Eosinophil cationic protein and myeloperoxidase in nasal secretion as markers of inflammation in allergic rhinitis

The inflammatory component of allergic rhinitis was studied by measuring the concentration and content of eosinophil cationic protein (ECP, specific for eosinophils) and myeloperoxidase (MPO, specific for neutrophils) in samples of nasal secretion from 20 pollen-allergic subjects. All secretion samples contained measurable concentrations of both proteins. The mean ECP concentrations on two occasions without pollen exposure were 950 and 1170 micrograms/l. The ECP concentration during the pollen season without any therapy (mean 1160 micrograms/l) did not differ significantly from the baseline values, but intranasal corticosteroid therapy resulted in a significant decrease (mean 530 micrograms/l). The concentration of MPO was about 10 times higher than that of ECP, but the changes in MPO were nonsignificant throughout the observation period. An inverse correlation was found between the threshold dose in histamine challenges and the ECP level expressed either as concentration or as content. Furthermore, the ECP concentration and content 1 day after a positive allergen challenge were both significantly correlated with the strength of the challenge reaction. Measurements of ECP in nasal secretions are useful for studying the presence and activity of eosinophils in the nasal mucosa, and may prove of value in clinical investigations on patients with allergic rhinitis.     

Histamine concentrations in nasal secretion and secretory activity in allergic rhinitis

The prerequisites for using the assayed histamine concentration in nasal secretion as an objective measure of disease activity in allergic rhinitis were investigated. It was demonstrated that in histamine determination procedures the presence of quenching substances in the nasal secretion could lead to underestimation of the histamine concentration. This bias was eliminated in a modified spectrofluorometric assay. Only an insignificant fraction of the histamine in samples collected by nasal spray washing was bound to unfiltrable particles or cells. The mean histamine concentration in nasal secretions from 15 healthy subjects was 11.2 micrograms/ml and in a group of nine patients with allergic rhinitis out of season 3.36 micrograms/ml. The histamine concentration in the latter group decreased during the pollen season and after positive allergen challenge. It is suggested that this decrease is caused by the increase in volume of the secretion during the allergic response. The use of lithium as an exogenous marker permitted quantitation of the increase in the relative amount of nasal secretion recovered by washing in the symptomatic subjects.     

Leukotriene C4 and histamine in early allergic reaction in the nose

We have examined the measurements of LTC4 and histamine in nasal lavage fluids and blown secretions as a possible model of the early mediator events during nasal allergy. A nasal challenge with grass pollen extract was undertaken on two separate occasions in 20 patients with a history of seasonal rhinitis and a positive immediate skin test to grass pollen. A 2 ml nasal lavage was performed before allergen challenge, and blown secretion collected separately 15 min after the provocation, followed by a final 2 ml nasal lavage. The dilution of nasal secretion by the lavage fluid was determined using 99mTc-labelled albumin as an exogenous marker added to the fluid. The amounts of admixture in the nasal lavages did not correlate to the concentrations of LTC4 and histamine, indicating that the variable amounts of nasal secretion in nasal lavage do not constitute a confounding variable for measurements of LTC4 and histamine. In the pre-challenge lavages, the median concentrations, of LTC4 and histamine were 1.7 and 52 nmol/l respectively. Following allergen challenge neither LTC4 nor histamine measured in nasal lavage showed any significant change from pre-challenge baseline values. However, measurements of both mediators in the blown secretion showed a significantly higher concentration than in the pre- or post-challenge lavage samples, compatible with transitory release during the acute allergic reaction. However, it seems doubtful whether measurements of LTC4 or histamine can be compared between blown secretion and nasal lavage fluid, even if the dilution factor is disregarded.(ABSTRACT TRUNCATED AT 250 WORDS)     

Symptom scores as measures of the severity of rhinitis

Methodological aspects of subjective symptom ratings were investigated in 103 symptomatic rhinitis patients. The patient's own overall rating registered on a visual analogue scale was compared with a summed symptom score calculated from ratings of sneezing, rhinorrhea and congestion. A significant correlation, but not complete correspondence, was found in patients with untreated rhinitis during the birch pollen season and after challenges with birch pollen or histamine. Comparisons between the overall rating and scores for individual symptoms gave lower degrees of correlation or non-significant correlations. When twenty-five patients were treated with an intranasal corticosteroid during the pollen season, both the overall rating and the summed symptom score decreased significantly. The changes in the two ratings for each Patient showed a moderate correlation. The patients' ratings of rhinorrhea correlated with an approximate measure of the volume of secretion after pollen challenge but not during the pollen season or after histamine challenge. It is recommended on the basis of these findings that, for measuring the severity of rhinitis, scores indicating the course of individual symptoms should not be combined into a summed score, but that the patient's overall rating of the condition should be used. Scores for individual symptoms can be used to draw more detailed conclusions about nasal pathophysiological features and about qualitative disimilarities between different modes of therapy.     

