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Molecular cloning and immunoglobulin E reactivity of a natural rubber latex lecithinase homologue, the major allergenic component of Hev b 4

Sunderasan E, Bahari A, Arif SA, Zainal Z, Hamilton RG, Yeang HY

Clin Exp Allergy, 2005 Nov;35(11):1490-5.
PMID: 16297147 DOI: 10.1111/j.1365-2222.2005.02371.x

BACKGROUND:
Hev b 4 is an allergenic natural rubber latex (NRL) protein complex that is reactive in skin prick tests and in vitro immunoassays. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Hev b 4 is discerned predominantly at 53-55 kDa together with a 57 kDa minor component previously identified as a cyanogenic glucosidase. Of the 13 NRL allergens recognized by the International Union of Immunological Societies, the 53-55 kDa Hev b 4 major protein is the only candidate that lacks complete cDNA and protein sequence information.

OBJECTIVE:
We sought to clone the transcript encoding the Hev b 4 major protein, and characterize the native protein and its recombinant form in relation to IgE binding.

METHODS:
The 5'/3' rapid amplification of cDNA ends method was employed to obtain the complete cDNA of the Hev b 4 major protein. A recombinant form of the protein was over-expressed in Escherichia coli. The native Hev b 4 major protein was deglycosylated by trifluoromethane sulphonic acid. Western immunoblots of the native, deglycosylated and recombinant proteins were performed using both polyclonal antibodies and sera from latex-allergic patients.

RESULTS:
The cDNA encoding the Hev b 4 major protein was cloned. Its open reading frame matched lecithinases in the conserved domain database and contained 10 predicted glycosylation sites. Detection of glycans on the Hev b 4 lecithinase homologue confirmed it to be a glycoprotein. The deglycosylated lecithinase homologue was discerned at 40 kDa on SDS-PAGE, this being comparable to the 38.53 kDa mass predicted by its cDNA. Deglycosylation of the lecithinase homologue resulted in the loss of IgE recognition, although reactivity to polyclonal rabbit anti-Hev b 4 was retained. IgE from latex-allergic patients also failed to recognize the non-glycosylated E. coli recombinant lecithinase homologue.

CONCLUSION:
The IgE epitopes of the Hev b 4 lecithinase homologue reside mainly in its carbohydrate moiety, which also account for the discrepancy between the observed molecular weight of the protein and the value calculated from its cDNA.

Matched MeSH terms: Allergens/immunology*
Minimal agreement between basophil activation test and immunoassay in diagnosis of penicillin allergy

Leecyous B, Bakhtiar F, Tang MM, Yadzir ZHM, Abdullah N

Allergol Immunopathol (Madr), 2020 06 09;48(6):626-632.
PMID: 32532468 DOI: 10.1016/j.aller.2020.01.006

INTRODUCTION: Basophil activation test (BAT) and immunoassays are the most widely used in vitro tests to diagnose IgE-mediated allergic reactions to penicillin. However, studies to determine if one test is interdependent from another are limited.
OBJECTIVE: The present study aimed to measure the agreement between BAT and immunoassay in diagnosis of penicillin allergy.
METHOD: BAT was performed using penicillin G (Pen G), penicillin V (Pen V), penicilloyl-polylysine (PPL), minor determinant mix (MDM), amoxicillin (Amx) and ampicillin (Amp) in 25 patients. Immunoassay of total IgE (tIgE) and specific IgE (sIgE) antibodies to Pen G, Pen V, Amx and Amp were quantified. Skin prick test (SPT) using PPL-MDM, Amx, Amp and Clavulanic acid were also performed.
RESULTS: Minimal agreement was observed between BAT and immunoassay (k=0.25). Of two BAT-positive patients, one patient is positive to Amx (59.27%, SI=59) and Amp (82.32%, SI=82) but sIgE-negative to all drug tested. This patient is also SPT-positive to both drugs. Another patient is BAT-positive to Pen G (10.18%, SI=40), Pen V (25.07%, SI=100) and Amp (19.52%, SI=79). In sIgE immunoassay, four patients were sIgE-positive to at least one of the drugs tested. The sIgE level of three patients was between low and moderate and they were BAT-negative. One BAT-positive patient had a high level of sIgE antibodies (3.50-17.5kU/L) along with relatively high specific to total IgE ratio ≥0.002 (0.004-0.007).
CONCLUSIONS: The agreement between BAT and immunoassay is minimal. Performing both tests provides little increase in the sensitivity of allergy diagnosis work-up for immediate reactions to penicillin.

Matched MeSH terms: Allergens/immunology
Middle turbinate edema as a diagnostic marker of inhalant allergy

Hamizan AW, Christensen JM, Ebenzer J, Oakley G, Tattersall J, Sacks R, et al.

