An analytical review of silicone immunology

Enterosorbents in complex therapy of food allergies: a focus on digestive disorders and systemic toxicity in children

The review analyzes mechanisms and concomitant factors in developing IgE-associated allergic diseases provoked by food allergens and discusses clinical symptoms and current approaches for the treatment of food allergies. The expediency of using enterosorbents in complex therapy of food allergies and skin and respiratory manifestations associated with gastroenterological disorders is substantiated. The review summarizes the experience of using enterosorbents in post-Soviet countries to detoxify the human body. In this regard, special attention is paid to the enterosorbent White Coal (Carbowhite) based on silicon dioxide produced by the Ukrainian company OmniFarma.

Effect of silicone on the collagen fibrillogenesis and stability

Collagen, the most abundant protein in mammals, is able to form fibrils, which have central role in tissue repair, fibrosis, and tumor invasion. As a component of skin, tendons, and cartilages, this protein contacts with any implanted materials. An inherent problem associated with implanted prostheses is their propensity to be coated with host proteins shortly after implantation. Also, silicone implants undergoing relatively long periods of contact with blood can lead to formation of thrombi and emboli. In this paper, we demonstrate the existence of interactions between siloxanes and collagen. Low-molecular-weight cyclic siloxane (hexamethylcyclotrisiloxane—D3) and polydimethylsiloxanes (PDMS) forming linear chains, ranging in viscosity from 20 to 12,000 cSt, were analyzed. We show that D3 as well as short-chain PDMS interact with collagen, resulting in a decrease in fibrillogenesis. However, loss of collagen native structure does not occur because of these interactions. Rather, collagen seems to be sequestered in its native form in an interlayer formed by collagen–siloxane complexes. On the other hand, silicone molecules with longer chains (i.e., PDMS with viscosity of 1000 and 12,000 cSt, the highest viscosity analyzed here) demonstrate little interaction with this protein and do not seem to affect collagen activity. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1275–1281, 2015

Silicone Allergy

OBJECTIVE

We introduce silicone allergy as a rare cause for cochlear implant extrusion and discuss its management.

STUDY DESIGN

Retrospective case series and literature review.

SETTING

Tertiary referral centers.

PATIENTS

Primary eligibility criteria included patients who experienced a delayed extrusion of their cochlear implants with negative wound cultures and had a suspected or a test-proven allergy to silicone components of an implant.

INTERVENTIONS

Silicone allergy testing, explantation of a cochlear implant containing allergenic silicone materials, reimplantation with a custom-made cochlear implant excluding an allergenic silicone component.

OUTCOME MEASURES

Uneventful wound healing and extrusion-free long-term follow-up after the reimplantation with a custom-made cochlear implant excluding an allergenic silicone component.

RESULTS

Three known cases of cochlear implant extrusion as a result of silicone allergy have been noted from 1991 through 2004 in three cochlear implant programs in the United States. All three devices extruded, resulting in explantation of the old device and reimplantation with a new custom-made device eliminating the allergenic silicone component. Wound cultures were negative in all cases. All three patients experienced a delayed extrusion of their devices. Two of these patients had a test-proven allergy to the implant's silicone components, whereas the third patient was presumed to have a hypersensitivity solely on the basis of a clinical presentation.

CONCLUSION

We propose that silicone allergy is a rare cause of cochlear implant extrusion. Patients experiencing cochlear implant extrusion, particularly with a delayed onset and negative wound culture results, should be tested for silicone allergy.

Anti-silicone antibodies and silicone containing breast implants

The detection of anti-silicone antibodies in patients with silicone breast implants (SBI) has been undertaken principally in the USA. We undertook a study of 20 women with SBI from different manufacturers from 6 weeks to 20 years after surgery, including those with ruptured implants. They were compared with three control groups: 20 women without implants, 20 women with auto-immune disease and 20 anonymous blood donors. Potential anti-silicone antibodies (IgG) were tested against a variety of silicone polymer antigens using an enzyme linked immunosorbent assay (ELISA) technique which had previously detected positive results in an uncontrolled series. Silicone-free collecting tubes were used. No differences were found between the patients with SBI and controls. However, samples that had been stored for the longest time, or frozen and thawed several times, had the highest levels. These false positives appear to be due to an unknown but human specific IgG binding phenomenon. We conclude that there is no demonstrable anti-silicone antibody formation in these patients with SBI and we would caution that the effect of storage may have been an important factor in previously published assay methods. This study supports the safety of silicone containing breast implants.

