Atopic dermatitis: Influence of bacterial infections on human monocyte and neutrophil granulocyte functional activities

Abstract

In 15 patients with atopic dermatitis (AD) and without concomitant viral or bacterial infections, chemotaxis, superoxide-anion (O 2 −) generation, and β-glucuronidase release of purified monocytes (MO) and neutrophils (PMN) were determined. Defined receptor-dependent stimulators (i.e., N-formyl-methionyl-leucyl-phenylalanine, C5a, and leukotriene B 4, as well as native and opsonized rymosan particles) were used for phagocyte stimulation. PMN functional activities in response to the stimuli tested were found to be normal in patients with AD and without infections. MO from these patients revealed a slight enhancement of O 2 − production after stimulation with opsonized rymosan and a small increase of N-formyl-methionyl-leucyl-phenylalanine-induced chemotaxis. Other MO functions tested were within the normal range. However, investigations of MO and PMN functions during the course of concomitant bacterial infections of three patients with AD demonstrated striking alterations of cellular responsiveness. These changes ranged from enhanced to decreased phagocyte functions, depending on the activity of the infectious disorder. Chemotaxis of PMN and MO was depressed around the third day after onset of the infectious disease. In the beginning of infection, there was a decreased O 2 − generation and β-glucuronidase release in PMNs. In MOs, both parameters were enhanced. The results of these investigations provide evidence that functional abnormalities of phagocytes observed in patients with AD are sequelae of concomitant skin infections and not signs of an intrinsic defect present in MOs and PMNs.