Int Forum Allergy Rhinol, 2017 01;7(1):37-42.
PMID: 27530103 DOI: 10.1002/alr.21835

BACKGROUND: Middle turbinate edema could be a characteristic feature of aeroallergen sensitization. In this study we sought to determine the diagnostic characteristics of middle turbinate edema as a marker of inhalant allergy.
METHODS: A cross-sectional diagnostic study was performed on patients who had undergone nasal endoscopy and allergy testing. Allergy status was determined by positive serology or epicutaneous testing. Endoscopy was reviewed by blinded assessors for middle turbinate head edema. Appearance was graded as either normal, focal, multifocal, diffuse, or polypoid edema. Receiver-operator (ROC) analysis, likelihood ratio (LR), sensitivity, specificity, and positive predictive value (PPV) were determined.
RESULTS: One hundred eighty-seven patients representing 304 nasal cavities were assessed (42% female, age 39.74 ± 14.7 years, 57% allergic). Diffuse edema (PPV 91.7%/LR = 8) and polypoid edema (PPV 88.9%/LR = 6.2) demonstrated the strongest association with inhalant allergy. Multifocal edema was used as a cut-off to represent inhalant allergy from ROC analysis, which demonstrated 94.7% specificity and 23.4% sensitivity. The PPV for multifocal was 85.1% and LR = 4.4.
CONCLUSION: Middle turbinate edema is a useful nasal endoscopic feature to predict presence of inhalant allergy and, although not sensitive, has excellent PPV.

Matched MeSH terms: Allergens/immunology
Low prevalence of latex sensitivity in South African spina bifida children in Cape Town

Johar A, Lim DL, Arif SA, Hawarden D, Toit GD, Weinberg EG, et al.

Pediatr Allergy Immunol, 2005 Mar;16(2):165-70.
PMID: 15787875

Spina bifida children have a high prevalence of latex allergy in studies reported from Europe and the USA. This study investigated the prevalence of latex allergy in a cohort of 24 spina bifida children at the Red Cross Children's Hospital from Cape Town, South Africa. The children were investigated using a detailed questionnaire, skin prick tests (ALK-Abello), ImmunoCap RASTs, Western blotting and ELISA, using the purified latex proteins Hev b1 and Hev b3 and whole latex preparation. A low overall prevalence of latex sensitization of 16.7% was found in the children. Children who were sensitive reacted to water insoluble to Hev b1 and Hev b3 proteins. The low prevalence of latex sensitization in the South African children may not be entirely explained by stringent latex avoidance. The children were from a low socioeconomic social status and 'hygiene' and other factors should be considered.

Matched MeSH terms: Allergens/immunology
Fulltext Insight into different environmental niches adaptation and allergenicity from the Cladosporium sphaerospermum genome, a common human allergy-eliciting Dothideomycetes

Yew SM, Chan CL, Ngeow YF, Toh YF, Na SL, Lee KW, et al.

Sci Rep, 2016 05 31;6:27008.
PMID: 27243961 DOI: 10.1038/srep27008

Cladosporium sphaerospermum, a dematiaceous saprophytic fungus commonly found in diverse environments, has been reported to cause allergy and other occasional diseases in humans. However, its basic biology and genetic information are largely unexplored. A clinical isolate C. sphaerospermum genome, UM 843, was re-sequenced and combined with previously generated sequences to form a model 26.89 Mb genome containing 9,652 predicted genes. Functional annotation on predicted genes suggests the ability of this fungus to degrade carbohydrate and protein complexes. Several putative peptidases responsible for lung tissue hydrolysis were identified. These genes shared high similarity with the Aspergillus peptidases. The UM 843 genome encodes a wide array of proteins involved in the biosynthesis of melanin, siderophores, cladosins and survival in high salinity environment. In addition, a total of 28 genes were predicted to be associated with allergy. Orthologous gene analysis together with 22 other Dothideomycetes showed genes uniquely present in UM 843 that encode four class 1 hydrophobins which may be allergens specific to Cladosporium. The mRNA of these hydrophobins were detected by RT-PCR. The genomic analysis of UM 843 contributes to the understanding of the biology and allergenicity of this widely-prevalent species.