Changes in airway inflammation following nasal allergic challenge in patients with seasonal rhinitis

BACKGROUND: Seasonal allergic rhinitis could predispose to the development of chronic bronchial inflammation as observed in asthma. However, direct links between nasal inflammation, bronchial inflammation and airway responsiveness in patients with seasonal allergic rhinitis and without asthma are not fully understood. The aim of this study was to analyse the changes induced by allergic nasal challenge outside the pollen season in airway responsiveness and bronchial inflammation of patients with seasonal allergic rhinitis. METHODS: Nine patients were evaluated after either grass pollens or placebo nasal challenge in a randomized cross-over double-blinded trial. Nasal parameters were recorded hourly and airway responsiveness was assessed by methacholine challenge. Cytological examinations and cytokine measurements were performed in nasal lavage and induced sputum. Eosinophil activation was investigated by eosinophil-cationic protein expression and secretion. RESULTS: Airway responsiveness was increased after allergic nasal challenge. Total eosinophils and eosinophils expressing eosinophil-cationic protein were increased in induced sputum after allergic nasal challenge. Both eosinophil number and eosinophil-cationic protein concentration in induced sputum were correlated to methacholine responsiveness. CONCLUSIONS: These results suggest that eosinophils participate to the bronchial inflammation in patients with seasonal allergic rhinitis following allergic nasal challenge outside the pollen season and might explain changes in airway responsiveness.     

Comparison of nasal immunohistology in patients with seasonal rhinoconjunctivitis treated with topical steroids or specific allergen immunotherapy

BACKGROUND: Specific allergen immunotherapy (SIT) and nasal steroids (NS) are considered effective anti-inflammatory treatments for allergic rhinitis, although their mechanism of action differs. OBJECTIVE: The aim of this study was to examine the effect of treatment with NS and SIT on different populations of inflammatory cells in the nasal mucosa and to compare cell numbers before and during the birch pollen season in patients with seasonal allergic rhinitis. METHODS: In a randomized, double-blind, double dummy comparative study, 41 patients with seasonal rhinoconjunctivitis were treated with birch SIT or NS (budesonide 400 microg daily). Treatment with NS started before the birch pollen season and at the same time SIT-treated patients reached the maintenance dose. Nasal biopsies for immunohistochemistry were obtained before the season and start of the treatments and at the peak of the pollen season during treatment. RESULTS: Symptoms of rhinoconjunctivitis increased significantly in both groups during the pollen season but less in the NS-treated group and the difference between the treatment groups was significant at the end of the season (P = 0.03). Immunohistochemistry of nasal biopsies from NS-treated patients showed significantly fewer CD1a+, IgE+ and Fc epsilonRI+ cells during the season compared with preseason (P = 0.02, P = 0.001 and P = 0.0004, respectively) and with seasonal values of the SIT-treated group (P = 0.002, P = 0.002 and P = 0.0004 respectively). CONCLUSION: Treatment with NS but not SIT decreased the numbers of CD1a+, IgE+ and Fc epsilonRI+ cells during the birch pollen season. Our data indicate that treatment with NS has a broader anti-inflammatory range than SIT.     

Tryptase in nasal fluid is a useful marker of allergic rhinitis

Tryptase is a mast cell-specific marker of degranulation. To investigate the possible diagnostic value of tryptase in allergic rhinitis, we measured the levels in both serum and native nasal fluid with a sandwich RIA-assay (Pharmacia). Twenty-three allergic patients and five patients with chronic ethmoidal sinusitis were included. Eighteen of the 23 allergic patients were tested within the pollen season or had perennial rhinitis; the remainder were tested at least 1 month out of the pollen season. None of the patients had detectable serum tryptase (>0.1 ng/ml). Also patients with chronic ethmoidal sinusitis showed no tryptase in nasal fluid. One of seven allergic patients tested out of season had slightly increased nasal tryptase of 1.8 ng/ml. In patients with active nasal allergy, the tryptase in nasal fluid ranged from 6.4 ng/ml to 640 ng/ml with a mean of 101 ng/ml and SD 173. These results show a clear distinction between active and non-active nasal allergy and other non-mast-cell-related nasal disease. Further, nasal tryptase release by natural allergen exposure is even higher than that observed in allergen challenge tests.     

