Nasal airway changes assessed by acoustic rhinometry and mediator release during immediate and late reactions to allergen challenge

A Model of Allergic Nasal Congestion in Dogs Sensitized to Ragweed

Background

Acoustic rhinometry is a noninvasive method that uses sound waves to measure dimensions of the nasal cavity.

Methods

In this study, nasal patency was measured by acoustic rhinometry in allergic Beagle dogs sensitized to ragweed allergen. Ragweed (0.03–0.3%) or vehicle were administered intranasally in isoflurane-anesthetized dogs.

Results

The instillation of ragweed caused a dose-related decrease in nasal cavity volume and minimal cross-sectional area (Amin) without adverse systemic effects. Nasal cavity volume and Amin decreased within 30 minutes after instillation of the highest ragweed dose by 35.1 ± 6.0% and 66.4 ± 13.8%, respectively, and persisted for at least 90 minutes. Oral administration of α-adrenergic agonist, d-pseudoephedrine (3 mg/kg), or histamine H1 antagonist chlorpheniramine (10 mg/kg) blocked the ragweed-induced nasal congestion.

Conclusion

These results suggest that the canine model may be used to study upper-airway diseases such as allergic rhinitis and to evaluate the pharmacologic activity of nasal decongestants.

Does rapid maxillary expansion affect nasopharyngeal airway? A prospective Cone Beam Computerised Tomography (CBCT) based study

BACKGROUND AND PURPOSE

There is limited literature discussing the three dimnesional (3D) impact of rapid maxillary expansion (RME) on upper airway. The purpose of this prospective Cone Beam Computerised Tomography (CBCT) based study is to assess the immediate 3D effects and to correlate the volumteric changes in the upper naspharyngeal airway spaces secondary to RME.

MATERIALS AND METHODS

Seventeen participants (8 male, 9 female, with a mean age of 12.6 ± 1.8 years), who required RME for the management of narrow maxillary arch, were recruited for this study. The prescribed expansion regimen was quarter turn (0.25 mm), twice a day until over-expansion was achieved. The mean period for the active phase was 14 days with a range of 12-21 days. Pretreatment (T1) and immediate post-expansion (T2) CBCT images were obtained and then processed using ITK snap and OnDemand3D softwar packages. Paired t-test and Interclass Correlation Coefficient (ICC) were used to assess the reproducibility of the measurements, student t-test (P < 0.05) and Pearson Correlation Coefficient (PCC) were applied to evaluate the volumetric changes in the nasopharyngeal airway spaces, linear dentolaveolar changes and correlate these changes.

MAIN FINDINGS

Though, the data of one patient was excluded from the study, owing to major differences (>5 degrees) in the head and neck posture between T1 and T2 CBCT scans, the study' findings shows that bonded RME is an effective dentoalveolar expander in growing patients (P= 0.01) with an average expansion of 3.7 mm and 2.8 mm in males and females respectively. Likewise, the upper nasopharynx (UNP) expanded significantly (15.2% in males and 12% in females). In comparison, the upper retropalatal space (URP) was significantly reduced, by almost one sixth of its original volume, more in males than females, 11.2% and 2.8% respectively. A strong direct correlation between the maxillary sinus volumetric changes, and between appliance expansion and dentoalveolar expansion were evident (PCC = 0.86, 0.75, respectively). There was also a moderate correlation between changes in the UNP and URP spaces.

CONCLUSIONS

RME was found to be an effective dentoalveolar expander and significantly augment the UNP and minimize the URP space. A similar comparative clinical study with long-term follow-up would be beneficial in accurately deteremining the clinical impact of RME on the airway and breathing as well as the stability of these effects.

