Induction of hypergammaglobulinemia and macrophage activation by silicone gels and oils in female A.SW mice

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.

[ASIA syndrome associated with breast implants: Fortuitous link or association?]

OBJECTIVE

The "Autoimmune/Autoinflammatory Syndrome Induced by Adjuvants" (ASIA syndrome) described in 2011 by Shoenfeld and Agmon-Levin is believed to be the consequence of several immunological dysfunctions triggered by exposure to an adjuvant. Controversies regarding the existence of this syndrome and its possible link to silicone breast implants (SBI) have been growing via social networks and patient groups. The objective of our review was to identify all published cases of ASIA syndromes in SBI carriers to determine the circumstances of onset, key characteristics, and possible biases.

METHOD

A literature search of the Pubmed database selecting only original articles written in English between 2011 and 2019 found 126 cases of ASIA syndromes, defined according to the criteria of Shoenfeld and Agmon-Levin, associated with SBI.

RESULTS

This syndrome was diagnosed in nearly ¾ cases in a context of prosthetic complications (rupture, effusion, peri-prosthetic shell, infection) with a median time interval of 4 years between SBI implantation and the onset of symptoms. Explantation of the SBI led to an improvement in symptoms in about half of the cases. However, animal, biological and histological studies have provided conflicting results on the links between silicone and dysimmune syndromes.

CONCLUSION

Women should be clearly, fairly and appropriately informed of our uncertainties about ASIA syndrome. Mandatory reporting of dysimmune syndromes occurring in silicone MI carriers would increase our knowledge of this still poorly understood condition, for which a genetic predisposition is being investigated.

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.

Autoimmune/inflammatory syndrome induced by adjuvants (Shoenfeld’s syndrome) – An update

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) has been widely described in many studies conducted thus far. The syndrome incorporates five immune-mediated conditions, all associated with previous exposure to various agents such as vaccines, silicone implants and several others. The emergence of ASIA syndrome is associated with individual genetic predisposition, for instance those carrying HLA-DRB1*01 or HLA-DRB4 and results from exposure to external or endogenous factors triggering autoimmunity. Such factors have been demonstrated as able to induce autoimmunity in both animal models and humans via a variety of proposed mechanisms. In recent years, physicians have become more aware of the existence of ASIA syndrome and the relationship between adjuvants exposure and autoimmunity and more cases are being reported. Accordingly, we have created a registry that includes at present more than 300 ASIA syndrome cases that have been reported by different physicians worldwide, describing various autoimmune conditions induced by diverse adjuvants.

In this review, we have summarized the updated literature on ASIA syndrome and the knowledge accumulated since 2013 in order to elucidate the association between the exposure to various adjuvant agents and its possible clinical manifestations. Furthermore, we especially referred to the relationship between ASIA syndrome and systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).

Intravascular large B-cell lymphoma associated with silicone breast implant, HLA-DRB1*11:01, and HLA-DQB1*03:01 manifesting as macrophage activation syndrome and with severe neurological symptoms: a case report

BACKGROUND

Silicone implants have been successfully used for breast augmentation and reconstruction in millions of women worldwide. The reaction to the silicone implant is highly variable; it can lead to local inflammatory symptoms, and sometimes to systemic symptoms and disease. Over 80 cases of anaplastic lymphoma kinase-negative anaplastic large cell lymphoma have been reported in patients with silicone breast implants and have been accepted as a new clinical entity. To the best of our knowledge, an intravascular large B-cell lymphoma associated with a silicone breast implant has not been reported previously.

CASE PRESENTATION

A 48-year-old Caucasian woman who presented with high fever was found to have splenomegaly on physical examination. A laboratory diagnosis revealed pancytopenia, hypertriglyceridemia, and hyperferritinemia. She developed signs of altered sensorium, hemiparesis, aphasia, and cauda equina syndrome. On further evaluation, she fulfilled the necessary five out of eight criteria for diagnosis of macrophage activation syndrome/hemophagocytic lymphohistiocytosis. Dexamethasone administration was followed by prompt improvement; however, 3 days later she again manifested high fever, which persisted despite administration of immunoglobulin and cyclosporine A. Her silicone breast implant was considered a possible contributor to her macrophage activation syndrome and was therefore removed. A histological examination of the capsule tissue showed an extensive lymphohistiocytic/giant cell foreign body reaction suggestive of autoimmune/inflammatory syndrome induced by adjuvants. However, the histological examination unexpectedly also revealed an intravascular large B-cell lymphoma.

