Displaying publications 21 - 40 of 129 in total

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  1. Norhafizah S, Salina H, Goh BS
    Eur Ann Allergy Clin Immunol, 2020 05;52(3):121-130.
    PMID: 31668057 DOI: 10.23822/EurAnnACI.1764-1489.119
    Summary: Introduction.The prevalence of allergic rhinitis in children with persistent otitis media with effusion in different countries varies between 82% to 93%. Many risk factors of otitis media with effusion has been studied and proven. However, its association with allergic rhinitis remains controversial. Objective. The main objective of this study is to determine the prevalence of allergic rhinitis in children with persistent otitis media with effusion. This study is also aimed to identify the risk factors of otitis media with effusion, common allergens associated with allergic rhinitis and determine the hearing threshold of children with otitis media with effusion. Methods.A hundred and thirty children were recruited. History taking, physical examination and hearing assessment were done in the first visit. Those with allergic rhinitis underwent skin prick test and treated with intranasal corticosteroid and antihistamine. A second examination and hearing assessment were then repeated after 3 months. Results.The prevalence of allergic rhinitis in children with persistent otitis media with effusion in this study was noted to be 80.3%. Among these children, dust mites appeared to be the most common allergen (87.7%). Another risk factor appeared to be families with more than 4 members per-household (96%). It is noted that that otitis media with effusion caused a hearing loss up to 33 dB. However, there was a statistically significant improvement of the hearing threshold during second visit after commencement of allergy treatment. It was also noted that the hearing threshold in allergic rhinitis group was significantly impaired compared to the non-allergic rhinitis group. Conclusions.Allergic rhinitis and larger family household appeared to be common risk factors in children with persistent otitis media with effusion. There is significant hearing loss noted in children suffering from otitis media with effusion and allergic rhinitis. The hearing threshold improved remarkably with medical therapy. This study hence clarifies the controversy on the association between allergic rhinitis and otitis media with effusion.
    Matched MeSH terms: Allergens/immunology
  2. Fu X, Norbäck D, Yuan Q, Li Y, Zhu X, Hashim JH, et al.
    Environ Int, 2020 05;138:105664.
    PMID: 32200316 DOI: 10.1016/j.envint.2020.105664
    Indoor microbial diversity and composition are suggested to affect the prevalence and severity of asthma by previous home microbiome studies, but no microbiome-health association study has been conducted in a school environment, especially in tropical countries. In this study, we collected floor dust and environmental characteristics from 21 classrooms, and health data related to asthma symptoms from 309 students, in junior high schools in Johor Bahru, Malaysia. The bacterial and fungal composition was characterized by sequencing 16s rRNA gene and internal transcribed spacer (ITS) region, and the absolute microbial concentration was quantified by qPCR. In total, 326 bacterial and 255 fungal genera were characterized. Five bacterial (Sphingobium, Rhodomicrobium, Shimwellia, Solirubrobacter, Pleurocapsa) and two fungal (Torulaspora and Leptosphaeriaceae) taxa were protective for asthma severity. Two bacterial taxa, Izhakiella and Robinsoniella, were positively associated with asthma severity. Several protective bacterial taxa including Rhodomicrobium, Shimwellia and Sphingobium have been reported as protective microbes in previous studies, whereas other taxa were first time reported. Environmental characteristics, such as age of building, size of textile curtain per room volume, occurrence of cockroaches, concentration of house dust mite allergens transferred from homes by the occupants, were involved in shaping the overall microbial community but not asthma-associated taxa; whereas visible dampness and mold, which did not change the overall microbial community for floor dust, was negatively associated with the concentration of protective bacteria Rhodomicrobium (β = -2.86, p = 0.021) of asthma. The result indicates complex interactions between microbes, environmental characteristics and asthma symptoms. Overall, this is the first indoor microbiome study to characterize the asthma-associated microbes and their environmental determinant in the tropical area, promoting the understanding of microbial exposure and respiratory health in this region.
    Matched MeSH terms: Allergens
  3. Han C, Chan WY, Hill PB
    Aust. Vet. J., 2020 Jan;98(1-2):17-25.
    PMID: 31742667 DOI: 10.1111/avj.12892
    OBJECTIVE: To determine the prevalence of positive allergen reactions in intradermal and IgE serological tests in dogs presenting to a dermatology referral centre in South Australia and the clinical efficacy of subsequent allergen-specific immunotherapy.

