The effect of omalizumab on nasal allergic inflammation.
BACKGROUND
In sensitized patients, coupling between IgE and FcepsilonRI receptors on mast cells leads to release of proinflammatory mediators and a subsequent influx of inflammatory cells to the affected organ. Omalizumab (Xolair; formerly rhuMAb-E25) binds to circulating IgE, thus preventing induction of the allergic process.


OBJECTIVE
We investigated the effect of treatment with omalizumab on seasonal allergic rhinitis and related changes in inflammatory cell numbers in nasal biopsy specimens.


METHODS
Patients were randomized to treatment with omalizumab or placebo before the pollen season; the treatment was started and continued during season. Symptoms and use of medication were recorded, and blood samples and nasal biopsy specimens were obtained before and during season. Immunocytochemistry was performed on biopsy sections through use of the following antibodies: anti-CD4, CD8 (T lymphocytes), EG2, and anti-eosinophil peroxidase (eosinophils), anti-tryptase (mast cells), human neutrophil lipocalin (neutrophils), and antibodies against IgE and FcepsilonRI.


RESULTS
During the season, blood eosinophils increased in placebo-treated patients but not in omalizumab-treated patients (P =.01); the difference between the treatment groups was significant (P =.04). Free IgE in serum decreased significantly (P =.0002) in omalizumab-treated patients but not in placebo-treated patients; the difference between the groups was significant (P =.0001). In nasal biopsy specimens, the number of eosinophil peroxidase-positive staining cells increased in the placebo-treated patients (P =.003) but not in the actively treated patients during the season; the difference between the groups was significant (P =.0001). The number of IgE(+) staining cells decreased significantly in the omalizumab group during the season in comparison with the placebo group (P =.04).


CONCLUSIONS
The clinical benefit of treatment with omalizumab is associated with an anti-inflammatory effect on cellular markers in blood and nasal tissue.
Plewako
Halina
H
Asthma and Allergy Research Group, Department of Respiratory Medicine and Allergology, Sahlgrenska University Hospital, Göteborg, Sweden.
Arvidsson
Monica
M
Petruson
Karin
K
Oancea
Iolanda
I
Holmberg
Kenneth
K
Adelroth
Ellinor
E
Gustafsson
Hans
H
Sandström
Thomas
T
Rak
Sabina
S
D000328:Adult; D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D001706:Biopsy; D004804:Eosinophils; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007150:Immunohistochemistry; D007249:Inflammation / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000276:immunology; D000069444:Omalizumab; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D016896:Treatment Outcome
D018926:Anti-Allergic Agents; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000069444:Omalizumab; D007073:Immunoglobulin E