Alternaria and Cladosporium Fungal Allergen Epitopes are Denatured by Sodium Hypochlorite

BACKGROUND: Fungal allergens are ubiquitous; however, little progress has been made understanding fungal allergenic material removal from indoor environments. PURPOSE: We investigated removal of environmental allergenic material derived from Alternaria and Cladosporium using sodium hypochlorite in vivo and in vitro. METHODS: Freeze dried allergen extract from Alternaria alternata and Cladosporium herbarum was treated with hypochlorite concentrations of 322, 88, 38, 16, 3, 0.3, and 0 mM, respectively. Remaining native allergenic material was quantified using enzyme immunoassay and remaining viable fungal material was evaluated. RESULTS: The results of treating Alternaria or Cladosporium extract with sodium hypochlorite are immediate and obvious. Concentrations greater than 100 mM remove color and concentrations between 100 and 38 mM partially uncolored the extract. Immunoassay for total antigenic and allergenic material remaining after treatment with sodium hypochlorite including 2 concentrations recommended for killing fungus confirmed a general destruction of antigenic and allergenic material at concentrations of 38 mM or greater. CONCLUSIONS: This work confirms the ability of solutions of sodium hypochlorite to denature fungal allergenic material from common outdoor and indoor fungi A. alternata and C. herbarum. Destruction of recognized antigenic and allergenic epitopes occurs at hypochlorite concentrations commonly used for household cleaning.