Cannabinoid receptor 2 as a regulator of inflammation induced oleoylethanolamide in eosinophilic asthma.

BACKGROUND: Oleoylethanolamide (OEA), an endogenously generated cannabinoid-like compound, has been reported to be increased in patients with severe asthma and aspirin-exacerbated respiratory disease. Recruitment of activated eosinophils in the airways is a hallmark of bronchial asthma. OBJECTIVE: We explored the direct contribution of cannabinoid receptor 2 (CB2), a cognate receptor of OEA, which induces eosinophil activation in vitro and in vivo. METHODS: We investigated OEA signaling in the eosinophilic cell line dEol-1 in peripheral blood eosinophils from people with asthma. In order to confirm whether eosinophil activation by OEA is CB2 dependent or not, CB2 small interfering RNA and the CB2 antagonist SR144528 were used. The numbers of airway inflammatory cells and the levels of cytokines were measured in bronchoalveolar lavage fluid, and airway hyperresponsiveness was examined in the BALB/c mice. RESULTS: CB2 expression was increased after OEA treatment in both peripheral blood eosinophils and dEol-1 cells. It was also elevated after OEA-induced recruitment of eosinophils to the lungs in vivo. However, SR144528 treatment reduced the activation of peripheral blood eosinophils from asthmatic patients. Furthermore, CB2 knockdown decreased the activation of dEol-1 cells and the levels of inflammatory and type 2 cytokines. SR144528 treatment alleviated airway hyperresponsiveness and eosinophil recruitment to the lungs in vivo. CONCLUSION: CB2 may contribute to the pathogenesis of eosinophilic asthma. Our results provide new insight into the molecular mechanism of signal transduction by OEA in eosinophilic asthma.

8-Iso-prostaglandin F2α as a biomarker of type 2 low airway inflammation and remodeling in adult asthma.

BACKGROUND: Although 8-iso-prostaglandin F2a has been proposed as a potential biomarker for oxidative stress in airway diseases, its specific role in asthma remains poorly understood. OBJECTIVE: To evaluate the diagnostic potential of 8-iso-prostaglandin F2a in assessing airway inflammation, airway remodeling, airway hyperresponsiveness, and oxidative stress in asthma. METHODS: Blood and urine concentrations of 8-iso-prostaglandin F2a were quantified using liquid chromatography-tandem mass spectrometry in 128 adults with asthma who had maintained antiasthma medications. Their correlations with clinical data, sputum cell counts, lung function parameters, and serum markers of epithelial/neutrophil activity and airway remodeling were then analyzed. RESULTS: The urinary 8-iso-prostaglandin F2a concentrations were significantly higher in patients with noneosinophilic asthma than in those with eosinophilic asthma (P < .05). The area under the curve was 0.678, indicating moderate diagnostic accuracy for noneosinophilic asthma. There were significant correlations with neutrophilic inflammation markers and airway remodeling markers (all P < .05). Negative correlations were observed with forced expiratory volume in 1 second (%), forced expiratory volume in 1 second/forced vital capacity, forced expiratory flow at 25% to 75% of forced vital capacity, and serum club cell protein 16 levels (all P < .05). High 8-iso-prostaglandin F2a concentrations were also noted in obese and smoking subgroups (all P < .05). However, the serum 8-iso-prostaglandin F2a concentrations were not correlated with these asthma-related parameters. CONCLUSION: Urinary 8-iso-prostaglandin F2a concentrations are a potential biomarker for phenotyping severe asthma, particularly noneosinophilic asthma, offering oxidative stress-induced epithelial inflammation/remodeling as an additional target in asthma management.

Role of club cell 16-kDa secretory protein in asthmatic airways.

