Do skin prick and conjunctival provocation tests predict symptom severity in seasonal allergic rhinoconjunctivitis?

Allergen Testing: A Review of the Indications, Procedures, and Limitations in Ocular Allergy

Allergen-based diagnostics are essential in the management algorithm of allergic diseases. Unlike systemic allergy, where the indications and interpretation of these diagnostic modalities are well established, their utility in ocular allergy is not well-defined. With the rising prevalence of ocular allergies and the need for personalized treatment strategies, there is a growing demand for precision allergen diagnostics. This review describes the commonly used tests with their indications, procedures, and limitations. A review of the literature was carried out on articles on allergen diagnostics in ocular allergy, and after excluding articles that were not relevant, 82 papers were included in the current review. IgE-mediated pathways contribute significantly to seasonal and perennial ocular allergy and partly to vernal keratoconjunctivitis. Most diagnostic techniques aim to detect IgE sensitization. In vivo tests include skin prick (SPT), intradermal, and patch tests. SPT is considered the gold standard and directly evaluates the presence of allergen-specific IgE in the skin. In vitro tests measure total and specific IgE from either tears or sera. Tear IgE measurement is relatively specific for allergic conjunctivitis and can provide insight into the potential allergens responsible for local sensitization. The conjunctival provocation test can help establish true allergy, especially in patients with polysensitization. This review also provides an overview of evidence in literature segregated based on the test employed. This includes 17 studies on only SPT; 42 studies on IgE measured in serum, tears, or both; and 20 studies which have evaluated both SPT and IgE. The pattern of allergen sensitization can guide recommendations for avoidance measures and immunotherapy. Thus, this could create a corticosteroid-sparing therapy avenue in these patients, reducing disease severity and resulting visual morbidity.

Does skin prick test response intensity predict symptom severity and efficacy of subcutaneous immunotherapy in allergic rhinitis?

OBJECTIVES

To investigate the effect of response intensity of allergen skin prick test (SPT) on symptom severity and long-term efficacy of dust mite subcutaneous immunotherapy (SCIT) in allergic rhinitis (AR).

METHODS

AR Patients diagnosed with dust mite allergy and completed 3 years of SCIT were collected and classified into three groups: grade 2 (SPT of + +), grade 3 (SPT of +  + +) and grade 4 (SPT of +  +  + +). Comparisons between groups were performed to examine the associations of SPT categories and symptom severity and the long-term efficacy of SCIT in AR.

RESULTS

181 AR patients were included. There was no significant difference in the baseline TNSS, SMS, RQLQ and VAS, and particularly to symptom severity grading among three SPT grade groups (P > 0.05). The moderate-severe AR was more likely to be smoking and accompany with asthma and had higher prevalence of sensitization to cockroach, mixed grass and tree pollen than mild AR (P < 0.05). Prevalence of sensitization to cockroach, mixed grass, ragweed and animal dander was increased in AR patients with asthma and allergic conjunctivitis (P < 0.05). Furthermore, after 3 years of SCIT, no statistical differences in TNSS, SMS, RQLQ, VAS and long-term efficacy were observed among the three SPT grade groups (P > 0.05). Similarly, long-term outcomes of patients with different SPT grades did not differ among different clinical characteristics and different efficacy determination criteria (P > 0.05).

CONCLUSIONS

The SPT response intensity cannot be used as an objective evaluation index for symptom severity and the long-term efficacy of SCIT in AR patients.

A nerve-goblet cell association promotes allergic conjunctivitis through rapid antigen passage

The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although pollinosis patients manifest symptoms within minutes after pollen exposure, the mechanisms of the rapid transport of the allergens remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by stromal cells, including macrophages and CD11b+ dendritic cells, correlated with surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible, rapid GAP formation and antigen acquisition were suppressed by topical lidocaine or trigeminal nerve ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a therapeutic target for allergic conjunctivitis.

Strong dose response after immunotherapy with PQ grass using conjunctival provocation testing

Background

Pollinex Quattro Grass (PQ Grass) is an effective, well-tolerated, short pre-seasonal subcutaneous immunotherapy to treat seasonal allergic rhinoconjunctivitis (SAR) due to grass pollen. In this Phase II study, 4 cumulative doses of PQ Grass and placebo were evaluated to determine its optimal cumulative dose.