Upregulation of nasal mucosal eotaxin in patients with allergic rhinitis during grass pollen season: effect of a local glucocorticoid

BACKGROUND: Allergic rhinitis is a common disease characterized by infiltration of eosinophils into the nasal mucosa during the periods of symptoms. Among chemokines, which attract cells to the site of inflammation, eotaxin is relatively specific for eosinophils. OBJECTIVE: We examined the influence of grass pollen season on nasal eotaxin expression in patients with seasonal allergic rhinitis, as well as the effect of a nasal glucocorticoid on this eotaxin expression. METHODS: Nineteen patients with allergic rhinitis received treatment with either nasal beclomethasone (400 microgram/day) or placebo over a grass pollen season. In these patients, nasal biopsies were taken prior to and during the peak of the pollen season and stained immunohistochemically for eotaxin and EG2 + eosinophils. Five healthy subjects served as controls and gave nasal biopsies once prior to the pollen season. RESULTS: Prior to pollen season, there was no significant difference in nasal eotaxin expression between patients with allergic rhinitis and healthy subjects. Grass pollen season induced significant increase in eotaxin expression in placebo-treated (P = 0.04; n = 9) but not in beclomethasone-treated rhinitis patients (P = 0.8; n = 10). During peak grass pollen season, the eotaxin expression in placebo-treated patients was significantly higher compared with healthy subjects outside season (P = 0.03). There was no significant correlation between the expression of eotaxin and the number of EG2 + eosinophils in nasal mucosa. The serum levels of eotaxin in rhinitis patients remained stable over the pollen season. CONCLUSION: Expression of eotaxin in nasal mucosa of grass-pollen allergic rhinitis patients is upregulated during pollen season and treatment with a nasal glucocorticoid protects against this upregulation.     

Immunoglobulins in nasal secretion with special reference to IgE. I. Methodological studies.

Different ways of collecting relatively large volumes of nasal secretion with as physiological a composition as possible were studied. Nasal secretion was collected by the so-called nasal spray washing method from 5 patients with allergic rhinitis due to pollen and 5 healthy persons during a pollen-free season. The collection was performed without any provocation and following nasal provocation with histamine or allergen solution. With the radioimmunosorbent test, in which the lower limit of measurement was 0.1 units/ml, IgE could be quantified in 52 of 60 analysed secretions. IgA, IgG and albumin were demonstrated in all secretions. In the allergic patients, following histamine and allergen provocation, a relative increase in the concentration of IgE and albumin and a significant decrease of the IgA/albumin ratio in nasal secretion was found. In the healthy subjects, such changes in the secretion were observed only after histamine provocation. Calculations also suggested some local production of IgE, but not at all of the same order of magnitude as of IgA.     

Eosinophils, secretory responsiveness and glucocorticoid-induced effects on the nasal mucosa during a weak pollen season

This study examined the seasonal effects on eosinophils and secretory responsiveness of the nasal mucosa in 22 patients with allergic rhinitis due to birch pollen (11 patients received placebo and 11 budesonide, 200 micrograms once daily in each nostril). The pollen counts during the study season were too low to produce a significant symptomatology. Hence, our findings demonstrate threshold alterations of the airway mucosa in allergic rhinitis and their inhibition by anti-inflammatory drug intervention. The patients were monitored for 8 weeks with daily recordings of pollen counts and symptom scores. Once every week a series of laboratory tests was carried out: the local eosinophil influx was determined using a Rhinobrush technique; the levels of eosinophil cationic protein (ECP) were analysed in nasal lavage fluids; and the secretory response to intranasal methacholine was measured. Treatments started after a 2-week run-in period. The proportion of eosinophils increased markedly in the placebo group and was elevated also during the last two study weeks when the pollen counts were practically nil. The secretory responsiveness to methacholine increased during the pollen season and returned to baseline towards the end of the study period. The topical glucocorticoid treatment reduced the proportion of eosinophils, the ECP levels, and the secretory response to methacholine compared to placebo. We conclude that the increased traffic and activity of eosinophils and less conspicuously the increased secretory responsiveness are expressions of the mucosal inflammation that precede the development of symptoms in seasonal allergic rhinitis.     