BACKGROUND: Club cell 16-kDa secretory protein (CC16) is a pneumoprotein and functions as an anti-inflammatory or antioxidant protein. However, altered levels of serum CC16 as well as their effect on airways inflammation have not been fully evaluated. METHODS: We recruited 63 adult asthmatics on maintenance medications and 61 healthy controls (HCs). The asthmatic subjects were divided into two groups according to the result of bronchodilator responsiveness (BDR) test: the present BDR (n = 17) and absent BDR (n = 46) groups. Serum CC16 levels were measured by ELISA. As an in vitro study, the effect of Dermatophagoides pteronyssinus antigen 1 (Der p1) on the production of CC16 in airways epithelial cells (AECs) according to a time-dependent manner was assessed; the effects of CC16 protein on oxidative stress system, airways inflammation and remodelling were tested. RESULTS: Serum CC16 levels showed significantly higher in the asthmatics than in the HCs (p < .001) with a positive correlation with FEV1 % (r = .352, p = .005). The present BDR group had significantly lower levels of serum CC16, FEV1 % and MMEF%, but showed higher level of FeNO than the absent BDR group. Serum CC16 levels (below 496.0 ng/mL) could discriminate the present BDR group from the absent BDR group (area under the curve = 0.74, p = .004). In vitro testing demonstrated that Der p1 exposure significantly induced CC16 release from AECs for 1 h, which was progressively decreased after 6 h and followed by MMP-9 and TIMP-1 production. These findings were associated with oxidant/antioxidant disequilibrium and restored by CC16 treatment (but not dexamethasone). CONCLUSION: Decreased CC16 production contributes to persistent airways inflammation and lung function decline. CC16 may be a potential biomarker for asthmatics with BDR.

Biomarkers for predicting type 2-high and uncontrolled asthma in real-world practice.

BACKGROUND: Blood eosinophil count (BEC), immunoglobulin (Ig) E, and fractional exhaled nitric oxide (FeNO) are key clinical indicators for identifying type 2 (T2) asthma. OBJECTIVE: To provide optimal cutoff points of T2 markers for assessing T2-high or uncontrolled asthma in real-world practice. METHODS: Various clinical and laboratory parameters were analyzed according to the result of T2 markers (BEC, serum-free IgE, and FeNO) in adults with asthma who had maintained antiasthmatic medications. The cutoff levels for representing uncontrolled asthma were determined using receiver operating characteristic analysis. Blood levels of periostin and eosinophil-derived neurotoxin were measured by enzyme-linked immunosorbent assay. Activation markers of circulating eosinophils (Siglec8+) and neutrophils (CD66+) were analyzed by flow cytometry. RESULTS: Of 133 patients with asthma, 23 (17.3%) had 3 T2 markers (BEC ≥ 300 cells/µL, serum-free IgE ≥ 120 ng/mL, and FeNO ≥ 25 parts per billion) and significantly higher levels of sputum eosinophils, blood eosinophil-derived neurotoxin, and Siglec8+ eosinophils but lower 1-second forced expiratory volume percentage, in addition to a higher rate of uncontrolled status (P < .05 for all). Furthermore, patients with uncontrolled asthma had significantly higher levels of FeNO and BEC with lower 1-second forced expiratory volume percentage (P < .05 for all). The optimal cutoff values for predicting uncontrolled asthma were found to be 22 parts per billion of FeNO levels, 161.4 cells/L of BECs, and 85.9 ng/mL of serum-free IgE levels. CONCLUSION: We suggest the optimal cutoff values of BEC, IgE, and FeNO for classifying T2-high or uncontrolled asthma, which could be applied as candidate biomarkers for targeting patients with asthma who require T2 biologics.

Down-regulated surfactant protein B in obese asthmatics.

BACKGROUND: Obesity is a common comorbid condition in adult asthmatics and known as a feature of asthma severity. However, the molecular mechanism under obesity-induced inflammation has not yet been fully understood. OBJECTIVE: Considering the essential role of hydrophobic surfactant protein B (SP-B) in lung function, SP-B was targeted to examine its involvement in the development of obesity-induced airway inflammation in asthmatics. METHODS: The aim was to examine an alteration in circulating SP-B according to obesity in adult asthmatics, 129 asthmatics were enrolled and classified into 3 groups (obese, overweight and normal-weight groups) according to body mass index (BMI). Circulating SP-B levels were determined by enzyme-linked immunosorbent assay. Four single nucleotide polymorphisms of SFTPB gene were genotyped. Serum ceramide levels were measured by liquid chromatography-tandem mass spectrometry. RESULTS: Significantly lower serum SP-B levels were noted in the obese group than in the overweight or normal-weight group (p = .002). The serum SP-B level was significantly correlated with serum levels of C18:0 ceramide and transforming growth factor beta 1 as well as BMI (r = -0.200; r = -0.215; r = -0.332, p < .050 for all). An inverse correlation was noted between serum SP-B and fractional exhaled nitric oxide levels in female asthmatics (r = -0.287, p = .009). Genetic predisposition of the SFTPB gene at 9306 A>G to the obese and overweight groups was noted. CONCLUSION: Obesity altered ceramide metabolism leading to pulmonary surfactant dysfunction and impaired resolution of airway inflammation, finally contributing to the phenotypes of obese asthmatics.