Olfaction in allergic rhinitis: A systematic review

Olfactory dysfunction is a key symptom in patients with allergic rhinitis (AR). Despite the implications for quality of life, relatively few articles have tested olfactory function in their investigations. The current systematic review aimed to investigate the following 2 questions: (1) What does AR do to human olfaction? (2) How effective is the treatment of AR in restoring the sense of smell? A comprehensive literature search was performed, and human studies of any design were included. A total of 420 articles were identified, and 36 articles were considered relevant. Data indicate that the frequency of olfactory dysfunction increases with the duration of the disorder, and most studies report a frequency in the range of 20% to 40%. Although olfactory dysfunction does not appear to be very severe in patients with AR, its presence seems to increase with the severity of the disease. There is very limited evidence that antihistamines improve olfactory function. In addition, there is limited evidence that topical steroids improve the sense of smell, especially in patients with seasonal AR. This is also the case for specific immunotherapy. However, many questions remain unanswered because randomized controlled trials are infrequent and only a few studies rely on quantitative measurement of olfactory function.

Comparison of two oral probiotic preparations in a randomized crossover trial highlights a potentially beneficial effect of Lactobacillus paracasei NCC2461 in patients with allergic rhinitis

Background

There is promising but conflicting evidence to recommend the addition of probiotics to foods for prevention and treatment of allergy. Based on previous studies with fermented milk containing Lactobacillus paracasei NCC2461, we aimed to compare the effect of a powder form of the latter probiotic with the effect of a blend of Lactobacillus acidophilus ATCC SD5221 and Bifidobacterium lactis ATCC SD5219 in patients with allergic rhinitis.

Methods

A double-blind, randomized, cross-over study, involving 31 adults with allergic rhinitis to grass pollen, was performed outside the grass pollen season (registration number: NCT01233154). Subjects received each product for 4-weeks in two phases separated by a wash-out period of 6 to 8 weeks. A nasal provocation test was performed before and after each 4-week product intake period, and outcome parameters (objective and subjective clinical symptoms; immune parameters) were measured during and/or 24 hours after the test.

Results

Out of the 31 subject enrolled, 28 completed the study. While no effect was observed on nasal congestion (primary outcome), treatment with NCC2461 significantly decreased nasal pruritus (determined by VAS), and leukocytes in nasal fluid samples, enhanced IL-5, IL-13 and IL-10 production by peripheral blood mononuclear cells in an allergen specific manner and tended to decrease IL-5 secretion in nasal fluid, in contrast to treatment with the blend of L. acidophilus and B. lactis.

Conclusions

Despite short-term consumption, NCC2461 was able to reduce subjective nasal pruritus while not affecting nasal congestion in adults suffering from grass pollen allergic rhinitis. The associated decrease in nasal fluid leukocytes and IL-5 secretion, and the enhanced IL-10 secretion in an allergen specific manner may partly explain the decrease in nasal pruritus. However, somewhat unexpected systemic immune changes were also noted. These data support the study of NCC2461 consumption in a seasonal clinical trial to further demonstrate its potentially beneficial effect.

Olfactory dysfunction in seasonal and perennial allergic rhinitis

CONCLUSIONS

The limitation in olfactory function in patients with seasonal allergic rhinitis (AR) can be ascribed to an increase in eosinophilic and mast cell activity in the olfactory cleft. Therefore, the decrease in olfactory functions seems to be predominantly caused by the inflammation of the epithelium and not by the obstruction of the nose caused by the inflammation.

OBJECTIVE

Olfactory dysfunction is frequently seen in patients with AR; however, little is known about the underlying pathophysiological mechanisms. Therefore, the aim of the present study was to examine the olfactory function in patients with seasonal or perennial AR, and to correlate the results with data obtained by analysis of nasal secretion and obstruction.

METHODS

Olfactory function was tested using the Sniffin´Sticks test in patients with seasonal or perennial AR and in a control group. Nasal secretion analysis included eosinophilic cationic protein (ECP) and tryptase testing. Nasal obstruction was evaluated by rhinomanometry.

RESULTS

Patients with AR (seasonal and perennial) showed impaired olfactory functions in comparison with the control group. Nasal secretion analysis showed increased values of ECP and tryptase in the seasonal group in comparison with controls. Rhinomanometry showed no differences in nasal flow between the three groups.

Effect of Lactobacillus paracasei ST11 on a nasal provocation test with grass pollen in allergic rhinitis

BACKGROUND

Probiotics have been associated with prevention and improvement of symptoms in atopic diseases such as atopic dermatitis. However, few studies exist that document their efficacy for upper airways allergies such as allergic rhinitis.

