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

Oral Immunotherapy for Allergic Conjunctivitis Using Transgenic Rice Expressing Hypoallergenic Antigens

Pollinosis, or allergic conjunctivitis and rhinitis induced by pollen, is one of the most common diseases worldwide. In Japan, Japanese cedar (Cryptomeria japonica) pollinosis is a predominant allergic condition that affects more than one-third of all Japanese individuals. Pharmacological treatments of allergic conjunctivitis include administration of antiallergic eye drops containing an antihistamine or mast cell stabilizer. However, these topical treatments provide transient relief from symptoms. The only available curative treatment for allergic diseases is allergen-specific immunotherapy. Sublingual immunotherapy for pollinosis has been found to be effective for suppression of ocular and nasal symptoms, but patient compliance is low. Oral administration of staple foods engineered to express allergens is a possible means of delivering antigens for immunotherapy, and its convenience would be expected to improve compliance. With the aim of developing more convenient, effective, and safe immunotherapies for allergic diseases, we have generated rice-based edible vaccines expressing antigens derived from dust mites or pollen from Japanese cedar, birch, or ragweed. In this study, we summarize the results of our immunotherapy studies using transgenic rice. Oral immunotherapy with transgenic rice seeds containing hypoallergenic modified forms of Japanese cedar pollen antigens was effective for both preventing allergic conjunctivitis and suppressing established disease in mice. Oral administration of transgenic rice seeds is thus a promising approach to immunotherapy for conjunctivitis and rhinitis induced by Japanese cedar pollen.

Immunotherapy With the SQ Tree SLIT-tablet in Adults and Adolescents With Allergic Rhinoconjunctivitis

PURPOSE

The SQ tree sublingual immunotherapy (SLIT)-tablet containing allergen extracts with the major allergen Bet v 1 from birch pollen is currently being developed for the treatment of tree pollen-induced allergic rhinitis/conjunctivitis with or without asthma. The aim of this Phase II trial was to investigate the dose-related efficacy and safety of the SQ tree SLIT-tablet.

METHODS

This study was a randomized, parallel-group, double-blind, placebo-controlled, multi-national trial conducted in Europe. A total of 637 participants were randomized equally to receive placebo or treatment with the SQ tree SLIT-tablet in doses of 0.5, 1, 2, 4, 7, or 12 development units (DU). Treatment was initiated ~16 weeks before onset of the 2013 birch pollen season (BPS) and was continued throughout the BPS with a total duration of at least 6 months. During the BPS and tree pollen season (TPS), subjects assessed rhinoconjunctivitis symptoms and medication use on a daily basis in an electronic diary; weekly assessments of rhinoconjunctivitis quality of life were also made.

FINDINGS

Analysis of the average daily symptom score during the BPS and the TPS showed that the difference between active treatment and placebo was statistically significant for the 7 DU group (BPS, P = 0.02; TPS, P = 0.03), with no clear dose-response relationship. All doses of the SQ tree SLIT-tablet induced changes from baseline in birch-specific IgE and IgG₄ that were statistically significant compared with placebo at all time points assessed (P < 0.0001) with a clear dose-response relationship for birch specific IgG₄. In general, the SQ tree SLIT-tablet was well tolerated, with the majority of treatment-related adverse events (≥95%) being mild or moderate in severity. The most frequently reported treatment-related adverse events were generally related to the sublingual administration of the tablet (ie, they occurred in the oral cavity).

IMPLICATIONS

The results from this trial suggest that the SQ tree SLIT-tablet in doses up to 12 DU has a tolerability profile suitable for at-home administration. The immunomodulatory changes indicate a dose-response relationship, but clinical efficacy parameters were inconclusive, probably due to low pollen counts, emphasizing the importance of pollen exposure for the outcome of a pollen allergy immunotherapy trial. EudraCT no: 2012-000031-59.

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.

Depigmented-polymerized mixed grass/birch pollen extract immunotherapy is effective in polysensitized patients

BACKGROUND

Although many patients with allergic rhinoconjunctivitis have symptoms due to sensitization with more than one pollen allergen, and mixed pollen extracts are widely used for allergen immunotherapy in practice, there are few published trials.

METHODS

We performed a 2-year multicentre, double-blind, placebo-controlled trial of subcutaneous immunotherapy with mixed depigmented-polymerized birch and grass pollen extract in 285 patients with allergic rhinoconjunctivitis symptomatic during both birch and grass pollen seasons. Primary outcome was combined symptom and medication score (SMS) assessed by daily visual analogue scales (VAS). Analysis included a placebo-based analysis examining the effect of treatment only on days when placebo patients were symptomatic.

RESULTS

There was a significant reduction in median SMS for actively treated patients (median 5.70 (interquartile range 2.62-10.02) compared with 7.07 (3.47-10.71) for placebo, P = 0.0385). Rhinitis quality-of-life scores were significantly better for active compared with placebo, and other secondary endpoints were not significantly different. Placebo-based analysis showed a 33.7% reduced SMS at year 2 for active treatment compared with placebo on days when placebo patients were symptomatic. Both birch pollen- and grass pollen-specific IgG4 increased with active treatment.