    DESIGN: Retrospective study.

    METHODS: Results from 108 intradermal allergy tests, 25 IgE serological assays and immunotherapy outcomes in 37 dogs were retrospectively analysed. Immunotherapy outcomes were determined as excellent, good, modest or failure using a global assessment of efficacy matrix which incorporated pruritus scores, lesion severity, medication requirements, and owner and clinician opinion.

    RESULTS: The most common positive reactions in intradermal allergy tests were Red clover (59%), Dermatophagoides farinae (29%), Tyrophagus putrescentiae (28%), Yellow dock (25%) and Malassezia pachydermatis (24%). In the IgE serological tests, Yorkshire fog grass (40%), Yellow dock (36%), Kentucky bluegrass (36%) and T. putrescentiae (36%) were the most commonly reported positive results. The outcome of allergen-specific immunotherapy was judged to be excellent in 20% of dogs, good in 15%, modest in 18% and a failure in 47%.

    CONCLUSION: As has been reported in other geographical areas, environmental mites and plant pollens frequently gave positive reactions in allergy tests in South Australia. However, the prevalence of individual allergen reactions differed between intradermal and IgE serological tests, with M. pachydermatis being identified as a common cause of hypersensitivity in intradermal tests but not in IgE serological assays. Immunotherapy was judged to be a beneficial treatment in 35% of dogs but was essentially unsuccessful in 65%.

    Matched MeSH terms: Allergens
  4. Siti Sarah CO, Md Shukri N, Mohd Ashari NS, Wong KK
    PeerJ, 2020;8:e9834.
    PMID: 32953271 DOI: 10.7717/peerj.9834
    Allergic rhinitis (AR) is a common disease affecting 400 million of the population worldwide. Nasal epithelial cells form a barrier against the invasion of environmental pathogens. These nasal epithelial cells are connected together by tight junction (TJ) proteins including zonula occludens-1 (ZO-1), ZO-2 and ZO-3. Impairment of ZO proteins are observed in AR patients whereby dysfunction of ZOs allows allergens to pass the nasal passage into the subepithelium causing AR development. In this review, we discuss ZO proteins and their impairment leading to AR, regulation of their expression by Th1 cytokines (i.e., IL-2, TNF-α and IFN-γ), Th2 cytokines (i.e., IL-4 and IL-13) and histone deacetylases (i.e., HDAC1 and HDAC2). These findings are pivotal for future development of targeted therapies by restoring ZO protein expression and improving nasal epithelial barrier integrity in AR patients.
    Matched MeSH terms: Allergens
  5. How KN, Yap WH, Lim CLH, Goh BH, Lai ZW
    Front Pharmacol, 2020;11:1105.
    PMID: 32848737 DOI: 10.3389/fphar.2020.01105
    Hyaluronic acid (HA), a major component of extracellular matrix has been widely applied in pharmaceutical and cosmetic industries due to its reported pharmacological properties. Various types of HA drug delivery system including nanoparticles, cryogel-based formulations, microneedle patches, and nano-emulsions were developed. There are studies reporting that several HA-based transdermal delivery systems exhibit excellent biocompatibility, enhanced permeability and efficient localized release of anti-psoriasis drugs and have shown to inhibit psoriasis-associated skin inflammation. Similarly HA is found in abundant at epidermis of atopic dermatitis (AD) suggesting its role in atopic AD pathology. Anti-allergenic effect of atopic eczema can be achieved through the inhibition of CD44 and protein kinase C alpha (PKCα) interaction by HA. Herein, we aim to evaluate the current innovation on HA drug delivery system and the other potential applications of HA in inflammatory skin diseases, focusing on atopic dermatitis and psoriasis. HA is typically integrated into different delivery systems including nanoparticles, liposomes, ethosomes and microneedle patches in supporting drug penetration through the stratum corneum layer of the skin. For instance, ethosomes and microneedle delivery system such as curcumin-loaded HA-modified ethosomes were developed to enhance skin retention and delivery of curcumin to CD44-expressing psoriatic cells whereas methotrexate-loaded HA-based microneedle was shown to enhance skin penetration of methotrexate to alleviate psoriasis-like skin inflammation. HA-based nanoparticles and pluronic F-127 based dual responsive (pH/temperature) hydrogels had been described to enhance drug permeation through and into the intact skin for AD treatment.
    Matched MeSH terms: Allergens
  6. Kailaivasan TH, Timbrell VL, Solley G, Smith WB, McLean-Tooke A, van Nunen S, et al.
    PMID: 32025301 DOI: 10.1002/cti2.1103
    Objective: Globally, grass pollens (GP) are major aeroallergen triggers of allergic rhinitis (AR) and asthma. However, patterns of allergic sensitisation to pollen of temperate (Pooideae: Lolium perenne) and subtropical (Chloridoideae: Cynodon dactylon and Panicoideae: Paspalum notatum) subfamilies in diverse climates remain unclear. This study aims to evaluate the level of allergic sensitisation and IgE specificity for major GP allergens representing the three subfamilies in biogeographically distinct regions.

