Soluble ICAM-1 as a regulator of nasal allergic reaction under natural allergen provocation.
BACKGROUND
Intercellular adhesion molecule-1 (ICAM-1) plays a key role in the early stage of the signal cascade leading to cellular extravasation and development of an inflammatory response. Recently, it has been reported that the soluble form of this adhesion molecule is present in human sera, possibly mediating biological actions.


OBJECTIVE
The purpose of this study was to investigate levels of soluble ICAM-1 (sICAM-1) and its receptors in patients with allergic rhinitis, and to discuss sICAM-1's biological function.


METHODS
The levels of sICAM-1 in sera and nasal epithelial lining fluids (ELF), the percentage of CD11a-positive lymphocytes in the peripheral blood, and scores of subjective symptoms from 14 patients with pollinosis (allergic group) were measured from pre- to post-season, results were compared with those from 10 non-allergic subjects (control group).


RESULTS
The levels of sICAM-1 in sera and ELF were upregulated, and CD11a-positive lymphocytes were downregulated during the in-season in the allergic group. In addition, levels of sICAM-1 sera from the allergic group remained high during the post-season, when levels of other parameters (symptoms, blood eosinophil counts, sICAM-1 in ELF and CD11a-positive lymphocytes) had roughly returned to the initial pre-season levels.


CONCLUSIONS
We demonstrate systemic and local upregulation of sICAM-1 and systemic downregulation of LFA-1 positive lymphocytes in patients with seasonal allergic rhinitis under natural allergen provocation, suggesting that sICAM-1 plays a role in regulating seasonal allergic inflammation.
Kato
M
M
Department of Immunology, Nagoya University School of Medicine, Japan.
Hattori
T
T
Kitamura
M
M
Beppu
R
R
Yanagita
N
N
Nakashima
I
I
D000328:Adult; D018845:CD11 Antigens / Q000032:analysis; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis / Q000502:physiology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*
D018845:CD11 Antigens; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1