CONCLUSIONS

The genetic background of our patient with silicone breast implants might have predisposed her to three rare and difficult to diagnose syndromes/diseases: macrophage activation syndrome/hemophagocytic lymphohistiocytosis, autoimmune/inflammatory syndrome induced by adjuvants, and intravascular large B-cell lymphoma. The simultaneous manifestation of all three syndromes suggests causal interrelationships. Human leukocyte antigen testing in all women who undergo silicon breast implantation could in the future enable us to better evaluate the risk of potential side effects.

The interaction of human macrophage subsets with silicone as a biomaterial

Silicones are widely used as biomaterials for medical devices such as extracorporeal equipments. However, there is often conflicting evidence about their supposed cell- and histocompatibility. Macrophages could mediate silicone-induced adverse responses such as foreign body reaction and fibrous encapsulation. The polarization behaviour of macrophages could determine the clinical outcome after implantation of biomaterials. Induction of classically activated macrophages (CAM) may induce and support uncontrolled inflammatory responses and undesired material degradation. In contrast, polarization into alternatively activated macrophages (AAM) is assumed to support healing processes and implant integration.This study compared the interaction of non-polarized macrophages (M0), CAM, and AAM with commercially available tissue culture polystyrene (TCP) and a medical grade silicone-based biomaterial, regarding the secretion of inflammatory mediators such as cytokines and chemokines. Firstly, by using the Limulus amoebocyte lysate (LAL) test the silicone films were shown to be free of soluble endotoxins, which is the prerequisite to investigate their interaction with primary immune cells. Primary human monocyte-derived macrophages (M0) were polarized into CAM and AAM by addition of suitable differentiation factors. These macrophage subsets were incubated on the materials for 24 hours and their viability and cytokine secretion was assessed. In comparison to TCP, cell adhesion was lower on silicone after 24 hours for all three macrophage subsets. However, compared to TCP, silicone induced higher levels of certain inflammatory and chemotactic cytokines in M0, CAM, and AAM macrophage subsets.Conclusively, it was shown that silicone has the ability to induce a pro-inflammatory state to different magnitudes dependent on the macrophage subsets. This priming of the macrophage phenotype by silicone could explain the incidence of severe foreign body complications observed in vivo.

Silicone implants and lymphoma: The role of inflammation

The risk of hematological malignancies is mainly determined by genetic background, age, sex, race and ethnicity, geographic location, exposure to certain chemicals and radiation; along with the more recently proposed immune factors such as chronic inflammation, immunodeficiencies, autoimmunity, and infections. Paradigmatic examples include the development of lymphoma in Sjögren's syndrome and Hashimoto thyroiditis, gastric MALT lymphoma in Helicobacter pylori infection, or lymphomas associated with infections by Epstein-Barr virus, human herpes virus 8 (HHV 8) and leukemia/lymphoma virus 1 (HTLV-1). A growing number of reports indicates an increased risk of lymphoma, particularly of the anaplastic large cell (ALCL) type. The implants, specifically those used in the past, elicit chronic stimulation of the immune system against the prosthetic material. This is particularly the case in genetically susceptible hosts. We suggest that polyclonal activation may result in monoclonality in those at risk hosts, ultimately leading to lymphoma. We suggest that patients with an inflammatory response against silicone implants be monitored carefully.

Severe ASIA syndrome associated with lymph node, thoracic, and pulmonary silicone infiltration following breast implant rupture: experience with four cases

Silicone has been considered biologically inert; thus it has been employed in many medical devices and nowadays is commonly used in plastic surgery for mammary prosthesis. It is well tolerated in most cases. However, autoimmune disorders and siliconomas with granulomatous reactions after silicone implant rupture have been described. We report cases of four women who developed systemic disorders following rupture of silicone breast implants resulting in lymph node and thoracic silicone infiltration. The symptoms in these cases, including arthralgia, myalgia, generalized weakness, severe fatigue, sleeping disturbances, cognitive impairment, memory loss, irritable bowel syndrome, and weight loss, clearly match the criteria of the recently defined autoimmune/inflammatory syndrome induced by adjuvants (ASIA).

