Allergen-specific immunotherapy in birch- and grass-pollen-allergic rhinitis. II. Side-effects

CircMIRLET7BHG, upregulated in an m6A-dependent manner, induces the nasal epithelial barrier dysfunction in allergic rhinitis pathogenesis

OBJECTIVE

Allergic rhinitis (AR) remains a frequent aspiratory allergic inflammatory disorder with a high incidence. Circular RNAs (circRNAs) have been revealed to participate in the pathogenesis of AR. This study investigated the biological function of circMIRLET7BHG (hsa_circ_0008668) in AR progression.

METHODS

Ovalbumin (OVA)-exposed human nasal epithelial cell line (HNEpC) and mice were adopted as the in vitro and in vivo models of AR. Immunofluorescence staining was used to determine epithelial tight junction protein expression. Target molecule levels were assessed by RT-qPCR and Western blotting. Localization of circMIRLET7BHG and IGF2BP1 was observed by RNA-FISH and immunofluorescence. Epithelial barrier damage was determined by transepithelial electrical resistance and fluorescein isothiocyanate-dextran (FD4) permeability. Serum concentrations of IgE, sIgE, IFN-γ, IL-4, and IL-5 were detected by ELISA. Apoptosis, pathological changes, and eosinophil infiltration in nasal mucosa tissues were evaluated by TUNEL, H&E, and Sirius red staining, respectively. Molecular mechanism was analyzed by RNA pull-down, RIP, and MeRIP assays.

RESULTS

An increased expression of circMIRLET7BHG was found in AR patients and experimental models. Down-regulation of circMIRLET7BHG attenuated OVA-induced allergic symptoms via relieving epithelial thicknesses, eosinophil infiltration, apoptosis, and inflammatory response in mice. Subsequently, circMIRLET7BHG deficiency prevented OVA-induced epithelial barrier dysfunction by reducing epithelial permeability, and inhibiting tight junction proteins. Mechanistically, methyltransferase-like 3 (METTL3) enhanced circMIRLET7BHG expression via m6A methylation, which enhanced ADAM10 mRNA stability via interaction with IGF2BP1.

CONCLUSION

METTL3-mediated m6A modification increased circMIRLET7BHG expression that consequently raised ADAM10 mRNA stability via interplay with IGF2BP1, thereby promoting AR by inducing epithelial barrier dysfunction.

A novel dose-adjustment protocol for interrupted subcutaneous immunotherapy for allergic rhinitis

Background: This study aimed to develop a novel dose strategy for subcutaneous immunotherapy to reduce medical waste and financial burdens for patients who are required to restart subcutaneous immunotherapy. Patients & methods: A prospective, nonrandomized concurrent controlled trial was performed to assess the safety and advantages of the novel dose-adjustment protocol compared with the conventional one. 76 subjects were grouped to receive novel or conventional dose-adjustment protocols. Results: The injections, visits and time needed to reach the pre-established dose with the novel regimen were decreased. Furthermore, there were no differences in side reactions between the two groups. Conclusion: The novel protocol seemed safe and well tolerated, offering the advantages of time efficiency and reduced healthcare costs.

Protective effect of miR-138-5p inhibition modified human mesenchymal stem cell on ovalbumin-induced allergic rhinitis and asthma syndrome

The objective of the study is to evaluate the protective effects of human mesenchymal stem cells (hMSCs) modified with miR‐138‐5p inhibitor against the allergic rhinitis and asthma syndrome (ARAS). MiR‐138‐5p or negative control was transfected into hMSCs, and fluorescence‐activated cell sorting was used to evaluate hMSC surface markers. Quantitative real‐time PCR (qRT‐PCR) was used to evaluate miR‐138‐5p, SIRT1, caspase‐3, IL‐6, IL‐1β and TNF‐α levels after TNF‐α and IL‐6 stimulations. hMSCs with or without miR‐138‐5p inhibition was intranasally administered into ARAS mice (n = 10 each group), followed by monitoring sneezing and nasal rubbing events to evaluate the allergic symptoms. Histamine, ovalbumin‐specific IgE, IgG2a, IgG1 and LTC4 release were monitored in the serum and nasal lavage fluid using enzyme‐linked immunosorbent assay. Expression of SIRT1 and HMGB1/TLR4 pathway in nasal mucosa was assessed. After miR‐138‐5p inhibitor transfection, the hMSC lineage was preserved. Binding between SIRT1 and miR‐138‐4p was observed, and miR‐138‐5p inhibition led to upregulation of SIRT1. Inhibition of miR‐138‐5p led to attenuated inflammatory responses of hMSCs upon TNF‐α and IL‐6 stimulation, and allergic symptoms in mice, as well as histamine and ovalbumin‐specific IgG release. hMSCs with miR‐138‐5p inhibition showed characteristics of activated SIRT1 and inhibited HMGB1/TLR4 pathway. Inhibition of miR‐138‐5p in hMSCs enhanced its effects in attenuating inflammatory responses and allergic reaction in the ARAS model, which is presumably regulated by SIRT1 and the HMGB1/TLR4 pathway.

Lack of effect of Timothy grass pollen sublingual immunotherapy tablet on birch pollen-induced allergic rhinoconjunctivitis in an environmental exposure unit

BACKGROUND

Timothy grass pollen allergen extract tablets (Grastek) are standardized sublingual immunotherapy tablets (SLIT-T) approved for the treatment of grass pollen-induced allergic rhinitis (AR) and conjunctivitis. Many grass allergic patients are also cosensitized to birch pollen. Whether Timothy grass SLIT-T can confer symptomatic benefits for birch pollen-induced AR symptoms is unknown.

OBJECTIVE

To evaluate the treatment effect of Timothy grass SLIT-T for birch pollen-induced AR in participants sensitized to both grass and birch pollen using an environmental exposure unit (EEU).

METHODS

This study was a phase 4, randomized, double-blind, placebo-controlled, parallel-group study that enrolled participants aged 18 to 65 years allergic to both timothy grass and birch pollen. After a baseline EEU birch pollen challenge, in which a minimum total nasal symptom score (TNSS) of 6 of 12 was required for enrollment, participants were randomized to receive Timothy grass SLIT-T or placebo taken once daily for 4 months. No confirmatory grass pollen challenge was performed. The primary end point was the change in TNSS averaged from assessments from hours 2 to 5 during the posttreatment birch pollen challenge compared with baseline. The secondary and exploratory end points included temporally identical changes in total ocular symptom score (TOSS), total rhinoconjunctivitis symptom score (TRSS), and individual symptom scores.

