Interleukin-10 regulation in normal subjects and patients with asthma.

Abstract Interleukin-10 or cytokine synthesis inhibitory factor has important antiinflammatory activities in immune diseases. We speculated that diminished IL-10 production in asthma would permit the unopposed synthesis of proinflammatory cytokines, contributing to the development and severity of asthma. Our data demonstrate constitutive secretion of IL-10 into bronchoalveolar lavage (BAL) fluid of normal, nonasthmatic subjects (130 ± 61 pg/ml; n = 8). Asthmatic patients' BAL fluid was characterized by diminished concentrations of IL-10 (9 ± 18 pg/ml; n = 8; p p p p -6 mol/L methylprednisolone; p