Incidence and outcomes of adverse drug reactions to first-line anti-tuberculosis drugs and their effects on the quality of life: A multicenter prospective cohort study.

BACKGROUND: In tuberculosis (TB) treatment, adverse drug reactions (ADRs) can interrupt treatment and decrease the quality of life (QoL). We aimed to prospectively investigate the incidence of ADRs to first-line anti-TB drugs and related outcomes and QoL. METHODS: Adult patients with TB who had been treated with first-line anti-TB drugs in five Korean hospitals were enrolled. ADR questionnaire surveys and blood tests were performed four times serially, and QoL was assessed on the fourth TB treatment week (±2 weeks). RESULTS: Of 410 enrolled patients with TB (males, 62%; mean age, 52.1 ± 18.1 years [those aged ≥65 years, 26.6%]), 67.8% experienced any ADRs (≥ grade 2) to TB drugs. The most common ADR was fatigue (53.2%), followed by itching (42.7%) and anorexia (41.7%). Older adult patients experienced relatively more ADRs, including anorexia, dyspepsia, rash, dizziness, anemia, abnormal hepatic/renal function tests, and increased uric acid levels (p < 0.05). Treatment regimens changed for 9.5% of patients owing to ADRs to anti-TB drugs. Patients with any ADRs and older adult patients had significantly lower QoL than their counterparts (p < 0.05). Old age (odds ratio [OR], 1.02) and being male (OR 2.65) were independently associated with ADRs, whereas active smoking (OR 4.73) and a relatively long treatment phase (OR 5.13) were independently associated with hepatotoxicity. CONCLUSION: ADRs to first-line anti-TB drugs were common and related to relatively low QoL, especially among older adults. Although 9.5% of patients had ADR-related regimen changes, most patients with ADRs completed treatments successfully.

Characteristics of Specialist-Diagnosed Asthma-COPD Overlap in Severe Asthma: Observations from the Korean Severe Asthma Registry (KoSAR).

BACKGROUND: While the clinical characteristics and outcomes of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) have been frequently compared with those of COPD or asthma, the prevalence and features of ACO in patients with severe asthma are unclear. OBJECTIVES: Evaluation of the prevalence and clinical features of ACO using the Korean severe asthma registry. METHODS: At the time of registration, ACO was determined in patients with severe asthma by attending specialists. Patients were classified into ACO and non-ACO groups, and the demographic and clinical characteristics of these two groups were compared. RESULTS: Of 482 patients with severe asthma, 23.7% had ACO. Patients in the ACO group were more likely to be male (P < .001), older (P < .001), and ex- or current smokers (P < .001) compared with those in the non-ACO group. Patients in the ACO group had lower mean forced expiratory volume in 1 second (P < .001) and blood eosinophil percentage (P = .006), but higher blood neutrophil percentage (P = .027) than those in the non-ACO group. The ACO group used more inhaled long-acting muscarinic antagonist (P < .001), methylxanthine (P = .001), or sustained systemic corticosteroid (P = .002). In addition, unscheduled emergency department visits due to exacerbation were more frequent in the ACO group (P = .006). CONCLUSION: Among patients with severe asthma, those with ACO were older, predominantly male, and were more likely to have a smoking history than those with asthma only. Patients with ACO used more systemic corticosteroid and had more frequent exacerbations related to emergency department visits than those with severe asthma only.

Ceramide/sphingosine-1-phosphate imbalance is associated with distinct inflammatory phenotypes of uncontrolled asthma.

