Higher levels of human TLR4 ligands (hTLR4-L) were detected in bedding dust samples obtained from patients with moderate/severe atopic dermatitis (AD) compared to non-AD patients in a recent study performed at the University of Colorado. AD is also associated with high burdens of Staphylococcus aureus. hTLR4-L was quantified using a novel hTLR4/MD2-CD14-transfected cell line with a luciferase reporter system in conjunction with a conventional limulus amebocyte lysate (LAL) assay in 29 bed or bedroom dust samples. The levels of hTLR4-L in bedding samples correlated with LAL levels, while floor dust levels did not show any differences between moderate/severe AD and non-AD samples. The observed association of AD with high hTLR4-L in ...