    Methods: Participants (GP-allergic with AR, 330; non-atopic, 29; other allergies, 54) were recruited in subtropical: Queensland, and temperate: New South Wales, Western and South Australia, regions. Clinical history, skin prick test (SPT), total and specific IgE to GP and purified allergens (ImmunoCAP) were evaluated. Cross-inhibition of sIgE with Pas n 1, Cyn d 1 and Lol p 1 by GP extracts was investigated.

    Results: Queensland participants showed higher sensitisation to P. notatum and C. dactylon than L. perenne GP. sIgE was higher to Pas n 1 and Cyn d 1, and sIgE to Pas n 1 and Cyn d 1 was inhibited more by Panicoideae and Chloridoideae, respectively, than Pooideae GP. Conversely, participants from temperate regions showed highest sensitisation levels to L. perenne GP and Lol p 1, and sIgE to Lol p 1 was inhibited more by Pooideae than other GP.

    Conclusion: Levels and patterns of sensitisation to subtropical and temperate GP in AR patients depended on biogeography. Knowledge of the specificity of sensitisation to local allergens is important for optimal diagnosis and choice of allergen-specific immunotherapy to maximise benefit.

    Matched MeSH terms: Allergens
  7. Hamizan AW, Azer M, Alvarado R, Earls P, Barham HP, Tattersall J, et al.
    Am J Rhinol Allergy, 2019 Sep;33(5):524-530.
    PMID: 31106562 DOI: 10.1177/1945892419850750
    Matched MeSH terms: Allergens/immunology
  8. Hempolchom C, Sookrung N, Srisuka W, Reamtong O, Sakolvaree Y, Chaicumpa W, et al.
    Parasitol Res, 2019 Aug;118(8):2353-2359.
    PMID: 31263951 DOI: 10.1007/s00436-019-06383-x
    Simulium dermatitis is an IgE-mediated skin reaction in animals and humans caused by the bites of black flies. Although Simulium nigrogilvum has been incriminated as the main human-biting black fly species in Thailand, information on its salivary allergens is lacking. Salivary gland extract of S. nigrogilvum females was subjected to sodium dodecylsulfate-polyacrylamide gel electrophoresis, and the separated components were applied onto nitrocellulose membranes for immunoblotting, which was performed by probing the protein blots with sera from 17 individuals who were allergic to the bites of S. nigrogilvum. IgE-reactive protein bands were characterized further by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Nine protein bands (79, 42, 32, 25, 24, 22, 15, 13, and 11 kDa) were recognized in the serum of the subjects. Four of the nine protein bands (32, 24, 15, and 11 kDa) showed IgE reactivity in all (100%) of the tested sera, and they were identified as salivary secreted antigen 5-related protein, salivary serine protease, erythema protein, and hypothetical secreted protein, respectively. Three other proteins, salivary serine protease (25 kDa), salivary D7 secreted protein (22 kDa), and hypothetical protein (13 kDa), reacted with > 50% of the sera. The relevance of the identified protein bands as allergens needs to be confirmed by using pure recombinant proteins, either in the in vivo skin prick test or in vitro detection of the specific IgE in the serum samples of allergic subjects. This will be useful for the rational design of component-resolved diagnosis and allergen immunotherapy for the allergy mediated by the bites of black flies.
    Matched MeSH terms: Allergens/immunology; Allergens/chemistry
  9. Mohd Khairi MD, Shahrjerdi B, Ramiza RR, Normastura R
    Med J Malaysia, 2019 Jun;74(3):205-208.
    PMID: 31256174
    OBJECTIVE: Chronic suppurative otitis media (CSOM) usually begins as a spontaneous perforation of tympanic membrane due to an acute infection of the middle ear. This study was aimed to evaluate the association between allergy and CSOM.