CONCLUSIONS

This study shows efficacy of mixed pollen extracts for immunotherapy for patients symptomatic to both birch and grass pollen allergens. The relatively modest effect may reflect 50% dose reduction for each allergen in the mixture. It supports VAS for symptom assessment and placebo-based analysis as useful for the analysis of immunotherapy trials. The safety of modified extracts may allow study of mixed extracts without dose reduction to improve efficacy.

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.

Immunotherapy is allergen-specific: a double-blind trial of mite or timothy extract in mite and grass dual-allergic patients

BACKGROUND

One hundred years ago, Noon [Lancet 1911;1:1572-1573], using conjunctival provocation testing (CPT), was the first to demonstrate the effectiveness of subcutaneous immunotherapy (SCIT) in grass-allergic subjects with hay fever. In this centenary year, we present data that, by use of CPT and allergen-specific IgG, replicate this observation and additionally confirm the allergen specificity of SCIT by using a double-blind design employing either grass or mite SCIT in dual grass- and mite-allergic individuals.

METHODS

Twenty adults (11 females) with perennial rhinoconjunctivitis and exacerbation of symptoms during the grass pollen season and in the autumn had immediate skin and conjunctival sensitivity and raised specific IgE to both Dermatophagoides farinae and Phleum pratense. Participants were randomly assigned to either timothy or D. farinae immunotherapy for 3 years. CPT and specific IgG tests to both allergens were performed annually. After 3 years, subjects gave their blinded overall evaluation.

RESULTS

Six mild-to-moderate general reactions occurred in 2 timothy- and 4 mite-treated patients. Four of these patients and 2 other patients withdrew from the study. Seven patients in each group completed the study. After 3 years of immunotherapy, the timothy CPT threshold concentration had increased 16- fold in timothy-treated patients (p < 0.05; between-group change, p < 0.05). The increase in the mite CPT threshold in mite- compared to grass-treated patients was 31-fold (p < 0.05). The overall assessment of conjunctival sensitivity was highly significant in favour of treatment (p < 0.015), as was that of allergen-specific IgG (p < 0.0001).

CONCLUSIONS

Allergen immunotherapy is allergen species-specific, as judged by decreased conjunctival sensitivity and changes in allergen-specific IgG concentrations.

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.

Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

BACKGROUND

Asymptomatic skin sensitization (AS) is a risk factor for the development of allergic symptoms. A meticulous definition of this condition requires a systematic assessment of clinical symptoms before inclusion.

OBJECTIVE

To examine the concordance between retrospective assessment of seasonal allergic symptoms and prospective seasonal symptom registration among subjects with AS.

METHODS

On the basis of a population survey, autumn 2002, including skin prick tests (positive if > or =3 mm) and a screening questionnaire, 87 subjects with AS to birch and/or grass pollen, birch and/or grass pollen allergic symptomatic subjects (n = 63) and healthy controls (n = 40) were included in January to March 2003, completed diary cards on symptom and medication use during the relevant seasons 2003, and were examined at follow up in autumn 2003. Allergy: positive SPT and symptoms > or = seven diary days.

RESULTS

Eleven AS subjects (birch: n = 10) subsequently developed allergic symptoms, yet nine admitted, at follow up, to have had symptoms before inclusion, or even denied pollen-related symptoms despite a significant diary. Compared with AS subjects sensitized to grass pollen, AS subjects sensitized to birch pollen had significantly larger skin prick reactions and more often and severe pollen symptoms.

CONCLUSION

In the context of double-sensitization, retrospective symptom assessment is not a reliable method for ensuring that subjects classified, as asymptomatically skin sensitized, are truly, asymptomatic. This matter should be considered in studies on allergy development.

Sublingual immunotherapy with grass pollen is not effective in symptomatic youngsters in primary care

BACKGROUND

Sublingual immunotherapy (SLIT) is considered safer and more convenient than subcutaneous therapy and therefore has been proposed as especially suitable for children and in primary care. Most efficacy studies in children lack power to be conclusive, and all have been performed in referral centers.

OBJECTIVE

To investigate the efficacy of SLIT with grass pollen allergen in children and adolescents with rhinoconjunctivitis in a primary care setting.

METHODS

Youngsters aged 6-18 years with hay fever were enrolled from general practices and randomly assigned to receive placebo or grass pollen mix for 2 years. The primary outcome was the mean daily total symptom score (scale 0-15) comprising sneezing, itching nose, watery running nose, nasal blockage, and itching eyes during the months May-August of the second treatment year.