BACKGROUND: Asthma is associated with inflammatory dysregulation, but the underlying metabolic signatures are unclear. This study aimed to classify asthma inflammatory phenotypes based on cellular and metabolic features. METHODS: To determine cellular and metabolic profiles, we assessed inflammatory cell markers using flow cytometry, sphingolipid (SL) metabolites using LC-MS/MS, and serum cytokines using ELISA. Targeted gene polymorphisms were determined to identify genetic predispositions related to the asthma inflammatory phenotype. RESULTS: In total, 137 patients with asthma and 20 healthy controls (HCs) were enrolled. Distinct cellular and metabolic profiles were found between them; patients with asthma showed increased expressions of inflammatory cell markers and higher levels of SL metabolites compared to HCs (P < .05 for all). Cellular markers (CD66+ neutrophils, platelet-adherent eosinophils) and SL metabolic markers (C16:0 and C24:0 ceramides) for uncontrolled asthma were also identified; higher levels were observed in uncontrolled asthma compared to controlled asthma (P < .05 for all). Asthmatics patients with higher levels of CD66+ neutrophils had lower FEV1(%), higher ACQ (but lower AQLO) scores, and higher sphingosine and C16:0 ceramide levels compared to those with low levels of CD66+ neutrophils. Asthmatics patients with higher levels of platelet-adherent eosinophils had higher S1P levels compared to those with lower levels of platelet-adherent eosinophils. Patients carrying TT genotype of ORMDL3 had more CD66+ neutrophils; those with AG/ GG genotypes of SGMS1 exhibited higher platelet-adherent eosinophils. CONCLUSION: Patients with uncontrolled asthma possess distinct inflammatory phenotypes including increased CD66+ neutrophils and platelet-adherent eosinophils, with an imbalanced ceramide/S1P rheostat, potentially involving ORMDL3 and SGMS1 gene polymorphisms. Ceramide/S1P synthesis could be targeted to control airway inflammation.

Real-life effectiveness of inhaler device switch from dry powder inhalers to pressurized metred-dose inhalers in patients with asthma treated with ICS/LABA.

BACKGROUND AND OBJECTIVE: Mixed inhaler device use for asthma is associated with worse inhaler technique and outcomes. Given that relievers are commonly prescribed as pressurized metred-dose inhalers (pMDI), changing preventers from dry powder inhalers (DPI) to pMDI may improve asthma outcomes. This study aimed to assess the persistence and effectiveness of switching from DPI to pMDI for inhaled corticosteroid and long-acting ß2 -agonist combination therapy (ICS/LABA). METHODS: This was a historical cohort study using Ajou University Hospital (Korea) patient records. Persistence of switch was defined as receiving ≥1 pMDI and no DPI after the switch. Effectiveness of switch was assessed as the proportion without severe asthma exacerbation and the proportion achieving risk domain asthma control (RDAC; no asthma-related hospitalization, antibiotics without upper respiratory diagnosis or acute course of oral corticosteroids) and overall asthma control (OAC; RDAC and ≤ 200 µg salbutamol/≤500 µg terbutaline average daily dose) comparing 1 year after and before the switch. RESULTS: Within 85 patients who switched from DPI to pMDI and persisted for a year, higher proportion were free from asthma exacerbation after the switch (mean difference in proportion = 0.129, 95% CI: 0.038-0.220). Switching to pMDI was also associated with better RDAC (75.3% vs 57.7%, P = 0.001) and OAC (57.7% vs 45.9%, P = 0.021). From the entire 117 patients who switched to fixed-dose combination (FDC)/ICS LABA pMDI, 76.1% (95% CI: 69.0-100.0%) patients persisted in the following 6 months. CONCLUSION: Switching to and persisting with pMDI was associated with decreased asthma exacerbations and improved asthma control. The majority of patients persisted with the switch to pMDI for ICS/LABA treatment.

Propacetamol poses a potential harm of adverse hypotension in male and older patients.