    METHODS: A case-control study was carried out among patients with CSOM (cases) and controls were those with no ear pathology. The presence of CSOM was made through a medical history and otoscopic examination. Allergen testing was done by the skin prick test.

    RESULTS: In all 124 subjects were recruited in this study with equal number of the cases and controls. The commonest positive reaction in the skin prick test in both groups was to house dust mites. Among CSOM cases, half (50%) of them had an allergy to Blomia tropicalis and 48.4% to Dermatophagoides while in the control group, 27.4% to Dermatophagoides and 25.8% to B. tropicalis. There were significant associations between CSOM and allergy to B. tropicalis (p=0.005), Dermatophagoides (p=0.016) and Felis domesticus (p=0.040). The prevalence of allergy at 95% confidence interval (95%CI) in CSOM and control groups were demonstrated as 59.7% (95%CI: 47.5, 71.9) and 30.6 % (95%CI: 19.1, 42.1) respectively. There was a significant association between allergy and CSOM (p=0.001).

    CONCLUSION: Indoor allergens are the most prevalent in our environment and therefore good control may difficult to achieve. The hypersensitivity states of the subject are likely to have a role in the pathogenesis of CSOM especially in the tropical countries where allergy occurs perennially.

    Matched MeSH terms: Allergens
  10. Chan WY, Selvarajah GT, Ajat M, Suzuki R, Tsukui T
    Vet Immunol Immunopathol, 2019 Jun;212:43-49.
    PMID: 31213251 DOI: 10.1016/j.vetimm.2019.05.002
    Canine atopic dermatitis (AD) is a chronic, inflammatory and pruritic allergic skin disease in dogs. House dust mites such as Dermatophagoides farinae are one of the known causative agents for the induction of canine AD worldwide. D. farinae protein Der f 2 is known as an important allergen involved in canine AD and recently, Zen-1 has also been identified as an allergenic protein. There is limited information on the prevalence and role of allergen sensitization to crude D. farinae extract (CDF), Der f 2 and Zen-1 among dogs diagnosed with AD in Malaysia. The aim of this study was to determine the proportion of CDF-, Der f 2- and Zen-1-specific reactive sera among dogs diagnosed with AD in Malaysia using an enzyme-linked immunosorbent assay (ELISA). Serum samples were collected from dogs diagnosed with AD from several veterinary clinics in Malaysia. The canine case records were retrieved and information on signalment, dermatological and non-dermatological histories, clinical presentation, food allergies, and exclusion of ectoparasitic, microbial and fungal skin infections were obtained through a survey form. All serum samples were evaluated to quantify the CDF-, Der f 2- and Zen-1-specific immunoglobulin E (IgE) levels. A total of 24.6%, 48.4% and 29.8% of dogs diagnosed with AD were positive for CDF-, Der f 2- and Zen-1-specific IgE, respectively. These results suggest that CDF-, Der f 2- and Zen-1 are important allergens that can contribute to AD in dogs in Malaysia, and serological testing can be performed to provide additional treatment options involving specific immunotherapies.
    Matched MeSH terms: Allergens/immunology
  11. Muhamad SA, Muhammad NS, Ismail NDA, Mohamud R, Safuan S, Nurul AA
    Exp Ther Med, 2019 May;17(5):3867-3876.
    PMID: 30988772 DOI: 10.3892/etm.2019.7416
    Asthma is a chronic inflammatory disorder in the airways that involves the activation of cells and mediators. Lignosus rhinocerotis (Cooke) Ryvardan or Tiger Milk mushroom is a medicinal mushroom that is traditionally used to treat inflammatory diseases including asthma. In this study, the protective effects of intranasal administration of L. rhinocerotis extract (LRE) in ovalbumin (OVA)-induced airway inflammation mouse model were investigated. Mice were sensitized by intraperitoneal (i.p) injection on days 0 and 14, followed by a daily challenge with 1% OVA from days 21 to 27. Following OVA challenge, LRE and dexamethasone were administered via intranasal and i.p. injection respectively. On day 28, the level of serum immunoglobulin (Ig)E, differential cell counts and T-helper (Th) 2 cytokines in bronchoalveolar lavage fluid (BALF) fluid, cell subset population in lung-draining lymph nodes (LNs), leukocytes infiltration and mucus production in the lungs of the animals was measured. Results demonstrated that intranasal administration of LRE significantly suppressed the level of inflammatory cell counts in BALF as well as populations of CD4+ T-cells in lung draining LNs. Apart from that, LRE also significantly reduced the level of Th2 cytokines in BALF and IgE in the serum in OVA-induced asthma. Histological analysis also demonstrated the amelioration of leukocytes infiltration and mucus production in the lungs. Overall, these findings demonstrated the attenuation of airway inflammation in the LRE-treated mice therefore suggesting a promising alternative for the management of allergic airway inflammation.
    Matched MeSH terms: Allergens
  12. Mac Aogáin M, Tiew PY, Lim AYH, Low TB, Tan GL, Hassan T, et al.
    Am J Respir Crit Care Med, 2019 04 01;199(7):842-853.
    PMID: 30265843 DOI: 10.1164/rccm.201807-1355OC
    RATIONALE: Allergic sensitization is associated with poor clinical outcomes in asthma, chronic obstructive pulmonary disease, and cystic fibrosis; however, its presence, frequency, and clinical significance in non-cystic fibrosis bronchiectasis remain unclear.