RESULTS

The difference in TNSS reduction after 4 months of therapy between the Timothy grass SLIT-T and placebo group was not significant (P = .83). Reductions in TOSS (P = .19) and TRSS (P = .67) were also comparable between groups. Findings between groups for individual symptom scores were similar (all P > .40), except for watery eyes, in which symptom reduction was slightly better in the placebo arm (P = .01). Timothy grass SLIT-T was well tolerated, and no serious adverse effects occurred.

CONCLUSION

A bystander effect of grass SLIT-T on birch pollen-induced AR symptoms was not detected. Symptomatic benefits of grass SLIT-T are likely allergen specific.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02394600.

Efficacy of 2 months of allergen-specific immunotherapy with Bet v 1-derived contiguous overlapping peptides in patients with allergic rhinoconjunctivitis: Results of a phase IIb study

BACKGROUND

An immunotherapy formulation consisting of 3 contiguous overlapping peptides (COPs) derived from Bet v 1, the major birch pollen allergen, showed good clinical tolerability in a previous phase I/IIa clinical trial.

OBJECTIVES

We sought to evaluate the efficacy and safety of allergen-specific immunotherapy using 2 dose regimens of Bet v 1 COPs versus placebo in subjects with birch pollen-induced allergic rhinoconjunctivitis.

METHODS

A randomized, double-blind, placebo-controlled phase IIb clinical trial was performed to assess the efficacy of Bet v 1 COP immunotherapy during the 2013 birch pollen season. Before the season, Bet v 1 COPs (50 and 100 μg in aluminum hydroxide) or placebo (saline and aluminum hydroxide) were administered as 5 subcutaneous injections to 239 adults with allergic rhinoconjunctivitis to birch pollen. Bet v 1 COPs at 25 or 50 μg were administered on day 1, and 50 or 100 μg was administered on days 8, 15, 29, and 57, respectively. Patients were monitored for adverse events during the treatment period and assessed for combined rhinoconjunctivitis symptom and medication scores, as well as quality of life.

RESULTS

Rhinoconjunctivitis symptom and medication scores improved in both Bet v 1 COP-treated groups, reaching statistical significance over placebo in the 50-μg group (least squares mean, -0.23; 26% improvement; P = .015). Both active groups showed significant improvement in quality of life and nighttime nasal symptom scores, supporting the primary end point findings. Bet v 1 COP injections were well tolerated, with a higher frequency of systemic adverse events in the 100-μg group.

CONCLUSION

Two months of preseasonal immunotherapy with 3 COPs derived from Bet v 1 at a 50-μg dose showed promising efficacy, small risk for systemic reactions, and immunomodulatory changes in this single-season, dose-finding, phase IIb trial in patients allergic to birch pollen.

Frequent occurrence of T cell-mediated late reactions revealed by atopy patch testing with hypoallergenic rBet v 1 fragments

Background

Late allergic reactions are common in the course of allergen-specific immunotherapy and even occur with allergy vaccines with reduced IgE reactivity.

Objective

We sought to study atopy patch test (APT) reactions and T-cell responses to the recombinant birch pollen allergen Bet v 1 and recombinant hypoallergenic T-cell epitope–containing Bet v 1 fragments in patients with birch pollen allergy with and without atopic dermatitis (AD).

Methods

A clinical study was conducted in 15 patients with birch pollen allergy with AD (group 1), 5 patients with birch pollen allergy without AD (group 2), 5 allergic patients without birch pollen allergy (group 3), and 5 nonallergic subjects (group 4) by performing skin prick tests and APTs with rBet v 1 and hypoallergenic rBet v 1 fragments. T-cell, cutaneous lymphocyte antigen (CLA)⁺ and CCR4⁺ T-cell and cytokine responses were studied by thymidine uptake, carboxyfluorescein diacetate succinimidyl ester staining, and Luminex technology, respectively.

Results

rBet v 1 and hypoallergenic rBet v 1 fragments induced APT reactions in not only most of the patients with birch pollen allergy with AD (11/15) but also in most of those without AD (4/5). Patients with birch pollen allergy with AD had higher Bet v 1–specific proliferation of CLA⁺ and CCR4⁺ T cells compared with patients with birch pollen allergy without AD. There were no differences in Bet v 1–specific CLA⁺ and CCR4⁺ proliferation and cytokine secretion in patients with and without APT reactions.

Conclusion

Hypoallergenic rBet v 1 fragments induce T cell–dependent late reactions not only in patients with birch pollen allergy with AD but also in those without AD, which can be determined based on APT results but not based on in vitro parameters.

A prospective multicenter study of systemic reactions in standardized specific immunotherapy for allergic rhinitis in China

BACKGROUND

Standardized allergen-specific immunotherapy (SIT) has been used in China for years. However, there is no extensive study of the safety of standardized SIT in Chinese patients until now. The aim of the current study is to perform a prospective and multicenter study to evaluate the systemic reactions (SRs) of standardized SIT in Chinese patients.

METHODS

The study was performed in 13 allergy centers in China, using the same vaccine and practice procedure. The length of observation period was 2 years. SRs were recorded and analyzed.

RESULTS

There were 666 patients included (261 children and 405 adults). All patients finished the initial phase and 47 patients withdrew during the maintenance phase. There were 0.47% (94/19,963) SRs in all injections (0.72% in children and 0.31% in adults); 8.26% (55/666) patients experienced SRs (12.26% children and 5.68% adults). The occurrence of SRs was significantly higher in children than that in adults (p < 0.01). A higher ratio of SRs was found among patients accompanied with asthma. There were 74.47% SRs of grade I, 15.96% SRs of grade II, 7.45% SRs of grade III, and 2.13% SRs of grade IV. There were 90.43% of SRs associated with the discomfort of lower respiratory tract.

CONCLUSION

This multicenter study showed that properly conducted standardized SIT was a safe treatment for allergic rhinitis in China. The incidence of SRs was higher in children than that in adults.