Glucocorticoid-induced attenuation of mucosal exudation of fibrinogen and bradykinins in seasonal allergic rhinitis

The mucosal plasma exudate with its proteins, enzymes, derived peptides, and matrix molecules is an important factor in inflammatory airway diseases. This study investigated whether topical glucocorticosteroid treatment influences mucosal exudation of bulk plasma (fibrinogen) and the generation of plasma-derived mediators (bradykinins) in seasonal allergic rhinitis. Twenty-two patients with birch-pollen-induced allergic rhinitis participated in a double-blind, randomized, placebo-controlled study during the birch pollen season in 1989. After a 2-week run-in period, the participants received treatment with budesonide (200 μg per nasal cavity and day) or placebo. The patients kept a diary to record their daily nasal symptoms (itching, sneezing, nasal blockage, and secretion). The amount of birch pollen in the air was determined with the aid of a Burkhard pollen trap. A nasal lavage was performed once a week, and the levels of bradykinins and fibrinogen were determined in the lavage fluid samples. The birch pollen season was very mild, resulting in only minor nasal symptoms. In spite of the low pollen exposure, treatment with budesonide reduced the lavage fluid levels of both bradykinins and fibrinogen. The present results show that topical glucocorticosteroid treatment attenuates plasma exudation and the generation of plasma-derived mediators in seasonal allergic rhinitis. This action may not result from simple vascular antipermeability effects of the drug but may rather reflect the anti-inflammatory efficacy of topical glucocorticoids in the airway mucosa.     

Immunoglobulins in nasal secretion with special reference to IgE. II. Seasonal studies of Timothy-specific IgE-antibody in patients with allergic rhinitis.

14 adult patients with allergic rhinitis due to timothy pollen were observed for 13 weeks during the grass pollen season. IgE, IgA and timothy-specific IgE antibodies could be quantified in all serum and secretion samples. Total IgE and specific IgE antibodies in both serum and secretion reached significantly higher levels in samples taken during and after the pollen season than before the season. These seasonal changes proved to be significantly more pronounced in nasal secretion than in serum. An indication of local production in the nasal mucosa of IgE, IgA and secific IgE antibodies was also found.     

Expression of Toll‐like receptors in nasal epithelium in allergic rhinitis

Toll‐like receptors (TLRs) are important in barrier homeostasis, but their role in airborne allergies is not fully understood. The aim was to evaluate baseline and allergen‐induced expression of TLR proteins in nasal epithelium during allergic rhinitis. Nineteen otherwise healthy non‐smoking volunteers both allergic to birch pollen and non‐allergic controls were enrolled. We took nasal biopsies before and after off‐seasonal intranasal birch pollen or diluent challenge. The expression of epithelial TLR1‐7, TLR9‐10, and MyD88 proteins was immunohistochemically evaluated from the nasal biopsies. The TLR1‐3 and TLR5‐10 mRNAs were observed by RNA‐microarray. Baseline epithelial expression of TLR proteins was wide and identical in controls and atopics. After off‐seasonal intranasal birch pollen challenge, a negative change in the expression score of TLR1 and TLR6 proteins was detected in the atopic group. TLR mRNA expression was not affected by birch pollen challenge. Nasal epithelium seems to express all known TLRs. The mechanisms by which TLR1, and TLR6 proteins could affect pollen allergen transport need further studies.     

IgE, IgG and IgA antibodies in serum and nasal secretion during parenteral hyposensitization

Eighteen adult patients with allergic rhinitis due to Timothy pollen were observed for 36 weeks before, during and after the grass pollen season. Eight patients were treated by parenteral hyposensitization with grass pollen extract, and ten patients who were given no immunotherapy served as controls. Timothy-specific IgE, IgG and IgA antibodies in samples of serum and nasal secretion were quantified by radioimmunological technique. In comparison with the control group, the serum concentration of Timothy-specific IgE antibodies increased significantly (P <0.05) during the preseasonal hyposensitization treatment and then decreased significantly (P <0.05) during and after the pollen season while this therapy was being continued. In the hyposensitized patients the serum concentration of both IgG and IgA antibodies increased highly significantly (P <0.01 and P <0.001, respectively) during immunotherapy. In nasal secretion quantitative changes of the three types of antibodies were usually less pronounced or not detectable at all. The concentration of IgG antibodies, however, showed some increase in the nasal secretion during hyposensitization. These minor increases in allergen-specific IgG and IgA antibodies in nasal secretion might explain why parenteral hyposensitization in allergic rhinitis often does not give complete relief from symptoms.     