Methods

Patients with grass pollen-induced SAR were randomised to either a cumulative dose of PQ Grass (5100, 14400, 27600 and 35600 SU) or placebo, administered as 6 weekly subcutaneous injections over 31-41 days (EudraCT number 2017-000333-31). Standardized conjunctival provocation tests (CPT) using grass pollen allergen extract were performed at screening, baseline and post-treatment to determine the total symptom score (TSS) assessed approximately 4 weeks after dosing. Three models were pre-defined (Emax, logistic, and linear in log-dose model) to evaluate a dose response relationship.

Results

In total, 95.5% of the 447 randomized patients received all 6 injections. A highly statistically significant (p < 0.0001), monotonic dose response was observed for all three pre-specified models. All treatment groups showed a statistically significant decrease from baseline in TSS compared to placebo, with the largest decrease observed after 27600 SU (p < 0.0001). The full course of 6 injections was completed by 95.5% of patients. Treatment-emergent adverse events were similar across PQ Grass groups, and mostly mild and transient in nature.

Conclusions

PQ Grass demonstrated a strong curvilinear dose response in TSS following CPT without compromising its safety profile.

Conjunctival provocation tests: prediction of seasonal allergy

PURPOSE OF REVIEW

The conjunctival provocation test (CPT) is often used to clearly identify the specific allergen causing the symptoms of allergic rhinoconjunctivitis but also to assess the clinical efficacy of an allergen immunotherapy (AIT). As there is no consensus about its predictive value, the aim of this publication is to evaluate under which conditions the CPT can predict the symptom severity during the allergy season after previous AIT.

RECENT FINDINGS

Three out of four randomized controlled trials (RCTs) showed a correlation between CPT reactivity and symptoms occurring under natural allergen exposure after previous AIT. Furthermore, one RCT found that performing the CPT 4 weeks after initiating AIT can identify early responders who also show a benefit during the season. Another RCT suggested that conducting the CPT prior to starting AIT can be used to identify patients who may benefit more from treatment than others.

SUMMARY

The assessment of the reviewed literature led us to the conclusion that the CPT has a predictive value and can consequently be used to assess the efficacy of an administered AIT if performed according to a standardized challenge protocol with high-quality allergen extracts.

Randomized controlled trials define shape of dose response for Pollinex Quattro Birch allergoid immunotherapy

BACKGROUND

The Birch Allergoid, Tyrosine Adsorbate, Monophosphoryl Lipid A (POLLINEX^® Quattro Plus 1.0 ml Birch 100%) is an effective, well-tolerated short course subcutaneous immunotherapy. We performed 2 phase II studies to determine its optimal cumulative dose.

METHODS

The studies were conducted in Germany, Austria and Poland (EudraCT numbers: 2012-004336-28 PQBirch203 and 2015-000984-15 PQBirch204) using a wide range of cumulative doses. In both studies, subjects were administered 6 therapy injections weekly outside the pollen season. Conjunctival Provocation Tests were performed at screening, baseline and 3-4 weeks after completing treatment, to quantify the reduction in Total Symptom Scores (as the primary endpoint) with each cumulative dose. Multiple Comparison Procedure and Modeling analysis was used to test for the dose response, shape of the curve and estimation of the median effective dose (ED₅₀ ), a measure of potency.

RESULTS

Statistically significant dose responses (P < .01 & .001) were seen, respectively. The highest cumulative dose in PQBirch204 (27 300 standardized units [SU]) approached a plateau. Potency of the PQBirch was demonstrated by an ED₅₀ 2723 SU, just over half the current dose. Prevalence of treatment-emergent adverse events was similar for active doses, most being short-lived and mild. Compliance was over 85% in all groups.

CONCLUSION

Increasing the cumulative dose of PQBirch 5.5-fold from 5100 to 27 300 SU achieved an absolute point difference from placebo of 1.91, a relative difference 32.3% and an increase in efficacy of 50%, without compromising safety. The cumulative dose response was confirmed to be curvilinear in shape.

Early nonreactivity in the conjunctival provocation test predicts beneficial outcome of sublingual immunotherapy

BACKGROUND

Clinical practice needs a common parameter that can provide an early, reliable estimation of the outcome of sublingual immunotherapy (SLIT) in an upcoming pollen season. We investigated whether the conjunctival provocation test (CPT) can predict the beneficial outcome of SLIT in patients with allergic rhinoconjunctivitis after 4 weeks of treatment.