Drugs and toxins: fact and fancy

The scientific approach has reduced the burden of disease in society and removed much of the mystery, yet there is still much subjective illness and unease. Fear of poisoned water, bad food, and bad air may have been of evolutionary advantage to early humans, and these fears remain potent in today's sophisticated world. Perhaps the twenty-first century will see an understanding at the molecular and genetic level of the mechanisms underlying belief and its consequences.

Association of silicone breast implants with immunologic abnormalities: a prospective study

PURPOSE

To study the possible association of silicone-breast-implant exposure and immunologic abnormalities within the Nurses' Health Study, an ongoing prospective cohort study of women.

SUBJECTS AND METHODS

From this cohort, we randomly selected 200 women who had been exposed to silicone breast implants and who had never reported connective tissue diseases during 14 years of follow-up, and 500 age-matched, nonexposed women, including 100 with definite connective tissue diseases validated by medical record review, 100 with at least one symptom of a connective tissue disease, 100 with diabetes, and 200 healthy controls. Assays for antinuclear antibodies (ANA), including anti-dsDNA, anti-ssDNA, anti-Sm/RNP/Ro/La, and anti-Scl-70, rheumatoid factor, immunoglobulins, serum complement, and C-reactive protein level, and anticardiolipin, antithyroglobulin, antithyroid microsomal, and antisilicone antibodies were performed by standard techniques in blood samples collected in 1989 or 1990 before collection of silicone-breast-implant exposure data in 1992.

RESULTS

ANA was positive (> or = 1:40) in 14% of women with silicone breast implants compared with 20% of healthy women (P = 0.11). Rheumatoid factor was positive (> or = 1:40) in 5% of women with silicone breast implants and 2% of healthy women (P = 0.16). Women with silicone breast implants had a significantly higher frequency of anti-ssDNA antibodies than healthy women (41% and 29%, P = 0.012). Duration of implant was associated with a higher frequency of anti-ssDNA antibodies (P = 0.03) but not with ANA or rheumatoid factor. No other significant differences in the frequencies of autoantibodies were observed in silicone breast implant-exposed women. Antisilicone antibodies were not found in any sample.

CONCLUSION

We found no increased frequency of any immunologic abnormalities in women exposed to silicone breast implants, except for anti-ssDNA, which has unknown clinical relevance.

Absence of longitudinal changes in rheumatologic parameters after silicone breast implantation: a prospective 13-year study

There have been numerous questions regarding the association of polysiloxane with connective tissue disease and alteration of host immune response. C-reactive protein, rheumatoid factor, and anti-streptolysin-O titers were measured in 218 patients. These studies are routinely used in the diagnosis of autoimmune disease and mixed connective tissue disease. This prospective study has been in progress since 1985. The first patients were seen in July of 1985, and those individuals willing to participate were followed from 1985 to 1998. The implants included saline-filled elastomer shells and polysiloxane gel-filled elastomer shells. These groups were examined separately and in combination for changes between preoperative and postoperative states. In each instance, there was no statistical increase or decrease. Each patient underwent a physical examination and completed a questionnaire focusing on signs and symptoms of autoimmune and connective tissue diseases. The laboratory data and subjective clinical results demonstrated no significant differences between a nonimplanted group versus the saline group alone, the gel group alone, or the combined groups. The data failed to suggest any causal relationship between implants and autoimmune or connective tissue diseases over the study period of 13 years (since 1985).