RESULTS

Out of 204 youngsters randomized, 168 entered the intention-to-treat analysis (91 verum, 77 placebo). The mean daily total symptom score did not differ between participants allocated to verum and those allocated to placebo (difference for verum minus placebo: -0.08, 95%CI, -0.66-0.50; P = .78). No differences were found for rescue medication-free days, disease-specific quality of life, and overall evaluation of the treatment effect. Local side effects were more frequent in the verum group (39% vs 17% of participants; P = .001).

CONCLUSION

Sublingual immunotherapy with grass pollen in a primary care setting is not effective in children and adolescents.

CLINICAL IMPLICATIONS

Currently, SLIT cannot be recommended for general practitioners as a therapeutic modality in youngsters with grass pollen allergy.

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.

Clinical efficacy and safety of sublingual immunotherapy with tree pollen extract in children

BACKGROUND

Subcutaneous immunotherapy has been the principal approach of immunotherapy in the treatment of allergic diseases. Several clinical studies with birch, alder or hazel pollen extract conducted as subcutaneous immunotherapy have been published suggesting a well-tolerated and clinically effective treatment. Only a few clinical studies of sublingual immunotherapy (SLIT) with these allergens have been published. This study investigated the clinical efficacy, safety and dose-response relationship of SLIT in children suffering from rhinoconjunctivitis with/without asthma.

METHODS

Eighty-eight children (5-15 years) with a history of tree pollen-induced allergic rhinoconjunctivitis with/without seasonal asthma for >or=2 years were included. Allergy to tree pollen was confirmed by positive skin-prick test, positive specific IgE and positive conjunctival provocation test. The extract used was a glycerinated mixture of Betula verrucosa, Corylus avellana and Alnus glutinosa 100,000 SQ-U/ml. Children were randomized into three groups receiving SLIT 5 days a week for up to 18 months; dose group 1: accumulated weekly dose of 24,000 SQ-U; dose group 2: accumulated weekly dose of 200,000 SQ-U; and placebo.

RESULTS

In the birch pollen season, dose group 2 showed a significant reduction of symptom (P = 0.01) and medication scores (P = 0.04) compared with placebo. Dose group 1 showed a significant reduction of symptom scores (P = 0.03). There were no statistical differences between dose groups 1 and 2. All children tolerated the treatment well.

CONCLUSION

SLIT with tree pollen extract provided dose-dependent benefits in tree pollen-allergic children in terms of significantly reduced symptoms and medication use. The treatment was well tolerated.

The effect of Gencydo injections on hayfever symptoms: a therapeutic causality report

OBJECTIVES

The aim of this study was to study the effect of Gencydo (Weleda AG, Arlesheim, Switzerland) injections on hayfever symptoms.

DESIGN

This is a therapeutic causality report based on the practices of 13 Dutch general practitioners.

SUBJECTS

Thirteen (13) patients with a mean history of hayfever with grass pollen allergy of 9 years duration, who in previous years used conventional hayfever medication because of the severity of symptoms during the pollen season.

INTERVENTIONS

Gencydo injections were given in 12 patients before the onset of and during the grass pollen season, and in one patient during the grass pollen season only.

OUTCOME MEASURES

Nasal and non-nasal hayfever symptom severity, use of rescue medication (antihistamines or corticosteroids), and subjective experiences of patients were used as outcome measures.

RESULTS

Nine (9) of 13 patients showed no increase of symptom severity during the so-called pollen season. Both the mean maximal total nasal symptom score per patient and the mean total nasal symptom score for the entire study group during the days with a grass pollen count >100 were mild. Percentages of individual "strong" or "severe" nasal symptom scores were low. There was no statistically significant difference in mean total nasal symptom score between the period when the pollen count was <100 and the period when it was >100. Conventional rescue medication for hayfever was used only eight times, all by one person. Nine (9) patients (69%) reported an improvement of symptoms (eight patients cited strong improvement and one patient noted slight improvement).

CONCLUSIONS

There are clear indications that Gencydo treatment was effective in a large subgroup of the research population.

Allergic diseases of the eye

The prevalence of ocular allergy is clearly underappreciated; it has been an underdiagnosed and undertreated area in primary care medicine. The ocular symptoms associated with the most common ocular allergy conditions,such as seasonal and perennial AC, are twice as likely to affect the allergy sufferer as nasal symptoms alone. The emergence of new medications for the specific treatment of ocular symptoms over the course of the past 15 years offers a new field for improved patient care by the primary and sub-specialty health care providers.

Clinical and patient based evaluation of immunotherapy for grass pollen and mite allergy

BACKGROUND

Treatment of allergic disease can be done by pharmacological intervention by allergen avoidance--in the following called standard care (SC), or by specific treatment with allergy vaccination; Specific Immunotherapy (SIT). The aim of this study were to evaluate the effects of subcutaneously administrated SIT compared to SC by objective (clinical/medical records) and subjective parameters (patient's opinion) in a before/after SIT study.