Low levels of CC16 in nasal fluid of children with birch pollen-induced rhinitis

BACKGROUND: Clara cell protein 16 (CC16; secretoglobin 1A1) is an anti-inflammatory protein mainly expressed in the epithelial cells in the airways. OBJECTIVE: To compare the levels of CC16 in nasal lavage (NAL) from children with intermittent allergic rhinitis and healthy controls and to study the effect of a local steroid. METHODS: Thirty schoolchildren with birch pollen allergy and 30 healthy controls from the same schools were included in the study. The NAL fluid was collected before the season, during the birch pollen season and, for the patients, after 1 week of treatment with a local steroid. Symptom scores were obtained on every occasion. CC16 and eosinophil cationic protein (ECP) were analyzed with enzyme-linked immunosorbent assay. RESULTS: The nasal fluid levels of CC16 were significantly lower in patients than in controls, before and during pollen season. Before the season, the median CC16 concentrations were 9.1 (range 1.1-117) microg/l in patients and 25.7 (6.1-110.2) microg/l in controls. During the season, the median CC16 concentrations in nasal fluid were 12.9 (2.3-89.7) microg/l in the allergic children and 22.0 (9.5-90.1) microg/l in the healthy controls (P = 0.0005). Symptom scores, nasal fluid eosinophils and ECP were higher in patients during the season. Treatment with a local steroid did not change the CC16 levels. CONCLUSIONS: Nasal fluid CC16 levels were lower in children with birch pollen-induced allergic rhinitis than in healthy controls both before and during the pollen season. We speculate that reduction in anti-inflammatory activity by CC16 may contribute to the pathogenesis of allergic rhinitis.     

Selective recruitment of eosinophils by substance P after repeated allergen exposure in allergic rhinitis

We have investigated the nasal response to substance P after pollen exposure in seasonal allergic rhinitic patients. Seven patients with strictly seasonal allergic rhinitis were studied during the pollen season, 24 h after nasal challenge with pollen. They received increasing doses of nebulized substance P (0 to 80 nmol) in each nostril. Responses were assessed by measurement of nasal airway resistance by posterior rhinomanometry and quantification of albumin, histamine, and inflammatory cells in the nasal lavage fluid. Nasal airway resistance increased in a dose-dependent manner after substance P challenge. Protein and albumin in nasal lavage fluids increased after administration of substance P: from 2.6 ± 0.3 to 6.8 ± 1.1 mg for protein (P≤0.01) and from 0.2 ± 0.1 to 3.1 ± 0.6 mg for albumin (P≤0.02). Expressed as a percentage of total protein, albumin increased from 10.5 ± 3.6% to 39.9 ± 3.5% (P≤0.02), suggesting occurrence of plasma leakage. No histamine release was observed after challenge with substance P. Total cell counts significantly increased from 11.4 ± 2.4 to 41.8 ± 17.3 × 10³ cells/ml after substance P (P≤0.05). Eosinophils were already numerous before substance P challenge (2.1 ± 0.7 × 10³ cells/ml), and the number of eosinophils markedly increased in all patients after substance P (for the whole group, 25.8 ± 13.3 cells/ml, P≤0.05). In contrast, the number of neutrophils only slightly increased in five patients, and changes did not reach significance for the group as a whole. Our results show that substance P induces nasal obstruction and albumin extrusion in allergic rhinitic patients after repeated pollen exposure. These vascular phenomena are associated with recruitment of eosinophils. Since substance P is known to be released after nasal allergen challenge, our data suggest a role for substance P in the chronic eosinophilic inflammation of the nasal mucosa observed in symptomatic allergic rhinitis.     

The significance of hypersensitivity to nuts in patients with birch pollen allergy

This study was performed in patients with allergic rhinitis/conjunctivitis to birch pollen to determine whether patients with additional hypersensitivity to nuts and apples differed from patients without such hypersensitivity; the determination was in terms of results of skin prick test (SPT), specific IgE antibodies (RAST), and symptoms during the pollen season. Forty-seven patients with birch pollen allergy were investigated by RAST against birch and hazel pollen and by SPT. They were treated in a randomized, double-blind, placebo-controlled study with fluticasone propionate aqueous nasal spray or placebo. The area of the SPTs was larger and the specific IgE values higher in patients with hypersensitivity to nuts and apples. These patients also had more symptoms during the pollen season. We conclude that hypersensitivity to nuts is an indication of a more severe allergy in patients with birch pollen allergic rhinitis.     