PURPOSE: Researchers recently suggested intravenous paracetamol as a potential cause of hypotension. We aimed to investigate risk factors of paracetamol- and propacetamol-associated adverse drug reactions (ADRs) in Korean individuals. METHODS: All adverse hypotension cases, regardless of suspected drug, and all ADRs associated with paracetamol and propacetamol use were collected from the Korea Adverse Event Reporting System database between 2011 and 2014. The seriousness, causality, and type of ADR were classified. RESULTS: Of 4,771 cases of adverse hypotension, 403 (8.4%) were reported to be related to propacetamol. This was comparable to the rate of hypotension associated with fentanyl (454, 9.5%), the major suspected drug of hypotension. Paracetamol-associated hypotension accounted for merely 1.2% (55 cases) of all hypotension cases. Among ADRs associated with propacetamol use, hypotension was the most common (37.1%), whereas cutaneous reactions were the primary paracetamol-associated ADR. Propacetamol/paracetamol-associated hypotension was frequently recorded in older patients (≥54 years) (53.9 ± 25.8 vs. 42.8 ± 21.7, P < 0.001) and taking more concomitant drugs (1.9 ± 5.0 vs. 1.1 ± 3.2, P < 0.001). Also, compared with other ADRs associated by propacetamol/paracetamol, hypotension was more commonly assessed as a serious outcome (27.3% vs. 11.4%, P < 0.001). Regarding concomitant medications, the risk for hypotension associated with propacetamol was significantly increased in patients simultaneously taking antibacterials (J01), cold preparations (R05), drugs for acid related disorders (A02), blood substitutes (B05), or antithrombotics (B01). CONCLUSIONS: Propacetamol was found to be a major suspected drug of pharmacologically associated hypotension in Korea. Older and male patients taking medications in combination with propacetamol/paracetamol should undergo monitoring of their blood pressure. Copyright © 2017 John Wiley & Sons, Ltd.

Neutrophil Extracellular DNA Traps Induce Autoantigen Production by Airway Epithelial Cells.

The hypothesis of autoimmune involvement in asthma has received much recent interest. Autoantibodies, such as anti-cytokeratin (CK) 18, anti-CK19, and anti-α-enolase antibodies, react with self-antigens and are found at high levels in the sera of patients with severe asthma (SA). However, the mechanisms underlying autoantibody production in SA have not been fully determined. The present study was conducted to demonstrate that neutrophil extracellular DNA traps (NETs), cytotoxic molecules released from neutrophils, are a key player in the stimulation of airway epithelial cells (AECs) to produce autoantigens. This study showed that NETs significantly increased the intracellular expression of tissue transglutaminase (tTG) but did not affect that of CK18 in AECs. NETs induced the extracellular release of both tTG and CK18 in a concentration-dependent manner. Moreover, NETs directly degraded intracellular α-enolase into small fragments. However, antibodies against neutrophil elastase (NE) or myeloperoxidase (MPO) attenuated the effects of NETs on AECs. Furthermore, each NET isolated from healthy controls (HC), nonsevere asthma (NSA), and SA had different characteristics. Taken together, these findings suggest that AECs exposed to NETs may exhibit higher autoantigen production, especially in SA. Therefore, targeting of NETs may represent a new therapy for neutrophilic asthma with a high level of autoantigens.

A Role of the ABCC4 Gene Polymorphism in Airway Inflammation of Asthmatics.

The ATP-binding cassette subfamily C member 4 gene encodes a transmembrane protein involved in the export of proinflammatory molecules, including leukotriene, prostaglandin, and sphingosine-1-phosphate across the plasma membrane. Those metabolites play important roles in asthma. We investigated the potential associations between ABCC4 gene polymorphisms and asthma phenotype. In total, 270 asthma patients and 120 normal healthy controls were enrolled for a genetic association study. Two polymorphisms (-1508A>G and -642C>G) in the ABCC4 promoter were genotyped. The functional variability of the promoter polymorphisms was analyzed by luciferase reporter assay. Inflammatory cytokine levels were measured by enzyme-linked immunosorbent assay. Serum and urinary eicosanoid metabolites, sphingosine-1-phosphate, were evaluated by quadrupole time-of-flight mass spectrometry. Asthma patients carrying the G allele at -1508A>G had significantly higher serum levels of periostin, myeloperoxidase, and urinary levels of 15-hydroxyeicosatetraenoic acid and sphingosine-1-phosphate (P = 0.016, P = 0.027, P = 0.032, and P = 0.010, resp.) compared with noncarrier asthma patients. Luciferase activity was significantly enhanced in human epithelial A549 cells harboring a construct containing the -1508G allele (P < 0.01 for each) compared with a construct containing the -1508A allele. A functional polymorphism in the ABCC4 promoter, -1508A>G, may increase extracellular 15-hydroxyeicosatetraenoic acid, sphingosine-1-phosphate, and periostin levels, contributing to airway inflammation in asthmatics.