METHODS

We conducted two separate prospective, randomized, double-blind, placebo-controlled, multicenter trials. Adults 18-75 years of age received placebo or SLIT tablets containing tree or grass pollen allergoids and underwent CPTs. Participants receiving SLIT were divided into two groups (reactive, nonreactive) according to their CPT reactions after 4 weeks of treatment. These two groups were compared with regard to clinical outcome parameters (total combined score, rhinoconjunctivitis total symptom score, total rescue medication score, well days) assessed during the pollen season for the 14-day (tree) or 30-day (tree/grass) peaks and for the entire 60-day seasons. Participants' global evaluations of therapy after completing treatment were also compared.

RESULTS

The tree pollen trial randomized 188 participants; 182 participants were evaluable, 76 of whom received SLIT and were suitable for this post hoc analysis. The grass pollen trial included 90 participants; 82 participants were evaluable, 44 of whom underwent SLIT. Comparing SLIT participants who reacted to the CPT after 4 weeks (tree: 77.6%; grass: 79.5%) with those who ceased to show a reaction (tree: 22.4%; grass: 20.5%) (tree: P = 0.0001; grass: P = 0.003), the total combined score for the 14-day (P = 0.017) and 30-day peaks (P = 0.042) as well as the rhinoconjunctivitis total symptom score assessed for the 14-day peak (P = 0.024) were significantly lower in the nonreactive group of the tree pollen trial. In the grass pollen trial, the nonreactive group rated their SLIT treatment significantly better (P = 0.019).

CONCLUSIONS

Using clinically meaningful outcome parameters during the pollen season, both trials independently led to similar results when comparing participants' reactions to the CPT 4 weeks after beginning SLIT. These results suggest that CPT allows an early estimation of allergic rhinoconjunctivitis symptoms before an upcoming season. Thus, the CPT can be used as a valuable parameter to predict the beneficial outcome of ongoing SLIT.

TRIAL REGISTRATION

Both trials registered with the Medical Ethics Committee of the North Rhine Medical Council (EudraCT numbers 2012-004916-79 (grass pollen trial) and 2013-002129-43 (tree pollen trial)) and the German Federal Ministry of Health (Paul-Ehrlich-Institut).

Reliability of a New Symptom Score in a Titrated Quantitative Conjunctival Provocation Test Supported by an Objective Photodocumentation

BACKGROUND

Allergen provocation tests are useful methods for proving the clinical relevance of an allergen-specific sensitization. Among these methods, the conjunctival provocation test (CPT) represents an easy-to-use tool. However, its readout parameters have not yet been internationally standardized or validated. Photodocumentation has been shown as a good option for objectifying a CPT reaction, supporting the local investigator assessment. Based on test-retest reliability of the score and an objective digital photoanalysis of the conjunctival redness, this study aimed to prove the reproducibility of a new CPT scoring system for use in clinical trials (ClinicalTrials.gov identifier: NCT02690740).

METHODS

A titrated quantitative CPT was conducted outside of the pollen season in a final cohort of 23 adult patients with birch or grass pollen-induced allergic rhinoconjunctivitis. Conjunctival symptoms were analyzed using a standardized symptom score. Conjunctival redness was also evaluated by an external observer and correlated with a digital photoanalysis using MATLAB software.

RESULTS

A test-retest correlation of 0.6 (p < 0.01) was found for the symptom score results. Likewise, a correlation of 0.65 (p < 0.01) was observed in the digital photoanalysis. The total symptom score showed a decrease in the mean value of 0.48 score points in the retest.

CONCLUSIONS

This study reveals both a valuable test-retest correlation of the proposed score as well as a good correlation of eye redness with the (objective) photodocumentation. Based on our results, we can recommend the use of this scoring system as a valuable clinical protocol for future clinical trials.

Conjunctival provocation test in diagnosis of peanut allergy in children

BACKGROUND

Peanut allergy frequently causes severe allergic reactions. Diagnosis includes detection of IgE to peanuts in serum or by skin prick tests. While children may have allergic sensitization without having clinical peanut allergy, oral peanut challenge is often required for accurate diagnosis. The conjunctival provocation test is used for diagnosis and evaluation of treatment effect in inhalant allergies, but it has not been evaluated as a tool for diagnosing peanut allergy.

OBJECTIVE

To investigate whether the conjunctival provocation tests may be feasible, accurate and safe in diagnosing clinically relevant peanut allergy in patients with suspected peanut allergy.