METHODS

The study included retrospectively all grass- and mite allergic 16-60 year old patients (N = 253) who had started SIT for grass pollen or mite allergy during the period 1.1.1996-1.1.2002 at The Allergy Unit, Aarhus University Hospital, or at a specialist practice in Aarhus. Relevant data were collected before/after treatment from medical records and from a specific designed questionnaire. The following indicators for effect were applied: Success of immunotherapy expressed as completion of up dosing phase, change in symptoms, a comparison of overall rhinoconjunctivitis symptoms, number of symptom free days per year, effect of pharmaceuticals, change in physical and psychological wellbeing and number of lost days from work/education and leisure activities.

RESULTS

Compliance for completed up dosing for SIT was 94 % (95 % CI 90-97). The questionnaire revealed that after SIT there were a significant reduction in degree of symptoms, 84 % (95 % CI 79-89) of the respondents achieved a reduction in over all rhinoconjunctivitis score, there were an increase in symptom free days per year, a decrease in days off/incapacity from work/education and leisure activities, an improved effect of the pharmaceuticals used for allergic symptoms and an improvement in physical and psychological wellbeing. The study also showed that SIT was more effective treating rhinoconjunctivitis symptoms than lung symptoms.

CONCLUSION

The study revealed great advantages of SIT compared to SC and a high compliance for SIT during the up dosing period.

Out-of-season recollection of drug use for seasonal IgE-mediated rhinitis: useful but an overestimation

BACKGROUND

The history of seasonal, IgE-mediated (allergic) rhinitis is often obtained postseasonally as a retrospective assessment. It is not known whether recollected drug use is representative for the in-seasonal medication history.

OBJECTIVES

To investigate the agreement between in-seasonal and out-seasonal reports on drugs and drug doses, and to investigate whether retrospective assessment was sufficiently sensitive to detect the effect of intervention.

MATERIAL AND METHODS

Thirty-five patients allergic to birch pollen were allocated to allergen-specific immunotherapy (SIT) or placebo in a double-blind study. Drug use was recorded daily during the season 2000 and out-seasonally 6 months after the seasons 1999 and 2000. The mean daily drug use was transformed into a 4-point categorical scale for simplicity and was calculated for the out-seasonal rating and for 6 in-seasonal periods of different durations. In-seasonal and postseasonal ratings were compared with the Cohen weighted kappa (kappa w).

RESULTS

We observed a high level of agreement between in-seasonal and retrospective reports of drugs used (kappa w > 0.60) and drug doses (kappa w > 0.50). The highest agreement was observed for the in-seasonal day, week, or 2 weeks with the highest drug intake. Out-seasonal ratings significantly overestimated the daily oral and nasal antihistamine use compared with in-seasonal periods >2 weeks. Despite being comparable pretreatment, only the SIT group had a significant decrease in recollected total drug use during SIT.

CONCLUSION

Out-seasonal recollection of hay fever drugs represented a period of a maximum 14 days. It appeared sufficiently sensitive to detect the effect of intervention.

Allergen-independent immunostimulatory sequence oligodeoxynucleotide therapy attenuates experimental allergic rhinitis

While effective for the prevention and treatment of allergic rhinitis (AR) symptoms, currently available medications do not reverse allergen specific hypersensitivities. Therefore, pharmacotherapeutics are not curative and their daily use is often required for years. These investigations were conducted to determine whether immunostimulatory sequence oligodeoxynucleotide (ISS-ODN) delivery protects previously sensitized mice from AR hypersensitivity responses and modulates their allergen specific immune profiles. Mice were first sensitized with ovalbumin (OVA) and alum, twenty-four hr before beginning a series of seven daily intranasal (i.n.) allergen challenges, subsets of mice received a single i.n. or intradermal (i.d.) dose of ISS-ODN or control oligodeoxynucleotide (C-ODN), a single intraperitoneal (i.p.) injection of dexamethasone (DXM), or no intervention. Mice receiving i.d. or i.n. ISS-ODN were found to have attenuated immediate and late phase effector cell responses to i.n. OVA challenge. Specifically, ISS-ODN treated mice had less histamine and cysteinyl leukotriene release and eosinophilic inflammation in their nasal passages than mice treated with C-ODN. In addition, splenocytes from ISS-ODN but not C-ODN treated mice displayed attenuated OVA-specific interleukin (IL)-4, IL-5, and IL-13 but increased interferon-gamma responses. Finally, ISS-ODN was generally a more effective treatment than DXM, both in blunting AR hypersensitivity responses and in shifting T helper 2 Th2-biased immune parameters towards Th1 dominance. As ISS-ODN delivery rapidly attenuated effector cell responses in this AR model in an allergen independent manner, the present results suggest that therapy with ISS-ODN alone may be an effective alternative to corticosteroid medications for the clinical management of AR.

The co-seasonal application of anti-IgE after preseasonal specific immunotherapy decreases ocular and nasal symptom scores and rescue medication use in grass pollen allergic children

BACKGROUND

Specific immunotherapy (SIT) and treatment with anti-immunoglobulin (Ig)E antibody are complementary approaches to treat allergic rhinoconjunctivitis, which may be used for single or combined treatment.

