Local nasal immunotherapy in allergic rhinitis to Parietaria. A double-blind controlled study

Specific local nasal immunotherapy: Single center experience on 324 patients

OBJECTIVE

To evaluate the efficacy and safety of specific local nasal immunotherapy (LNIT) in patients with allergic rhinitis.

MATERIALS AND METHODS

A retrospective single-center study of 324 patients with allergic rhinitis (191 allergic to mites, 133 allergic to Grarninaceae or Parietaria pollen) treated with specific LNIT was carried out. As control group, 158 patients without allergic rhinitis were enrolled. All patients were evaluated before and after 32 weeks of treatment by subjective analysis of their self-reported symptoms and by objective analysis of nasal provocation test, nasal resistance by anterior rhinomanometry, and mucociliary clearance time.

RESULTS

Clinical efficacy of LNIT for allergy to mites and pollens was confirmed by the differences in the symptoms score between the active group and the placebo group. The nasal provocation test and the rhinomanometric analysis confirm the result with a difference statistically significant. No differnces in mucociliary clearance time were found.

CONCLUSIONS

Specific LNIT is a valide alternative to subcutaneous and sublingual administration. It is effective, safe, well tolerated by the patient, it can be done at home with fewer systemic reactions.

LNIT-Local nasal immunotherapy in allergic rhinitis: revisited evidence and perspectives

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) is a personalized treatment approach for the allergic airway disease. The most common routes of administration are subcutaneous and sublingual. Local nasal immunotherapy (LNIT) presents another alternative route for allergen desensitization. Nasal mucosa is the first entry site of pathogens and numerous lymphoid organs are located in this area, making LNIT a favorable method for triggering immune tolerance. LNIT has shown promising results in reducing symptoms and medication use in allergic rhinitis patients. Over time, difficulties in dosing adjustments have made this method less popular. Recent advances in intranasal drug delivery systems warrant re-examination of LNIT as a viable option for the treatment of the allergic airway disease.

RECENT FINDINGS

The scope of the review includes evidences of LNIT in human trials including comparison with placebo and conventional method of immunotherapy. Recent articles regarding the mechanism of LNIT and the challenges of intranasal drug delivery are reviewed. Advances in the LNIT delivery system which have overcome previous limitations demonstrate promising effects.

SUMMARY

LNIT presents a judicious alternative for noninjection AIT. The evidences from previous clinical trials and the novel improvement of drug delivery system will lead into the future allergen vaccine production.

Local nasal immunotherapy for allergic rhinitis: A systematic review and meta-analysis

INTRODUCTION

Local nasal immunotherapy (LNIT), an alternative noninjection immunotherapy method, is theoretically an efficient method for inducing immunotolerance directly in the affected organ. LNIT is more convenient and less invasive than injection immunotherapy, with fewer systemic reactions. The development of adjuvants to overcome LNIT's limitations raises the possibility of it being an alternative allergen immunotherapy.

OBJECTIVES

To evaluate the clinical and immunological efficacy and safety of LNIT for patients with allergic rhinitis.

METHODS

A systematic search for randomized controlled trials comparing LNIT and placebo was performed using OVID Medline and Embase. Outcomes were total nasal symptom score (TNSS), symptom-medication score (SMS), medication score, immunological assessment, and nasal provocation threshold. Data were pooled for meta-analysis.

RESULTS

A total of 20 studies with 698 participants were included. The LNIT group had greater posttreatment improvement in TNSS, SMS, and medication score than control (TNSS: standardized mean difference [SMD], -1.37 [95% confidence interval [CI], -2.04 to -0.69]; SMS: SMD, -1.55 [95% CI, -2.83 to -0.28]; and medication score: SMD, -1.09 [95% CI, -1.35 to -0.83]). Immunological assessments showed no significant differences in serum-specific IgE (mean difference [MD], 6.35; 95% CI, -4.62 to 17.31), nasal IgE (MD, -0.59; 95% CI, -1.99 to 0.81), or nasal eosinophil cationic protein (MD, 7.63; 95% CI, -18.65 to 33.91). Only serum IgG significantly increased with LNIT (MD, 0.45; 95% CI, 0.20, 0.70). Posttreatment, nasal provocation threshold was higher with LNIT (MD, 27.30; 95% CI, 10.13-44.46). No significant adverse events were reported.

