Mast cell degranulation is thought to be an important component of the pathogenesis of allergic rhinitis. Quantitative studies on mast cells in nasal mucosa after allergen exposure have given widely divergent results, ranging from an overall decrease via redistribution to an overall increase. We investigated this problem by employing a combination of anti-IgE and toluidine blue staining of biopsy specimens. In allergic patients anti-IgE was found to identify all mast cells and toluidine blue to detect mast cells that were not (totally) degranulated. The study was composed of two parts done in different patient groups. In the first part of the study biopsies were performed in 23 patients with isolated grass-pollen allergy, once during natural provocation in the summer and once in the winter. Biopsies were also performed in 12 controls. Non-allergic controls were found to have the same number of mast cells in the lamina propria as asymptomatic allergic patients. The controls seldom have mast cells in the epithelium. The patients with isolated grass-pollen allergy showed an increase in the numbers of mast cells in the lamina propria during natural provocation and the same seemed to occur in the epithelium as well. During natural provocation almost all of the mast cells in the epithelium and half of those in the lamina propria were degranulated. In the second part of the study 17 patients with isolated grass-pollen allergy and four controls were challenged daily with allergen extract during a 2-week period in the winter. During this period biopsies were performed at eight different occasions, i.e. once before, six occasions during and once after the provocation period. The results of this part of the study showed that during provocation mast cells migrate to the surface of the nasal mucosa, where they become degranulated, and that the pool of mast cells in the lamina propria was apparently replenished by migration of mast cells from the vessels in the lamina propria. The total number of mast cells in the lamina propria remained approximately the same while the mast cells residing in an increasingly thick layer measured from the basal membrane into the lamina propria became degranulated. After 2 weeks, 82% of the mast cells in the lamina propria was degranulated and it was only in the deepest layers that some toluidine blue positive cells were found.(ABSTRACT TRUNCATED AT 400 WORDS)

APC are influenced by allergen provocation. This study supports the hypothesis that (IgE+) LC are involved in allergic rhinitis. The role macrophages play remains doubtful.

In a 1-year, placebo-controlled, double-blind, randomized study the long-term effect of Fluticasone Propionate Aqueous Nasal Spray (FPANS) in 42 patients with a perennial allergic rhinitis was studied with regard to safety and efficacy. Twenty-nine patients completed the entire treatment period. After 1 year of treatment no deleterious changes consequent on therapy were observed in nasal mucosal biopsies. The appearance of the epithelial layer, the degree of cellular infiltration, the extent to which the sinusoids were dilated and the degree of tissue oedema improved or remained unchanged in 93% of the patients of the FPANS group, versus 75% of the placebo group, and worsened in 7% of the FPANS group versus 25% of the placebo group. Assessment of the changes in haematological, biochemical, urinary, plasma cortisol levels, and in the findings during nasal examination revealed no significant differences between the two treatment groups. After 1 year of treatment symptom scores for sneezing, nasal itching, and total symptom score were significantly better in the FPANS treated group (P < 0.05, P < 0.05, P < 0.01). An initial reduction in total symptom score was found after 4 weeks FPANS treatment with a further reduction after 8 months of FPANS treatment. These findings suggest that the maximum efficacy of topical intranasal steroids is reached after long-term treatment, and thus advocates longer usage before treatment is stopped because of presumed inefficacy.

Little is known about cellular infiltrates in nasal mucosa and the differences between these infiltrates in allergic and non-allergic patients. A reproducible and objective method making use of monoclonal antibodies for the quantification and characterization of cellular infiltrates in biopsy specimens of nasal mucosa is described. This method was used to study quantitative differences in cellular infiltrates in the epithelium and lamina propria of the nasal mucosa of patients with isolated grass pollen allergy, non-allergic patients with nasal polyps, and controls. A surprisingly wide variation was found in all groups. In all groups the T lymphocytes were much more numerous than the B lymphocytes. The number of CD8+ cells exceeded the number of CD4+ cells in the epithelium but in the lamina propria the numbers were approximately equal. Significant differences between the three groups were found with respect to the number of CD1+, IgE+, neutrophils and cytoplasmic IgG4+ cells. No significant differences were found in the numbers of CD4+, CD8+, CD14+, CD22+, HLA-DR+, IgGl-3+ cells or eosinophils. The use of biopsy in combination with monoclonal antibodies is an easy and well-tolerated method to study immunological reactions in the nasal mucosa. The results of this study indicate a possible role for a T-cell-mediated response in allergic rhinitis.

Vasomotor rhinitis (VMR) is a disorder of unknown pathogenesis. Forty patients with VMR were carefully selected on the basis of inclusion and exclusion criteria proposed by Mygind and Weeke. Nasal biopsy specimens were taken in the patient group as well as in a group of ten controls. Brush cytology was also taken in the VMR group. Inflammatory cells were identified and counted in the nasal mucosa, with the use of immunohistochemical techniques and a panel of monoclonal antibodies. Eosinophils were studied with the use of BMK13, EG2, and Giemsa. Mast cells were studied with anti-chymase (B7), anti-tryptase (G3) and toluidine blue. Sections were stained with IgE as well. There was no significant difference in the number of eosinophils, mast cells and IgE-positive cells between the two groups. Additionally, in contrast with other reports, in sections that were double-stained with anti-chymase and anti-tryptase, single chymase-positive cells were found.