OBJECTIVE

A randomized, double-blind, placebo-controlled trial was conducted to compare the efficacy of single and combined treatment with SIT and anti-IgE (Omalizumab) in reducing symptom severity and rescue medication use.

METHODS

A total of 221 subjects with birch and grass pollen allergic rhinoconjunctivitis aged 6-17 years were analysed during the grass pollen season. Group A (SITbirch + placebo) served as a reference group obtaining no effective treatment for grass pollen allergy. Group B received anti-IgE monotherapy during grass pollen season, group C SIT grass pollen monotherapy, and group D the combined treatment of SIT and Omalizumab.

RESULTS

Preseasonal treatment with grass pollen SIT alone compared with SIT with the nonrelated allergen did not reduce symptoms or rescue medication use. Anti-IgE monotherapy significantly diminished rescue medication use and number of symptomatic days. The combined treatment with SIT and anti-IgE showed superior efficacy on symptom severity compared with anti-IgE alone.

CONCLUSIONS

Co-seasonal Omalizumab therapy showed considerable effects in children with seasonal allergic rhinitis. The combination of SIT plus Omalizumab was clinically superior to each treatment alone during the first year of observation.

Increased expression of allergen-induced in vitro interleukin-10 and interleukin-18 mRNA in peripheral blood mononuclear cells of allergic rhinitis patients after specific immunotherapy

BACKGROUND

During specific pollen immunotherapy (SIT) there is a local mucosal shift from Th2- to Th1- type cytokine predominance, with IL-12 having a major role in this shift. IL-10-induced tolerance is supposed to be a key phenomenon in venom immunotherapy (VIT). However, the role of Th1-promoting cytokines, on the one hand, and the role of regulatory cytokines, on the other hand, have not been studied in parallel during SIT.

OBJECTIVE

This study was undertaken to analyse the allergen-induced in vitro mRNA expression of Th1-type effector cytokine IL-18 and regulatory cytokines IL-10 and TGF-beta during SIT in peripheral blood mononuclear cells (PBMC) of allergic rhinitis (AR) patients.

METHODS

Thirty patients with AR undergoing pollen SIT and 10 patients with AR who were not treated with SIT were included in the study. The symptoms and medications were registered post-seasonally before the beginning of SIT and after 1 year of therapy. PBMC samples were collected and stimulated with pollen allergen extract prior to the treatment, at the maintenance phase in 12 patients and after 1 year of the treatment. The cytokine mRNA expression was assessed using kinetic real-time RT-PCR (TaqMan).

RESULTS

There was a clear increase in the treated AR patients, in comparison with untreated AR patients, in the expression of both IL-10 (mean change from baseline (SEM): 3.1 (0.8) vs. -0.3 (0.3), P<0.002, Mann-Whitney U-test) and IL-18 (2.7 (0.9) vs. -0.2 (0.6), P<0.03) mRNA after 1 year. The clearest increase in IL-10 mRNA expression was seen in patients who did not benefit at all (6.0 (2.3), P<0.001 vs. untreated) and the least increase in patients that had the greatest reduction of symptoms (0.8 (0.6), n.s. vs. untreated) at 1 year. The clearest increase in IL-18 mRNA expression was seen in patients with moderate outcome (3.4 (1.6), P<0.04 vs. untreated). In intermediate samples, taken when the maintenance dose was reached, the peak expression of allergen-induced IL-10 mRNA was associated with the most favourable outcome of SIT (P=0.01, Fisher exact test). A similar trend was seen in IL-18 mRNA expression.

CONCLUSIONS

The results suggest that an early and transient increase in allergen-specific IL-10 and IL-18 mRNA expression in PBMC is essential for the therapeutic outcome after 1 year of SIT.

In vitro allergen-induced mRNA expression of signaling lymphocytic activation molecule by PBMC of patients with allergic rhinitis is increased during specific pollen immunotherapy

BACKGROUND

Specific immunotherapy (SIT) acts by inducing a shift from T(H)2 to T(H)1 cell response on mucous membranes, reducing allergic inflammation. New genes expressed primarily in T(H)1-type cells have been found. Of these genes, signaling lymphocytic activation molecule (SLAM) promotes T-cell proliferation and IFN-gamma production. Nothing is known about its role in T(H)2-T(H)1 switch during SIT.

OBJECTIVE

We sought to analyze the mRNA expression of SLAM and other T(H)1-associated genes, interleukin-12 receptor beta2 (IL-12Rbeta2) and T-box expressed in T cells (T-bet), and compare them with the clinical outcome of the therapy.