CONCLUSIONS

LNIT is a safe alternative allergen immunotherapy route without significant adverse events. It improves clinical symptoms, reduces medication usage, and increases the nasal provocation threshold.

Parietaria Allergy: An Intriguing Challenge for the Allergist

Parietaria pollen is the most important cause of pollen allergies in the Mediterranean area, as Parietaria is widespread in this region. Many issues are associated with Parietaria allergy, including the duration of the pollen season (many doctors in fact believe that it lasts throughout the year), pollen load (which seems to be increasing over time), the impact of age (on IgE production and symptom severity), inflammatory changes (after pollen exposure), and the choice of allergen immunotherapy (AIT). In addition, molecular diagnostics allows for the defining of a correct diagnosis, differentiating between mere sensitization and true allergy. This review considers these topics and will hopefully help the allergist in clinical practice. Parietaria allergy is an intriguing challenge for the allergist in clinical practice, but it may be adequately managed by knowing the peculiarities of respective territories and the clinical characteristics of each patient.

Health Risks and Benefits of Chickpea (Cicer arietinum) Consumption

Chickpeas (CPs) are one of the most commonly consumed legumes, especially in the Mediterranean area as well as in the Western world. Being one of the most nutritional elements of the human diet, CP toxicity and allergy have raised health concerns. CPs may contain various antinutritional compounds, including protease inhibitors, phytic acid, lectins, oligosaccharides, and some phenolic compounds that may impair the utilization of the nutrients by people. Also, high consumption rates of CPs have enhanced the allergic problems in sensitive individuals as they contain many allergens. On the other hand, beneficial health aspects of CP consumption have received attention from researchers recently. Phytic acid, lectins, sterols, saponins, dietary fibers, resistant starch, oligosaccharides, unsaturated fatty acids, amylase inhibitors, and certain bioactive compounds such as carotenoids and isoflavones have shown the capability of lowering the clinical complications associated with various human diseases. The aim of this paper is to unravel the health risks as well as health-promoting aspects of CP consumption and to try to fill the gaps that currently exist. The present review also focuses on various prevention strategies to avoid health risks of CP consumption using simple but promising ways.

New Routes of Allergen Immunotherapy

Objectives

Allergen immunotherapy is the only cure for immunoglobulin E mediated type I respiratory allergies. Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are the most common treatments. In this article, we reviewed new routes of allergen immunotherapy.

Methods

Data on alternative routes to allow intralymphatic immunotherapy (ILIT), epicutaneous immunotherapy (EPIT), local nasal immunotherapy (LNIT), oral immunotherapy (OIT), and oral mucosal immunotherapy (OMIT) were gathered from the literature and were discussed.

Results

ILIT features direct injection of allergens into lymph nodes. ILIT may be clinically effective after only a few injections and induces allergen-specific immunoglobulin G, similarly to SCIT. A limitation of ILIT is that intralymphatic injections are required. EPIT features allergen administration by using patches mounted on the skin. EPIT seeks to target epidermal antigen–presenting Langerhans cells rather than mast cells or the vasculature; this should reduce both local and systemic adverse effects. LNIT involves the spraying of allergen extracts into the nasal cavity. Natural or chemically modified allergens (the latter, termed allergoids, lack immunoglobulin E reactivity) are prepared in a soluble form. OIT involves the regular administration of small amounts of a food allergen by mouth and commences with low oral doses, which are then increased as tolerance develops. OMIT seeks to deliver allergenic proteins to an expanded population of Langerhans cells in the mucosa of the oral cavity.

Conclusions

ILIT, EPIT, LNIT, OIT, and OMIT are new routes for allergen immunotherapy. They are safe and effective.

Allergen immunotherapy: routes, safety, efficacy, and mode of action

Allergic rhinitis, allergic conjunctivitis, and allergic asthma have been steadily increasing in prevalence in recent years. These allergic diseases have a major impact on quality of life and are a major economic burden in the US. Although allergen avoidance and pharmacotherapy are currently the mainstays of therapy, they are not always successful in treating patients' symptoms effectively. If a patient fails allergen avoidance and medical therapy, immunotherapy may be indicated. Furthermore, immunotherapy is the only therapy that may change the course of the disease and induce long-term remission. Though subcutaneous administration has been the standard route for immunotherapy for many decades, there are several other routes of administration that have been and are currently being studied. The goal of utilizing alternative routes of immunotherapy is to improve safety without decreasing the efficacy of treatment. This paper will review the novel routes of immunotherapy, including sublingual, oral, local nasal, epicutaneous, and intralymphatic.