METHODS

This cross-sectional case-control study in children with clinical or laboratory suspected peanut allergy included 102 children recruited from the regional paediatric departments and specialist practices during one year from April 2011. A peanut-tolerant control group of 28 children of similar age was recruited locally. A double-blind placebo-controlled conjunctival provocation test with peanut extract was performed in all children, while oral peanut provocation was performed as double-blind placebo-controlled challenge in children with suspected peanut allergy and as an open challenge in the control children.

RESULTS

All 81 children with a positive double-blind placebo-controlled oral food challenge (OFC) also had a positive conjunctival provocation test. None of the children with negative conjunctival provocation test had a positive OFC. The sensitivity and the specificity of the conjunctival provocation test were 0.96 and 0.83, respectively. No children had severe adverse reaction caused by the conjunctival provocation test, whereas 23 children suffered an anaphylactic reaction to the OFC.

CONCLUSION AND CLINICAL RELEVANCE

Conjunctival allergen challenge appears to be feasible, accurate and safe in diagnosing children referred for suspected peanut allergy.

Allergen-Associated Immunomodulators: Modifying Allergy Outcome

The prevalence of allergies is increasing since mid twentieth century; however the underlying causes of this increase are not fully clear. Understanding the mechanism by which a harmless protein becomes an allergen provides us with the basis to prevent and treat these diseases. Although most studies on allergen immunogenicity have traditionally focused on structural properties of the proteins, it is increasingly clear that allergenicity cannot be determined only based on structural features of the allergenic proteins. In fact, allergens do not encounter human facings as isolated molecules but contained in complex mixtures of proteins, carbohydrates and lipids, such as pollen grains or foods. As a result, attention has lately been directed to examine whether allergen-associated molecules exhibit immune-regulatory properties. The present review aims to illustrate some examples of how non-protein molecules accompanying the allergen can modulate allergic responses.

Conjunctival provocation tests: a predictive factor for patients' seasonal allergic rhinoconjunctivitis symptoms

BACKGROUND

No parameters currently exist that can reliably predict the impact of preseasonal immunotherapy on the symptoms occurring during the season.

OBJECTIVE

The purpose of our studies was to prove a correlation between preseasonal conjunctival allergen challenge and coseasonal primary clinical endpoints using the total combined score, ie, a combination of symptoms and medication score, as the primary outcome parameter.

METHODS

Twelve weeks before both the birch and the grass pollen seasons, 2 separate prospective, double-blind, randomized, controlled studies were conducted followed by posttrial observations for each study during the active season. In the studies, patients who reacted to conjunctival allergen challenge were treated with sublingual immunotherapy tablets that contain either birch and/or alder or grass pollen allergoids.

RESULTS

In all, 158 patients were included in the grass and 160 in the tree pollen study; of these, 100 and 109 patients, respectively, took part in the posttrial observations. When comparing patients with and without a positive reaction in the final conjunctival allergen challenge, the results revealed a significant difference in the total combined score (grass: P < .001; birch: P = .025). The same applied to the rescue medication score (P = .005; P = .025). A significant difference regarding the rhinoconjunctivitis symptom score was shown in the grass pollen study (P = .002), and the difference of well days was significant in the tree pollen study (P = .049).

CONCLUSION

When comparing patients based on their reaction to allergen challenge after immunotherapy, each study leads to similarly significant results. Therefore, conjunctival allergen challenge can be used effectively as a parameter to predict allergic rhinoconjunctivitis symptoms during the season in patients treated with preseasonal sublingual immunotherapy tablets. Whether this can be transferred to untreated patients needs to be determined.

Environmental exposure chambers in allergen immunotherapy trials: Current status and clinical validation needs

As required by the European Medicines Agency and the US Food and Drug Administration for pivotal trials involving allergen immunotherapy (AIT) products, clinical efficacy assessment is currently based on double-blind, placebo-controlled field studies with natural allergen exposure during the allergen season. However, this study design is associated with several drawbacks, such as the high variability of allergen exposure in different trial sites or seasons and the presence of confounding environmental factors. On the contrary, environmental exposure chambers (EECs) aim to operate with a stable and reproducible allergen exposure under highly standardized environmental conditions. Technical validation parameters for different EECs worldwide have been published by several groups. However, full clinical validation of EEC study outcomes is required for their classification as an appropriate alternative to natural allergen exposure for AIT product efficacy assessment. Some clinical validation parameters have already been addressed for EEC units. The reliability of provoked symptoms in repeated EEC sessions is high, but the predictive power of EEC settings for the clinical response on natural exposure and the impact of seasonal priming on test results still have to be validated systematically, as does the inter-EEC variability. Thus the authors recommend a continued in-depth validation of EECs to exploit the potential of this technology for future AIT product development.