Incidence and risk factors for subcutaneous immunotherapy anaphylaxis: the optimization of safety

Fatal reactions related to subcutaneous allergen immunotherapy are rare: one event in 2.5 million injections has been reported in the USA and none in Europe. The prevalence of very severe systemic reactions (systemic adverse events [SAEs]) is one in 1 million injections. Though the serious events rate is decreasing and the majority of SAEs (∼0.2% per injection) are moderate and reversible, they still represent a major concern. Uncontrolled asthma, long-term therapy with β-blockers and high degree of allergen sensitivity are generally considered risk factors. The relevance of other conditions, like previous local reactions, the use of extracts conjugated with adjuvants and accelerated build-up schedules is controversial, as well as the role of preventative strategies. A careful risk assessment of patients and optimal administration procedures may significantly decrease the risk of SAEs. However, more uniform safety data are required and an accurate safety profile should be provided for every allergen product.

Accelerated immunotherapy schedules

Rush and cluster immunotherapy schedules are accelerated immunotherapy build-up schedules. A cluster immunotherapy schedule involves the patient receiving several allergen injections (generally 2-4) sequentially in a single day of treatment on nonconsecutive days. The maintenance dose is generally reached in 4-8 weeks. In rush immunotherapy protocols, higher doses are administered at 15- to 60-min intervals over a 1- to 3-day period until the maintenance dose is achieved. This review will serve as an update for accelerated immunotherapy schedules. The review will include recent investigations demonstrating the safety of cluster schedules in atopic dermatitis, pediatric patients, and inhalant allergen mixtures and an accelerated protocol utilizing an infusion pump for allergen delivery. There has also been further elucidation on the immunological changes which occur during accelerated immunotherapy. Finally, new studies analyzing systemic reaction risk factors are discussed.

Immunologic effect and tolerability of intra-seasonal subcutaneous immunotherapy with an 8-day up-dosing schedule to 10,000 standardized quality-units: a double-blind, randomized, placebo-controlled trial

BACKGROUND

International guidelines recommend that allergen-specific immunotherapy for pollen-induced rhinoconjunctivitis is initiated preseasonally. However, because subjects often present to physicians with allergy symptoms during the pollen season, "within-season" initiation of specific immunotherapy is of special interest.

OBJECTIVE

We evaluated the immunomodulatory effects and tolerability of subcutaneous immunotherapy (SCIT) with Standardized Quality (SQ) 6-grass mix and rye allergen extract, using an 8-day intra-seasonal up-dosing schedule to 10,000 SQ-units (SQ-U).

METHODS

In a 9-week, multicenter, randomized, double-blind, placebo-controlled trial, adults (mean age, 34.6 years; 99.3% whites) with grass pollen-induced rhinoconjunctivitis (mean disease duration, 15.1 years) were randomized 3:1 to receive SCIT or placebo. Treatment was initiated during the 2008 pollen season, with an 8-day up-dosing from 100 to 10,000 SQ-U (6 daily injections) followed by 2 maintenance injections of 10,000 SQ-U at intervals of 2 and 4 weeks, respectively. The primary end point examined immunologic effects, assessing the difference in IgE-blocking factor (serum components competing with IgE for allergen binding) between SCIT and placebo at week 9. Secondary/explorative end points included the difference in IgE-blocking factor, specific IgG(4), and specific IgE at various times. Tolerability (adverse events, local and systemic allergic reactions) of the up-dosing schedule was also evaluated.

RESULTS

Of the 148 treated subjects 144 (SCIT n = 109; placebo n = 35) were analyzed for the primary parameter. Immunologic response (significantly higher increase in IgE-blocking factor and IgG(4) levels) occurred with SCIT versus placebo at week 9 (IgE-blocking factor, P = 0.0017; IgG(4,)P = 0.0215). Significant differences were observed as early as week 3. AEs were reported in 60.7% of SCIT- and 30.6% of placebo-treated subjects, with no treatment-related serious AEs. Local allergic reactions occurred in 46.4% of SCIT and 8.3% of placebo subjects (χ(2) test, P < 0.0001). No significant difference was observed between groups in the incidence of systemic reactions (7.1% SCIT vs 5.6% placebo; χ(2) test, P = 0.7413).

CONCLUSIONS

This trial provides the first description of short (8-day) intra-seasonal up-dosing with SCIT, which induced immunologic effects after only 3 weeks, and was generally well tolerated, although it induced a marked increase in the rate of local reactions compared with placebo. ClinicalTrials.gov identifier NCT00807547; ALK trial ID SHX0562.

Allergic conjunctivitis: a comprehensive review of the literature

Ocular allergy represents one of the most common conditions encountered by allergists and ophthalmologists. Allergic conjunctivitis is often underdiagnosed and consequently undertreated. Basic and clinical research has provided a better understanding of the cells, mediators, and immunologic events, which occur in ocular allergy. New pharmacological agents have improved the efficacy and safety of ocular allergy treatment. An understanding of the immunologic mechanisms, clinical features, differential diagnosis, and treatment of ocular allergy may be useful to all specialists who deal with these patients. The purpose of this review is to systematically review literature underlining all the forms classified as ocular allergy: seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratocongiuntivitis, contact allergy, and giant papillary conjunctivitis.

Allergen-specific immunotherapy of allergy and asthma: current and future trends

Allergen-specific immunotherapy is the only immunomodulatory and etiological therapy of allergy and asthma. Conventional specific immunotherapy (SIT) with whole-allergen extract is antigen specific, effective on multiple organs, efficient on asthma in defined conditions, provides long-lasting protection and is cost effective. Moreover, SIT is able to prevent the course of rhinitis to asthma. SIT has its drawbacks: the long duration of treatment, the unsatisfactory standardization of allergen extracts and a questionable safety level. Novel approaches are aimed at drastically reducing adverse anaphylactic events, shortening the duration of therapy and improving its efficacy. Novel promising approaches have based their formulation on a limited set of recombinant allergens or chimeric molecules as well as on hypoallergenic allergen fragments or peptides. The simultaneous use of adjuvants with immunomodulatory properties may contribute to improve both the safety and efficacy of allergen-SIT of allergy and asthma.