Effects of pristane alone or combined with chloroquine on macrophage activation, oxidative stress, and TH1/TH2 skewness

We investigated the protective role of chloroquine against pristane-induced macrophage activation, oxidative stress, and Th1/Th2 skewness in C57BL/6J mice. Those mice were treated with pristane alone or combined with chloroquine. Hematological and biochemical parameters, macrophage phagocytic function, the oxidant/antioxidant index, cytokine for IFN-γ, TNF-α, IL-4, and IL-6, and the isotypes of IgG2a and IgG1 were determined. And the expression of T-bet/GATA-3 and IL-12/IL-10 mRNA in spleen were analyzed by real-time PCR. We found that pristane treatment for a period of 12 or 24 weeks triggered macrophage activation syndrome, characterized by hemophagocytosis in spleen and peripheral blood, enhanced lipid phagocytosis by peritoneal macrophages in vitro, erythropenia and leucopenia, increased anti-Smith, lactic dehydrogenase, triglyceride, and ferritin, as well as hypercytokinemia of IFN-γ, TNF-α, IL-4, and IL-6. In parallel, a significant increase in lipid peroxidation and a decrease in superoxide dismutase, glutathione, and catalase activity, as well as a skewed Th1/Th2 balance in spleen, were observed. However, chloroquine supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that pristane administration induces macrophage activation, oxidative stress, and Th1/Th2 skewness, which can be attenuated by chloroquine.

Medical-grade silicone induces release of proinflammatory cytokines in peripheral blood mononuclear cells without activating T cells

For more than 40 years, silicone implants had been employed in aesthetic, cosmetic medicine, and plastic surgery. Although adverse reactions produced by these products are rare, cases of immuno-mediated reactions have been reported. To evaluate the aspects of immuno-reactivity to medical-grade silicone dermal filler, peripheral blood mononuclear cells (PBMC) of 39 individuals were studied. PBMC used include individuals with silicone injection-related delayed adverse reactions, with silicone injections, and healthy control. Silicone induced production of TNF-alpha and IL-6 in all three groups. Notably, elevated production of IL-6 was observed in nonstimulated PBMC and also the percentage of CD4(+)CD69(+) T cells was higher in PHA-stimulated PBMC from individuals with silicone injection-related adverse reactions when compared with other two groups. However, IFN-gamma was not released in silicone-stimulated or silicone+LPS-stimulated PBMC from any group and no production of IL-2 was measured indicating no proliferative response of PBMC. Subsequently, no CD4(+)CD69(+) T cells were observed in these conditions. Finally, the inflammatory response in silicone-stimulated cultures of monocyte-derived macrophages with autologous lymphocytes is lesser than that observed in PBMC. In conclusion, silicone induces a release of proinflammatory cytokines but does not act as a polyclonal activator of CD4(+) T cells. Thus, silicone is mounting an immune response in individuals with silicone-related adverse effects but is not silicone antigen-dependent.

Polydimethylsiloxane: An effective immune adjuvant and slow-release cytokine medium for local cancer treatment

Background and Aim

Silicone oil or gel has well-defined chemotactic properties on monocytes and lymphocytes in vivo. It results in fibrotic reaction when spread into the human tissues either incidentally or purposely and can slowly release any physically-enclosed lyophilized compounds due to its viscosity. Our aim is to investigate whether polydimethylsiloxane could be considered as an effective medium in the local treatment of cancer.

Materials and Methods

Our study was conducted between January 2004 and December 2006 on 15 patients with various types of cancer. The criteria for selection included patients with locally-advanced tumor that was rapidly growing and life threatening and those who had poor quality of life and general wellbeing. The patients were already discharged from the cancer centre before joining the study, after they had already received their chemoradiation protocol. Once a week for one month, different areas of the tumor were injected with 0.25 ml of polydimethylsiloxane medical grade (viscosity: 350 centistokes at 30°C), mixed with 300,000 units of lyophilized human IL-2. Tumor biopsies were taken before the study was started and one week after the last injection for the histopathological analysis of the percentage of severe inflammatory reaction using an image analysis system. CT scans of the tumor were taken before the injection cycle was started and one week after the last injection in order to determine the percentage change in the size of the tumor. The quality of life and general wellbeing of the patients was assessed at the beginning of the stud, and one week after the study was over by using the Karnofsky performance test.