Novel routes for allergen immunotherapy: safety, efficacy and mode of action

Allergen immunotherapy is the only curative treatment of IgE-mediated type I respiratory allergies. Subcutaneous immunotherapy (SCIT) is used as a reference therapy and has transformed allergic treatments; it improves symptoms (asthma and rhinitis) as well as the quality of life of patients. SCIT requires repetitive administration and carries the risk of severe systemic adverse effects, including anaphylaxis. Sublingual immunotherapy is now a valid noninvasive alternative to SCIT, as a safe and efficacious treatment for respiratory allergies. In this article, we compare various routes of allergen immunotherapy, including SCIT and sublingual immunotherapy, as well as more exploratory routes currently under investigation (i.e., intralymphatic, epicutaneous, intranasal and oral). We discuss their respective advantages, as well as their foreseen modes of action.

Local nasal specific immunotherapy for allergic rhinitis

The possibility of producing local hyposensitization by administering allergens via mucosal routes was envisaged at the beginning of 1900, and local nasal immunotherapy has been extensively studied since the 1970s. Presently, there are 21 randomized controlled trials being conducted with the most common allergens, consistently showing the clinical efficacy of local nasal immunotherapy for rhinitis. Other advantages are that it has an optimal safety profile and can be self-administered at home by the patient. Moreover, there are several data from animal models and from humans that confirm the immunomodulatory effect of intranasally administered antigens. On the other hand, local nasal immunotherapy seems to be effective only on rhinitis symptoms and requires a particular technique of administration. For these reasons, its clinical use is progressively declining in favour of the sublingual route although nasal immunotherapy is validated in official documents and remains a viable alternative to injection.

Novel ways for immune intervention in immunotherapy: mucosal allergy vaccines

Allergen-specific immunotherapy is currently the only curative treatment for allergy. Subcutaneous immunotherapy (SCIT) has been successfully used to treat patients who are allergic to insect venom, house dust mites, or tree or grass pollens. In the context of potentially severe, albeit infrequent, side effects associated with SCIT, mucosal routes of administration are being investigated to conduct allergenic desensitization. This article reviews recent developments in the field of nasal, oral, and sublingual immunotherapy as they relate to safety, clinical efficacy, and immune mechanisms of action. Implications for the design and development of improved allergy vaccines that could be used through such nonparenteral routes are discussed. Specifically, allergen presentation platforms and adjuvants facilitating the targeting of immune cells at mucosal surfaces to promote tolerance induction are reviewed.

Pharmacokinetics of radiolabelled Par j 1 administered intranasally to allergic and healthy subjects

BACKGROUND

Local nasal immunotherapy is accepted as an alternative to the injection route for allergic rhinitis. Despite this, little is known about the kinetics of the allergen after nasal delivery in allergic subjects.

OBJECTIVE

We aimed at assessing the biodistribution of 123I-radiolabelled Par j 1 in Parietaria-allergic subjects, in comparison with healthy volunteers.

METHODS

Purified Par j 1 was radiolabelled with 123I and sprayed into the nostrils of three control subjects and three Parietaria-allergic volunteers. Dynamic and static scintigraphic images of the head were recorded at serial times and blood samples were obtained to measure the plasma radioactivity, and to assess the presence of circulating radiolabelled species by gel chromatography.

RESULTS

In Parietaria-sensitized subjects, the radiolabelled allergen was rapidly cleared from the nasal cavity and transported to pharynx, and little local persistence was seen. This differed from healthy subjects where nasal clearance of the tracer was slower and nasal radioactivity persisted up to 24 h. The increase in plasma radioactivity paralleled swallowing of the allergen in both groups, and plasma chromatographic profile did not differ between allergic and healthy volunteers.

CONCLUSIONS

Sensitization to the allergen affects its local biodistribution. Gastrointestinal absorption is relevant also for the intranasal route.

