Undetectable Interferon-α Serum Levels in a Patient with Atopic Dermatitis

Abstract

A 3-year-old body was evaluated for the possible diagnosis of hyperimmunoglobulin E syndrome (HIES). From the age of 4 months he developed significant atopy and was subsequently diagnosed with severe atopic dermatitis, asthma, and allergic rhinitis, with moderately high total serum IgE levels. Because IgE production has been shown to be regulated by cytokines produced by the CD4⁺ helper T lymphocyte subsets, we measured the circulating levels of cytokines representative of these cellular subsets in this patient. We therefore measured serum levels of interleukin-4 (IL-4), the Th2 subset-derived cytokine that upregulates IgE synthesis, as well as the levels of interferon-γ and interferon-α (IFN-γ/α), cytokines produced by the Th1 subset that inhibit IL-4-mediated IgE upregulation. We found that in this patient, IL-4 levels were normal, indicating normal Th2 activity. The levels of IFN-γ were higher than normal, but the serum IFN-α levels in this patient were undetectable and were actually below the normal range. Thus, even though both IFN-γ and IFN-α have been shown to be necessary for controlling IL-4 actions, the selective absence of IFN-α, even in the presence of normal or increased amounts of IFN-γ, could permit IL-4 induced IgE production. Lack of IFN-α may explain this patient's recurrent infections, as well as IgE-induced atopic conditions. Our data in this study with the patient showing selective deficiency of IFN-α but not of IFN-γ provide support for the role of IFN-α in the pathogenesis of atopic dermatitis. The findings in this patient clearly warrant further studies of IFN-α in patients with atopic disorders.