Hyaluronic acid viscosupplements from avian and non-mammalian sources exhibit biocompatibility profiles with unique, source-specific, antigenic profiles.

The objective of this study was to evaluate and compare the biocompatibility profiles of hyaluronic acid (HA) viscosupplements from avian and non-mammalian sources. Inflammatory and immune reactions were assessed in models of both clinically relevant and stringent immunological exposure conditions. Experiments were conducted to evaluate tissue reactions and immunological responses and assess antibody formation with the capacity to bind directly to and cross-react with the different viscosupplements. Mice were exposed to viscosupplements using the air pouch inflammation model and specific immunization using Freund's complete adjuvant (FCA). Murine pouch membrane tissue reactions revealed generally mild to moderate responses, with cellular infiltration and cytokine profiles of pouch tissue characteristic of predominantly fibroblastic responses rather than marked inflammatory reactions. In vitro testing indicated that pouch injections did not elicit detectable T-cell proliferative responses, while antibody assays revealed that mice immunized with viscosupplements in FCA and subsequently boosted were capable of mounting an antibody response with a range of specificities. High reactivity to avian serum albumin was seen in sera from mice injected with HA from an avian source, while low positive reactivity to the bacterial antigen Staphylococcal Lipotechoic Acid was observed in sera from mice injected with HA from bacterial sources. These specificities did not indicate any propensity to cross-react, suggesting that patients with adverse immune responses to HA from an avian source should be unresponsive to subsequent injection with HA from a non-avian source. Overall, the findings demonstrate that viscosupplements exhibit good biocompatibility profiles in the murine air pouch, but when provoked to elicit immunological reactions exhibit unique antigenic spectra. These findings suggest that an immunologically mediated immune reaction directed against avian proteins should not necessarily be a contraindication for the administration of non-avian viscosupplements.