Noninjection routes for immunotherapy

Allergen specific immunotherapy, together with drugs and allergen avoidance, is a cornerstone in the management of respiratory allergy. The traditional subcutaneous route is burdened with the risk of severe adverse events; therefore, safer routes of administration (noninjection or local routes) have been investigated and developed. Controlled trials failed to demonstrate the clinical efficacy and the safety of oral and bronchial administration, and these routes have been abandoned. Local nasal immunotherapy proved effective and safe in 17 of 18 controlled trials; thus it is considered a viable route of immunotherapy. Nevertheless, nasal immunotherapy is effective in rhinitis only and requires a particular administration technique; therefore its use is slowly declining. The sublingual route is supported by numerous controlled trials showing its efficacy in asthma and rhinitis in adults and children. The safety profile, assessed in clinical trials and postmarketing surveillance studies, is satisfactory; the most frequent side effects are gastrointestinal complaints, which can be easily managed by proper dose adjusting. Sublingual immunotherapy is now accepted by the World Health Organization as a valid alternative to the subcutaneous route also in children. Although the long-lasting efficacy has been recently documented for the sublingual route, several points still need to be elucidated, including mechanisms of action, optimal dosage, cost-effectiveness, and adherence.

Appropriate and inappropriate use of immunotherapy

OBJECTIVE

The primary objective of this review is to discuss indications for appropriate and inappropriate use of allergen immunotherapy (IT), including discussion of contraindications, adverse events, and alternative protocols and methods.

DATA SOURCES

A review of the literature on indications, contraindications, adverse events, and alternative methods and protocols associated with allergen IT was conducted.

STUDY SELECTION

The opinion of the author was used to select and review relevant data.

RESULTS

Clinical trials have proven the benefit of allergen IT, for allergic rhinitis, asthma, and anaphylaxis because of stinging insects, such as Hymenoptera and fire ants. Allergen IT may improve quality of life and decrease medication requirement for allergic rhinitis and asthma, especially for younger patients, and probably will assist in the prevention of the progression of allergic disease from rhinitis to asthma. Subcutaneous allergen IT is well established as clinically effective through multiple, blinded, placebo-controlled studies. The data for alternate therapies and routes of therapy are extensively reviewed and critiqued.

CONCLUSIONS

Allergen IT is a highly valuable form of treatment of IgE-mediated diseases. Documentation of sensitivity to allergen sensitization associated with symptoms is critical before use of allergen IT. Symptoms should also be of sufficient duration and severity to warrant IT. Before allergen IT is used, there must be an available allergen extract that is suitable for treatment of the relative sensitivity. It is essential for patients receiving allergen IT to understand the treatment principle, the frequency of injections, the duration of treatment, the risk and signs of adverse events, the magnitude of the efficacy, and the essential nature of patient compliance. Subcutaneous allergen IT is the only current mode of therapy in the United States that has been shown to be effective.

A multicenter trial of specific local nasal immunotherapy

OBJECTIVE

To assess the efficacy and safety of specific local nasal immunotherapy (LNIT) in powder form in patients with allergic rhinitis, using subjective and objective parameters.

STUDY DESIGN

A double-blind randomized multicenter trial of 102 patients with allergic rhinitis who were treated with specific LNIT for 8 consecutive months.

METHODS

After identifying allergens with the skin prick test and sensitization threshold dose with the specific nasal provocation test, 102 patients were selected, of whom 55 were allergic to mites and 47 were allergic to Graminaceae or Parietaria pollen. The specific treatments were self-administered using an insufflator in two phases (phase 1: increasing doses; phase: 2, maintenance dose). Patients were evaluated before and after 32 weeks of treatment by subjective analysis of their self-reported symptoms and by objective analysis of nasal provocation test, nasal resistance by anterior rhinomanometry, and mucociliary clearance time.

RESULTS

Clinical efficacy of LNIT for allergy to mites and pollens was confirmed by the differences in the symptoms score between the active group and the placebo group. The nasal provocation test results confirmed that this difference was statistically significant. The rhinomanometric analysis gave positive results for the treated group mainly in LNIT for mites. No differences in mucociliary clearance time were found.

CONCLUSIONS

Specific LNIT is effective for allergic rhinitis and appears to offer considerable advantages over other hyposensitization methods. It can be done at home, patient compliance is good, and the treatment is safe.

