Hyporesponsiveness to inhibitory agents of alveolar macrophages and polymorphonuclear leukocytes primed by platelet activating factor.

In this study, it was presented that PAF and LTB4 exert a priming effect on PMNs to promote their superoxide anion production. PMNs preincubated with PAF of normal controls or PMNs from asthmatic patients are activated and their responsiveness to inhibitory stimuli such as antiallergic drugs and corticosteroid are attenuated. In conclusions, inflammatory cells of asthmatics may be activated by various mediators and play an important role in the progress of airway damage.