    OBJECTIVES: To determine the frequency and geographic variability that exists in a sensitization pattern to common and specific allergens, including house dust mite and fungi, and to correlate such patterns to airway immune-inflammatory status and clinical outcomes in bronchiectasis.

    METHODS: Patients with bronchiectasis were recruited in Asia (Singapore and Malaysia) and the United Kingdom (Scotland) (n = 238), forming the Cohort of Asian and Matched European Bronchiectasis, which matched recruited patients on age, sex, and bronchiectasis severity. Specific IgE response against a range of common allergens was determined, combined with airway immune-inflammatory status and correlated to clinical outcomes. Clinically relevant patient clusters, based on sensitization pattern and airway immune profiles ("immunoallertypes"), were determined.

    MEASUREMENTS AND MAIN RESULTS: A high frequency of sensitization to multiple allergens was detected in bronchiectasis, exceeding that in a comparator cohort with allergic rhinitis (n = 149). Sensitization was associated with poor clinical outcomes, including decreased pulmonary function and more severe disease. "Sensitized bronchiectasis" was classified into two immunoallertypes: one fungal driven and proinflammatory, the other house dust mite driven and chemokine dominant, with the former demonstrating poorer clinical outcome.

    CONCLUSIONS: Allergic sensitization occurs at high frequency in patients with bronchiectasis recruited from different global centers. Improving endophenotyping of sensitized bronchiectasis, a clinically significant state, and a "treatable trait" permits therapeutic intervention in appropriate patients, and may allow improved stratification in future bronchiectasis research and clinical trials.

    Matched MeSH terms: Allergens/adverse effects*; Allergens/immunology*
  13. Soegiarto G, Abdullah MS, Damayanti LA, Suseno A, Effendi C
    Asia Pac Allergy, 2019 Apr;9(2):e17.
    PMID: 31089459 DOI: 10.5415/apallergy.2019.9.e17
    Background: The prevalence of allergy among Surabaya school children is currently unknown.

    Objective: To identify the prevalence of the common allergic sensitization and allergic diseases among school children and undergraduate students in suburban of Surabaya by epidemiologic data collection.