Local and systemic immunotherapy in nasal allergy

Two assays have been done to evaluate the effect of immunotherapy in nasal allergy. First, a trial of nasal immunotherapy and second, the study of mediator release after vaccines. Local immunotherapy, applied directly, triggers different response mechanisms. Specific nasal immunotherapy started before seasonal or perennial symptoms peak, has been done by increasing the doses of allergen three times a week during a 3-month period and a manutention period of a weekly nasal puff of the same allergen. Symptom scores and drug consumption have been registered. The results have been compared with the scores obtained in the same patients over the same period of the same year before immunotherapy. In perennial rhinitis blockage, rhinorrea, sneezing and itching scores all decreased. In seasonal rhinitis, a similar score decrease was obtained for blockage, rhinorrea, sneezing and itching. Pharmacological scores also decreased. These data point to a short-term effect of nasal immunotherapy. Tryptase release has been evaluated in nasal washings after nasal challenge with a Parietaria (Pellitory wall) extract before and after specific systemic immunotherapy, in order to evaluate changes in mast cells reactivity. Eight patients were studied, all allergic to Parietaria. Nasal provocation tests have been done before the season with increasing doses of 10, 100 and 1000 PNU and tryptase assayed in nasal washings at 10, 20 and 30 min after provocation. Immunotherapy decreased tryptase release after nasal challenge. The data point to the effect of systemic specific immunotherapy on mast cell reactivity.

Clinical efficacy and tolerability of a steady dosage schedule of local nasal immunotherapy. Results of preseasonal treatment in grass pollen rhinitis

BACKGROUND

Local nasal immunotherapy (LNIT) is an effective and safe alternative to conventional subcutaneous immunotherapy. A specific nasal provocation test (SNPT) could be used to indicate the optimal subclinical dose to carry out LNIT.

OBJECTIVE

We hypothesize that LNIT could be carried out with only one predefined dose for all patients, so we have evaluated the efficacy and the tolerability of LNIT administered at steady dosages in patients with seasonal allergic rhinitis.

METHODS

Twenty grass pollen-sensitized patients suffering from seasonal allergic rhinitis were studied in a randomized, double-blind, placebo-controlled trial. The treatment was carried out according to a schedule based on the administration of a steady subclinical dosage of the allergenic extract, selected on the basis of the sensitivity threshold of the SNPT. The patients were divided into two groups of 10 people each, which were treated either with grass pollen extract in a hydroglyceric solution or with placebo.

RESULTS

During the peak pollen period, with regard to the placebo (P) group, in the grass treated (GT) group a significant decrease of both nasal symptoms (P = .021) and consumption of antihistamines (P = 0.047) was found. Furthermore, only in the GT group was the provocative dose assessed by the SNPT significantly lower (P = .049) at the end of the treatment. In this group of patients an inverse correlation between such provocative dose and the nasal symptom score reported during the peak pollen period was also evidenced (r = 0.708; P = .038). Adverse reactions to LNIT were mild, rare, and did not interfere with the completion of the therapeutic schedule.

CONCLUSIONS

Our study indicates that LNIT, when administered at steady dosages, may be proposed as a treatment for grass pollen seasonal allergic rhinitis as it appears to be effective and well tolerated.

Decrease of allergen-specific T-cell response induced by local nasal immunotherapy

BACKGROUND

The clinical efficacy and safety of local nasal immunotherapy (LNIT) with lyophilized 'macronized' powder has been demonstrated. However, the immunological changes possibly induced by LNIT which may account for the clinical improvement are still unclear.

OBJECTIVE

To investigate the effects of a successful LNIT-treatment on the allergen-driven T cell response, cytokine secretion and IgE and IgG antibody production.

METHODS

Three groups (untreated, subcutaneous immunotherapy- SIT- and LNIT-treated) of grass-sensitive patients suffering from seasonal rhinitic symptoms were ramdomized for the 2-year study. The proliferative response of PBMC to purified Rye-1 allergen and serum levels of grass-specific IgE and IgG were evaluated before treatment and during the 2-year subsequent pollination periods. The proliferative response of allergen-specific short-term T-cell lines, as well as production of allergen-driven cytokine by PBMC, were also assessed.

RESULTS

Both SIT and LNIT induced a significant reduction of symptom scores during the pollination season. SIT, but not LNIT, induced a significant change in serum levels of allergen-specific IgE and IgG antibody. By contrast, both SIT and LNIT reduced the increase of the proliferative response of allergen-specific T cells driven by natural allergen exposure and significantly decreased T cell proliferation to low doses of allergen, as shown also by the mitogenic index of allergen-specific T-cell lines. A reduced IL-4 and IFNgamma production by PBMC of LNIT- and SIT-treated patients was also observed in the absence of a clearcut TH2-TH1 switch.

