Am. J. Respir. Crit. Care Med., Vol 150, No. 6, Dec 1994, 1653-1659.
Allergen-specific challenge induces intercellular adhesion molecule 1 (ICAM-1 or CD54) on nasal epithelial cells in allergic subjects. Relationships with early and late inflammatory phenomena
G Ciprandi, C Pronzato, V Ricca, G Passalacqua, M Bagnasco and GW Canonica
Department of Internal Medicine, University of Genoa, Italy.
Intercellular adhesion molecule 1 (ICAM-1 or CD54) expression on epithelial
cells (EC) has been demonstrated to play a role in the local molecular
events of inflammation following allergen-specific conjunctival challenge.
In the light of these observations, we evaluated the possible expression of
ICAM-1 on nasal EC after allergen- specific challenge. Three groups of
subjects were studied: (1) 14 symptomless patients sensitized to mites, (2)
15 symptomless patients sensitized to pollen, and (3) 10 healthy volunteers
as controls. The study was performed during winter. At baseline we found
that both pollinosic and healthy subjects did not express CD54 on
epithelial cells, whereas mite-sensitive patients showed a mild expression
(possibly caused by a persistent natural allergen exposure). In addition,
clinical and cellular responses were induced by lower allergen dosages in
mite-sensitive patients compared with pollen- sensitive patients. CD54 was
detectable in all the allergic patients but not in the control subjects 30
min after challenge. At 6 h all patients showed a marked inflammatory
infiltration and CD54 persistence on EC: such an infiltration was more
relevant in patients developing clinical late-phase reaction (LPR).
Finally, 24 h after challenge EC CD54 expression persisted, as well as a
cellular infiltrate mainly caused by eosinophils (the latter being more
pronounced in mite- sensitive individuals). CD54 should be regarded as an
early and sensitive marker of inflammation in both LPR-positive and
LPR-negative patients. A cellular inflammatory infiltrate was detectable in
both LPR- positive and LPR-negative subjects, although relevant differences
in eosinophil counts were observed between the two groups. The study
emphasizes the importance of the different events of inflammation in
allergy.
