title: Stability of standardized grass, dust mite, cat, and short ragweed allergens after mixing with mold or cockroach extracts.
abstract: BACKGROUND
  Limited data are available on the immunochemical compatibilities of standardized and nonstandardized allergen extracts in immunotherapy vaccines. Extract combinations recommended in immunotherapy practice parameters are based primarily on theoretical considerations rather than on actual product compatibilities.
  
  
  OBJECTIVE
  To determine the stabilities of standardized grass, short ragweed, dust mite, and cat extracts after mixing with fungal and cockroach extracts at final product concentrations similar to those recommended for maintenance immunotherapy injections.
  
  
  METHODS
  Mixtures were prepared using individual products from multiple sources at variable glycerin concentrations and were analyzed after storage for up to 1 year at 2 degrees C to 8 degrees C. Quantitative analyses included radial immunodiffusion assays for cat Fel d 1 and short ragweed Amb a 1 and human IgE enzyme-linked immunosorbent assay inhibitions for meadow fescue grass and dust mite allergens. Immunoblot analyses provided qualitative patterns of IgE binding.
  
  
  RESULTS
  Meadow fescue grass allergens were unstable after mixing with fungal or cockroach extracts but were highly compatible with dust mite extracts from numerous commercial sources. Fescue and dust mite allergen recoveries varied considerably when mixed with different mold extracts. The presence of cockroach extracts reduced dust mite allergen potencies but retained moderate levels of cat and short ragweed allergen activities. In all cases examined, glycerin provided concentration-dependent improvements in allergen recoveries.
  
  
  CONCLUSIONS
  Several allergen extract combinations generally regarded as unstable by current practice parameters seem to possess considerable biochemical compatibilities. Use of these mixtures in immunotherapy vaccines is supported for practitioners seeking to optimize formulations, doses, and treatment regimens for their patients.
authors: Research and Development Laboratory, Greer Laboratories Inc, Lenoir, North Carolina 28645, USA. tgrier@greerlabs.com
authors: Thomas J
authors: TJ
authors: Grier
authors: Dawn M
authors: DM
authors: LeFevre
authors: Elizabeth A
authors: EA
authors: Duncan
authors: Robert E
authors: RE
authors: Esch
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000276:immunology; D031164:Ambrosia / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D002415:Cats; D003058:Cockroaches; D045424:Complex Mixtures / Q000592:standards*; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay; D005658:Fungi; D005990:Glycerol; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D005779:Immunodiffusion; D007167:Immunotherapy / Q000592:standards*; D010940:Plant Proteins / Q000276:immunology; D039981:Pyroglyphidae / Q000276:immunology*; D011817:Rabbits; D014020:Tissue Extracts
chemical_list: D000485:Allergens; C026967:Amb a I protein, Ambrosia artemisiifolia; D052179:Antigens, Plant; D045424:Complex Mixtures; D006023:Glycoproteins; D010940:Plant Proteins; D014020:Tissue Extracts; C059296:Fel d 1 protein, Felis domesticus; D005990:Glycerol