioma. Thereafter, experimental background and speculation concerning the immunological pathophysiology of silica and asbestos-exposed patients are discussed.

Soluble Interleukin-2 Receptor as an Indicator of Immunological Disturbance Found in Silicosis Patients

Silicosis patients (SILs) possess not only respiratory disorders but also alterations in autoimmunity. To determine an early indicator of immunological disturbance in SILs, the role of serum-soluble interleukin (IL)-2 receptor (sIL-2R) was analyzed. Of ten SILs, immunological clinical parameters such as immunoglobulin (Ig) G, complements, the titer of autoantibodies including anti-nuclear antibodies (ANA), anti-Scl-70 antibody (Ab) and anti-centromere (CM) Ab, and experimental indicators such as serum-soluble Fas, serum IL-2, CD25+ cells in CD4+ or CD8+ fractions, and sIL-2R were divided from respiratory parameters such as % vital capacity (%VC), percentage of forced expiratory volume in 1 second (FEV1.0%) and v25/Ht (liter/second/m(body height) by a correlation assay. Additionally, a stepwise regression test showed that sIL-2R was correlated with Ig G, ANA and anti-CM Ab. Furthermore, factor analysis revealed that sIL-2R contributed to the subpopulation of SILs with poorer immunological status in the absence of alterations in respiratory status. By defining healthy donors as 1, SILs as 2 and patients with systemic sclerosis as 3 for immunopathological progression status as metric variables, sIL2R and ANA showed a strong positive correlation. This suggests that sIL-2R is a good clinical indicator of immunological disturbance found in SILs without clinical manifestations of any disturbance in autoimmunity. Further analysis using a large-scale number of patients should be performed to confirm these findings.

Altered systemic serologic parameters in patients with silicone mammary implants

BACKGROUND

The most common local complication in patients with silicone mammary implants (SMIs) is excessive peri-SMI connective tissue capsule formation and its subsequent contracture. However, considerable controversy remains as to whether these implants also cause systemic side effects. The present study was undertaken to identify possible alterations of serological markers in SMI patients that may herald systemic side effects.

METHODS

We investigated several systemic serological parameters in 143 individuals, 93 of whom had received SMIs and 50 were controls. The patients were grouped according to the severity of capsular contracture (Baker scores I-IV) and the duration of SMI implants (less than 1 year, between 1 and 5 years, more than 5 years). We also included control groups (female blood donors, nurses with possible professional silicone exposure). Patients with breast cancer and subsequent SMI-reconstruction were excluded from the study since they are generally considered immunocompromised. The following parameters were determined: anti-neutrophil cytoplasmatic autoantibodies (cANCA), anti-nuclear autoantibodies (ANA), anti-cardiolipin antibodies (CL-Ab), rheumatoid factor (RF), complement components (C3, C4), circulating immune complexes (CIC), procollagen III (a marker of active fibrosis), anti-polymer antibodies (APA) and soluble intercellular adhesion molecule-1 (sICAM-1).

RESULTS

The following parameters were increased in the sera of SMI patients: CIC, procollagen III, APA, sICAM-1.

CONCLUSIONS

We found a set of parameters in serum that correlate with fibrosis development and the duration of the implants in otherwise healthy SMI carriers. Future studies will clarify whether these serological abnormalities will be useful in predicting clinical disease, and also further assess the sensitivity and specificity of these parameters. Our present recommendation as a result of this study is that SMI patients with persistent abnormal serological parameters should be monitored closely by a clinical team that includes rheumatologists.

The X and why of xenobiotics in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic autoimmune liver disease characterized by inflammation and destruction of intrahepatic biliary epithelial cells, ultimately leading to liver failure. The serological hallmark of PBC is the presence of high-titer antimitochondrial antibodies (AMA) against the inner lipoyl domain of E2 subunits of 2-oxo-acid dehydrogenase complexes, in particular the E2 component of the pyruvate dehydrogenase complex (PDC-E2). The initiating events triggering the autoimmune response are not yet identified but the hypothesis of molecular mimicry is a widely proposed mechanism for the development of autoimmunity in PBC. Several candidates, including bacteria and viruses, have been suggested as causative agents, but also environmental factors, such as chemical xenobiotics, have been implicated in the pathogenesis of primary biliary cirrhosis. In this review, we will discuss our current knowledge of the immunoreactivity of xenobiotically modified PDC peptide antigens. In addition, we will provide a working hypothesis how xenobiotic modification of antigens might occur that ultimately leads to the breaking of self-tolerance and the induction of PBC.

