Bronchial asthma is a disease with many unsolved problems and despite an
increased availabili ty of anti-asthma drugs, morbidi ty and mortality
from this disease are not improving. It is now recognized that asthma
should be considered as a chronic inflammatory disease of the lung
resulting in bronchial hyperreactivity and subsequent symptoms. The
mechanisms underlying airways inflammation and bronchial hyperreactivity
have now become a focal point of research in the quest for knowledge
about how the management of this disease can be improved. Platelet
activating factor (PAF-acether AGEPC) is a naturally occurring
ether-linked phospholipid discovered in 1972 associated with IgE
mediated allergic responses which has potent effects on platelet
activation. PAF is now recognized as a molecule having a diverse range
of biological effects relevant to allergic inflammation and asthma
including the abili ty to induce long lasting airway inflammation and
associated increases in bronchial reactivity. Certain activities of PAF
are known to be secondary to platelets activation raising the
possibility that this blood element plays a role in the pathogenesis of
asthma.