THE FRACTION OF EXHALED NITRIC OXIDE (FENO) AND FORCED OSCILLATION TECHNIQUE (FOT) CAN PREDICT BRONCHIAL HYPERRESPONSIVENESS AGAINST ACETYLCHOLINE IN TREATED ASTHMATICS

BACKGROUND

The bronchial hyperresponsiveness (BHR) test is useful to diagnose or evaluate effect of therapy in asthmatics, but invasive. On the other hands, the fraction of exhaled nitric oxide (FENO) is a useful noninvasive marker of eosinophilic airway inflammation in asthmatics. And also, the forced oscillation technique (FOT) is a noninvasive method that is used to measure respiratory mechanics, including respiratory resistance and reactance at multiple frequencies.

AIM

To evaluate the complementary roles of FENO and FOT to predict bronchial hyperresponsiveness in adult stable asthmatic patients taking inhaled corticosteroids.

METHODS

From our outpatient clinic, we recruited 115 stable asthmatics that were being treated with inhaled corticosteroids at the time of the study. For each subject, we measured FENO by using an offline methods (CEIS' method); and we measured resistance at 5Hz (R5), resistance at 20Hz (R20), R5-R20, reactance at 5Hz (X5), frequency of resonance (Fres), and low-frequency reactance area (ALX), by using a MostGraph FOT machine. We also used spirometry to test BHR to acetylcholine (PC_20Ach).

RESULTS

LogPC_20Ach was significantly correlated with FENO, R5, R20, R5-R20 and %FEV₁. The ROC curve decided that the cutoff point of FENO was 37.8ppb (AUC=0.647, sensitivity 83.3%, specificity 55.6%, p=0.007) and that of R5 was 3.03cmH₂O/L/S (AUC=0.684, sensitivity 72.2%, specificity 52.8%, p=0.001) and that of R20 was 2.77cmH₂O/L/S (AUC=0.684, sensitivity 74.5%, specificity 59.4%, p=0.001). When R5 was >3.03 and FENO was >37.8ppb, 25 of 38 subjects (65.7%) had bronchial hyperresponsiveness. If R5 was <3.03 and FENO was <37.8 ppb, only 5 of 29 (17.2%) subjects had. When R20 was >2.77 and FENO was >37.8ppb, 29 of 43 subjects (67.4%) had bronchial hyperresponsiveness. If R20 was <3.03 and FENO was <37.8ppb, only 2 of 18 (11.1%) subjects had.

CONCLUSION

Combining R5 or R20 and FENO can predict the level of bronchial hyperresponsiveness in adult stable asthmatics.

Molecular-based allergy diagnosis of allergic bronchopulmonary aspergillosis in Aspergillus fumigatus-sensitized Japanese patients

BACKGROUND

Distinguishing between patients with allergic bronchopulmonary aspergillosis (ABPA) and Aspergillus fumigatus (Af)-sensitized asthmatic patients without ABPA is sometimes difficult owing to the IgE-cross-reactivity between Af and other fungal allergens.

OBJECTIVE

To establish the usefulness of molecular-based allergy diagnostics using allergen components from Af in distinguishing ABPA from Af-sensitized asthma without ABPA.

METHODS

Sera from Japanese patients with ABPA (n = 53) and Af-sensitized asthma without ABPA (n = 253) were studied. The levels of IgE and IgG antibodies to allergen components from Af and IgE antibodies to different fugal allergen extracts were measured by ImmunoCAP. Comorbid atopic dermatitis (AD) was taken into consideration in the sensitization profile analysis.

RESULTS

Patients with ABPA possessed significantly higher levels of IgE antibodies to Asp f 1, and Asp f 2 than asthmatic patients without ABPA. The areas under the receiver operating characteristic curves for the levels of IgE to Asp f 1 and Asp f 2 as diagnostic markers of ABPA were 0.75 and 0.78, respectively. The presence of IgE positivity to Asp f 1 and/or Asp f 2 resulted in increased sensitivity while losing little specificity. Comorbid AD was associated with higher levels of IgE to Asp f 6 (manganese superoxide dismutase from Af, a ubiquitous pan-allergen in fungi) and low but positive levels of IgE to other Af-components, which hampered the serological discrimination of ABPA.

CONCLUSIONS AND CLINICAL RELEVANCE

The levels of IgE to Asp f 1 and/or Asp f 2 can effectively differentiate ABPA from Af-sensitized asthma, suggesting that the amounts of IgE specific for these molecules are markers for genuine Af-sensitization in ABPA. However, comorbid AD must be taken into consideration in the interpretation of high IgE to Asp f 6. Establishing of IgE-sensitization profiles using panel of Af-allergen components provides valuable information for distinguishing genuine vs. cross-reactive sensitization in Af-sensitized patients.