METHODS

PBMC from 30 patients allergic to pollen undergoing SIT were collected during the therapy. Control PBMC were collected from 10 patients with allergic rhinitis not participating in SIT and from 10 nonallergic subjects. Cells were stimulated in vitro with pollen allergen extracts. SLAM, IL-12Rbeta2, and T-bet mRNA expressions were studied by real-time quantitative RT-PCR technique (Taqman). Symptom scoring and medication scoring were registered before commencement of SIT and after 1 year of the therapy.

RESULTS

Before the treatment, in vitro allergen-induced SLAM mRNA expression in PBMC was significantly lower in the patients with allergic rhinitis than in the healthy control subjects. After 1 year of the treatment, SLAM mRNA expression was increased in the patients undergoing SIT and was associated with IFN-gamma mRNA expression and inversely associated with the symptom improvement. At the maintenance dose, an increase in SLAM mRNA expression was associated with the clinical symptom improvement at 1 year. No changes were seen in IL-12Rbeta(2) or T-bet mRNA expressions.

CONCLUSIONS

SLAM mRNA expression in PBMC is modulated during the course of SIT, and an early and transient increase of SLAM mRNA expression is associated with clinical symptom improvement.

Clinical efficacy of sublingual and subcutaneous birch pollen allergen-specific immunotherapy: a randomized, placebo-controlled, double-blind, double-dummy study

BACKGROUND

Both sublingual allergen-specific immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) have a documented clinical efficacy, but only few comparative studies have been performed.

OBJECTIVE

To investigate the clinical efficacy of SLIT vs SCIT and secondary to compare SLIT and SCIT with placebo and to evaluate the relative clinical efficacy in relation to systemic side-effects.

METHODS

A 3-year randomized, placebo-controlled, double-blind, double-dummy study including 71 adult birch pollen hay fever patients treated for two consecutive years after a baseline year. Allocation to treatment groups was based on disease severity in the baseline season, gender and age.

RESULTS

Clinical efficacy was estimated in 58 patients completing the first treatment year by subtracting baseline data and by calculating the ratio first treatment season vs baseline. SLIT diminished the median disease severity to one-half and SCIT to one-third of placebo treatment. No statistical significant difference between the two groups was observed. Both for symptoms and medication scores actively treated patients showed statistically significant and clinical relevant efficacy compared with placebo. SLIT treatment only resulted in local mild side-effects, while SCIT resulted in few serious systemic side-effects.

CONCLUSION

Based on the limited number of patients the clinical efficacy of SLIT was not statistically different from SCIT, and both treatments are clinically effective compared with placebo in the treatment of birch pollen rhinoconjunctivitis. The lack of significant difference between the two treatments does not indicate equivalent efficacy, but to detect minor differences necessitates investigation of larger groups. Due to the advantageous safety profile SLIT may be favored.

Intranasal immunotherapy is more effective than intradermal immunotherapy for the induction of airway allergen tolerance in Th2-sensitized mice

Immunotherapy (IT) by injection more readily induces clinical tolerance to stinging insects than to respiratory allergens. However, while systemic immunization induces adaptive responses systemically, the induction of mucosal immunity generally requires local Ag exposure. Taken together, these observations suggest that the poor success rate of systemic IT for asthma could be a consequence of inadequate immune modulation in the airways. In support of this position, investigations presented in this report demonstrate that allergen IT more effectively induces airway allergen tolerance in Th2-sensitized mice, when delivered by the intranasal (i.n.) vs the intradermal (i.d.) route. Moreover, compared with native allergen, allergen immunostimulatory sequence oligodeoxynucleotide conjugate proved to be a more effective i.n. IT reagent for protecting allergic mice from airway hypersensitivity responses. Furthermore, for both native allergen and allergen immunostimulatory sequence oligodeoxynucleotide conjugate, i.n. and i.d. IT delivery were similarly effective in modulating systemic immune profiles in Th2-sensitized mice, while only i.n. IT had significant immunomodulatory activity on B and T cell responses in the airways. The present investigations may be the first to suggest that i.n. IT is more effective than i.d. IT for the treatment of asthma. Furthermore, our results suggest that modulating airway rather than systemic immunity may be the more important therapeutic target for the induction of clinical tolerance to respiratory allergens.

Retrospective assessment of seasonal allergic symptoms: over-rating but useful

BACKGROUND

The history of the severity of seasonal allergic symptoms is often obtained post-seasonally as a retrospective assessment. Correct rating is essential when determining the efficacy of pharmaceutical treatment, indications for allergen-specific immunotherapy (SIT), or inclusion into controlled clinical studies.

OBJECTIVES

To investigate the agreement between in- and post-seasonal ratings of seasonal symptoms, and to investigate whether the effect of SIT could be detected retrospectively.

MATERIAL AND METHODS

Thirty-five birch pollen-allergic patients were allocated to SIT or placebo in a double-blind study. Assessment of severity of symptoms from the nose, eyes and lungs were performed daily during the season 2000, and post-seasonally 6 months after the season in 1999 and 2000. A four-point verbal descriptor scale (VDS-4) was used at all occasions. A mean in-seasonal symptom rating was calculated for four periods: the day, the week and the 2 weeks with the highest symptoms score, and the arithmetic season (the period covering the mid-90% of the accumulated pollen count). In- and post-seasonal ratings were compared with Cohen's weighted kappa (kappaw).