Sublingual immunotherapy in allergic rhinitis

Current treatment options for allergic rhinitis (AR) include allergen avoidance and environmental control, pharmacotherapy, nasal surgery and immunotherapy. Among these, immunotherapy is the only therapeutic option that modifies fundamental immunologic mechanism by inducing desensitization. Specific allergen immunotherapy has been used for 1 century since 1911 and subcutaneous immunotherapy (SCIT) has been demonstrated to be effective in asthma and AR. However, SCIT has several disadvantages such as inconvenience, invasiveness and potentially severe systemic reactions. Thus, sublingual immunotherapy (SLIT) has recently received much attention around the world as a treatment for AR and is now widely used to replace the subcutaneous route. SLIT has recently been introduced in Korea and is now available for AR treatment in the Asia-Pacific region. This review offers better understanding of SLIT for AR by summarizing published articles and our previous works regarding proposed mechanisms, indication and efficacy, safety and adverse events, and compliance.

Immunologic effects and tolerability profile of in-season initiation of a standardized-quality grass allergy immunotherapy tablet: a phase III, multicenter, randomized, double-blind, placebo-controlled trial in adults with grass pollen-induced rhinoconjunctivitis

BACKGROUND

The summary of product characteristics of the grass allergy immunotherapy tablet (AIT) (Phleum pratense grass pollen allergen extract) states that clinical effect may be observed in the first pollen season of treatment, if treatment is initiated ≥2 months (8 weeks) before the start of the grass pollen season. However, because patients with grass allergy may first present to physicians during the season, immediate treatment initiation (ie, in-season initiation) may increase treatment compliance and reduce the risk for disease progression compared with asking patients to return before the next pollen season to initiate treatment. This "in-season approach" may offer more patients the potentially beneficial treatment option of specific immunotherapy. However, to date, the immunomodulatory effects and tolerability of in-season treatment initiation is unknown.

OBJECTIVE

The aim of this study was to assess the immunologic effects and tolerability of in-season initiation of treatment with the grass AIT.

METHODS

This multicenter, randomized, double-blind, placebo-controlled trial was carried out in Germany and Austria. Adults with grass pollen allergy (positive skin-prick test and specific grass-pollen immunoglobulin [Ig] E) and grass pollen-induced moderate to severe persistent rhinoconjunctivitis were enrolled. Patients were randomly assigned to receive once-daily grass AIT or placebo, starting during the 2008 grass pollen season and continuing for 8 to 10 weeks. The primary end point was change from baseline in IgE-blocking factor (serum components competing with IgE for allergen binding). Secondary end points included changes from baseline in specific IgE and IgG(4) and measures of tolerability (assessed mainly by adverse events [AEs]). Blood samples for immunologic assessment were obtained by the investigators at baseline and after treatment. All AEs observed by the investigator and/or reported by the patient were recorded throughout the trial and follow-up.

RESULTS

A total of 276 patients were enrolled and formed the full analysis set (mean age, 35 years; 55% men, 45% women; 99% white; mean weight, 76 kg; history of asthma, 41%; mean duration of grass allergy, 15.1 years). No major differences in medical history were found between the grass AIT group (n = 219) and the placebo group (n = 57). The change from baseline in mean concentration of IgE-blocking factor was significantly greater with grass AIT compared with placebo (+0.14 vs +0.05; P < 0.0001). The changes from baseline in specific IgE and specific IgG(4) concentrations were significantly greater with AIT compared with placebo (IgE, +0.59 vs +0.21 log kU/L; IgG(4), +0.18 vs +0.04 log relative units; both, P < 0.0001). At least 1 AE was reported in 58% of patients in the AIT group and in 40% of patients in the placebo group. Most AEs considered related to AIT were mild or moderate events in the mouth, throat, and/or ears (eg, oral pruritus). Four serious AEs were reported in the AIT group (sinusitis, road traffic accident, salmonellosis, meniscus lesion), but all were considered unlikely to be related to treatment. Three percent of the grass AIT group and 2% of the placebo group were withdrawn from the trial due to an AE.

CONCLUSIONS

In-season initiation of grass AIT was associated with an immunomodulatory response in terms of induction of IgE-blocking factor, specific IgE, and specific IgG(4). In-season initiation of grass AIT was generally well tolerated in this group of adults with moderate to severe grass pollen-induced rhinoconjunctivitis. These findings are consistent with those related to the preseasonal initiation of AIT therapy.

Clinical efficacy of house dust mite-specific immunotherapy in asthmatic children

BACKGROUND

Immunotherapy has been widely used in the treatment of allergic diseases. We evaluated the clinical efficacy of specific immunotherapy with extracts of Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) in children with asthma.

METHODS

All 40 children had moderate-to-severe asthma and positive allergen tests for Dp and Df. All required daily medication. They were randomly assigned to two groups: Half of them received immunotherapy with subcutaneous injections of Dp and Df extracts, while the other half were not given immunotherapy. Participants were followed up for more than 6 months.

RESULTS

Children in both groups had apparent improvements in medication use and symptoms after 6 months. The mean medication scores declined from 3.6 +/- 1.14 to 1.7 +/- 0.66 in the immunotherapy group (p < 0.01) and from 3.35 +/- 0.87 to 2.4 +/- 1.09 in the control group (p < 0.01). There was a significant difference between the two groups (mean difference 0.95; p < 0.01). The symptom score improved in the immunotherapy group from 2.65 +/- 0.98 to 1.20 +/- 1.00 (p < 0.01) and in the control group from 2.55 +/- 0.99 to 1.40 +/- 0.88 (p < 0.01), with a significant difference between the two groups (mean difference 0.3; p < 0.01). The number of office visits in the immunotherapy group was greater than that of the controls, but the frequencies of emergency room visits and hospitalization decreased.

CONCLUSION

Our study showed that specific immunotherapy with Dp and Df was beneficial for asthmatic children.

Systemic tolerability of specific subcutaneous immunotherapy with index-of-reactivity-standardized allergen extracts administered using clustered regimens: a retrospective, observational, multicenter study

BACKGROUND

Subcutaneous immunotherapy is an etiological therapy for certain IgE-mediated diseases. It is usually administered in 2 phases: induction and maintenance. Administration in clustered schedules during the induction phase may be a valid alternative to reach the maintenance dose early if the treatment is well tolerated.

OBJECTIVES

To compare the tolerability of different clustered schedules in subcutaneous immunotherapy with standardized allergen extracts administered and to identify factors associated with increased risk of systemic reactions (SRs).

METHODS

Retrospective, observational, multicenter study in patients with allergic respiratory disease.

