Impaired H2 histamine granulocyte response in active atopic eczema

Many clinical abnormalities in atopic eczema have been attributed to an imbalance in autonomic nervous system control, specifically a partial blockade of beta-adrenergic responsiveness. The lysosomal enzyme beta-glucuronidase is released from granulocytes during in vitro incubation with complement-activated zymosan particles. Isoproterenol will inhibit the release of this lysosomal enzyme from the granulocyte and the isoproterenol effect is associated with increased granulocyte cyclic AMP formation. In atopic eczema and asthma, this granulocyte response to isoproterenol is impaired. Histamine also inhibits in vitro zymosan induced release of beta-glucuronidase and this is an H2 histamine effect. In asthma, this H2 histamine response is diminished. In the following study, we found a similar impairment in histamine inhibition of beta-glucuronidase release and formation of granulocyte cAMP in atopic eczema. This defect was found only in granulocytes from patients with active eczema. Thus in active atopic eczema, defects in the pharmacological response of the granulocyte are not limited to beta-adrenergic agonists but include H2 histamine activity.