Severe or life-threatening asthma exacerbation: patient heterogeneity identified by cluster analysis

BACKGROUND

Severe or life-threatening asthma exacerbation is one of the worst outcomes of asthma because of the risk of death. To date, few studies have explored the potential heterogeneity of this condition.

OBJECTIVES

To examine the clinical characteristics and heterogeneity of patients with severe or life-threatening asthma exacerbation.

METHODS

This was a multicentre, prospective study of patients with severe or life-threatening asthma exacerbation and pulse oxygen saturation < 90% who were admitted to 17 institutions across Japan. Cluster analysis was performed using variables from patient- and physician-orientated structured questionnaires.

RESULTS

Analysis of data from 175 patients with severe or life-threatening asthma exacerbation revealed five distinct clusters. Cluster 1 (n = 27) was younger-onset asthma with severe symptoms at baseline, including limitation of activities, a higher frequency of treatment with oral corticosteroids and short-acting beta-agonists, and a higher frequency of asthma hospitalizations in the past year. Cluster 2 (n = 35) was predominantly composed of elderly females, with the highest frequency of comorbid, chronic hyperplastic rhinosinusitis/nasal polyposis, and a long disease duration. Cluster 3 (n = 40) was allergic asthma without inhaled corticosteroid use at baseline. Patients in this cluster had a higher frequency of atopy, including allergic rhinitis and furred pet hypersensitivity, and a better prognosis during hospitalization compared with the other clusters. Cluster 4 (n = 34) was characterized by elderly males with concomitant chronic obstructive pulmonary disease (COPD). Although cluster 5 (n = 39) had very mild symptoms at baseline according to the patient questionnaires, 41% had previously been hospitalized for asthma.

CONCLUSIONS & CLINICAL RELEVANCE

This study demonstrated that significant heterogeneity exists among patients with severe or life-threatening asthma exacerbation. Differences were observed in the severity of asthma symptoms and use of inhaled corticosteroids at baseline, and the presence of comorbid COPD. These findings may contribute to a deeper understanding and better management of this patient population.

Blocking CD28 signal in steroid resistant asthma

To investigate the mechanism of steroid resistance in severe asthma, effect of CD28 signal blockade on T cell activation and asthma model was analyzed.

PBMC obtained from mild (steroid sensitive, SS), steroid dependent (SD), and steroid resistant (SR) asthmatics were stimulated with mitogens. Der f 2-specific Th clones were established and effects of glucocorticoids (GCs) on the proliferation and cytokine synthesis were analyzed. Steroid responsiveness of murine Th clones reactive to ovalbumin were analyzed. Unprimed BALB/c mice were transferred with these clones and then antigen challenged. Effect of GC on BALF eosinophilia was evaluated. CTLA4-Ig was administered through nasal inhalation or venous injection.

IL-5 production by PBMC of SS asthmatics was significantly reduced after ICS administration, but that of SD asthma remained high. IC50 values for the suppression of cytokine synthesis and proliferation responses by dexamethasone was not different among SS, SD, or SR asthmatics. Addition of CD28 signal induced steroid resistance in IL-2 and PI-3 kinase dependent manner. Murine SS and SR Th clones were selected based on the steroid sensitivity of their proliferation responses in vitro. Airway infiltration of eosinophils and lymphocytes of mice transferred with SS clones were effectively inhibited by GC. In contrast, those of mice transferred with SR clones were not significantly inhibited. Administration of CTLA4-Ig significantly suppressed the proliferation of GC-treated SR clones in vitro, and the BALF eosinophilia of mice transferred with SR clones in vivo.

Costimulatory signal mediated through CD28 seems crucial for the induction of steroid resistance and might be a target for therapeutic intervention.

PHYSIOLOGIC AIRWAY RESPONSES TO INHALED HISTAMINE AND ACETYLCHOLINE IN PATIENTS WITH MILD ASTHMA AS ANALYZED BY FORCED OSCILLATION

BACKGROUND AND AIMS

Asthma is a chronic disease characterized by airway inflammation; it is sometimes difficult to diagnose. For clinical diagnosis, forced oscillation technique (FOT) measures airway reactance and resistance. By FOT, we investigated respiratory resistance and ventilation perfusion ratio inequality in adults with mild asthma.