RESULTS

Data from 1,147 patients were collected. Thirty-nine patients (3.4%) experienced 42 SRs (0.6% of doses). According to the European Academy of Allergy and Clinical Immunology SR grading system, there were 7 grade 0 reactions (16.7%), 26 grade 1 reactions (61.9%), 8 grade 2 reactions (19.0%), and 1 grade 3 reaction (2.4%). There were no grade 4 SRs (anaphylactic shock). We observed a higher risk of SRs in patients who received an initial dose higher than 0.3 index of reactivity (IR); only 2 reactions occurred after administration of the initial dose of the regimen, both with 0.4 IR. The remainder appeared in subsequent injections, although never with a dose lower than 0.35 IR.

CONCLUSIONS

Clustered regimens with IR-standardized extracts are an alternative to classic immunotherapy thanks to their low incidence of SRs compared with other rapid regimens during the induction phase. The ideal clustered regimen should start at an initial dose no greater than 0.35 IR to minimize the incidence of SRs.

Local and systemic reactions occurring during immunotherapy: an epidemiological evaluation and a prospective safety-monitoring study

The efficacy of specific immunotherapy in allergic patients with IgE-mediated rhino-conjunctivitis, asthma and allergic reaction for stinging insects suggests the opportunity of improving technical procedures to minimize risk and optimise the safety of immunotherapy. This study investigated both local and systemic reactions, occurring in a population of 218 patients undergoing immunotherapy, in an attempt to correlate them with some parameters as well as age, sex and allergenic extracts. The epidemiological evaluation was based on the administration of a questionnaire to 218 patients in order to assess possible reactions to immunotherapy. The following data were evaluated: personal data, diagnosis, specific allergens, adverse reactions undergone during treatment, number of reactions and symptoms. The patients were followed-up by the medical staff of the Section of Allergological and Immunological Disease (SAID), University of Bari (Bari-Italy) for compilation of questionnaires. We found a correlation between female sex and adverse reactions. Among 107 patients referring reactions to the immunotherapy, 71 patients (66.3%) presented only local reactions; 11 patients (10.3%) systemic reactions and 25 patients (23.4%) systemic reactions associated with local reactions. Parietaria was mostly involved in patients with local reactions, instead, in patients with systemic reactions the prevalent allergens seem to be Dermatophagoides and grass-pollen. Rhinitis was the most frequent diagnosis for patients who have presented both local and systemic reactions. In our study, we had frequently mild systemic reactions and some cases of respiratory difficulties, while it is evident that in our group of patients no cases of anaphylaxis occurred. In addition, we considered some events before the administration of immunotherapy, such as assumption of drugs, meals, exposure to sun, stress or physical activity and the percentage of adverse reactions. On the light of a small number of fatality, immunotherapy represents a safer therapy for allergic diseases; nevertheless, our data suggest that safety is strictly correlated with prescriptions by specialists, administration by trained physicians and accurate follow-up of patients. In particular it is recommended to avoid some events before the administration of immunotherapy, above all the assumption of drugs and physical exercise.

Allergic rhinitis and its impact on asthma update: allergen immunotherapy

The Allergic Rhinitis and its Impact on Asthma document was first published in 2001. Since then, new data on specific immunotherapy have appeared. This review is intended as an update to the original document. MedLine (2001 to June 2006) was searched with appropriate key words, and panelists were asked to identify further relevant articles. Randomized controlled trials were considered for the evaluation of efficacy. For the evaluation of safety and additional effects, studies with lower grades of evidence were included. The clinical efficacy of injection immunotherapy in rhinitis and asthma was confirmed, as well as the safety, provided that recommendations are followed. Studies have demonstrated the long-term efficacy and the preventive effect of immunotherapy in reducing the onset of new sensitizations. One randomized open trial demonstrated that in children with allergic rhinitis, injection immunotherapy may reduce the risk of developing asthma. There is strong evidence that sublingual immunotherapy is effective in allergic rhinitis in adults. Recent meta-analyses demonstrated its efficacy in allergic rhinitis in children and in asthma, although more definitive trials are required. Current data indicate that sublingual immunotherapy is safe and the rate of adverse reactions is not greater below 5 years of age. One randomized open trial showed that in children with allergic rhinitis, sublingual immunotherapy reduced the onset of asthma. Further studies are needed to identify the optimal maintenance dose and to elucidate the mechanism of action. Novel approaches for immunotherapy are currently under evaluation, including the use of adjuvants, peptides, and DNA-conjugated and recombinant allergens.

Allergen injection immunotherapy for seasonal allergic rhinitis

BACKGROUND

Allergic rhinitis is the most common of the allergic diseases. Despite improved understanding of the pathophysiology of allergic rhinitis and advances in its pharmacological treatment, its prevalence has increased worldwide. For patients whose symptoms remain uncontrolled despite medical treatment, allergen injection immunotherapy is advised. An allergen-based treatment may reduce symptoms, the need for medication and modify the natural course of this disease.

OBJECTIVES

To evaluate the efficacy and safety of subcutaneous specific allergen immunotherapy, compared with placebo, for reducing symptoms and medication requirements in seasonal allergic rhinitis patients.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1 2006), MEDLINE (1950 to 2006), EMBASE (1974 to 2006), Pre-MEDLINE, KOREAMED, INDMED, LILACS, PAKMEDINET, Scisearch, mRCT and the National Research Register. The date of the last search was February 2006.

SELECTION CRITERIA

All studies identified by the searches were assessed to identify randomised controlled trials involving participants with symptoms of seasonal allergic rhinitis and proven allergen sensitivity, treated with subcutaneous allergen specific immunotherapy or corresponding placebo.

DATA COLLECTION AND ANALYSIS

Two independent authors identified all studies reporting double-blind, placebo controlled randomised trials of specific immunotherapy in patients with seasonal allergic rhinitis due to tree, grass or weed pollens. Two authors independently performed quality assessment of studies. Data from identified studies were abstracted onto a standard extraction sheet and subsequently entered into RevMan 4.2.8. Analysis was performed using the Standardised Mean Difference (SMD) method and a random-effects model; P values < 0.05 were considered statistically significant. The primary outcome measures were symptom scores, medication use, quality of life and adverse events.