Subcutaneous Immunotherapy for Allergic Asthma in a Single Center of Korea: Efficacy, Safety, and Clinical Response Predictors.

Allergen-specific immunotherapy is the only causal treatment for allergic diseases. However, the efficacy of immunotherapy may vary around the world due to differences in climate, the nature of aero-allergens and their distribution. The aim of this study was to describe the effects of subcutaneous immunotherapy (SCIT) in Korean adults with allergic asthma (AA). As a retrospective cohort study, we reviewed medical records for 627 patients with AA in Korea who were sensitized to house dust mite (HDM) and/or pollens and who underwent SCIT with aluminum hydroxide adsorbed allergen extract from 2000 to 2012. Rates of remission, defined as no further requirement of maintenance medication, over time were determined by means of life tables and extension of survival analysis. Herein, 627 asthmatic patients achieved remission within a mean of 4.7 ± 0.2 years. The cumulative incidence rates of remission from AA were 86.9% upon treatment with SCIT. Baseline forced expiratory volume in the first second (FEV1) ≥ 80% (hazard ratio [HR], 3.10; 95% confidence interval [CI], 1.79-5.39; P < 0.001), and maintenance of immunotherapy for more than 3 years (HR, 1.82; 95% CI, 1.21-2.72; P = 0.004) were significant predictors of asthma remission during SCIT. In 284 patients on SCIT with HDM alone, initial specific immunoglobulin E (IgE) levels to Dermatophagoides pteronyssinus and Dermatophagoides farinae did not show significant difference between remission and non-remission group after adjusting demographic variables. In conclusion, SCIT was effective and safe treatment modality for patients with AA. Initial FEV1 ≥ 80% and immunotherapy more than 3 years were found to be associated with favorable clinical responses to SCIT.

Altered Systemic Adipokines in Patients with Chronic Urticaria.

BACKGROUND: Increasing evidence suggests that adipokines affect immune responses and chronic urticaria (CU) is associated with an altered immune response related to chronic systemic inflammation. Our objectives were to investigate whether adipokines are involved in CU pathogenesis and to outline relationships between adipokines and urticaria severity and quality of life. METHODS: Serum adiponectin, leptin, lipocalin-2 (LCN2), interleukin (IL)-10, IL-6, and tumor necrosis factor (TNF)-α concentrations were measured by enzyme-linked immunosorbent assays in 191 CU patients and 89 healthy controls. The effect of LCN2 on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced neutrophil chemotaxis was assessed using migration assays. CU severity was assessed based on the urticaria activity score (UAS). To explore relationships between adipokines and UAS and the chronic urticaria-specific quality of life (CU-QoL) questionnaire, a structural equation model was used. RESULTS: Mean levels of serum LCN2, TNF-α, IL-6, and IL-10 were significantly higher in CU patients than in controls. Adiponectin levels were significantly lower in patients with CU than in controls. While serum IL-6 levels were significantly higher in refractory CU patients, compared to responsive CU individuals, LCN2 levels were significantly lower. LCN2 inhibited fMLP-induced neutrophil migration. LCN2 showed a direct relationship with UAS (ß = -0.274, p < 0.001), and UAS was found to contribute to CU-QoL (ß = 0.417, p < 0.001). CONCLUSIONS: Our results highlighted an imbalance in pro- and anti-inflammatory adipokines in CU patients. We suggest that LCN2 could be a differential marker for disease activity and the clinical responses to antihistamine treatment in CU patients. Modulation of systemic inflammation may be a therapeutic strategy for treating severe, refractory CU.

Regional differences in vitamin D levels and incidence of food-induced anaphylaxis in South Korea.

