Long-term effectiveness and safety of recombinant human interferon gamma therapy for atopic dermatitis despite unchanged serum IgE levels

Objective: To assess the long-term effects of recombinant human interferon gamma treatment of atopic dermatitis (AD). Design: Case series. Patients were treated for up to 24 months. Selling: University dermatology outpatient clinics in Ann Arbor, Mich, and Portland, Ore. Patients: Twenty- four of 32 eligible patients who participated in a previously reported, 12- week, double-blind, placebo-controlled study of recombinant human interferon gamma treatment for AD were enrolled. Intervention: Patients self- administered recombinant human interferon gamma, 50 μg/m², by daily subcutaneous injection. Main Outcome Measures: Overall response; body surface area of involvement; clinical severity scores for pruritus, erythema, edema, excoriations, dryness, scaling, and lichenification; other atopic symptoms; and laboratory parameters, including serum IgE levels, were monitored at quarterly visits. Results at 1 and 2 years were compared with baseline values. Results: All efficacy parameters improved (P<.05). For example, pruritus was reduced by 50% after both 1 (n = 24, P<.001) and 2 (n = 16, P = .005) years. Allergic conjunctivitis and allergic rhinitis also improved (P<.01). Eosinophil counts decreased significantly (P<.001). IgE levels increased. Clinical improvement more closely correlated with changes in eosinophil counts (r=0.30.5) than with changes in IgE levels (r=0.0-0.2). Only 1 patient discontinued therapy because of adverse effects (flulike symptoms). Conclusions: The initial efficacy and adverse effects reported for recombinant human interferon gamma treatment of patients with AD were maintained after 2 years of long-term use. Recombinant human interferon gamma seems to be a well-tolerated and effective agent in the long-term therapy of patients with AD. Therapies that correct cellular immune defects, but not humoral immune defects, may be effective in the treatment of patients with AD.