Expression of the T cell receptor Vbeta repertoire in a human T cell resistant to asbestos-induced apoptosis and peripheral blood T cells from patients with silica and asbestos-related diseases

To explore the effects of asbestos and silica on the human immune system, an experimental model of low-dose and long-term exposure was established using a human HTLV-1-immortalized polyclonal T cell line, MT-2 (MT-2Org). MT-2 cells were continuously exposed to asbestos at a concentration (10 microg/ml) which does not induce complete cell death during short-term exposure. After acquiring resistance to CB-induced apoptosis (designated MT-2Rst), an immunological comparison was made between the MT-2Org and MT-2Rst lines in terms of T cell receptor-Vbeta (TcR-Vbeta) expression. MT-2Rst cells showed excess expression of various TcR-Vbeta, although TcR-Vbeta-overpresenting cells were characterized as undergoing apoptosis due to first contact with CB. Patients with asbestos-related diseases (ARD), such as asbestosis and malignant mesothelioma, were compared with silicosis (SIL) patients as a disease control and with healthy donors (HD). SIL and ARD not only differed in their causative materials, silica and asbestos as mineral silicates, but also in terms of complications; autoimmune disorders in SIL and tumors in ARD. ARD patients showed a restricted overpresentation of TcR-Vbeta without clonal expansion, whereas SIL patients revealed significant overpresentation of TcR-Vbeta 7.2. These experimental and clinical analyses indicate the superantigenic and dysregulation of autoimmunity-inducing effects of asbestos and silica, respectively.

Reduced function of CD4+25+ regulatory T cell fraction in silicosis patients

The quality and quantity of CD4+25+ regulatory T cells (Treg) in silicosis patients (SIL) were examined and compared with results from healthy donors (HD) because SIL often develop autoimmune diseases along with pulmonary disorders. Peripheral blood mononuclear cells from 57 SIL and 50 HD were analyzed for Treg. Treg frequency and clinical parameters were subjected to a factor analysis. Treg and CD4+25- T cells (Tneg) from five HD and five SIL, sorted by flow-cytometer, were used for functional assays of Treg, the expression pattern of Treg specific genes (FoxP3, GITR and CTLA-4) and activation-related genes (CD122 and CD123). Although the actual frequency of Treg did not differ between SIL and HD, the age-corrected level was reduced in SIL. The factor analysis showed that Treg frequency was positively associated with the serum level of IL-2. The inhibitory effect of Treg on Tneg activation was decreased when the Treg:Tneg ratio was 1:1/4 to 1/2. In addition, Treg dominancy of FoxP3 and CTLA-4 expression and Tneg dominancy of CD132 expression found in HD were lost in SIL. These results indicated that the Treg fraction in SIL may be substituted with chronically activated T cells due to recurrent exposure to silica, resulting in a reduction in the frequency and function of Treg. Since the reduction of Treg may precede the clinical manifestation, as silicosis may be a pre-clinical status for autoimmune diseases, control of Treg function using cell and/or gene therapy may be a good way to manage autoimmune disease.

Induction of CD69 antigen expression in peripheral blood mononuclear cells on exposure to silica, but not by asbestos/chrysotile-A

While cases of silicosis are often complicated by various autoimmune disorders, patients with asbestosis develop malignant tumors such as lung cancer and malignant mesothelioma. These differences may derive from different biological effects, particularly on immunological cells, of silica and asbestos. To find differences between silica and asbestos, the early activation antigen, CD69, on T cells was examined because dysregulated and continuous activation of T cells may promote the survival of self-recognizing T cells. After cultivation of peripheral blood mononuclear cells with or without silica or chrysotile-A, an asbestos, only silica induced CD69 expression on the lymphocytes. This induction of CD69 expression was mediated by protein kinase C activation. In addition, cell-cell contact mediated by HLA-DR was more important than soluble factors secreted from silica-phagocytosed cells such as IL-1beta, IL-6, and IL-8, even though IL-6 and IL-8 were produced during the culture of PBMCs with silica and chrysotile-A. It should be examined how these activated, CD69-expressing lymphocytes affect other immune systems as well as alter themselves in terms of cytokine production and cell-cell interaction, leading to autoimmune disorders in silicosis patients.

Setons and serum IgG titers to silicone

PURPOSE

To determine whether exposure to silicone shunts used in refractory glaucomas increases serum IgG binding to silicone and whether this response is associated with shunt-related complications or poor postoperative intraocular pressure control.

METHODS

Sera from 12 patients (13 eyes) who had undergone placement of silicone seton implants were examined for IgG binding to silicone. Patients were monitored postoperatively for the occurrence of complications and intraocular pressure elevation (mean duration of exposure to silicone and follow-up, 25.1 months; range, 2.5-86 months).

RESULTS

The levels of serum IgG binding in 4 of the 12 patients were two standard deviations above the mean for control sera. No patients had titers greater than 46 arbitrary units (AU). Four patients developed shunt-related complications; the serum IgG binding to silicone for their sera ranged from 24 to 46 AU. Serum IgG binding values were not significantly correlated with poor postoperative intraocular pressure control, or with a history of autoimmune disease or malignancy, type of glaucoma, previous intraocular surgery, or chronic uveitis.