CONCLUSIONS

These data suggest that a common mechanism of both LNIT and SIT is the induction of T-cell tolerance, thus providing a rational basis to explain why LNIT may be clinically successful in allergic patients with rhinits.

Nasal immunotherapy in weed-induced allergic rhinitis

BACKGROUND

Nasal immunotherapy with single allergen extracts, following premedication with cromolyn, has been reported to be effective in treating seasonal and perennial allergic rhinitis.

METHODS

We conducted a double-blind, placebo-controlled study to assess the efficacy, tolerability, and mechanism of action of nasal immunotherapy for allergic rhinitis caused by weed pollens from three unrelated families. Twenty-seven weed-allergic patients underwent baseline nasal provocation and titrated skin test with a mixed weed extract containing ragweed, sage, and Chenopod extracts. Patients were randomized to receive either mixed weed extract or placebo. Nasal immunotherapy was self-administered daily to alternate nostrils preceded by 5.2 mg intranasal cromolyn. Beginning with 1:2500 wt/vol the concentration was increased to 1:10 wt/vol over an average period of 36 days. The maintenance dose (1:10 wt/vol) was administered daily for 12 to 16 weeks through the weed pollen season. Patients recorded nasal and eye symptoms and the use of rescue medications throughout the study. A nasal lavage for cytokine levels and nasal scraping with Rhinoprobe for nasal cytology were performed at the peak of the weed season. Nasal provocation and titrated skin tests with mixed weed extract were repeated after the weed season. Nasal lavage and scraping were also performed before and 24 hours after the final nasal provocation.

RESULTS

During the peak weeks of the weed season the group receiving mixed weed extract by nasal instillation, compared with those treated with placebo, had significantly lower total nasal symptom scores, total eye symptom scores, and symptom medication scores. There were no significant differences in the nasal cytology or cytokines levels between the two groups, except for elevated IL-10 in the nasal lavage in the treated group at the peak of the season. Nasal symptoms and medication use were higher preseasonally in the active treatment group.

CONCLUSION

Nasal immunotherapy with aqueous mixed weed extract administered with cromolyn sodium pretreatment for 17 to 21 weeks was effective in reducing both nasal and ocular symptoms of weed pollen-induced allergic rhinitis. There were increased nasal symptoms in the treated group preseasonally.

Clinical efficacy and safety of local nasal immunotherapy

Local nasal immunotherapy represents an alternative route of allergen administration. It was proposed to overcome the risk of systemic reactions rarely reported during the traditional subcutaneous immunotherapy. Some studies carried out in the past generally showed good efficacy but poor tolerability. The aqueous extracts mostly used in these studies carry some drawbacks such as the volume effect, self-digestion and the difficulty of administering reproducible dosages. The recent availability of allergen extracts in powder form has led to better stability and standardization. The studies carried out with these freeze-dried allergens showed clinical efficacy and good tolerability in perennial (mite, cat) and seasonal (grass, birch, Parietaria) allergic rhinitis. According to these findings this new local nasal immunotherapy with extract in powder form represents a suitable alternative to the traditional immunotherapy in the treatment of allergic rhinitis.

Local nasal immunotherapy: experimental evidences and general considerations

The possibility of local hyposensitization in allergies was envisaged since the first decades of the century and then sporadically employed, whereas controlled clinical trials of local nasal immunotherapy (LNIT) were performed only during the last 20 years. Studies currently available agree on the clinical efficacy of the treatment. LNIT was demonstrated capable of reducing symptoms both in pollen- and mite-induced rhinitis, and of modifying the specific target organ responsivity. Indeed, aqueous extracts appeared to be more effective than modified ones but were also charged by troublesome local side effects, while the recently introduced powdered extracts seemed to overcome this problem, maintaining a favourable clinical effectiveness. In a recent study we demonstrated a significant effect of LNIT on local allergic inflammation. LNIT reduced both the inflammatory infiltration and ICAM-1 expression on nasal epithelial cells upon specific nasal challenge. The effects on specific challenge appeared long-lasting, but the clinical efficacy seemed to depend strictly upon preseasonal treatment. LNIT with powdered extracts appears an effective, safe and well-tolerated treatment for allergic rhinitis. Nevertheless, its particular administration technique requires a careful choice of patients. Finally, a socioeconomical analysis shows a favourable cost/benefit ratio for LNIT if compared to classic subcutaneous immunotherapy.