Silicon and matrix macromolecules: new research opportunities for old diseases from analysis of potential mechanisms of breast implant toxicity

An understanding of the normal and essential integration of the element silicon in biosystems, as well as knowledge of its fundamental chemistry, are crucial to understanding its role in health and disease. Modern organosilicon chemistry, based in part on the artificial silicon-carbon bond, coincided with the emergence of the biomaterials and bioengineering fields fifty years ago, and was thought to be a fortunate coincidence according to conventional wisdom that high-molecular-weight polymeric siloxanes were chemically and biologically inert. These concepts have been challenged by reports of silicone migration and degradation following insertion of gel-filled breast implants, claims of a novel systemic illness appearing in many breast implant recipients, and investigations implicating varied and permeating immunotoxic mechanisms of disease causation by breast devices. The present study develops additional potential pathogenetic ideas based on alterations of cell biochemistry by silicon-containing compounds, and offers correlation of the patients' diverse clinical features with plausable disruption of basic biological processes. This in turn raises new questions concerning everyday environmental exposure, has broad implications for multiple other diseases, can provide alternative directions for future investigative research, and may contribute to the ongoing redefinition of immune dysfunction and inflammation.

Silicone elastomer cerebrospinal fluid shunt systems. Council on Scientific Affairs, American Medical Association

A 1995 resolution of the American Medical Association House of Delegates, introduced by the American Academy of Neurology, the American Association of Neurological Surgeons, and the Congress of Neurological Surgeons, asked the American Medical Association Council on Scientific Affairs to add the use of hardened silicone shunts to its study of the effects of silicone gel used in breast implants. On consideration of the important differences between the two materials, silicone elastomer ("hardened silicone") and silicone gel, the Council on Scientific Affairs elected to address the subject of silicone elastomer shunt systems separately. This report describes the different types of medical-grade silicone used in medical devices, the incidence of hydrocephalus and its causes and treatment, and the use of cerebrospinal fluid shunt systems made of silicone elastomer. Published case reports of possible immunological disease in patients who have had silicone elastomer cerebrospinal fluid shunt systems implanted are reviewed. The Council on Scientific Affairs concluded that the evidence presented does not support the occurrence of immune-mediated systemic reactions to implanted silicone elastomer cerebrospinal fluid shunt systems. The local granulomatous or inflammatory responses observed in some patients with silicone shunt systems have not been shown to be immunologically mediated; similar reactions have been described with other implanted foreign bodies.

Silicone breast implants and systemic rheumatic disease. Some smoke but little fire to date

For over 20 years silicone breast implants have been used for cosmetic and breast reconstruction purposes. They have been recently banned by the American Food and Drug Administration other than for reconstruction or in the setting of a study. Complications of rupture, leaking, bleeding, capsular thickening and contracture are acknowledged but the potential of silicone implants in causing classic rheumatic diseases or a new syndrome has caused much controversy; there are millions of dollars at stake in legal suits. The biological plausibility of silicone breast implants causing disease is not without merit. The epidemiological evidence linking the two are reviewed. There is considerable concern as to whether there will ever be a definitive study of the question.

The influence of silicone implantation on type II collagen-induced arthritis in mice

OBJECTIVE

To determine whether silicone implantation exacerbates autoimmune disease in a murine experimental model of arthritis.

METHODS

DBA/1 mice were implanted with silicone in the form of an elastomer, gel, or oil, and immunized with type II collagen. The influence of silicone implantation on collagen-induced arthritis and the immune response to type II collagen were determined by comparison against control mice receiving sham implantation. Adjuvant effects of silicone implantation were examined by measuring cytokine levels in implanted animals and assessing autoantibodies against proteins extracted from recovered silicone implants.

RESULTS

No adverse influence of silicone implantation on the clinical aspects of collagen-induced arthritis was observed. Further, polydimethylsiloxane silicone oil failed to serve as an adjuvant in the immune or arthritogenic response to type II collagen in mice. Cytokine analysis indicated that tumor necrosis factor alpha levels were lower and interleukin-2 levels were higher in silicone-implanted mice. The development of arthritis increased protein binding to implanted elastomers and gel, and autoantibodies against silicone-bound proteins were present in sera from arthritic mice and absent in sera from nonarthritic mice.

CONCLUSION

The data suggest that silicone implantation may result in autoantibodies against silicone-bound proteins, and the presence of arthritis may either provoke or increase the level of such autoantibodies. However, silicone implantation did not increase the incidence or severity of disease compared with sham-operated controls. Thus, it appears that autoantibodies against silicone-bound proteins may not have pathologic significance in this experimental model of arthritis.