BACKGROUND: Previous studies have suggested low vitamin D as a potential risk factor for food allergy/anaphylaxis. However, few studies have investigated the association between vitamin D and food-induced anaphylaxis (FIA) in South Korea. OBJECTIVE: To examine regional differences in serum vitamin D levels and FIA incidence. METHODS: We used nationwide data collected from 2011 to 2013. Data on vitamin D were obtained from the Korea National Health and Nutrition Examination Survey; data on FIA were obtained from the Health Insurance and Assessment Service. Districts were grouped into region 1 (lower solar radiation) and region 2 (higher solar radiation). We examined differences in FIA incidence and vitamin D levels between the regions, adjusting for age. RESULTS: The study included 2,814 patients with FIA and 15,367 people with available serum vitamin D measurements. Age-adjusted FIA incidence was 2.2 per 100,000 person-years in region 1 and 1.8 per 100,000 person-years in region 2 (relative risk, 1.23; 95% confidence interval, 1.09-1.39). Age-adjusted serum vitamin D levels were 16.5 ng/mL in region 1 and 17.8 ng/mL in region 2 (mean difference, 1.3 ng/mL; 95% confidence interval, 0.9-1.9). After stratification by age, sex, and area of residence, region 1 still had higher FIA incidence and lower vitamin D levels than region 2. CONCLUSION: The present study found a higher incidence of FIA in regions with lower vitamin D levels in the population. Further investigation is necessary to identify any direct associations between vitamin D and food allergy/anaphylaxis.

Serum S100A8 and S100A9 Enhance Innate Immune Responses in the Pathogenesis of Baker's Asthma.

BACKGROUND: S100A8 and S100A9 can be produced by lipopolysaccharide-stimulated granulocytes and provoke an innate immune-mediated airway inflammation. Involvement of S100A8 and S100A9 has been implicated in asthma. To further understand the role of S100A8 and S100A9 during innate immune responses in baker's asthma, we investigated the associations of serum S100A8 and S100A9 with exposure to bakery allergens and polymorphisms of the Toll-like receptor 4 (TLR4) gene. METHODS: Totally, 381 bakery workers and 100 unexposed healthy controls were recruited. Skin prick tests for bakery allergens were performed. Serum levels of S100A8, S100A9, myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, and interleukin (IL)-8 were measured using ELISA. Predictive values of serum S100A8 and S100A9 in bakery workers were evaluated by receiver-operating characteristic (ROC) curves. Polymorphisms of TLR4 -2027Ax2192;G and -1608Tx2192;C were genotyped. RESULTS: Higher serum levels of S100A8 and S100A9 were noted in bakery workers compared to the normal controls (p < 0.001); however, no significant differences were noted according to work-related symptoms. The area under the ROC curve of serum S100A8 was 0.886 for occupational exposure (p < 0.001). The TLR4 -1608CC genotype was significantly associated with a higher serum S100A8 level (p = 0.025). Serum S100A8 and S100A9 levels were correlated with serum levels of MPO (r = 0.396 and 0.189, respectively), TNF-α (r = 0.536 and 0.280, respectively), and IL-8 (r = 0.540 and 0.205, respectively; p < 0.001 for all). CONCLUSION: S100A8 and S100A9 are involved in innate immune responses under the regulation of TLR4 polymorphisms in baker's asthma pathogenesis. Serum S100A8 could be a potential biomarker for predicting occupational exposure to wheat flour in bakery workers.

Predictors of Asthma Control by Stepwise Treatment in Elderly Asthmatic Patients.

The geriatric population is increasing, and asthma severity increases with age. We determined the predictors of asthma control, exacerbation, and the factors that affect asthma-specific quality of life (A-QOL) in elderly asthmatic patients. This was a prospective, multicenter, real-life study for 6 months with stepwise pharmacologic treatment based on the Global Initiative for Asthma (GINA) guideline. A total of 296 asthmatic patients aged ≥ 60 yr were recruited from 5 university centers in Korea. The improved-asthma control group was defined as the group of patients who maintained well-controlled or improved disease and the not-improved asthma control group was defined as the remaining patients. Fewer number of medications for comorbidities (2.8 ± 3.3 in the improved vs. 4.5 ± 4.4 in the control) and higher physical functioning (PF) scale (89.8 ± 14.2 in the improved vs. 82.0 ± 16.4 in the control) were significant predictors in the improved-asthma control group (OR = 0.863, P = 0.004 and OR = 1.028, P = 0.018, respectively). An asthma control test (ACT) score of ≤ 19 at baseline was a significant predictor of asthma exacerbation (OR = 3.938, P = 0.048). Asthma duration (F = 5.656, P = 0.018), ACT score (F = 12.237, P = 0.001) at baseline, and the presence of asthma exacerbation (F = 5.565, P = 0.019) were significant determinants of changes in A-QOL. The number of medications for comorbidities and performance status determined by the PF scale may be important parameters for assessing asthma control in elderly asthmatic patients.