CONCLUSIONS

Although elevation of serum IgG binding to silicone may be noted in some patients receiving silicone seton shunts, individual levels do not seem to predict the development of shunt-related complications. Since the number of patients tested, the frequency of elevated IgG binding values, and the complication rate were relatively low in this study, it is difficult to exclude some clinicopathologic correlations. However, the results are in accord with previous studies of silicone ocular devices suggesting that clinically significant reactions to silicone ophthalmic implants must be rare events, and hence do not necessitate altering the use of these important devices.

Alterations in immune parameters in foundry and pottery workers

To assess the immune competence of workers occupationally exposed to mainly silica, peripheral blood lymphocytes, serum immunoglobulins (IgG, IgA and IgM), C3 and C4 complement protein concentrations of foundry and pottery workers were evaluated and compared to healthy controls with no history of silica and other chemical exposure. The absolute number and percentage of functionally different subsets of peripheral blood mononuclear lymphocytes, i.e. T, T-suppressor and natural killer cells were unchanged. However, T-helper lymphocytes in pottery (P<0.05) and B cells in foundry (P<0.01) workers were significantly lower when compared to their controls. In addition, silica-exposed foundry workers had a significant reduction in the IgG, IgA and IgM levels. No significant differences were observed in the serum complement C3 and C4 levels of the workers. These results suggest that human chronic exposure to mainly silica and other chemicals originating from foundry and pottery settings may be detrimental to the immune system.

Pathogenetic and diagnostic aspects of siliconosis

Silicones have an adverse effect on human health well beyond that suggested by the recent superficial public controversy. The evidence for immune responses to injected/implanted silicones is extensive, detailed, often very specific, and not at all new. Comprehending the immunopathogenicity, realized and potential, of silicone has grown as our general understanding of the immune system has developed. Several major issues in furthering this comprehension pertain to the nature of the essential epitope, special risk of silicones to women, and definition of the chronic disease complex so evident clinically, one defying classification within currently traditional disease categories and states. The commentary presented here emphasizes the immunopathic evidence, explores the question of the essential epitope, estimates the minimal threshold of silicone load for immune reactivity, presents a profile of autoantibodies for siliconosis, and calls attention to specific silicone-based female contraceptive modalities. The silicone content of personal care products, not always revealed by retail package labeling, is explored as a potential sensitizing factor in the environment.

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.

Restricted and shared patterns of TCR beta-chain gene expression in silicone breast implant capsules and remote sites of tissue inflammation

Silicone breast implants (SBI) induce formation of a periprosthetic, often inflammatory, fibrovascular neo-tissue called a capsule. Histopathology of explanted capsules varies from densely fibrotic, acellular specimens to those showing intense inflammation with activated macrophages, multinucleated giant cells, and lymphocytic infiltrates. It has been proposed that capsule-infiltrating lymphocytes comprise a secondary, bystander component of an otherwise benign foreign body response in women with SBIs. In symptomatic women with SBIs, however, the relationship of capsular inflammation to inflammation in other remote tissues remains unclear. In the present study, we utilized a combination of TCR beta-chain CDR3 spectratyping and DNA sequence analysis to assess the clonal heterogeneity of T cells infiltrating SBI capsules and remote, inflammatory tissues. TCR CDR3 fragment analysis of 22 distinct beta variable (BV) gene families revealed heterogeneous patterns of T cell infiltration in patients' capsules. In some cases, however, TCR BV transcripts exhibiting restricted clonality with shared CDR3 lengths were detected in left and right SBI capsules and other inflammatory tissues. DNA sequence analysis of shared, size-restricted CDR3 fragments confirmed that certain TCR BV transcripts isolated from left and right SBI capsules and multiple, extracapsular tissues had identical amino acid sequences within the CDR3 antigen binding domain. These data suggest that shared, antigen-driven T cell responses may contribute to chronic inflammation in SBI capsules as well as systemic sites of tissue injury.

Dynamics of wound healing after silicone device implantation

A large surgical wound is required for implantation of silicone mammary devices. Formation of capsules around silicone devices follows wound healing processes except that the healing is conformed and significantly delayed by the physical presence of the implant. Multilayered capsules are thicker and lymphocytic and plasmalymphocytic vasculitis, markers for delayed hypersensitivity, also correlate with thicker capsules. Polyurethane-coated devices induce very thick capsules that remain so for over 20 years. By contrast, gel and saline content devices show maximum thickness at 6. 5 years. Active T(H) lymphocyte memory does not differ by implant type for individuals with devices in place and that for gel content devices peaks at 10.5 years. There was a significant decrease in T cell indexes only after the removal of saline content devices. Comparison of the rate of formation of the periprosthetic capsule with the healing time of large wounds of similar size indicates that silicone devices interfere with the healing process, requiring substantially more time. This extended period has the potential for enhancing autoimmune conversion as a consequence of persistent delayed hypersensitivity.