MAIN RESULTS

We retrieved 1111 publications of which 51 satisfied our inclusion criteria. In total there were 2871 participants (1645 active, 1226 placebo), each receiving on average 18 injections. Duration of immunotherapy varied from three days to three years. Symptom score data from 15 trials were suitable for meta-analysis and showed an overall reduction in the immunotherapy group (SMD -0.73 (95% CI -0.97 to -0.50, P < 0.00001)). Medication score data from 13 trials showed an overall reduction in the immunotherapy group (SMD of -0.57 (95% CI -0.82 to -0.33, p<0.00001)). Clinical interpretation of the effect size is difficult. Adrenaline was given in 0.13% (19 of 14085 injections) of those on active treatment and in 0.01% (1 of 8278 injections) of the placebo group for treatment of adverse events. There were no fatalities.

AUTHORS' CONCLUSIONS

This review has shown that specific allergen injection immunotherapy in suitably selected patients with seasonal allergic rhinitis results in a significant reduction in symptom scores and medication use. Injection immunotherapy has a known and relatively low risk of severe adverse events. We found no long-term consequences from adverse events.

Accelerated immunotherapy schedules: review of efficacy and safety

OBJECTIVE

To provide a comprehensive evaluation of accelerated immunotherapy build-up schedules in terms of adverse reactions and clinical efficacy.

DATA SOURCES

Peer-reviewed studies and review articles were selected from the PubMed database for articles published in the years 1976 to 2006 using the following keywords: rush, cluster immunotherapy in combination with allergic rhinitis, asthma, Hymenoptera, and imported fire ant.

STUDY SELECTION

Studies were selected if they provided safety and efficacy information on accelerated allergen immunotherapy schedules. Most of the studies reviewed were double-blind, placebo controlled, but some open-observational studies were included if they provided immunotherapy safety or other information the author thought was relevant.

RESULTS

A wide range of systemic reactions were reported in the literature with inhalant allergens: ranging from 27% to 100% of the patients in rush immunotherapy studies and 0% to 79% of patients in the cluster studies. Predictors of systemic reactions with rush immunotherapy were forced expiratory volume in 1 second less than 80% of predicted and a high degree of skin test reactivity. Premedication clearly reduces the risk of systemic reactions with rush immunotherapy, but the effect on cluster schedules was not as clear.

CONCLUSION

Accelerated immunotherapy build-up schedules in selected patients may provide a rapid alternative to conventional build-up schedules without a significant increase in risk.

Side-effects of allergen-specific immunotherapy: a prospective multi-centre study

BACKGROUND AND OBJECTIVE

The safety of allergen-specific immunotherapy (SIT) is a parameter of great interest in the overall assessment of the treatment. A clinical database was developed in order to obtain early warnings of changes in the frequency and severity of side-effects and sufficient data for the evaluation of possible risk factors.

METHODS

During a 3-year period, four allergy centres in Copenhagen, Denmark, included data from all patients initiating SIT to a common database. Information on initial allergic symptoms, allergens used for treatment, treatment regimens and systemic side-effects (SSEs) during the build-up phase was collected.

RESULTS

A total of 1,038 patients received treatment with 1,709 allergens (timothy, birch, mugwort, house dust mite (HDM), cat, and wasp and bee venom), 23,047 injections in total. Most SIT patients completed the updosing phase without side-effects, but there was a significant difference between allergens: wasp (89%), birch (82%), HDM (81%), cat (74%) and grass (70%) (P=0.004). A total of 582 SSEs were registered in 341 patients. Most side-effects were mild grade 2 reactions (78%). A difference in severity between allergens was observed (P=0.02), with grass giving most problems. The type of allergen but not patient- or centre-related parameters seemed predictive of side-effects.

CONCLUSIONS

Allergen extracts differ in their tendency to produce side-effects. Multi-centre studies like the present one allow more patients to be evaluated, and thereby provide a more efficient surveillance of side-effects. Online Internet-based registration to a central national database of every allergen injection would be an even more powerful tool for evaluation of risk factors and surveillance of side-effects.

Fatalities following allergen immunotherapy

Allergen immunotherapy has been in use for nearly 100 yr and has become an important method of reducing allergic symptoms in select patients with allergic rhinitis, asthma, and insect venom hypersensitivity. Unfortunately, immunotherapy has been associated with anaphylaxis and death. Although the relative risk of severe reactions to immunotherapy is low, the number of such reactions has increased since the introduction of standardized and more potent extracts. There are a number of risk factors associated with such severe anaphylactic reactions. Such risk factors include errors in dosage, failure to reduce the dosage after a longer than scheduled interval, administration of the wrong extract, inadvertent intravenous administration, failure to postpone injection because of infection or asthma exacerbation, failure to observe patients for appropriate length of time, failure to adhere to guidelines for established contraindications, concurrent use of beta-adrenergic blocking agents, uses of mixtures of allergens, immunotherapy during the active allergy season, and types of allergens. In this review, we focus on these and other risk factors in attempts to reduce the risk of anaphylaxis following allergen immunotherapy.

Health-Economic Analyses of subcutaneous Specific Immunotherapy for grass pollen and mite allergy

OBJECTIVE

To investigate the health and monetary consequences of treating allergy with specific immunotherapy (SIT) compared with symptomatic treatment/standard care among patients with grass pollen or mite allergy.

METHODS

We performed an economic analysis based on 253 grass- and/or mite allergic patients who started SIT from 1.1.1996 to 1.1.2002 at the Allergy Unit, Aarhus University Hospital and at a specialist practice in Aarhus. Relevant data were collected before, during and after SIT treatment from the national health service based on each patient's personal identification number and medical records and from a specifically designed questionnaire. A cost-benefit analysis including direct and indirect costs before, during and after SIT was performed. In addition direct costs were related to the clinical effect (improvement in well-being) in the form of a cost-effectiveness analysis.

RESULTS

The direct cost per patient/year before SIT (equivalent to standard care) was DKK 2,580. The investment in SIT was DKK 27,545 (in present values) per patient over a 4-year period. After SIT the cost was reduced to DKK 1,072 per patient/year. In the long term, prospective introduction of SIT incurred additional present-value direct costs of DKK 13,676 per patient treated and DKK 2,784 per patient/year of improved well-being. However, when indirect costs were included in the economic evaluation SIT was shown to be net beneficial.

