Usefulness of Allerkin House Dust Mite Extract for Nasal Provocation Testing

Selection of allergen extract for immunotherapy in polysensitized allergic rhinitis patients

Aim: To evaluate the criteria used by allergists in selecting an immunotherapy extract (allergen immunotherapy [AIT]-extract) in rhinitis patients with polysensitization. Methods: First, a cross-sectional study was carried out by evaluating different factors that influence the medical choice of AIT-extract. Second, a literature review was performed by evaluating the diagnostic performance of atopy tests. Results: A total of 419 patients were included (84 children, 149 adolescents and 186 adults). Anamnesis, atopy tests and exposure to pets were the main factors for choosing the AIT extract. The sensitivity and specificity of atopy tests were high for Dermatophagoides spp., (>80%), moderate for pets (60%) and indeterminate for Blomia tropicalis. Conclusion: NCTs could be necessary for AIT-extract selection in polysensitized allergic rhinitis patients.

Utility of silver birch and house dust mite extracts derived from licensed sublingual tablets for nasal allergen challenge

BACKGROUND

Nasal allergen challenge (NAC) is used to investigate the effects of allergen exposure and assess treatment efficacy in allergic rhinitis (AR). This study aims to establish dose-responses to NAC using licensed silver birch (SB) pollen and house dust mite (HDM) sublingual tablets as sources of the allergen extracts in participants with AR.

METHODS

Sixteen volunteers with HDM-induced perennial AR and 15 volunteers with SB pollen-induced seasonal rhinitis underwent a graded up-dosing NAC with extracts derived from HDM allergen (Acarizax®) and SB (Itulazax®) tablets, respectively. Total nasal symptom score (TNSS, range 0-12) and peak nasal inspiratory flow (PNIF) were recorded before, at 10 min and at the end of the NAC. The dose of each allergen that provoked a TNSS of at least 7 ("provoking dose 7") in most allergic participants was identified. NACs using the "provoking dose 7" were performed on 5 non-allergic individuals to test for irritant effects. The "provoking dose 7" of HDM extract was used in a subgroup of two SB allergic, non-HDM allergic, volunteers, and vice versa for SB extract, to test for allergen specificity of the responses.

RESULTS

Most patients experienced a TNSS of at least 7/12 at a median concentration of 1500 AU/mL for both SB pollen and HDM. The average decline in PNIF at this dose was 63.15% for SB and 63.99% for HDM. NACs using the 1500 AU/mL concentrations were performed on 5 non-allergic individuals with no symptomatic or PNIF response. 1500 AU/mL of HDM extract produced no symptoms in SB allergics nor 1500 AU/mL SB extract in HDM allergics.

CONCLUSION

For both SB and HDM extracts, the optimal allergen dose for NAC to cause a moderate-severity response ("provoking dose 7/12") was 1500 AU/mL. Licensed sublingual allergen tablets provide a readily available and inexpensive source of SB and HDM extracts for use in future interventional studies in AR.

Correlation of Multiple Allergen Simultaneous Test with Nasal Provocation Test of House Dust Mite

Objectives: Compared with the skin prick test, relationship between the multiple allergen simultaneous test (MAST) and nasal provocation test (NPT) has rarely been evaluated. We evaluated the relationship between the results of the MAST and NPT against house dust mites in the Korean population. Methods: Medical records of patients who underwent both MAST and NPT were reviewed. Positive MAST was diagnosed when the levels of immunoglobulin E (IgE) specific for Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus (DP) were ≥2 positivity or ≥0.70 IU/ml. During the NPT, changes in subjective symptoms, including nasal obstruction, rhinorrhea, sneezing, itching, ocular discomfort, and peak nasal inspiratory flow (PNIF), were measured. The correlation between NPT and MAST results was statistically analyzed. Results: A total of 96 participants were enrolled in this study: 26 were assigned to the MAST-positive group, and 70 were assigned to the MAST-negative group. Changes in subjective symptoms before and after the nasal allergen challenge were significantly associated with the MAST results. Changes in PNIF before and after the nasal allergen challenge were also significantly associated with the MAST results. We found that a cutoff value of "a subjective total nasal symptom change" of more than 17.5 had a sensitivity of 68.6% and a specificity of 69.2%, while a cutoff value of "a PNIF change" of more than 6.51 had a sensitivity of 67.1% and a specificity of 69.2%. Conclusion: NPT was significantly associated with MAST, and further studies regarding the relationship between NPT using various allergen conditions and MAST are warranted.

