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Assessing the Allergenic Potential of Molds Found in Water-Damaged Homes in a Mouse Model
Ward, M., L. Copeland, J. Lehmann, D. Doerfler, AND S. Vesper. Assessing the Allergenic Potential of Molds Found in Water-Damaged Homes in a Mouse Model. INHALATION TOXICOLOGY. Taylor & Francis, Inc., Philadelphia, PA, 26(8):474-484, (2014).
Damp/moldy indoor environments, which have resulted from flooding events and may increase as a result of climate change, have been associated with asthma exacerbation. Certain molds found in significantly higher or lower concentrations in asthmatics’ homes compared to control homes have been categorized as Group 1 (G1) and Group 2 (G2) molds, respectively. Our goal was to compare the allergy induction of selected G1/G2 molds to house dust mite (HDM) in our mouse allergy/asthma model. Female BALB/c mice were exposed to mold (0-80 µg) or HDM (20 µg) extract by intratracheal aspiration. Airway responses (methacholine challenge) were measured (day 1) and serum and bronchoalveolar lavage fluid were collected (day 2) after the final exposure. The G1 molds induced low to moderate responses and required higher doses to achieve antigen-specific IgE results similar to those induced by HDM. Compared to HDM responses, the G2 mold in this study required lower doses to induce a similar response. These data indicate that the capacity of molds to induce allergic responses varies and that the G1/G2 categorization is not indicative of allergy induction potential. However, these studies do not preclude the utility of this categorization for the identification of unhealthy building dampness.
This study demonstrates the complex nature of molds and their differing capacities to induce responses associated with allergic asthma. Although, at this time human exposure levels and sensitization thresholds are unknown for most allergens including molds/fungi, these data suggest a threshold dose for the induction of allergic responsiveness. Current methodology requires that assessing the allergic/asthmatic potential of molds needs to be performed on an individual basis. These studies along with our previous studies with G1 (Stachybotrys chartarum) /G2 (Penicillium chrysogenum) categorized molds suggest that the G1/G2 categorization is not indicative of allergy induction potential. However, these studies do not address asthma exacerbation nor do they preclude the utility of this categorization for the identification of unhealthy building dampness.
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB
ENVIRONMENTAL PUBLIC HEALTH DIVISION
CARDIOPULMONARY AND IMMUNOTOXICOLOGY BRANCH