Results

Our treatment was well tolerated by the patients. They had a significant improvement in their quality of life and general well being (p = 0.0005). The prognosis of the patients before the beginning of the study ranged between 1 and 6 months, while their overall survival after treatment was between 2 and 12 months, with three patients still remaining alive. A significant decrease in the tumor size was observed at the end of the study in 12 patients (p < 0.0001). Such a decrease was associated with a significant increase in the percentage of the tumor containing a severe immune reaction (p <0.0001). A significant correlation was found between the percentage reduction in tumor size and the percentage of tumor immune reaction (r² = 0.968; p < 0.0001).

Conclusion

Polydimethylsiloxane could be used as an effective cytokine medium in the local treatment of cancer. When injected inside the tumor, it is capable of creating and modulating an effective, slow and persistent antitumor immune response. Moreover, it is capable of improving the overall survival as well as the quality of life and general well being of the cancer patients.

Cutting edge: K63-linked polyubiquitination of NEMO modulates TLR signaling and inflammation in vivo

Transcription factor NF-kappaB controls the expression of multiple genes involved in immunity and inflammation. The initial activation and duration of NF-kappaB signaling is regulated by posttranslational modifications to IkappaB kinase, which earmarks inhibitors of NF-kappaB for degradation. Prior studies suggest that K63-linked ubiquitination of NEMO (NF-kappaB essential modulator), an IkappaB kinase regulatory subunit, is critical for NF-kappaB and MAPK signaling following engagement of Ag receptors. We now demonstrate that NF-kappaB and MAPK pathways are largely unaffected in primary cells from mice harboring a ubiquitination-defective form of NEMO, NEMO-KR. TLR- but not Ag receptor-induced cellular responses are impaired in NEMO-KR mice, which are more resistant to LPS-induced endotoxic shock than wild-type animals. Thus, one function of NEMO ubiquitination is to fine tune innate immune responses under TLR control.

Functional analysis of histone methyltransferase g9a in B and T lymphocytes

Lymphocyte development is controlled by dynamic repression and activation of gene expression. These developmental programs include the ordered, tissue-specific assembly of Ag receptor genes by V(D)J recombination. Changes in gene expression and the targeting of V(D)J recombination are largely controlled by patterns of epigenetic modifications imprinted on histones and DNA, which alter chromatin accessibility to nuclear factors. An important component of this epigenetic code is methylation of histone H3 at lysine 9 (H3K9me), which is catalyzed by histone methyltransferases and generally leads to gene repression. However, the function and genetic targets of H3K9 methyltransferases during lymphocyte development remain unknown. To elucidate the in vivo function of H3K9me, we generated mice lacking G9a, a major H3K9 histone methyltransferase, in lymphocytes. Surprisingly, lymphocyte development is unperturbed in G9a-deficient mice despite a significant loss of H3K9me2 in precursor B cells. G9a deficiency is manifest as modest defects in the proliferative capacity of mature B cells and their differentiation into plasma cells following stimulation with LPS and IL-4. Precursor lymphocytes from the mutant mice retain tissue- and stage-specific control over V(D)J recombination. However, G9a deficiency results in reduced usage of Iglambda L chains and a corresponding inhibition of Iglambda gene assembly in bone marrow precursors. These findings indicate that the H3K9me2 epigenetic mark affects a highly restricted set of processes during lymphocyte development and activation.

Serum proteins and paraproteins in women with silicone implants and connective tissue disease: a case-control study

Prior studies have suggested abnormalities of serum proteins, including paraproteins, in women with silicone implants but did not control for the presence of connective-tissue disease (CTD). This retrospective case–control study, performed in tertiary-care academic centers, assessed possible alterations of serum proteins, including paraproteins, in such a population. Seventy-four women with silicone implants who subsequently developed CTD, and 74 age-matched and CTD-matched women without silicone implants, were assessed in the primary study; other groups were used for additional comparisons. Routine serum protein determinations and high-sensitivity protein electrophoresis and immunofixation electrophoresis were performed for detection of paraproteins. Women with silicone implants, either with or without CTD, had significantly lower serum total protein and α₁-globulin, α₂-globulin, β-globulin, γ-globulin, and IgG levels compared with those without silicone implants. There was no significant difference, however, in the frequency of paraproteinemia between women with silicone implants and CTD (9.5%) and age-matched and CTD-matched women without silicone implants (5.4%) (odds ratio, 1.82; 95% confidence interval, 0.51–6.45). Paraprotein isotypes were similar in the two groups, and the clinical characteristics of the 13 women with paraproteinemia were comparable with an independent population of 10 women with silicone breast implants, CTD, and previously diagnosed monoclonal gammopathies. In summary, this first comprehensive study of serum proteins in women with silicone implants and CTD found no substantially increased risk of monoclonal gammopathy. Women with silicone implants, however, had unexpectedly low serum globulin and immunoglobulin levels, with or without the subsequent development of CTD. The causes and clinical implications of these findings require further investigation.