Appropriate Antigen Concentrations and Timing of a Nasal Provocation Test

PURPOSE

We aimed to determine appropriate antigen concentrations and the right time to evaluate intranasal changes when performing a nasal provocation test (NPT). Also, we sought to analyze the diagnostic usefulness of individual nasal symptom and peak nasal inspiratory flow (PNIF).

MATERIALS AND METHODS

We divided 46 patients into allergic rhinitis (AR) group (n=19) and a non-allergic rhinitis (NAR) group (n=27). We performed intranasal challenge with 100 AU/mL of Dermatophagoides pteronyssinus (DP) and measured changes in nasal symptoms [scored using the visual analogue scale (VAS)] and PNIF%. If the patient showed significant changes, VAS and PNIF were assessed again after another 15 minutes. In patients without significant changes, we administered 1000 AU/mL and measured changes in nasal symptoms and PNIF% after 15 and 30 minutes.

RESULTS

Fifteen minutes after the 100 AU/mL challenge, the AR group showed more significant VAS changes in all nasal symptoms, total nasal symptom score (TNSS), and PNIF% change than the NAR group. Among the AR group, patients who did not respond to 100 AU/mL exhibited less significant differences relative to the NAR group, even after 1000 AU/mL challenge. Receiver operating characteristic curve analysis for VAS changes 15 minutes after 100 AU/mL challenge revealed that all nasal symptoms had area under the curve (AUC) values of ≥0.84 (p<0.001). TNSS change had an AUC value of 0.929 (p<0.001), while PNIF% change had an AUC value of 0.834.

CONCLUSION

We could determine the optimal concentration (100 AU/mL), timing (15 minutes after challenge), and parameters (changes in TNSS and PNIF%) when performing NPT.

Korean Modification of Nasal Provocation Test with House Dust Mites Antigen following EAACI Guidelines

Objectives

We evaluated the usefulness of the standardized nasal provocation test (NPT) protocol recently published by the European Academy of Allergy and Clinical Immunology (EAACI) and compared the utility of several parameters for diagnosing allergic rhinitis (AR) caused by house dust mites (HDM). Subjective parameters were nasal and ocular symptoms measured using a visual analog scale (VAS), and objective parameters were peak nasal inspiratory flow (PNIF), minimal cross-sectional area (MCA), and total nasal volume (TNV).

Methods

Before and after spraying Dermatophagoides pteronyssinus (DP) allergen (1,000 AU/mL, 100 μL) into both nostrils of 13 patients with AR (AR group) and 22 patients with non-AR (NAR group), we used VAS scores to measure nasal symptoms (nasal obstruction, rhinorrhea, sneezing, and itching) and ocular symptoms and assessed PNIF, MCA, and TNV.

Results

The AR group had significantly worse symptoms than the NAR group 15 minutes after DP challenge (P<0.001). After 30 minutes, nasal obstruction and rhinorrhea remained worse in the AR group (P<0.001); a similar but less marked difference was seen for sneezing (P=0.012) and itching (P=0.039). Ocular symptoms, PNIF, MCA, and TNV differed between groups after both 15 and 30 minutes (P<0.05). The area under the receiver operating characteristic curve was higher for nasal obstruction (0.977), rhinorrhea (0.906), and TNV (0.979) than for sneezing (0.755), itching (0.673), and MCA (0.836).

Conclusion

NPT performed according to the EAACI guidelines could help diagnose AR caused by HDM. TNV and VAS changes in nasal obstruction and rhinorrhea had higher diagnostic accuracy than other parameters.