Recommendations for the standardization of clinical outcomes used in allergen immunotherapy trials for allergic rhinoconjunctivitis: an EAACI Position Paper

BACKGROUND

Allergen immunotherapy (AIT) has been thoroughly documented in randomized controlled trials (RCTs). It is the only immune-modifying and causal treatment available for patients suffering from IgE-mediated diseases such as allergic rhinoconjunctivitis, allergic asthma and insect sting allergy. However, there is a high degree of clinical and methodological heterogeneity among the endpoints in clinical studies on AIT, for both subcutaneous and sublingual immunotherapy (SCIT and SLIT). At present, there are no commonly accepted standards for defining the optimal outcome parameters to be used for both primary and secondary endpoints.

METHODS

As elaborated by a Task Force (TF) of the European Academy of Allergy and Clinical Immunology (EAACI) Immunotherapy Interest Group, this Position Paper evaluates the currently used outcome parameters in different RCTs and also aims to provide recommendations for the optimal endpoints in future AIT trials for allergic rhinoconjunctivitis.

RESULTS

Based on a thorough literature review, the TF members have outlined recommendations for nine domains of clinical outcome measures. As the primary outcome, the TF recommends a homogeneous combined symptom and medication score (CSMS) as a simple and standardized method that balances both symptoms and the need for antiallergic medication in an equally weighted manner. All outcomes, grouped into nine domains, are reviewed.

CONCLUSION

A standardized and globally harmonized method for analysing the clinical efficacy of AIT products in RCTs is required. The EAACI TF highlights the CSMS as the primary endpoint for future RCTs in AIT for allergic rhinoconjunctivitis.

Objectifying the conjunctival provocation test: photography-based rating and digital analysis

BACKGROUND

Patients with allergic rhinoconjunctivitis are susceptible to both nasal and ocular symptoms. The conjunctival provocation test (CPT) is an established diagnostic procedure used in allergic rhinoconjunctivitis, particularly to document a patient's current reactivity to allergens. To date, there are no international guidelines defining the CPT. No approved evaluation method exists for interpreting CPT results. This paper aims to establish the digital analysis of macroimages as an objective, validated and standardized method for interpreting CPT results.

METHODS

In a clinical immunotherapy trial with 155 patients, treatment progress was documented based on the CPT. Local investigators used a symptom score to grade tearing, reddening and the patients' subjective perception of symptoms (mucosal irritation). A central observer rated conjunctival hyperemia via digital photography. Digital image analysis software was utilized to determine conjunctival hyperemia.

RESULTS

Spearman's correlation between the local investigators' and the central observer's ratings was r = 0.729 (p < 0.001); the percentage of total agreement was 48% (based on 739 photos). Digital image analysis (based on 48 photos) had a high percentage of total agreement with the central observer's ratings (69%) but a low percentage of total agreement with the investigators' ratings (38%). The corresponding correlations were r = 0.264 and 0.064, respectively.

CONCLUSION

Photography-based rating by a central observer may represent a valuable supplement to the local investigator's assessment for making an objective evaluation of CPT results. Digital image analysis possesses the potential of being an objective evaluation method compared to the wide-spread subjective evaluation by the investigators.

Determination of sIgE to rPhl p 1 is sufficient to diagnose grass pollen allergy

BACKGROUND

New diagnostic tools such as the basophil activation test (BAT) and component-resolved diagnosis (CRD) are promising for Hymenoptera venom or food allergy. A clear benefit for inhalant allergens has not yet been shown. Our aim was to compare new and established tests for grass pollen allergy.

METHODS

Forty-nine patients with grass pollen allergy and 47 controls were prospectively enrolled in the study. A symptom score was calculated for each patient. Conjunctival provocation tests (CPT), skin prick tests (SPT), BAT, and sIgE determination including CRD were performed. Sensitivity and specificity were compared and results were correlated with the symptom score.