OBJECTIVE

To investigate the effect of short-term oral administration of Lactobacillus paracasei ST11 on a nasal provocation test (NPT) with grass pollen.

METHODS

Thirty-one adult volunteers with allergic rhinitis were enrolled in a randomized, double-blind, placebo-controlled study, based on two 4-week cross-over periods of product consumption (ST11-fermented milk vs. placebo), separated by a wash-out period of 6-8 weeks. Objective and subjective clinical parameters of NPT as well as systemic and nasal immunological parameters were compared between the two treatment periods (registration number: NCT 011 50 253).

RESULTS

Subjects that received ST11-fermented milk had lower nasal congestion than subjects under placebo (visual analogical scale; P<0.05). Nasal pruritus followed the same trend. However, no significant change in combined nasal reaction threshold was observed between the two periods. IL-5 secretion by peripheral blood mononuclear cells and serum allergen-specific IgG4 were significantly lower in ST11-fermented milk group compared to placebo group. IL-8 and IL-10 secretion followed the same trend.

CONCLUSION AND CLINICAL RELEVANCE

Short-term treatment with ST11-fermented milk before NPT significantly improved a clinical marker of NPT (subjective nasal congestion) and down-regulated systemic immune markers (IL-5 from peripheral blood mononuclear cells and serum IgG4). These data strongly suggest that probiotics may down modulate key parameters of allergic rhinitis and warrant future evaluation in seasonal trials.

Levocetirizine better protects than desloratadine in a nasal provocation with allergen

BACKGROUND

Direct comparisons of antihistamines are rare but very much needed. Newly available antihistamine preparations, levocetirizine, the R-enantiomer of racemate cetirizine, and desloratadine, an active metabolite of loratadine, have been recently released for allergic rhinitis.

OBJECTIVE

We sought to compare levocetirizine and desloratadine in a nasal provocation test (NPT) with grass pollen.

METHODS

Twenty-four volunteers with grass pollen allergy and a history of rhinitis were enrolled in a double-blind, placebo-controlled, crossover study. Three NPTs were performed in a dose-escalating manner during the out-of-season period 4 hours after a single dose of levocetirizine (5 mg), desloratadine (5 mg), or placebo.

RESULTS

CONCLUSIONS

This study demonstrates a better overall protection of a single dose of levocetirizine compared with desloratadine in an NPT with grass pollen allergen. In contrast to late-phase inflammatory markers, which were unaffected, extravascular leakage of the early-phase marker albumin was significantly limited by levocetirizine.

Laser surgery of the inferior turbinate for allergic rhinitis with seasonal exacerbation: an acoustic rhinometry study

Laser surgery has been used to successfully treat patients with perennial allergic rhinitis. We examined whether the numbers and types of sensitized allergens influence the effects of surgery. Two different groups (those allergic to house dust mites only, and those allergic to house dust mites and Japanese cedar pollen) prospectively underwent the same course of laser turbinectomy during the pollen dispersion season. The symptom scores for nasal obstruction significantly decreased in both groups, but the improvement of sneezing and rhinorrhea was less pronounced in the pollen group. We used acoustic rhinometry to measure postoperative changes in the nasal dimensions. Four months after treatment, the minimum cross-sectional area and nasal cavity volume had increased, respectively, by 61.7% and 30.7% in the house dust group, and by 30.7% and 16.2% in the pollen group. We conclude that laser surgery can be successfully applied to patients whose allergies show seasonal exacerbation by airborne pollen.

Evaluation of acoustic rhinometry in a nasal provocation test with allergen

BACKGROUND

The objective was to validate acoustic rhinometry (AR) in a nasal challenge with allergen.

METHODS

Nasal response to allergen provocation was based on clinical and symptom scores, cross-sectional changes of the nasal mucosa as measured by AR with the Rhinoklack system, and peak nasal inspiratory flow (PNIF), in atopic and nonatopic volunteers.