METHODS

We examined 58 adult patients with mild asthma having no inhaled corticosteroid treatment, and 10 adult patients with post-infectious prolonged cough. Using a MostGraph-01 FOT instrument, we evaluated these patients before and after bronchial hyperresponsiveness to acetylcholine (ACh) or histamine (Hist). We measured the following conditions: change of resistance at 5Hz (R5) and 20Hz (R20), R5-R20, reactance at 5Hz, frequency of resonance (Fres), low-frequency reactance area (ALX), and forced expiratory volume in 1 second (FEV1).

RESULTS

There were significant changes of R5, R20, R5-R20, X5, Fres, ALX after provocations for ACh or Hist in all patients with asthma, but not in patients with post-infectious prolonged cough. We calculated the percent decrease in FEV1 after provocation with ACh or Hist. For Ach, this decrease in FEV1 correlated with changes in R20 and Fres for all patients. For Hist, the percent decrease in FEV1 correlated with changes in R5, R20, Fres, and ALX for all patients. Furthermore, we investigated these correlations in patients with normalized bronchial hyperresponsiveness to ACh or Hist. For Ach, the percent decrease in FEV1 correlated with changes in Fres or R5-R20. For Hist, this decrease in FEV1 correlated with changes in R5, R20, and Fres. ROC analysis was used to evaluate the diagnostic value of the ratio of change of Fres in BHR to Hist. The area under the curve was 0.7808 (95% CI=0.657-0.904). A reasonably high specificity (100.0%) and a high sensitivity (53.8%) with a cut-off point of 1.5 in the ratio before and after of Fres were obtained.

CONCLUSION

The changes in FOT parameters (before and after bronchial airway responses) may detect airway resistance and ventilation perfusion ratio inequality even in adult patients with asthma having normalized bronchial hyperresponsiveness to ACh or Hist. That results may be useful for an early diagnosis of asthma.

Platelet activation markers overexpressed specifically in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is characterized by respiratory reactions on ingestion of COX-1 inhibitors and cysteinyl leukotriene overproduction. The hypersensitivity reaction is induced by low doses of aspirin that inhibit COX-1 in platelets.

OBJECTIVE

We sought to explore the role of platelets in the pathogenesis of AERD in patients under stable conditions and during an aspirin challenge test.

METHODS

Stable patients with AERD (n = 30), aspirin-tolerant asthma (ATA; n = 21), or idiopathic chronic eosinophilic pneumonia (n = 10) were enrolled. Platelet activation was estimated based on expression levels of P-selectin (CD62P), CD63, CD69, and GPIIb/IIIa (PAC-1) in peripheral platelets; percentages of circulating platelet-adherent leukocytes; and plasma levels of soluble P-selectin (sP-selectin) and soluble CD40 ligand (sCD40L).

RESULTS

In the stable condition, expression of all surface markers on platelets, the percentage of platelet-adherent eosinophils, and the plasma levels of sP-selectin and sCD40L were significantly higher in patients with AERD compared with those in patients with ATA. P-selectin and CD63 expression on platelets and plasma sP-selectin and sCD40L levels were positively correlated with the percentage of platelet-adherent eosinophils. Among these markers, P-selectin expression and plasma sP-selectin levels positively correlated with urinary concentrations of leukotriene E4. Additionally, plasma sP-selectin and sCD40L levels were negatively correlated with lung function. In contrast, platelet activation markers in patients with AERD did not change during the aspirin challenge test.

CONCLUSION

Peripheral platelets were activated more in patients with stable AERD compared with those in patients with stable ATA, patients with idiopathic chronic eosinophilic pneumonia, and control subjects. Platelet activation was involved in cysteinyl leukotriene overproduction and persistent airflow limitations in patients with AERD.

IgE Abs to Der p 1 and Der p 2 as diagnostic markers of house dust mite allergy as defined by a bronchoprovocation test

BACKGROUND

Limited information is available regarding the clinical usefulness of measuring the levels of IgE to allergen components from house dust mites (HDMs) in the diagnosis of genuine HDM allergy.

METHODS

To evaluate the diagnostic usefulness of measuring levels of serum IgE antibodies (Abs) to allergen components from Dermatophagoides pteronyssinus (DP) as a predictor of immediate asthmatic response (IAR) to bronchoprovocation, we studied 55 DP-sensitized asthmatic patients who underwent a bronchoprovocation test using crude DP extract. The levels of IgE Abs to crude DP, nDer p 1, rDer p 2, and rDer p 10 in patients who showed IAR (n = 41) were compared with those in patients who showed no IAR (n = 14).