Vascularized adipose tissue grafts from human mesenchymal stem cells with bioactive cues and microchannel conduits

Vascularization is critical to the survival of engineered tissues. This study combined biophysical and bioactive approaches to induce neovascularization in vivo. Further, we tested the effects of engineered vascularization on adipose tissue grafts. Hydrogel cylinders were fabricated from poly(ethylene glycol) diacrylate (PEG) in four configurations: PEG alone, PEG with basic fibroblast growth factor (bFGF), microchanneled PEG, or both bFGF-adsorbed and microchanneled PEG. In vivo implantation revealed no neovascularization in PEG, but substantial angiogenesis in bFGF-adsorbed and/or microchanneled PEG. The infiltrating host tissue consisted of erythrocyte-filled blood vessels lined by endothelial cells, and immunolocalized to vascular endothelial growth factor (VEGF). Human mesenchymal stem cells were differentiated into adipogenic cells, and encapsulated in PEG with both microchanneled and adsorbed bFGF. Upon in vivo implantation subcutaneously in immunodeficient mice, oil red O positive adipose tissue was present and interspersed with interstitial fibrous (IF) capsules. VEGF was immunolocalized in the IF capsules surrounding the engineered adipose tissue. These findings suggest that bioactive cues and/or microchannels promote the genesis of vascularized tissue phenotypes such as the tested adipose tissue grafts. Especially, engineered microchannels may provide a generic approach for modifying existing biomaterials by providing conduits for vascularization and/or diffusion.

Immune reactions associated with silicone-based ventriculo-peritoneal shunt malfunctions in children

The implantation of ventriculo-peritoneal (VP) shunting systems is the most commonly performed neurological procedure in children with hydrocephalus. Although the overall complication risk is low, the cumulative risk of shunt failure is high and unfortunately results in a high prevalence of revision surgeries. In this study, we explored the concept that some pediatric patients may develop an immune response to either the proteins attached to the silicone implant surface or to the biomaterial itself, and that this reaction may contribute to VP shunt failure in some individuals. The data displays that the sterile shunt malfunction group had a higher rate of protein deposition and increased levels of autoantibodies to the extracted surface proteins as compared to individuals with functioning shunting systems. The precise nature of the shunt-bound proteins that serve as antigens in this experiment have not yet been determined. The data also indicated that some individuals develop antibodies to polymeric substances that cross-react with partially polymerized acrylamide. The detection of significant amounts of shunt-bound protein, antibody responses to these proteins and to polymeric substances suggest that an immunological response to these proteins may play a role in the mechanism behind sterile shunt malfunctions.

Autoimmunity induced by adjuvant hydrocarbon oil components of vaccine

Adjuvant oils such as Bayol F (Incomplete Freund's adjuvant: IFA) and squalene (MF59) have been used in human and veterinary vaccines despite poor understanding of their mechanisms of action. Several reports suggest an association of vaccination and various autoimmune diseases, however, few were confirmed epidemiologically and the risk of vaccination for autoimmune diseases has been considered minimal. Microbial components, not the adjuvant components, are considered to be of primary importance for adverse effects of vaccines. We have reported that a single intraperitoneal injection of the adjuvant oils pristane, IFA or squalene induces lupus-related autoantibodies to nRNP/Sm and -Su in non-autoimmune BALB/c mice. Induction of these autoantibodies appeared to be associated with the hydrocarbon's ability to induce IL-12, IL-6, and TNF-alpha, suggesting a relationship with hydrocarbon's adjuvanticity. Whether this is relevant in human vaccination is a difficult issue due to the complex effects of vaccines and the fact that immunotoxicological effects vary depending on species, route, dose, and duration of administration. Nevertheless, the potential of adjuvant hydrocarbon oils to induce autoimmunity has implications in the use of oil adjuvants in human and veterinary vaccines as well as basic research.