Specific nasal provocation test with powder allergen

Reported here are the results of a large-scale trial conducted under the guidance of Prof. Giovanni Motta, which I coordinated. A total of 656 patients with nasal hyperreactivity were recruited in 51 Italian centres (18 in the north of Italy, 20 in central Italy and 13 in the south). The trial's results were as follows. 1) A clear clinical prevalence of sensitization to different allergens in the different areas of Italy, which could be roughly classified thus: a) in Northern Italy birch and grasses were in the main species; b) in Central Italy mites prevailed but oleaceae were also significant; c) in Southern Italy parietaria and oleaceae were the prevailing species. 2) Most cases were sensitive to several allergens, although a considerable proportion (22%) actually presented reactions only to one allergen and those responding account of the patients sensitive to only one allergen and those responding to a main allergen, the proportion of patients reacting clinically to only one allergen rises to 64%. 4) The specific nasal provocation test (sNPT) offers specificity comparable to in vivo diagnostic methods such as the prick test, and in vitro methods such as RAST, but is much more sensitive. 5) The sNPT can be done in any season. 6) The sNPT is highly specific below a threshold value of nasal reactivity, which can be identified for each allergen studied and expressed in Allergenic Units. 7) In patients in whom the prick test shows multiple sensitivity, the specific NPT identifies the allergen presumably responsible for the nasal reactions (main allergen). In the light of these findings double-blind specific immunotherapy was started, to last 1 year, in 107 patients (49 given placebo and 58 active treatment), with nasal allergy to grasses, parietaria and mites. The results of this treatment were as follows: 74.1% of patients presented a reduction in nasal resistance, measured by dynamic anterior rhinomanometry, indicating relief of nasal obstruction; mucociliary transport time became normal in 81% of patients, meaning that rhinorrhoea had become less marked; there was significant rise in the nasal reactivity threshold in 74.1% of patients, illustrating the degree of desensitization achieved; nasal IgA increased by 62.5% of patients and IgG in 55.2% indicating improvement in the local immunological picture. No such improvements were detectable in the patients given placebo. In conclusion, therefore, the findings of this trial in allergic rhinitis underline that the specific NPT proved more sensitive than other in vivo and in vitro diagnostic methods and is unquestionably a fundamental investigational approach for assessing nasal allergies, identifying the allergens causing the symptoms and setting up rational local immunotherapy. The sNPT also showed the efficacy of specific intranasal immunotherapy.

Preseasonal intranasal immunotherapy in birch-alder allergic rhinitis. A double-blind study

A double-blind, placebo-controlled study was carried out to test the clinical efficacy and safety of local nasal immunotherapy (LNIT) in powder form. Twenty-two patients suffering from allergic rhinitis strictly associated with early spring symptoms, with positive skin prick tests and RAST for birch-alder, all responders to a specific nasal provocation test (NPT), received randomly active or placebo treatment for 4 months. Immunotherapy consisted of administration of a set of capsules containing progressively increasing amounts of birch (Betula pendula) and speckled alder (Alnus incana) allergens in powder form with controlled granulometry. The active (birch-alder) and placebo (lactose) group completed the treatment according to a similar schedule. During the pollen season (March-April), the patients who took the active treatment reported less sneezing and rhinorrhea than the placebo group, on the basis of a symptoms score, and the differences were statistically significant; the need for drugs (terfenadine) was also significantly reduced. These findings agreed well with the results of specific NPT after the treatment; only patients in the active group had a higher threshold dose of nasal specific reactivity to birch-alder allergens than in tests before the LNIT.

Local nasal immunotherapy with extract in powder form is effective and safe in grass pollen rhinitis: a double-blind study

BACKGROUND

Local nasal immunotherapy has been studied, by means of an extract in powder form, in patients with allergic rhinitis caused by grass pollen.

METHODS

Thirty-two patients allergic to grass were studied for 37 weeks in a double-blind controlled trial. Subjects were selected on the basis of a positive history, skin test result, RAST finding, and result of intranasal challenge to grass pollen. Two 16-patient groups were randomly assigned to active or placebo treatment. The treatment lasted 26 weeks (14 for the build-up phase, 12 for the maintenance period).

RESULTS

No significant differences were observed in nasal symptoms during the treatment. During the pollen season the mean weekly symptom and medication scores were significantly lower in the treated group, compared with the control group, even considering each allergic symptom separately. Moreover, only in the treated group was a significant increase of specific nasal threshold to grass pollen observed after treatment.