    Methods: A multistage simple random sampling was done to select 5 primary schools, 8 secondary schools (4 of junior high schools and senior high schools, respectively), and 1 university from 5 districts in Surabaya city. Out of 550 invited respondents, 499 (128 primary school, 221 secondary school, and 150 undergraduate) respondents gave their consent. A complete personal history, allergic symptoms, environmental exposure of common allergens was obtained from interview and the physical examinations were performed. Skin prick test (SPT) was done using 45 different allergen extracts. Total serum IgE and specific IgE radioallergosorbent test levels were measured for respondents with allergic manifestations.

    Results: There was an increasing SPT positivity among study respondents, from primary school, secondary school, to undergraduate students (21.90%, 28.95%, to 45.30% respectively). Cockroach (42.85%) and fungi/mold spore (42.85%) were the most common allergens in primary school children. House dust mites was the most common allergen in secondary school (63.16%) and undergraduate students (58.82%). Urticaria and rhinitis were the commonest allergic diseases manifestation. History of atopy was positive in 60.79% of the allergic respondents.

    Conclusion: The prevalence of allergic sensitization among school children and undergraduate students in Surabaya suburb areas were increased compared to previous estimates in 1998. While house dust mites are known as important allergens, surprisingly cockroach was the common allergen among the younger school children.

    Matched MeSH terms: Allergens
  14. Pang SL, Ho KL, Waterman J, Rambo RP, Teh AH, Mathavan I, et al.
    Sci Rep, 2019 Mar 20;9(1):4933.
    PMID: 30894561 DOI: 10.1038/s41598-019-40879-x
    Group 21 and 5 allergens are homologous house dust mite proteins known as mid-tier allergens. To reveal the biological function of group 21 allergens and to understand better the allergenicity of the rDer f 21 allergen, we determined the 1.5 Å crystal structure of rDer f 21 allergen from Dermatophagoides farinae. The rDer f 21 protein consists of a three helical bundle, similar to available structures of group 21 and homologous group 5 allergens. The rDer f 21 dimer forms a hydrophobic binding pocket similar to the one in the Der p 5 allergen, which indicates that both of the homologous groups could share a similar function. By performing structure-guided mutagenesis, we mutated all 38 surface-exposed polar residues of the rDer f 21 allergen and carried out immuno-dot blot assays using 24 atopic sera. Six residues, K10, K26, K42, E43, K46, and K48, which are located in the region between the N-terminus and the loop 1 of rDer f 21 were identified as the major IgE epitopes of rDer f 21. Epitope mapping of all potential IgE epitopes on the surface of the rDer f 21 crystal structure revealed heterogeneity in the sIgE recognition of the allergen epitopes in atopic individuals. The higher the allergen-sIgE level of an individual, the higher the number of epitope residues that are found in the allergen. The results illustrate the clear correlation between the number of specific major epitope residues in an allergen and the sIgE level of the atopic population.
    Matched MeSH terms: Allergens
  15. Hamizan AW, Rimmer J, Alvarado R, Sewell WA, Tatersall J, Barham HP, et al.
    Am J Rhinol Allergy, 2019 Mar;33(2):178-183.
    PMID: 30656948 DOI: 10.1177/1945892418825224
    BACKGROUND: Specific immunoglobulin E (sIgE) within the nasal airway is likely to be the most ideal marker of allergic status, but little is known of the normative values in asymptomatic patients and those with rhinitis.

    OBJECTIVE: The aim of this study was to assess the diagnostic characteristics of inferior turbinate tissue biopsy sIgE in asymptomatic and rhinitic patients.

    METHODS: A diagnostic cross-sectional study was undertaken, involving patients who underwent inferior turbinate surgery with or without other surgical interventions. Inferior turbinate tissue biopsy was performed during surgery and was assessed for allergen sIgE (dust mite, grass [temperate or subtropical], and animal epithelium) using an automated immunoassay. Tissue sIgE was assessed among asymptomatic patients and those with nasal symptoms. Data were presented as median (interquartile range). A receiver operating curve was used to predict the diagnostic utility of turbinate tissue sIgE in determining allergic rhinitis.

