title: Immunogenicity studies of cosmetically administered nonanimal-stabilized hyaluronic acid particles.
abstract: BACKGROUND
  Hypersensitivity resulting from humoral or cellular immunologic mechanisms is the least well-documented of adverse events associated with dermal fillers.
  
  
  OBJECTIVE
  Humoral and cellular immunogenicity of nonanimal-stabilized hyaluronic acid (NASHA) was studied in prospective clinical trials involving nasolabial fold augmentation.
  
  
  METHODS
  In two randomized clinical studies, 150 (10 centers) and 283 (17 centers) subjects received NASHA as Restylane and/or Perlane (both QMed, Uppsala, Sweden; mean, 69 mg) for dermal augmentation. Serum immunoglobulin (Ig)E and IgG anti-NASHA were measured by immunoassay at 0, 6, and 24 weeks and IgE anti-NASHA by intradermal skin testing (ID-ST) at 0 and 24 weeks. The 24-week ID-ST site was biopsied 3 days later for histopathologic evidence of cell-mediated immunity.
  
  
  RESULTS
  Of 433 subjects, 42 systemic adverse experiences were reported by 37 participants; all but 1 were judged by investigators to be unrelated to NASHA administration. All ID-STs and IgE anti-NASHA results were negative, indicating no IgE sensitization. Serologically, 91.8% of 425 subjects were negative for IgG anti-NASHA (<1.5 microg/mL) at all time points, whereas 7.8% had positive enrollment IgG anti-NASHA (range, 1.5-18.5 microg/mL) that remained essentially unchanged over the study period. The 24-week ID-ST biopsies showed no histological evidence for NASHA-induced cell mediated lymphocytic inflammatory reactions (Type IV hypersensitivity) or superficial dermal edema (Type 1 hypersensitivity).
  
  
  CONCLUSIONS
  NASHA administration does not elicit clinical/laboratory evidence for cellular or humoral immune responses in 98% of individuals, supporting the conclusion that Restylane and/or Perlane are not commonly immunogenic or allergenic.
authors: Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. rhamilto@Jhmi.edu
authors: Robert G
authors: RG
authors: Hamilton
authors: Jur
authors: J
authors: Strobos
authors: N Franklin
authors: NF
authors: Adkinson
mesh_terms: D003357:Cosmetic Techniques; D004342:Drug Hypersensitivity / Q000175:diagnosis / Q000209:etiology*; D005145:Face; D005260:Female; D005782:Gels; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000276:immunology*; D007118:Immunoassay; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007267:Injections; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012882:Skin Tests
chemical_list: D005782:Gels; D007074:Immunoglobulin G; C502935:Perlane; D007073:Immunoglobulin E; D006820:Hyaluronic Acid; C445361:Restylane