Concentration-dependent regulation of thyrotropin receptor function by thyroid-stimulating antibody

Thyrotropin receptor (TSHR) Ab's of the stimulating variety are the cause of hyperthyroid Graves disease. MS-1 is a hamster mAb with TSHR-stimulating activity. To examine the in vivo biological activity of MS-1, mice were treated with purified MS-1 intraperitoneally and the thyroid response evaluated. MS-1 induced a dose-dependent increase in serum thyroxine (T4), with a maximum effect after 10 proportional, variant g of MS-1 was administered. MS-1-secreting hybridoma cells were then transferred into the peritoneum of nude mice to study chronic thyroid stimulation. Serum MS-1 levels detected after 2 weeks were approximately 10-50 proportional, variant g/ml, and the serum TSH was suppressed in all animals. Serum triiodothyronine levels were elevated, but only in animals with low serum MS-1 concentrations. In addition, there was a negative correlation between serum T4 and the serum MS-1 concentrations. These in vivo studies suggested a partial TSHR inactivation induced by excessive stimulation by MS-1. We confirmed this inactivation by demonstrating MS-1 modulation of TSHR function in vitro as evidenced by downregulation and desensitization of the TSHR at concentrations of MS-1 achieved in the in vivo studies. Thus, inactivation of the TSHR by stimulating TSHR autoantibodies (TSHR-Ab's) in Graves disease patients may provide a functional explanation for the poor correlation between thyroid function and serum TSHR-Ab concentrations.

Multinucleated giant cells in periretinal silicone granulomas are associated with progressive proliferative vitreoretinopathy

PURPOSE

To determine the histologic features of granulomatous reactions in persilicone periretinal proliferation.

PATIENTS AND METHODS

This retrospective study included 12 patients with recurrent retinal detachment and persilicone granulomatous proliferation after vitrectomy for proliferative vitreoretinopathy (PVR). All patients underwent reoperation for membrane surgery. Immunohistochemical study of the excised periretinal membranes was performed with cytokeratins, GFAP, vimentin, CD68, CD45, and lysozyme antibodies.

RESULTS

The cellular characteristics of periretinal granulomas allow differentiation of two types of tissue. Spongy tissue (nine cases) showed an accumulation of mature vacuolated macrophages that contained silicone without multinucleated giant cells (MGC). The second type (three cases) consisted of an accumulation of sparsely vacuolated macrophages, epithelioid cells, and MGC. The MGC corresponded to transition forms of foreign body giant cells (FBGC). Spongy tissue was associated with anatomic success (58.3% of cases) and with stabilized PVR (66.7% of cases) at the time of the membrane surgery. MGC were associated with prolonged silicone oil tamponade, recurrent retinal detachment, and progressive PVR.

CONCLUSIONS

Intraocular silicone oil can lead to periretinal foreign body granulomas. FBGC are occasionally observed and were associated with progressive PVR.

Activation of macrophages by silicones: phenotype and production of oxidant metabolites

BACKGROUND

The effect of silicones on the immune function is not fully characterized. In clinical and experimental studies, immune alterations associated with silicone gel seem to be related to macrophage activation. In this work we examined in vivo, phenotypic and functional changes on peritoneal macrophages early (24 h or 48 h) and late (45 days) after the intraperitoneal (i.p.) injection of dimethylpolysiloxane (DMPS) (silicone). We studied the expression of adhesion and co-stimulatory molecules and both the spontaneous and the stimulated production of reactive oxygen intermediates and nitric oxide (NO).

RESULTS

The results presented here demonstrate that the fluid compound DMPS induced a persistent cell recruitment at the site of the injection. Besides, cell activation was still evident 45 days after the silicone injection: activated macrophages exhibited an increased expression of adhesion (CD54 and CD44) and co-stimulatory molecules (CD86) and an enhanced production of oxidant metabolites and NO.

CONCLUSIONS

Silicones induced a persistent recruitment of leukocytes at the site of the injection and macrophage activation was still evident 45 days after the injection.

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.