RESULTS

While the frequencies of positivity for IgE Abs to nDer p 1 and rDer p 2 among the entire study population were 89 and 86%, respectively, all patients with IAR tested positive for both of them with high IgE concentrations. The areas under the receiver operating characteristic curves for IgE to nDer p 1 and rDer p 2 as predictors of IAR were 0.913 and 0.906, respectively. The specificity of IgE to nDer p 1 and rDer p 2 was higher than IgE to crude DP even at low cut-off points.

CONCLUSIONS

IgE to nDer p 1 and/or rDer p 2 was highly predictive of allergen-induced IAR. These findings validate the clinical usefulness of measuring the levels of IgE to nDer p 1 and rDer p 2 as a diagnostic tool for genuine HDM allergy.

[Comparison of exhaled nitric oxide levels measured by two offline methods and the NO breath® method in Japan]

BACKGROUND

The fraction of exhaled nitric oxide (FeNO) is a useful marker of eosinophilic airway inflammation in asthmatics. Clinical application of FeNO measurement in Japan is expected increase because the procedure is now covered through health insurance. However, the measurement system used is known to affect FeNO results, and it remains unknown whether results from offline methods correlate with those from traditional online methods, such as NO breath®.

METHODS

The study population comprised 48 patients at our hospital. FeNO levels were measured by using two offline methods (Sievers and CEIS) and a standard online method, NO breath®

RESULTS

FeNONO breath levels were significantly correlated with FeNOSievers(r=0.875) and FeNOCEIS(r=0.888) levels. FeNONO breath levels were nearly equal to FeNOSievers results (FeNONO breath=1.05×FeNOSievers), but both of these levels were lower (p=0.02) than FeNOCEIS data (FeNONO breath=0.74×FeNOCEIS). A Bland-Altman plot of values obtained by the NO breath® and Sievers methods revealed that the NO breath® result was lower than the Sievers level when FeNO was low but was higher than the Sievers level when FeNO was high.

CONCLUSION

Differences exist in the levels of FeNO measurement by three methods (two offline methods and NO breath®): conversion equations are needed to compare the FeNO levels obtained by using these three methods. In addition, NO breath® may be more useful to distinguish asthmatic patients from non-asthmatics, compared with Sievers method.

Oral mite anaphylaxis caused by mite-contaminated okonomiyaki/ pancake-mix in Japan: 8 case reports and a review of 28 reported cases

BACKGROUND

Anaphylaxis after the ingestion of foods contaminated with mites has recently been recognized. Case series and case reports thus far have shown that mite-contaminated wheat flour is the major cause of oral mite anaphylaxis. However, we have found 8 cases of oral mite anaphylaxis which were caused by mite-contaminated okonomiyaki-mix, a savory Japanese style pancake mix, in our hospital.

METHODS

In addition to our 8 cases, the databases of MEDLINE and ICHUSHI were systematically searched for patients with oral mite anaphylaxis in Japan.

RESULTS

Thirty-six patients including our 8 cases with oral mite anaphylaxis were identified. Thirty-four out of 36 cases (94%) ingested okonomiyaki or takoyaki, prepared at home using okonomiyaki-mix or takoyaki-mix which was previously opened and stored for months at ambient temperature. Microscopic examination of culprit mixes of 16 cases including our 1 case revealed contamination of mites such as Dermatophagoides farina (Der f) (5 cases), Tyrophagus putrescentiae (Tyr p) (4 cases), and Dermatophagoides pteronyssinus (Der p) (3 cases). The specific IgE to each mite is generally upregulated in these patients. Especially, the titers of specific IgE to Der p and Der f were more than class 2 in all cases.

CONCLUSIONS

Mite-contaminated flavored flour is the major cause of oral mite anaphylaxis in Japan.

Age-specific characteristics of inpatients with severe asthma exacerbation

BACKGROUND

The characteristics of inpatients with severe asthma exacerbation remain unclear. It is considered that the characteristics of inpatients with severe asthma vary depending on age. However, these are rarely investigated. The objective of this study is to investigate the differences in characteristics among different age groups. We considered that it is necessary to understand the characteristics of each age group so that we can establish strategies in preventing severe asthma exacerbation.

METHODS

All asthma inpatients who were hospitalized between 2004 and 2011 with SpO2 <90% (in room air), were breathless at rest, and showed increased respiratory rate and pulse rate were examined. We compared the characteristics among the young age group, middle age group, and advanced age group.

RESULTS

The total number of patients was 204. In the young age group, the percentages of patients with irregular visits and non visits to a medical institution were high. This group showed high percentages of smokers and pet owners. The percentage of continuous ICS users in this group was 25.9%. The middle age group had high rates of aspirin-intolerant asthma. The percentage of continuous ICS users in this group was 60.2%. In the advanced age group, the percentages of patients with hypertension/heart disease, diabetes mellitus, and COPD were high. This group showed good treatment adherence. The percentage of continuous ICS users in this group was 77.4%.