CONCLUSION

This study reveals that SIT is associated with initial resource investments and subsequent resource savings in the long term compared with standard care. When all consequences are measured in monetary terms, and assuming that sick days are associated with a loss of productivity, this analysis suggests that SIT increases societal welfare. This conclusion also holds if there is no loss of productivity.

Safety of subcutaneous specific immunotherapy with pollen allergen extracts for respiratory allergy

BACKGROUND

Specific immunotherapy (SIT) is a well-documented treatment for respiratory allergy. However, the major risk of SIT is the development of systemic anaphylactic reactions.

OBJECTIVES

To evaluate the safety of SIT given by subcutaneous route for 3 years to patients with seasonal allergic rhinitis (AR) with or without asthma.

METHODS

A prospective open-label study of immunotherapy (Chenopodium album, Bermuda grass, or both) in 181 consecutive patients with AR with or without asthma. After an initial dose-escalation phase, a maintenance dose of 0.5 ml of 100,000 PNU/ml was administered monthly for 3 years. The occurrence and severity of systemic reaction (SR) and local reaction was recorded and graded according to the WHO position paper.

RESULTS

Of 181 patients enrolled, 57 (31%) did not complete the study (53 due to poor compliance and 4 due to systemic side effects). All 4 patients who developed SR had asthma and all the SR occurred during the dose- escalation phase. Three patients had moderate SR (grade 2), while 1 patient had severe reaction (grade 3). Three of the SR occurred within the first 20 min after injection and 1 SR occurred 2 h after injection. None of the reactions were life threatening and were managed easily. Total rhinitis symptom score decreased from 11.8 at baseline to 7.46 at the end of treatment (p<0.001). The size of the skin prick test reaction to the main sensitising allergen was reduced from 7.48 +/- 2.26 mm at baseline to 5.60 +/- 2.18 mm at the end of treatment, p<001.

CONCLUSION

If a strict protocol is used, SIT is safe in AR patients with or without mild asthma and may result in significant subjective and objective improvement.

Systemic reactions to immunotherapy: influence of composition and manufacturer

BACKGROUND

Although immunotherapy clearly demonstrated the benefit of reducing allergic symptoms, it has the drawback of adverse events, mainly systemic reactions that could be very inconvenient for patients and even life-threatening.

OBJECTIVE

The aim of the present study was to assess the incidence of systemic reactions to immunotherapy in a large number of patients, and its potential relationship with the characteristics of therapy, such as allergen composition or manufacturing laboratory.

METHODS

This study analysed the administration of specific immunotherapy during a period of 5 years, involving 1212 patients affected by respiratory hypersensitivity or hymenoptera venom anaphylaxis. Commercial extracts were supplied by five different laboratories. All the patients were attended at an out-clinic immunotherapy unit by the same experienced staff. Immunotherapy was given following a conventional schedule, modified according the usual recommendations.

RESULTS

A total of 250 adverse reactions have been recorded, resulting in a frequency of 0.84% over the total number of injections. Seventy-nine of them (32%) were systemic reactions (0.27% SR/injection). The 79 systemic reactions were observed in 60 patients (5% of the patients). The frequency of systemic reactions was significantly lower (P < 0.01) on the group of mites than on the other groups. The frequency of systemic reactions varies according to the manufacturing laboratory. In the case of mite extracts, although one of the laboratories had a lower frequency of adverse systemic reactions, it did not reach the level of statistical significance. However, in relation to pollen extracts, preparations of one of the manufacturers had a significantly lower frequency of systemic reactions. Concerning the time of occurrence, 27% of systemic reactions were delayed, thus they appeared at least 30 min after the vaccine injection, most of them due to pollen extracts.

CONCLUSION

This is a preliminary study to evaluate the factors that could facilitate the appearance of systemic reactions demonstrating that not only the composition but also the manufacturer is connected to systemic reactions. Although further studies are needed to clearly establish the influence of manufacturer on frequency and time of appearance of systemic reactions, it seems necessary to reach a wide consensus on allergen extract standardization methods.

A pre-seasonal birch/hazel sublingual immunotherapy can improve the outcome of grass pollen injective treatment in bisensitized individuals. A case-referent, two-year controlled study

BACKGROUND

The study tests the hypothesis of a reduction of priming due to tree allergy in patients sensitised to both birch/hazel and grass pollen undergoing an associated preseasonal Sublingual/Injective immunotherapy.

METHODS

36 out of 49 bisensitized candidates were pair-matched into 18 case-referent couples. During two years all patients were administered preseasonal grass-SIT and one patient in each couple received also birch/hazel-SLIT. Diary cards were fulfilled for three consecutive grass pollen seasons. Specific Nasal Provocation Test (NPT) for grass and aspecific bronchial challenge were done; sera were analyzed for specific IgE and IgG.

RESULTS

During the peak of the grass pollen season both groups showed a significant improvement in total symptom-score. Conjunctivitis and cough improved significantly more in patients with associated therapies. While antihistamine score decreased significantly in both groups, antiasthmatics did only in the SLIT-SIT group. The follow-up documented a significant increase in grass- and birch-specific IgG and a decrease in grass-specific IgE. Grass-NPT threshold was clearly higher in SLIT-SIT-group (p = 0.01) and only in this group PD20 methacholine improved significantly (p < 0.05).

CONCLUSIONS

Combined birch/hazel-SLIT and grass-SIT are safe and improve clinical outcomes of SIT alone in young bisensitized patients. Priming reduction is supported by specific NPT and bronchial hyperresponsiveness.

Current opinion of immunotherapy for ocular allergy

PURPOSE OF REVIEW

Allergic conjunctivitis is common and may be the most prominent or the only feature of allergies. Immunotherapy has been used as a primary treatment for allergies since the early 1900s. Currently the use of immunotherapy for allergic rhinoconjunctivitis is well established and has been shown to decrease the development of bronchial hyperreactivity and asthma. However, the role of immunotherapy for primary treatment of allergic conjunctivitis is unclear. We reviewed the studies where immunotherapy was used with particular attention to the affects on ocular allergies.

RECENT FINDINGS

There are many schedules and methods of delivering immunotherapy. Recent studies have started to assess ocular symptoms as one of the parameters to monitor efficacy of therapy. They follow the affects of immunotherapy on conjunctival provocation tests, ocular symptoms, or the use of eye drops. The literature suggests that using the various immunotherapy modalities at different schedules, ocular symptoms improved even when immunotherapy was used on a rush schedule.