RESULTS

After allergen challenge, mean variation in minimal cross-sectional area (deltaMCA), as measured by AR, or in peak nasal inspiratory flow (deltaPNIF) in nonatopic volunteers, was -0.4+/-14.3% and 5.2+/-15.7%, respectively, compared to baseline. This allowed the determination of a reaction threshold of -29% for deltaMCA and of -26% for deltaPNIF. All but one of the 30 atopic patients reached the AR reaction threshold, whereas all patients reached the PNIF reaction threshold. AR and PNIF closely correlated with clinical and symptom scores for nasal congestion, since there was no significant difference at reaction threshold between both methods.

CONCLUSIONS

In an allergen provocation test, AR appears to be as specific and sensitive as peak nasal inspiratory flow, with the advantage of being independent of the patient's active cooperation. Discrepancies between both methods emphasize the role of nasal cavity anatomy in measuring nasal congestion by AR.

Comparison of the effects of terfenadine with fexofenadine on nasal provocation tests with allergen

BACKGROUND

Fexofenadine, the hydrochloride salt of terfenadine active metabolite, is a nonsedative, noncardiotoxic antihistamine derivative for the treatment of allergic rhinitis.

OBJECTIVE

We sought to compare the effects of terfenadine and fexofenadine on nasal provocation tests with allergen.

METHODS

A preliminary provocation test (screening phase) was performed in 25 patients with a history of seasonal allergic rhinitis to grass pollen to determine the combined nasal reaction threshold, which was defined as 2 of the 3 following criteria: (1) at least a 40% decrease in peak nasal inspiratory flow and/or a 30% decrease in minimal cross-sectional area as measured by acoustic rhinometry, nasal secretions of 0.5 g, and 5 to 10 sneezes per minute. Patients were then included into a double-blind, randomized, 2-way crossover study to receive terfenadine or fexofenadine 120 mg 2 hours before provocation. Rhinorrhea, sneezing, peak nasal flow, and minimal nasal cross-sectional area, as well as symptom scores for nasal congestion and itchiness, were recorded at each allergen concentration up to the reaction threshold. The whole study was performed out of allergy season.

RESULTS

Fexofenadine was as potent as terfenadine in limiting pruritus and nasal congestion. Rhinorrhea and sneezing were better controlled by fexofenadine than by terfenadine. Overall, the allergen concentration necessary to reach the combined reaction threshold was increased after treatment with both drugs. Comparison between screening and each treatment phase indicated that the shift in allergen concentration to reach the reaction threshold was significantly greater after fexofenadine than after terfenadine (P =. 033).

CONCLUSION

After oral administration, fexofenadine provided better protection than terfenadine against the immediate allergic reaction.

The value of acoustic rhinometry in assessing nasal responses to cat exposure

BACKGROUND

Acoustic rhinometry (AR) uses sonar principles to map the anatomy of the nasal cavity and has been used in other studies to assess acute airway responses to allergen exposure.

OBJECTIVE

The purpose of this study was to evaluate the utility of AR in assessing acute airway responses to cat allergen exposure by using a well-characterized cat exposure model.

METHODS

Thirty subjects with a history of cat-induced rhinitis and a positive skin prick test response to cat allergen underwent an environmental cat challenge. Of these 30 subjects, 10 also had repeat challenges at lower levels of antigen to determine whether there was a dose response. Five subjects with negative skin test responses to cat were recruited as control subjects. During the 1-hour cat exposure, upper and lower respiratory symptoms were scored every 5 minutes, and spirometry and AR were obtained every 15 minutes.

RESULTS

Although 29 of 30 subjects had changes in AR measurements, no correlations were detected between upper respiratory symptom scores and any of the changes observed in AR. In comparing the baseline challenges with lower antigen level challenges, upper respiratory symptom scores differed significantly (P = .002), whereas AR responses were nearly identical. Subjects without cat allergy did exhibit less response by AR (P = .05 to .13), but the greatest differences remained in the upper respiratory symptoms scores (P < .0001).

CONCLUSION

We conclude that although AR does provide an objective measure of nasal response to allergen exposure, it has significant limitations. These are evidenced by the lack of correlation with symptoms, the inability to measure a dose response, and the changes noted even among the control subjects.