Environmental and bronchoalveolar lavage Dermatophagoides pteronyssinus antigen levels in atopic asthmatics

Overnight environmental home exposure to Dermatophagoides pteronyssinus in IgE-sensitized individuals is often clinically associated with increased morning symptoms of rhinitis and/or asthma. We have investigated whether household exposure to D. pteronyssinus is associated with the presence of immunoreactive D. pteronyssinus I antigen (Der p I) in bronchoalveolar lavage (BAL) fluid in nine atopic asthmatics sensitized to D. pteronyssinus. Significant environmental concentrations of D. pteronyssinus were noted by light microscopy and immunoassay in the subjects' bedroom carpets (13.4 +/- 3.8 micrograms immunoreactive Der p I/g dust), mattresses (27.3 +/- 7.2 micrograms immunoreactive Der p I/g dust), and living room carpets (5.9 +/- 1.5 micrograms immunoreactive Der p I/g dust). Immunoreactive Der p I was measurable in 20-fold concentrated BAL fluids (3.4 +/- 1.0 ng/ml concentrated BAL fluid) after overnight home exposure. A 24-h hospitalization in a D. pteronyssinus controlled environment (< 0.02 micrograms Der p I/g dust) resulted in a significant decrease in BAL Der p I concentrations (0.8 +/- 0.6 ng/ml). In vivo studies in nine asthmatics challenged endobronchially with D. pteronyssinus (5-60 ng Der p I) induced significant airway eosinophilia. These studies demonstrate that environmental exposure to microgram amounts of D. pteronyssinus is associated with airway recovery of small nanogram amounts of Der p I.