CONCLUSIONS

The characteristics of inpatients with severe asthma vary depending on age. We need to establish countermeasures for asthma exacerbation according to the characteristics of patients depending on age.

Actinomycosis in the mandible: CT and MR findings

SUMMARY

Mandibular actinomycosis is an uncommon disease. We retrospectively reviewed 6 patients with pathologically proven mandibular actinomycosis who underwent both CT and MR imaging to evaluate the characteristic imaging findings. CT results showed an irregularly marginated lesion with increased bone marrow attenuation, osteolysis, and involvement of the skin in all patients. Periosteal reaction and intralesional gas were seen in 4 patients. MR imaging results revealed low signal on T1-weighted and high signal on T2-weighted images of the mandible, and moderate heterogeneous enhancement was seen in all patients who received intravenous contrast. Cervical lymphadenopathy was not observed. Involvement of the masseter, lateral pterygoid, and medial pterygoid muscles was seen in 4 patients, whereas parotid gland and submandibular gland as well as parapharyngeal space involvement were seen in 3 patients. Familiarity with the imaging findings of mandibular actinomycosis may help to diagnosis this entity.

Characteristic power Doppler sonographic images of tumorous and non-tumorous buccal space lesions

OBJECTIVES

The aim of this study was to evaluate the characteristic power Doppler sonographic images of buccal space tumorous and non-tumorous lesions.

METHODS

48 patients with buccal space lesions were evaluated with greyscale sonography followed by power Doppler sonography with a 12 MHz linear transducer. On greyscale sonography, buccal space lesions were assessed for the boundary (clear or unclear), echogenicity (hypoechoic or isoechoic) and internal architecture (homogeneous or heterogeneous). Power Doppler sonography was performed to evaluate the vascular signals within the buccal space lesions.

RESULTS

48 lesions were found in the 48 patients; of these 48 lesions, 28 were tumourous and 20 were non-tumourous. In the 28 tumours, 15 cases showed clear boundaries, 15 cases were hypoechoic relative to adjacent tissues and 22 cases presented with a heterogeneous appearance on greyscale sonography. The internal vascularity of 19 tumours was shown using power Doppler sonography. In the 20 non-tumorous lesions, 11 cases showed clear boundaries, 17 cases were hypoechoic relative to adjacent tissues and 13 cases presented with a homogeneous appearance on greyscale sonography. 18 non-tumorous lesions showed no internal vascularity using power Doppler sonography. Logistic multivariate regression analysis between the tumour group and the non-tumorous lesions group demonstrated that the internal architecture (odds ratio = 8.270, p = 0.029) and vascular signals (odds ratio = 17.533, p = 0.003) were significant variables.

CONCLUSIONS

Power Doppler sonography is a useful technique for the differential diagnosis of tumorous and non-tumorous buccal space lesions.

Markers for step-down of inhaled corticosteroid therapy in adult asthmatics

BACKGROUND

Treatment guidelines recommend the use of inhaled corticosteroids (ICS) as first-line therapy for all stages of persistent asthma. However, it is unknown whether ICS dose reduction in adult asthmatics is compatible with maintaining asthma control. Moreover, there are no predictors of efficacy in maintaining asthma control upon ICS reduction.

METHODS

We recruited 90 adult patients with moderate or severe asthma but no clinical symptoms of asthma for at least 6 months. All patients reduced their ICS doses by half but continued taking other asthma-related medications. As a primary outcome, we measured asthma exacerbations during the 12 months following ICS reduction. We also further monitored patients from the above study who had maintained total asthma control for 12 months after ICS reduction and who had continued on their reduced doses of ICS or had further reduced, or stopped, their ICS.

RESULTS

Forty of ninety patients (44.4%) experienced exacerbations after ICS reduction (time to first exacerbation: 6.4 ± 3.6 months). Multivariate logistic regression modeling revealed a rank order of predictors of success in ICS reduction while retaining asthma control: acetylcholine (ACh) PC(20) (p < 0.01); length of time with no clinical symptoms before ICS reduction (p < 0.01); FeNO (p = 0.028); and forced expiratory volume in 1 s (FEV(1); % predicted) (p = 0.03). Finally thirty-nine of 50 patients maintained total asthma control for at least 2 years after the initial ICS reduction.

CONCLUSIONS

In asthma patients with normalized AChPC(20) of 20mg/mL or 10mg/mL and no clinical symptoms for at least 12 or 24 months it may be possible to successfully reduce ICS without increasing exacerbations for long time.