RESULTS

Agreement between in-seasonal and retrospective ratings was fair to moderate (kappaw: 0.30-0.60). Post-seasonal ratings were most related to symptoms experienced in the week with the highest symptom scores, and least related to the arithmetic season. The post-seasonal ratings were significantly skewed towards higher symptom scores than the mean of in-seasonal ratings in periods >or= 2 weeks. Despite being comparable before intervention, only in the SIT-treated group was a significant decrease in post-season ratings of severity of rhinoconjunctivitis apparent (P < 0.05). Asthma scores were not reduced but fewer patients in the SIT group reported lung symptoms (P < 0.001).

CONCLUSION

Post-seasonal assessment of seasonal allergic symptoms generally describes a shorter period than the arithmetic season. Post-season assessment tends to over-rate average symptom severity, but appears sufficiently sensitive to detect treatment efficacy.

Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults: a 3-year follow-up study

BACKGROUND

The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults.

OBJECTIVE

The purposes of this investigation were to provide a clinical characterization of skin test-positive subjects without symptoms and to ascertain the predictive values of common allergologic tests.

METHODS

Asymptomatic adults with positive skin prick test results for birch (n = 15), nonatopic control subjects (n = 25), and birch pollen-allergic patients (n = 6) were followed through use of daily diary cards during 3 consecutive birch pollen seasons. At inclusion and at the 3-year follow-up visit, conjunctival and nasal challenges, intradermal late-phase reaction evaluation, and measurement of specific IgE were performed.

RESULTS

Asymptomatic sensitized subjects defined a clinically significant phenotype between nonatopic and allergic subjects in terms of specific IgE levels and susceptibility to conjunctival provocation testing. Sixty percent (n = 9) of the asymptomatic sensitized subjects developed clinical allergy. This was associated with an initial birch skin prick test weal diameter of > or =4 mm, a positive conjunctival provocation test result, and specific IgE of > or =CAP class 2, as well as with the presence of other allergies. Specific IgE of > or =CAP class 2 was 87.5% predictive for allergy development, whereas a negative conjunctival provocation test result was 100% negatively predictive. Nasal provocation testing possessed no additional prognostic information. No changes in clinical phenotype were seen in nonatopic or birch-allergic subjects.

CONCLUSION

Asymptomatic skin sensitization is a risk factor for later allergy development. At risk is any subject with target organ sensitivity, an elevated specific IgE level, and/or a skin prick test weal diameter of >4 mm.

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.

Ocular allergy guidelines: a practical treatment algorithm

The treatment of ocular allergy requires a better understanding of the spectrum of clinical disorders involving various components of the immune system, and of interactions at the conjunctival surface. The immune response focuses primarily on the different levels of activity of Th2 lymphocytes and various other immune cells associated with allergic disorders, including mast cells, eosinophils, fibroblasts, and epithelial and endothelial cells. Ocular allergic disorders include seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), giant papillary conjunctivitis (GPC) and atopic keratoconjunctivitis (AKC), which, through immunopathological and molecular immunological techniques, can all be better appreciated as being part of a larger spectrum of an atopic disease state. In SAC, pathological changes, such as increased mast-cell activation, the presence of migratory inflammatory cells, and early signs of cellular activation at the molecular level, are minimal. In PAC, these changes are more pronounced in line with the increased duration of allergenic stimulation. In more chronic forms of allergic conjunctivitis, such as VKC in children and AKC in adults, the following changes are evident: a persistent state of mast cell, eosinophil and lymphocyte activation; noted switching from connective-tissue to mucosal-type mast cells; increased involvement of corneal pathology; and follicular development and fibrosis. The treatment of acute and more chronic forms of allergic conjunctivitis has focused in the past on symptomatic relief of symptoms, but with a better understanding of the mechanisms involved we can now provide interventional therapeutic strategies and symptomatic relief. Our advances in the basic understanding of these conditions are providing the foundation for guidelines that improve the ocular health of patients with ocular allergies.

Optimized conjugation ratios lead to allergen immunostimulatory oligodeoxynucleotide conjugates with retained immunogenicity and minimal anaphylactogenicity

BACKGROUND

Immunotherapy has gradually fallen out of favor for the treatment of many allergic diseases because of the overall convenience, safety, and efficacy of medications. However, investigations suggest that allergen/immunostimulatory sequence oligodeoxynucleotide (ISS-ODN) conjugates (AICs) might have improved safety and efficacy compared with allergen extracts.

OBJECTIVE

We determined whether changes in the ISS-ODN conjugation ratio would effect the immunogenicity and allergenicity of AIC.