SUMMARY

The initiation of immunotherapy for allergic rhinoconjunctivitis has been shown to switch the immune response to T helper 1 and thus avoid the progression of other atopic conditions. Current literature shows that using many allergens with different forms of immunotherapy appear to have a significant improvement in ocular allergy symptoms and this can be achieved rapidly and safely in most patients. Whether using immunotherapy early in allergic conjunctivitis will alter the progression of other atopic conditions remains to be investigated.

Clustered schedules in allergen-specific immunotherapy

BACKGROUND

Injective immunotherapy is traditionally performed with a build-up phase lasting 3 to 4 months. The costs, decreasing compliance from both patients and clinicians and inconveniences due to this schedule may be overcome using different schedules.

METHODS AND RESULTS

A revision of the published papers with clustered schedules has been made. Attention has been focussed on tolerance and its relationships with relevant parameters such as kind of extract (aqueous or depot), allergens and their pharmaceutical presentation, schedule followed, use or not of a premedication, clinical manifestations of patients before treatment. For a better revision, papers dealing with clustered schedules have been divided into two groups. The first group includes 20 papers not designed to study the clustered schedule but using it to study other parameters affected by specific immunotherapy. The second group includes 9 papers specifically or mainly designed to study the clustered schedule. A huge difference in the rate of side effects could be assessed among different papers, even in studies run with similar allergens from the same producer and with a similar schedule.

CONCLUSIONS

Summarizing the results of the revision, the following conditions seem to lead to the optimal tolerance of the clustered schedule: use of a premedication; use of a depot preparation; use of no more than 4 administrations per cluster; administration of 1-2 clusters per week and of 4 to 6 clusters in total. These results seem promising but further efforts are required to better define the optimal clustered schedule.

The safety and efficacy of subcutaneous birch pollen immunotherapy - a one-year, randomised, double-blind, placebo-controlled study

BACKGROUND

There is only very limited documentation of the efficacy and safety of high-dose subcutaneous birch pollen immunotherapy (IT) in double-blind, placebo-controlled (DBPC) studies. Birch pollen is a major cause of allergic morbidity in northern Europe and in eastern parts of North America.

METHODS

Thirty-five patients with severe rhinoconjunctivitis (hay fever) to birch pollen were allocated to double-blinded clustered IT with a depot birch pollen extract (Betula verrucosa) or placebo injections. Seven patients in each group had concomitant self-reported seasonal asthma. Treatment was conducted as a clustered regimen and was performed in a specialist unit. Symptom scores from nose, eyes, and lungs, and use of oral and topical antihistamines, beta-2-agonists, and oral corticosteroids were recorded daily during the season of 2000. Sensitivity to allergen provocation in skin, conjunctiva, and nasal mucosa was measured before and after 10 months of treatment. Post-seasonal assessment of symptom severity was performed using a simple questionnaire.

RESULTS

IT reduced the symptom score for both rhinoconjunctivitis and asthma (P-values < 0.05), total medication score (P < 0.02) and use of oral antihistamines (P < 0.01). IT reduced specific conjunctival sensitivity (P < 0.05), skin prick test, and especially cutaneous late-phase response diameters (P < 0.00001), and increased general well-being on post-seasonal evaluation (P < 0.01). IT was safe, with side-effects at the same level as placebo.

CONCLUSIONS

High-dose, subcutaneous IT is efficacious and safe in patients with severe birch pollen rhinoconjunctivitis and asthma.

The dental patient with asthma. An update and oral health considerations

OVERVIEW

Asthma is a serious global health problem that has steadily increased in prevalence during the past two decades. New classification and treatment guidelines have been published, and dental providers need to be aware of these changes.

LITERATURE REVIEWED

The authors searched textbooks and MEDLINE, looking for the most updated medical information on asthma, as well as for previous publications on treatment of asthmatic patients in a dental setting.

RESULTS

More than 9,000 articles on asthma were published in English between 1997 and 2000. From 1960 until 2000, approximately 40 articles specifically addressed asthma and dental care. The authors reviewed more than 300 articles from the medical literature and all articles after 1980 that directly focused on oral health issues for importance and relevance.

CONCLUSIONS

Recent information regarding the etiology, pathogenesis and treatment of asthma had not been adequately addressed in the dental literature. Dental care of asthmatic patients may necessitate considerations beyond what has previously been published in the dental literature.

CLINICAL IMPLICATIONS

In the treatment of asthma, as with treatment of most medical conditions, oral health care providers play a role that is important in terms of both the patient's overall health and the systemic condition's effect on oral health. This article provides dentists with a timely update on asthma and the relationship between asthma and oral health, and it offers suggestions for safe and appropriate dental care.

Allergen-specific immunotherapy in birch- and grass-pollen-allergic rhinitis. I. Efficacy estimated by a model reducing the bias of annual differences in pollen counts

BACKGROUND

Evaluation of the efficacy of allergen-specific immunotherapy (IT) with pollen extracts is complicated by annual variation in pollen intensity. Our study aimed to evaluate the efficacy of birch and grass IT, taking into consideration these variations.

METHODS

After 1 year of observation, 52 patients with rhinoconjunctivitis and allergy to birch as well as grass pollen were allocated to double-blinded clustered IT with aluminum-adsorbed extract produced from either birch (Betula verrucosa) pollen or grass (PIleum pratense) pollen. After 1 year of treatment, the patients continued IT with their original extract and also received the other extract. During the three consecutive pollen seasons, the rhinoconjunctivitis symptom score and the use of antihistamines, eye-drops, and oral prednisolone were recorded. Longitudinal data analysis was used to investigate the relation between different pollen counts and the magnitude of clinical efficacy.

RESULTS

An effect of IT was found on symptom score, antihistamine intake, and eye-drop use for both birch and grass (P values <0.05). The mean reduction in symptom score/medication by IT ranged from 24% to 95%, depending on mean seasonal pollen counts. A minimum mean seasonal grass-pollen count of 20-30 pollen grains m3 was required for the efficacy of grass IT to emerge.

CONCLUSIONS

A model was developed for evaluation of efficacy in longitudinal IT studies, taking the differences in annual pollen counts into consideration. The model showed a significant beneficial role of pollen IT in rhinoconjunctivitis patients allergic to birch and grass pollen.