A new murine model of allergic rhinitis by repeated intranasal Cry j 1 challenge

To evaluate the long-lasting effects of new therapeutic approaches to allergies, we established a new model of allergic rhinitis by repeated challenges with intranasal Cry j 1, a common Japanese cedar (Cryptomeria japonica) pollen allergen, in B10.S mice. We sensitized B10.S mice subcutaneously with Cry j 1/alum three times at 1-week intervals. Five weeks after the final sensitization, we challenged the mice by instilling Cry j 1 intranasally for 5 consecutive days starting 1 day after intranasal histamine pretreatment (challenge-1). We challenged the mice by instilling histamine and Cry j 1 intranasally again 12 weeks later (challenge-2). There were significantly more sneezes after challenge-2 than challenge-1. Cry j 1-specific IgE levels in serum were significantly increased in both challenge-1 and 2 after continuous nasal antigen challenge. Serum levels of anti-Cry j 1 IgE in challenge-2 was 2.3 times higher than after challenge-1. Thus, we have established a new model of seasonal allergic rhinitis in B10.S mice by repeated intranasal antigen challenge, and this model may help elucidate mechanisms of allergic rhinitis and the development of new drugs.     

Effects of topical budesonide and levocabastine on nasal symptoms and plasma exudation responses in seasonal allergic rhinitis

This study compares the effects of two topical nasal treatments for allergic rhinitis, budesonide and levocabastine, on symptom development during seasonal pollen exposure. Additionally, the protective effects of drug treatments on allergen-challenge-induced responses (symptoms and microvascular exudation of plasma) are examined late into the pollen season. Forty-four patients with seasonal allergic rhinitis to birch pollen participated in this single-blind, randomized, and placebo-controlled study. Topical nasal treatment with either levocabastine (200 p.g b.i.d.: n = 16), budesonide (200 μg b.i.d.; n = 16), or placebo (n= 12) was instituted before the start of the pollen season and continued for 5 weeks until the end of the birch pollen season. The participants kept diaries for scores of nasal and ocular symptoms. Nasal allergen challenges with increasing doses of a birch pollen extract (10², 10³ and lC SQ-U) were carried out both before, when patients were asymptomatic and without treatment, and late into the pollen season. A nasal lavage followed each challenge, and the lavage fluid levels of albumin were measured as an index of the acute inflammatory response of the allergic mucosa. The birch pollen season was rather mild, producing only small increases in nasal symptoms. Budesonide treatment reduced the total nasal symptoms compared to placebo (P<0.01) and to levocabastine (P<0.05), while levocabastine treatment did not differ significantly from placebo. Ocular symptoms and use of rescue medication did not differ between placebo and the active treatments. At the end of the pollen season, both treatments reduced allergen-challenge-induced nasal symptoms compared to placebo (P<0.01). Only budesonide reduced allergen-challenge- induced increments of albumin levels in postchallenge nasal lavage fluids (P<0.05, in comparison with placebo). The results suggest that budesonide reduces both seasonal and allergen-challenge-induced nasal symptoms, while levocabastine is effective against allergen-challenge-induced symptoms also during the season. In addition, the topical steroid treatment, but not the antihistamine, inhibits the inflammatory exudation evoked by allergen challenge in patients with active seasonal disease.     

Local nasal immunotherapy for birch allergic rhinitis with extract in powder form

Background Traditional subeutaneous immunotherepy has been proved effective in birch pollenosis. It has, however, some drawbacks as systeic reactions, which are rare but important. Local nasal immunotherapy (LNIT)represents a potential safer route of allergen administration.
Objective To study the clinical efficacy and safety of local nasal immunotherapy by means of an extract in powder form as treatment of birch allergic rhinitis.
Methods Thirty birch allergic patients have been selected on the basis of a positive history, skin test, radioalllergosorbent test assay (RAST)and specific nasal challange. Two 15 patient groups were randomly assigned to the active treatment or to the placebo one. Treatment lasted 22 weeks (14 for the build-up phase and eight for the maintenance period)and symptoms were recorded during the treatment and the birch pollen season.
Results The clinical efficacy of LNIT is suggested by a significant reduction of medication score only in the treated group during the pollen season, although the symptom score was significant increase of specific nasal thereshold dose was obserbved after treatment only in the active treated group. Mild adverse reaction to LNIT, limited to the upper respiratory tract, were reported during the treatment in the active group, but they did not interface with LNIT schedule. No asthmatic or systemic reaction were observed.
Conclusions This Study Indicates that LNIT with allergen in powder form has proven clinically effective in the treatment of birch allergic rhinitis. Further studies are needed to establish weather this treatment can be considered a real alternative to the traditional subeutaneous immunotherapy in birch allergic rhinitis.