The potential utility of iodinated contrast media (ICM) skin testing in patients with ICM hypersensitivity.

Both immediate and delayed hypersensitivity reactions to iodinated contrast media (ICM) are relatively common. However, there are few data to determine the clinical utility of immunologic evaluation of ICM. To evaluate the utility of ICM skin testing in patients with ICM hypersensitivity, 23 patients (17 immediate and 6 delayed reactions) were enrolled from 3 university hospitals in Korea. With 6 commonly used ICM including iopromide, iohexol, ioversol, iomeprol, iopamidol and iodixanol, skin prick (SPT), intradermal (IDT) and patch tests were performed. Of 10 patients with anaphylaxis, 3 (30.0%) and 6 (60.0%) were positive respectively on SPTs and IDTs with the culprit ICM. Three of 6 patients with urticaria showed positive IDTs. In total, 11 (64.7%) had positive on either SPT or IDT. Three of 6 patients with delayed rashes had positive response to patch test and/or delayed IDT. Among 5 patients (3 anaphylaxis, 1 urticaria and 1 delayed rash) taken subsequent radiological examinations, 3 patients administered safe alternatives according to the results of skin testing had no adverse reaction. However, anaphylaxis developed in the other 2 patients administered the culprit ICM again. With 64.7% (11/17) and 50% (3/6) of the sensitivities of corresponding allergic skin tests with culprit ICM for immediate and delayed hypersensitivity reactions, the present study suggests that skin tests is useful for the diagnosis of ICM hypersensitivity and for selecting safe ICM and preventing a recurrence of anaphylaxis caused by the same ICM.

Association of serum periostin with aspirin-exacerbated respiratory disease.

BACKGROUND: Recent studies recommend periostin as a systemic biomarker of eosinophilic airway inflammation to predict responses to novel treatments that targets eosinophilic TH2-driven inflammation in asthmatic patients. OBJECTIVE: To investigate the clinical implications of serum periostin levels in patients with aspirin-exacerbated respiratory disease (AERD) based on its overlapping TH2-mediated pathogenesis with the eosinophilic asthma. METHODS: Serum periostin levels were measured by human periostin enzyme-linked immunosorbent assay (ELISA) in serum samples from 277 adults with asthma. Serum periostin levels were compared between patients with AERD and aspirin tolerant asthma (ATA) with other asthma phenotypes, such as severe or nonsevere asthma and eosinophilic or noneosinophilic asthma. The association of serum periostin levels with clinical parameters (including disease severity and comorbid condition) was analyzed. RESULTS: Serum periostin levels were significantly higher in patients with AERD vs ATA, patients with severe asthma vs nonsevere asthma, and patients with eosinophilic asthma vs noneosinophilic asthma (P=.005, P=.02, and P=.001, respectively). Multivariate regression analysis revealed serum periostin levels as a significant parameter to predict AERD phenotype (P=.006) together with severe asthma phenotype (P=.04). In addition, serum periostin levels correlated with blood eosinophil counts (Spearman ñ = 0.244, P<.001) and sputum eosinophil counts (Spearman ñ = 0.261, P < 0.001). Higher serum periostin levels were noted in comorbid AERD patients with more severe chronic rhinosinusitis (Lund-Mackay stages 3 and 4) than those with less severe chronic rhinosinusitis (Lund-Mackay stages 1 and 2) (P = .03). CONCLUSION: Serum periostin levels are significantly elevated in AERD patients and associated with AERD phenotype and disease severity.