RESULTS

Single determination of sIgE to rPhl p 1 showed the best balance between sensitivity (98%) and specificity (92%). Use of additional components, such as rPhl p 2 and 5, did not increase sensitivity. Generally, sensitivity of tests was high: SPT 100%, ISAC-112 100%, sIgE to timothy grass 98%, BAT 98%, ISAC-103 84%, and CPT 83%. Specificity ranged from 79% (SPT) to 96% (CPT). All test results and calculated values (e.g. ratio sIgE/tIgE) did not correlate with symptom severity. Asymptomatic sensitization to timothy grass in controls was rare in the CAP (11%) and predominantly due to Phl p 1 sensitization.

CONCLUSION

rPhl p 1 was sufficient to diagnose grass pollen allergy, and sIgE patterns were the same in symptomatically and asymptomatically sensitized subjects. The testing of multiple components was of minor importance, and no test correlated with symptom severity.

Allergic rhinitis: an updated overview

Allergic rhinitis is a major medical and socioeconomic problem due to its troublesome local symptoms,negative impact on quality of life, association with reduced productivity and increased absenteeism, its widespread nature, and the rapidly rising medical costs associated with the disease. Its handling depends on improved understanding of genetic, biological, environmental, and lifestyle predisposing factors, and the development of new and effective treatment strategies, both medically and focusing on the way we are living.

Respiratory allergy to fungi in Barcelona, Spain: clinical aspects, diagnosis and specific treatment in a general allergy unit

BACKGROUND

The importance of hypersensitivity to fungal allergens is a relatively unknown and somewhat controversial subject.

METHODS

An open prospective study was carried out in just one centre to determine the clinical and epidemiological characteristics as well as the diagnostic usefulness of skin prick and conjunctiva provocation tests, associated with total and specific IgE determination in two groups of patients, one of which was monosensitised to fungi and the other of which had multiple sensitisations, including fungi.

RESULTS

Rhinitis, exclusive or associated with asthma, was the main consultation cause (88% in monosensitised patients). Severe asthma was rarely found. In the polysensitised group, 64% were simultaneously allergic to moulds and mites. Alternaria alternata was the most common sensitising fungus, although a considerable number of cases were associated with other species such as Cladosporium, Penicillium and/or Aspergillus. The skin prick test gave the highest sensitivity and specificity. In 67% of the cases, the specific IgE was found between classes 3 and 4. The conjunctival provocation test was an innocuous and highly useful method for verifying the diagnosis and determining the degree of clinical sensitisation. A large number of patients exclusively allergic to fungi received specific immunotherapy, and it was generally well tolerated.

CONCLUSIONS

This protocolised study shows the importance of Alternaria and other fungi sensitisations in rhinitis alone or associated with asthma. Combined diagnosis of prick test, specific IgE and conjunctiva provocation test is very useful for deciding specific immunotherapy.

Is there any correlation between the results of skin-prick test and the severity of symptoms in allergic rhinitis?

BACKGROUND

This study was designed to determine whether there is any correlation between results of the skin-prick test and the severity of symptoms in allergic rhinitis.

METHODS

We retrospectively evaluated 150 patients with persistent or intermittent allergic rhinitis confirmed by positive skin tests and scaled from 1 to 4 according to the size of the wheal. The symptoms including sneezing, nasal obstruction, rhinorrhea, and nasal itching were ranked according to their severity (0 for no symptoms, 1 for mild, 2 for moderate, and 3 for severe). We investigated the correlation between the skin tests' positivity and symptoms score, rhinoconjunctivitis quality-of-life questionnaire (RQLQ), and visual analog scale (VAS) scores.

RESULTS

Of the 150 patients, 98 had persistent and 52 had intermittent allergic rhinitis. Some patients had multiple allergen sensitivity. Each skin test group was compared with respect to symptom scores, RQLQ, or VAS scores. There was no statistically significant correlation between the size of the wheal and symptoms score, RQLQ, or VAS scores. There was also no correlation between the type of allergen and symptoms score.

CONCLUSION

The skin-prick test can be applied to support the diagnosis of allergic rhinitis, but one can not predict the severity of illness by stratifying the size of the skin-prick test result.

Basophil activation test compared to skin prick test and fluorescence enzyme immunoassay for aeroallergen-specific Immunoglobulin-E

Background

Skin prick test (SPT) and fluorescence enzyme immunoassay (FEIA) are widely used for the diagnosis of Immunoglobulin-E (IgE)-mediated allergic disease. Basophil activation test (BAT) could obviate disadvantages of SPT and FEIA. However, it is not known whether BAT gives similar results as SPT or FEIA for aeroallergens.