    RESULTS: A total of 160 patients (41.89 ± 14.65 years, 36.9% females) were included. The median tissue sIgE concentration among the asymptomatic nonatopic group of patients was 0.09 (0.08-0.10) kUA/L and tissue sIgE > 0.10 kUA/L was determined as a positive threshold. Inferior turbinate tissue sIgE was shown to be a predictive test for allergic rhinitis (area under curve: 0.87, 95% confidence interval: 0.84-0.90) with 90% sensitivity and 89% negative predictive value.

    CONCLUSION: Inferior turbinate tissue biopsy sIgE is a sensitive tool to predict allergic rhinitis. The threshold value of 0.1 kUA/L corresponded well with the asymptomatic nonatopic group of patients. This method detects sIgE in the nasal mucosa and may be a useful test for allergic rhinitis in future research.

    Matched MeSH terms: Allergens/immunology
  16. Reginald K, Chew FT
    Sci Rep, 2019 02 07;9(1):1556.
    PMID: 30733527 DOI: 10.1038/s41598-018-38313-9
    Der p 2 is a major dust mite allergen and >80% of mite allergic individuals have specific IgE to this allergen. Although it is well characterized in terms of allergenicity, there is still some ambiguity in terms of its biological function. Three-dimensional structural analysis of Der p 2 and its close homologues indicate the presence of a hydrophobic cavity which can potentially bind to lipid molecules. In this study, we aimed to identify the potential ligand of Der p 2. Using a liposome pulldown assay, we show that recombinant Der p 2 binds to liposomes prepared with exogenous cholesterol in a dose dependent fashion. Next, an ELISA based assay using immobilized lipids was used to study binding specificities of other lipid molecules. Cholesterol was the preferred ligand of Der p 2 among 11 different lipids tested. Two homologues of Der p 2, Der f 2 and Der f 22 also bound to cholesterol. Further, using liquid chromatography-mass spectrometry (LC-MS), we confirmed that cholesterol is the natural ligand of Der p 2. Three amino acid residues of Der p 2, V104, V106 and V110 are possible cholesterol binding sites, as alanine mutations of these residues showed a significant decrease in binding (p 
    Matched MeSH terms: Allergens/metabolism*; Allergens/chemistry
  17. Reginald K, Tan CL, Chen S, Yuen L, Goh SY, Chew FT
    Sci Rep, 2018 08 06;8(1):11743.
    PMID: 30082894 DOI: 10.1038/s41598-018-30224-z
    We previously identified an expressed sequence tag clone, Der f 22, showing 41% amino acid identity to published Der f 2, and show that both genes are possible paralogues. The objective of this study was to characterize the genomic, proteomic and immunological functions Der f 22 and Der f 2. The full-length sequence of Der f 2 and Der f 22 coded for mature proteins of 129 and 135 amino acids respectively, both containing 6 cysteine residues. Phylogenetic analysis of known group 2 allergens and their homologues from our expressed sequence tag library showed that Der f 22 is a paralogue of Der f 2. Both Der f 2 and Der f 22 were single gene products with one intron. Both allergens showed specific IgE-binding to over 40% of the atopic patients, with limited of cross-reactivity. Both allergens were detected at the gut region of D. farinae by immunostaining. Der f 22 is an important allergen with significant IgE reactivity among the atopic population, and should be considered in the diagnostic panel and evaluated as future hypoallergen vaccine therapeutic target.
    Matched MeSH terms: Allergens/classification; Allergens/metabolism*; Allergens/chemistry
  18. Kulthanan K, Chusakul S, Recto MT, Gabriel MT, Aw DCW, Prepageran N, et al.
    Allergy Asthma Immunol Res, 2018 Jul;10(4):370-378.
    PMID: 29949833 DOI: 10.4168/aair.2018.10.4.370
    PURPOSE: Across Hong Kong, Malaysia, the Philippines, Singapore, Thailand and Vietnam, (referred to as Asia) approximately 30-53 million individuals of the 151 million employed suffer from allergic rhinitis (AR) and urticaria. It is estimated that approximately 90% of patients with these allergic conditions are insufficiently treated, impacting the socioeconomic burden in terms of absence from work and decreased productivity. This study aims to estimate the socioeconomic burden of allergies in Asia and the cost savings that their adequate management can provide. Due to the limited availability of regional data, this study focused AR and urticaria in selected countries.