CONCLUSIONS

This study indicates that local nasal immunotherapy with allergen in powder form can be a suitable alternative to the traditional subcutaneous immunotherapy in terms of clinical efficacy and safety in grass-allergic rhinitis.

Monomeric chemically modified allergens: immunologic and physicochemical characterization

Allergenic extracts (Der p, grass, and Parietaria) or single allergens such as Par j I (the major allergen of Parietaria) and ovalbumin (OA), a food allergen widely used in animal models, were chemically modified by reaction with potassium cyanate (KCNO), which transforms the epsilon-amino group of the lysine of proteinaceous allergens into ureido groups. KCNO-modified (carbamylated) allergens have low allergenic potency, as demonstrated in vitro (RAST inhibition) and in vivo (passive cutaneous anaphylaxis). When used to immunize rabbits, carbamylated allergens still induce IgG antibodies able to cross-react with native allergens (immunoblotting experiments). An interesting feature distinguishing carbamylated allergens from other chemically modified allergens is the preservation of the native monomeric dimension as demonstrated by SDS-PAGE analysis. Results are discussed from the perspective of clinical application of carbamylated allergens.

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

BACKGROUND

Traditional subcutaneous immunotherapy has been proved effective in birch pollenosis. It has, however, some drawbacks as systemic 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, radioallergosorbent test assay (RAST) and specific nasal challenge. 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 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 significantly lower in the treated group for 1 week only. Moreover, a significant increase of specific nasal threshold dose was observed 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 interfere 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 whether this treatment can be considered a real alternative to the traditional subcutaneous immunotherapy in birch allergic rhinitis.

Immunotherapy with Alpare in patients with respiratory allergy to Parietaria pollen: a two year double-blind placebo-controlled study

Allergy to Parietaria judaica pollen causes significant morbidity in many areas of the world. In addition to rhinitis, patients who are allergic to this pollen have a high incidence of asthma. The pollinating season is long, making this particular allergy challenging for clinicians to treat. This study was designed to determine if immunotherapy with an alum adsorbed partially purified Parietaria extract (Alpare Parietaria) containing a targeted maintenance dose of 12,500 BUs was effective in decreasing rhinitis symptoms in patients allergic to Parietaria. Using a double-blind placebo-controlled technique 36 patients received placebo or active extract for 2 years. Twenty (11 placebo and nine active) completed the 2 year study. Efficacy of treatment was evaluated by determining changes in skin reactivity, visual analog scores, diary symptom scores and end of study assessments. Reactions were monitored as well. Skin-test suppression was marginally significant in the actively treated group after 1 year and showed even more significant suppression after the second year. Nasal block, rhinorrhoea and sneezing all were significantly decreased in the active group. The nasal provocation test did not show a significant change after 1 year, in either group, but after 2 years of treatment the active group did show significant improvement. Although almost all patients in the actively treated group experienced local reactions, the incidence of systemic reactions was not different between the two groups. In conclusion, immunotherapy with this extract at this dose was effective in ameliorated rhinitis symptoms in patients allergic to Parietaria judaica.

A double-blind, placebo-controlled trial of local nasal immunotherapy in allergic rhinitis to Parietaria pollen

We assessed the efficacy and safety of local nasal immunotherapy (LNIT) using an extract in macronized powder form of Parietaria pollen, a very important allergenic plant in the Mediterranean and other parts of the world. Twenty-six patients aged 13-37 years, with seasonal allergic rhinitis to this pollen, were enrolled in a double-blind placebo-controlled trial, carried out from autumn 1991 to the end of June 1992. They were selected on the basis of a positive skin-prick test, radioallergosorbent test (RAST) and intranasal challenge to Parietaria antigen. Patients were randomly divided into two groups of 13; the first group was given Parietaria antigen, and the second placebo. We recorded mean weekly symptom scores and drug consumption for 17 weeks during the pollen season in the year 1992, and specific serum-IgE and IgG levels. Three patients in the active group withdrew from the study because of bronchial symptoms. A significant difference was observed in mean weekly nasal symptom scores, in drug consumption and in specific nasal threshold to Parietaria allergenic extract in the treated and control groups. No difference was observed in serum IgE and IgG levels. Serum IgE levels rose significantly only in the control group after the pollen season. This study indicates that LNIT may be a useful alternative to traditional subcutaneous immunotherapy in patients with allergic rhinitis.