Objectives

In this study, we compared the results of SPT, BAT and FEIA for different aeroallergens.

Methods

We performed BAT, SPT and FEIA in 41 atopic subjects (symptomatic and with positive SPT for at least 1 of 9 common aeroallergens) and 31 non-atopic subjects (asymptomatic and with negative SPT).

Results

Correlations between SPT and BAT, SPT and FEIA, and BAT and FEIA results were statistically significant but imperfect. Using SPT as the "gold standard", BAT and FEIA were similar in sensitivity. However, BAT had lower specificity than FEIA. False positive (BAT^posSPT^neg) results were frequent in those atopic subjects who were allergic by SPT to a different allergen and rare in non-atopic subjects. The false positivity in atopic subjects was due in part to high levels of serum Total-IgE (T-IgE) levels in atopic individuals that lead to basophil activation upon staining with fluorochrome-labeled anti-IgE.

Conclusion

As an alternative to SPT in persons allergic to aeroallergens, BAT in its present form is useful for distinguishing atopic from non-atopic persons. However, BAT in its present form is less specific than FEIA when determining the allergen which a patient is allergic to. This is due to IgE staining-induced activation of atopic person's basophils and/or nonspecific hyperreactivity of atopic person's basophils.

Increased IL-5 and IL-13 cytokine level in ex vivo stimulated whole blood cells from grass pollen allergic donors correlate with seasonal exposure

There is a need for simple and physiological assays to characterize the immune status of allergic individuals. Whole blood samples from 15 adult subjects (10 with positive clinical history to grass pollen and 5 with negative clinical history) were obtained before the start (April 2010) and during the middle of the grass pollen season (June 2010). The investigators were blinded to the allergic status of the subjects. A skin prick test (SPT) to grass pollen was carried out at the end of the study. Cytokines (IL-5, IL-13, IL-10 and IFNγ) and activation of T-lymphocytes were determined after ex vivo culture of whole blood cells. IL-5, IL-10 and IL-13 cytokines were significantly elevated in allergic individuals during the middle of the season (p≤0.02) compared to the start. This assay can be a valuable tool in clinical trials especially in pediatric population where limited quantities of blood are available to study immune responses.

Climate change, aeroallergens, and pediatric allergic disease

The degree to which aeroallergens are contributing to the global increase in pediatric allergic disease is incompletely understood. We review the evidence that links climate change to changes in aeroallergens such as pollen and outdoor mold concentrations and, subsequently, aeroallergen association with pediatric allergic disease. We specifically explore the evidence on both the exacerbation and the development of allergic disease in children related to outdoor pollen and mold concentrations. Pediatric allergic diseases include atopic dermatitis or eczema, allergic rhinitis or hay fever, and some types of asthma in children, typically defined as < 18 years of age. We discuss how the timing of aeroallergen exposure both in utero and in childhood could be associated with allergies. We conclude that the magnitude and type of health impacts due to climate change will depend on improved understanding of the relationship between climatic variables, multiple allergen factors, and allergic disease. Improved public-health strategies such as adequate humidity control, optimum air filtration and ventilation, and improved anticipatory public-health messaging will be critical to adaptation.

Allergic conjunctivitis and nasal allergy

Allergic conjunctivitis (AC) can be divided into the primary form (caused by an allergic reaction occurring primarily in the conjunctivae) and the secondary form (induced by allergic reaction originating primarily in the nasal mucosa, where the released mediators can reach conjunctiva through the lacrimal system, the blood, the lymphatic network, or the neurogenic network). Patients with primary AC develop an immediate, late, or delayed conjunctival response (CR) during conjunctival provocation tests. Patients with secondary AC develop an immediate, late, or delayed type of secondary CR, induced by the nasal allergic reaction, due to the nasal allergen challenge. Various hypersensitivity mechanisms may be involved in the particular CR types. The secondarily induced AC and CRs can only be confirmed by nasal provocations tests, performed by rhinomanometry combined with recording of conjunctival signs. The existence of the primary and secondarily induced AC has an impact on treatment of this disorder.