    METHODS: Published literature, information from statistical bureaus, clinician surveys and extrapolation of selected data from the European Union were used to determine the socioeconomic costs of AR and urticaria.

    RESULTS: Many patients in Asia suffer from perennial allergies and experience symptoms of AR and urticaria for up to 298 days per year. An estimate of the indirect costs of patients insufficiently treated for AR and urticaria amounts to USD 105.4 billion a year, which equates to USD 1,137-2,195 per patient due to absenteeism and presenteeism. Adherence to guideline-approved treatment can lead to estimated savings of up to USD 104 billion.

    CONCLUSIONS: The current study suggests that within Asia, the socioeconomic impact of AR and urticaria is similar to that seen in the European Union in spite of the lower wages in Asia. This is due to the mainly perennial allergens prevailing in Asia, whereas the sensitization patterns observed in the European Union are dominated by seasonal exposure to pollen. These results underline the need for governmental initiatives to increase public awareness on the prevention and treatment of these and other allergic diseases as well as greater research funding and large-scale studies to reduce their growing socioeconomic burden in coming years.

    Matched MeSH terms: Allergens
  19. Soon JM
    Food Res Int, 2018 06;108:455-464.
    PMID: 29735079 DOI: 10.1016/j.foodres.2018.03.068
    Food allergen labelling is mandatory and regulated whilst precautionary allergen labelling (PAL) remains voluntary in most countries. It is the aim of this study to identify the food allergens declared in food products sold in a developing country and to what extent food allergens and PAL are emphasised in the products. A total of 505 food and beverages (snacks, baked goods, confectionary, baby food, condiments & jams, beverages, powder & paste, instant food, chilled & frozen food and canned food) were evaluated in Malaysia. Soybean represents the largest group of food allergen declared in labels, followed by wheat and milk products. Thirteen variations of contains statement were found with "Contains [allergen(s)]" being the most common (55.02%). There were 22 different types of "may contain" statements with 'May contain traces of [allergen(s)]' being the most common advice labelling used (55.41%). Different font type or emphasis such as brackets (51.57%) and bold font (33.86%) were used to inform consumers about presence of allergens. The national regulations on food allergen labelling are then critically contrasted with other Asian countries and the EU Regulation No. 1169/2011, which represents one of the most stringent food regulations in the world. Improving current allergen labelling limitations and practices would be of great benefit to consumers to prevent risk of food hypersensitivity.
    Matched MeSH terms: Allergens/adverse effects*
  20. Goh YY, Keshavarzi F, Chew YL
    Dermatitis, 2018 5 16;29(3):151-161.
    PMID: 29762208 DOI: 10.1097/DER.0000000000000376
    BACKGROUND: Atopic dermatitis (AD) is a chronic relapsing, noncontagious skin inflammation characterized by dry skin and itch. Mutation in filaggrin gene leads to defective skin barrier, allowing entry of allergen and eliciting immunological response.

    OBJECTIVES: The aims of this study were to investigate the prevalence of AD in Malaysian children and to understand the pattern of drug therapy. Such information could be useful to establish the relationship between ethnicity and family history of atopy and the development of associated signs and symptoms.

    METHODS: A cross-sectional survey was conducted among children attending kindergartens and nurseries. Standardized questionnaires were filled out by parents.

    RESULTS: Overall prevalence of AD was 13.4%. Of 384 participants recruited, the highest prevalence was observed in males, Malays, participants younger than 2 years, and those with atopic background such as asthma, hay fever, and family history of atopic diseases. Calamine and white soft paraffin were the preferred choice of nonprescription drugs, whereas topical hydrocortisone seemed to be the preferred choice of prescription drug in the management of AD.

    CONCLUSIONS: The overall prevalence is comparable to that reported in the International Study of Asthma and Allergies in Childhood Phase One. There is an association between ethnicity and AD prevalence. Topical corticosteroids and emollients are the mainstay of AD management among Malaysians.

    Matched MeSH terms: Allergens
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