Fibroin allergy. IgE mediated hypersensitivity to silk suture materials.

Abstract

Delayed-type hypersensitivity with granulomatous lesions to silk sutures is rather rare. Yet, braided silk sutures often act as a non-immunologic foreign-body and cause a granulomatous inflammatory reaction years after surgery. We report here a case of recurrent granulomas with remarkable infiltration of eosinophils that may have resulted from an IgE-mediated hypersensitivity reaction to silk fibroin, a component of the braided silk suture. Under normal circumstances exposure to fibroin is rather rare. Therefore, the present patient may have developed this reaction to the silk sutures used in a previous surgery.

Silk-based biomaterials

“…In addition, in the preparation of this review no references were found in the literature that implicated black braided silk in inducing hypersensitivity and allergic reactions. Kurosaki et al [30] concluded that the hypersensitivity in their single case may have been the result of patient sensitization to silk from a prior surgical procedure 7 years earlier. The type of silk used in this earlier exposure was unknown (e.g., virgin vs. black braided).…”

“…Virgin silk, like most proteins, is a potential allergen [28,29] causing a Type I allergic response in some cases [30]. Delayed allergic responses to silk (an average of 10 months after initial exposure) induced some patient complications including asthma and specific upregulation in IgE levels [29,31].…”

“…Fibroin degradation products could also potentially be involved in adverse biological responses. For example, one case was reported where fibroin (black braided silk) may have induced a Type I allergic reaction [30]. However, the authors clarified later that there were no cases in the literature that implicated black braided silk as inducer of IgE hypersensitivity reactions.…”

“…Kurosaki et al [30] (b) Patient sensitized to silk 7 years prior in an independent surgical procedure a ?=Type of silk used was not specified, e.g., virgin silk or black braided; Virgin=virgin silk containing sericin; Black braided=black braided extracted silk fibroin (e.g., no sericin) coated in waxes or silicone. (2) indicates histiocytes and foreign-body giant cells, and cluster of lymphocytes and a few plasmacytes, and Extensive (3) includes histiocytes, foreign-body giant cells, and diffuse, scattered lymphocytes and plasmacytes.…”

“…Absorbable and non-degradable biomaterials generally do not induce a T-cell mediated hypersensitivity immune response (as was observed with sericin) [30]. However, while rare, sensitization to fibroin due to pre-exposure or a failed phagocytic response can result in the formation of a granuloma years after the implantation of black braided silk [30]. Some common materials that have been shown to induce a FBR are detailed in Table 3.…”