Allergic asthma is a complex immunologically mediated disease associated with increased oxidative stress and altered antioxidant defenses. It was hypothesized that alpha-tocopherol (alpha-T) decreases oxidative stress and therefore its absence may influence allergic inflammatory process, a pathobiology known to be accompanied by oxidative stress. Therefore, selected parameters of allergic asthma sensitization and inflammation were evaluated following ovalbumin sensitization and re-challenge of alpha-T transfer protein (TTP) knock-out mice (TTP(-/-)) that have greatly reduced lung alpha-T levels (e.g.<5%) compared to their litter mate controls (TTP(+/+)). Results showed that severe alpha-T deficiency result in a blunted lung expression of IL-5 mRNA and IL-5 protein and plasma IgE levels compared with TTP(+/+) mice following immune sensitization and rechallenge, although lung lavage eosinophil levels were comparable in both genomic strains. It is concluded that the initial stimulation of immune responses by the TTP(-/-) mice were generally blunted compared to the TTP(+/+) mice, thus diminishing some aspects of subsequent allergic inflammatory processes