Seasonal and perennial allergic conjunctivitis: the possible role of nasal allergy

BACKGROUND

There is a link between conjunctiva and nose. Nasal allergy is suspected to be involved in some cases of conjunctivitis. This work aims to investigate the possible role of nasal allergy in seasonal (SAC) and perennial (PAC) allergic conjunctivitis and the value of nasal challenges with allergens (nasal provocation tests [NPTs]) for the diagnostic procedures of the conjunctivitis.

METHODS

In 61 adults suffering from SAC or PAC with a positive history and skin tests, but responding insufficiently to the local treatment, 122 NPTs and 61 control nasal challenges with phosphate-buffered saline (PBS) were performed using rhinomanometry combined with recording of ocular response. In 16 control subjects suffering only from allergic rhinitis without a history of conjunctivitis, 16 positive NPTs were repeated and supplemented with registration of ocular features.

RESULTS

Of the 61 patients, 55 developed 103 positive nasal responses of various types (P < 0.01), 82 of which were accompanied by significant conjunctival response (P < 0.01) without any corneal involvement. No significant ocular responses were recorded during 61 control PBS challenges (P > 0.05) as well as during 16 challenges in control subjects (P > 0.1).

CONCLUSIONS

These results illustrate a possible involvement of nasal allergy in some patients with allergic conjunctivitis (SAC and PAC) and the value of the nasal challenges with allergen combined with registration of the ocular features in the diagnostic approach to these disorders.

Skin tests, T cell responses and self-reported symptoms in children with allergic rhinitis and asthma due to house dust mite allergy

BACKGROUND

In allergic responses, a distinction is made between an early-phase response, several minutes after allergen exposure, and a late-phase response after several hours. During the late phase, eosinophils and T cells infiltrate the mucosa and play an important role in inflammation.

OBJECTIVE

The aim of this study was to examine the relationship between allergen-induced late-phase skin responses and in vitro T cell reactivity. In addition, the relationship between allergen-induced skin or T cell responses and the severity of self-reported symptoms was studied in children with house dust mite allergy.

METHODS

A total of 59 house dust mite-allergic children (6-18 years) were recruited in general practice. These children or their parents rated their nasal and asthma symptoms on diary cards during 1 month. Allergen skin tests were performed and read after 15 min (early phase) and 6 h (late phase). Allergen-specific T cell proliferation was determined, and Th2 cytokine (IL-5 and IL-13) secretion was analysed.

RESULTS

The size of the late-phase skin response correlated with in vitro T cell proliferation (r(s)=0.38, P=0.003) but not with Th2 cytokine secretion (r(s)=0.16, P=0.2 for both IL-5 and IL-13). Moreover, the late-phase skin response and T cell proliferation correlated with asthma symptoms (r(s)=0.30, P=0.02 for skin response and r(s)=0.28, P=0.03 for T cell proliferation) but not with nasal symptoms (r(s)=0.19, P=0.15 for skin response and r(s)=0.09, P=0.52 for T cell proliferation). The early-phase skin response correlated with the nasal symptom score (r(s)=0.34, P=0.01) but not with asthma symptom scores (r(s)<0.005, P=0.97).

CONCLUSION

In this study, the late-phase skin test response correlated with in vitro T cell proliferation but not with Th2 cytokine secretion. We found weak or no correlations between late-phase skin responses and symptoms of asthma or rhinitis in children with house dust mite allergy. This suggests that late-phase skin responses reflect certain T cell properties but are of limited value for the evaluation of airway symptoms in atopic children.

Evidence-based recommendations regarding the differential diagnosis and assessment of nasal congestion: using the new GRADE system

Nasal congestion is an important symptom in nasal pathology and can be defined as an objective restriction of nasal cavity airflow because of mucosal pathology and/or increased mucus secretion (excluding anatomical variants). Using the new Grading Recommendations Assessment, Development and Evaluation system, evidence-based recommendations are made that will encompass different clinical questions regarding diagnostic modalities of nasal congestion: (i) their usefulness in assessment of presence and severity of congestion; (ii) their usefulness in assessment of etiological pathology responsible for congestion; and (iii) their usefulness in follow up and treatment effectiveness evaluation of nasal congestion.

Potential bias in ophthalmic pharmaceutical clinical trials

To make clinicians aware of potential sources of error in ophthalmic pharmaceutical clinical trials that can lead to erroneous interpretation of results, a critical review of the study design of various pharmaceutical ophthalmic clinical trials was completed. Discrepancies as a result of study shortcomings may explain observed differences between reported ophthalmic trial data and observed clinical results.