METHODS

Immunogenicity was determined by means of AIC vaccination of mice, followed by analysis of antigen-specific antibody and cytokine responses. The allergenicity of AIC was determined in mast cell release studies and in murine models of anaphylaxis and the Arthus reaction.

RESULTS

AIC induced a stronger immune response than allergen alone or allergen mixed with ISS-ODN, but higher-level ISS-ODN conjugation reduced its immunogenicity modestly. In mast cell degranulation studies AIC was approximately 100-fold less allergenic than native allergen, with stepwise increases in the ODN conjugation ratio leading to stepwise decreases in allergenicity. In anaphylaxis studies death rates were reduced from 100% with native allergen challenge to as low as 0% with high-ratio ISS-ODN AIC challenge. Similar results were obtained in an Arthus reaction model.

CONCLUSION

These investigations establish that AIC is both significantly more immunogenic and less allergenic than native allergens and the techniques used might have further utility for the standardization and optimization of AIC formulations for use in allergic patients.

Effect of 2-year placebo-controlled immunotherapy on airway symptoms and medication in patients with birch pollen allergy

BACKGROUND

Birch pollen is a common allergen in northern, central, and eastern Europe. Earlier studies of specific immunotherapy using birch pollen extract were not placebo-controlled or were only preseasonal. Long-term, placebo-controlled studies with subcutaneously administered standardized birch pollen extract are lacking.

OBJECTIVE

The aim of this study was to evaluate the effect of immunotherapy with birch pollen extract on airway symptoms and use of medication in adult birch pollen-allergic patients in a double-blind, placebo-controlled trial.

METHODS

Forty-nine patients with histories of birch pollen allergy from the upper and lower airways, positive skin prick test and conjunctival provocation test results, and in vitro specific IgE to birch pollen (Betula verrucosa ) extract were included. Immunotherapy with birch pollen extract was given during 2 consecutive years in a double-blind, randomized, placebo-controlled study. Clinical symptom scores from the upper and lower airways and use of rescue medication were registered throughout the pollen season.

RESULTS

Forty-six patients reached the maintenance dose and were maintained on that dose during the 2-year study. The median symptom scores during the 1997 and 1998 seasons were 1.3 and 2.6, respectively, in the specific immunotherapy group and 2.1 and 4.3, respectively, in the placebo group. The differences between the groups were significant (P =.05 in 1997 and P =.005 in 1998). The placebo group used significantly more rescue medication during both seasons than the specific immunotherapy group (P =.004 for 1997 and P =.004 for 1998).

CONCLUSION

Specific immunotherapy with birch pollen extract is an effective and safe treatment for reducing clinical allergy symptoms and medication use in birch pollen-allergic patients during the pollen season.

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.

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

BACKGROUND

Allergen-specific immunotherapy (IT) involves the risk of side-effects. Different side-effect profiles have been reported for different allergens, and it would be of great benefit to be able more precisely to predict patient- and allergen-related risk factors.

METHODS

Fifty-two patients with rhinoconjunctivitis and allergy to birch as well as grass pollen participated in a 3-year IT study, with a baseline year followed by 2 years of treatment. During the first treatment year, the patients received double-blinded IT with either birch (Betula verrucosa) or grass (Phleum pratense) pollen extracts adsorbed to aluminum hydroxide. The following year, the other allergen extract was added. Assessment of systemic reactions (SRs) was performed, and related to patient pretreatment parameters such as seasonal symptoms and medication requirement, skin prick test (SPT), conjunctival provocation test (CPT), nasal provocation test (NPT), total and specific IgE, basophil histamine release (HR), eosinophil count (EOS), eosinophil cationic protein (ECP), and eosinophil protein X (EPX).

RESULTS

In total, 44 and 47 patients started IT with birch- and grass-pollen extracts, respectively. All SRs occurred during the dose-increase phase. No life-threatening SRs were observed. There were a higher number of patients with SRs during IT with grass pollen than IT with birch pollen, 21 vs five patients (P<0.001), with SRs to 3.3% of grass-pollen injections compared to 0.7% of birch-pollen injections (P<0.0001). The SRs of birch-pollen IT were mild, consisting of rhinoconjunctivitis and oral-pharyngeal itching, whereas asthma and urticaria episodes were observed in the grass-pollen IT. No difference was found in sensitivity to birch and grass, when measured by SPT, CPT, NPT, specific IgE, or HR, and no difference was found in age, duration of allergic symptoms, prevalence of asthma, mean seasonal birch/grass symptom score, eye-drop use, or antihistamine or prednisolone intake between the group with and without subsequent SRs to IT. No difference was found in EOS, serum ECP, or EPX, between the group with and without subsequent SRs to IT.

CONCLUSIONS

IT with grass-pollen extract seems to be associated with a higher number and more severe SRs than birch-pollen IT. Neither demographic data nor diagnostic tests of allergy such as specific IgE, HR, SPT, CPT, and NPT could identify the patients with subsequent SRs.