Matched MeSH terms: Allergens/immunology
Fulltext Inhalation of honey reduces airway inflammation and histopathological changes in a rabbit model of ovalbumin-induced chronic asthma

Kamaruzaman NA, Sulaiman SA, Kaur G, Yahaya B

BMC Complement Altern Med, 2014;14:176.
PMID: 24886260 DOI: 10.1186/1472-6882-14-176

Honey is widely used in folk medicine to treat cough, fever, and inflammation. In this study, the effect of aerosolised honey on airway tissues in a rabbit model of ovalbumin (OVA)-induced asthma was investigated. The ability of honey to act either as a rescuing agent in alleviating asthma-related symptoms or as a preventive agent to preclude the occurrence of asthma was also assessed.

Matched MeSH terms: Allergens/immunology
Improved Diagnosis of the Polysensitized Allergic Rhinitis Patients Using Component Resolved Diagnosis Method

Mohamad Yadzir ZH, Bakhtiar F, Misnan R, Abdullah N, Leecyous B, Murad S

Iran J Allergy Asthma Immunol, 2016 Apr;15(2):156-60.
PMID: 27090369

Allergy diagnosis needs to be improved in polysensitized patients due to the existence of possible confounding factors in this type of patients. Component resolved diagnosis (CRD) is a new concept in the investigation of polysensitized patients. The aim of this study was to evaluate if the utilization of ImmunoCAP ISAC improve the diagnosis of the polysensitized allergic rhinitis patients. Skin prick test (SPT) to 58 crude allergen extracts and CRD (ImmunoCAP ISAC) were carried out for 5 polysensitized allergic rhinitis patients. Two patients had a shellfish allergy and avoidance of shellfish was the only way to prevent an allergic reaction. In contrast, although the remaining three patients had low risk for shellfish allergy, but they were the best candidates for immunotherapy using mite extracts. CRD and particularly ImmunoCAP ISAC have proven to be a valuable diagnostic tool in polysensitized patients. ImmunoCAP ISAC helps refine the individual patient's sensitization profile and predict the potential risk of allergic reactions and improve the selection of patients for immunotherapy.

Matched MeSH terms: Allergens/immunology
Immunochemical characterization of edible bird's nest allergens

Goh DL, Chua KY, Chew FT, Liang RC, Seow TK, Ou KL, et al.

J Allergy Clin Immunol, 2001 Jun;107(6):1082-7.
PMID: 11398089

BACKGROUND: We have previously described anaphylaxis induced by edible bird's nest (BN) and demonstrated that this condition is IgE mediated.
OBJECTIVES: This study aimed at describing the immunochemical properties of the BN allergens. Comparative studies between 3 commercially available sources (according to the country of origin) of BN were also made.
METHODS: Crude extracts of commercially available processed BN from Sarawak (Malaysia), Thailand, and Indonesia and fresh unprocessed BN from the caves of Sarawak were obtained by means of aqueous extraction. Specific IgE toward these sources were determined by using fluorescence allergosorbent tests (FASTs). Cross-reactivity studies between the 3 sources of commercially available processed BN were carried out by means of FAST inhibition. Immunochemical characterization by means of IgE immunoblot, periodate treatment, and heat stability studies were carried out on fresh unprocessed BN from Sarawak.
RESULTS: Serum from allergic patients showed differences in IgE binding to the 3 sources of commercially available BN, with the highest levels of specific IgE recorded with the Sarawak source (P

Matched MeSH terms: Allergens/immunology*
Fulltext IgE-binding residues analysis of the house dust mite allergen Der p 23

Pang SL, Matta SA, Sio YY, Ng YT, Say YH, Ng CL, et al.

Sci Rep, 2021 01 13;11(1):921.
PMID: 33441720 DOI: 10.1038/s41598-020-79820-y

House dust mites (HDMs) are one of the major causes of allergies in the world. The group 23 allergen, Der p 23, from Dermatophagoides pteronyssinus, is a major allergen amongst HDM-sensitized individuals. This study aims to determine the specific immunoglobulin E (sIgE) binding frequency and IgE-binding residues of recombinant Der p 23 (rDer p 23) allergen amongst a cohort of consecutive atopic individuals in a tropical region. We performed site-directed mutagenesis and carried out immuno-dot blot assays using 65 atopic sera. The immuno-dot blot assays results indicated that the two residues K44 and E46 which are located at the N-terminal region are the major IgE-binding residues. The rDerp-23 sIgE titers are strongly correlated to the number of IgE-binding residues for rDer p 23 (P

Matched MeSH terms: Allergens/immunology
Identification of tropomyosin as major allergen of white squid (Loligo edulis) by two-dimensional immunoblotting and mass spectrometry

Yadzir ZH, Misnan R, Murad S

Southeast Asian J. Trop. Med. Public Health, 2012 Jan;43(1):185-91.
PMID: 23082569

IgE-mediated allergic reaction to squid is one of the most frequent molluscan shellfish allergies. Previously, we have detected a 36 kDa protein as the major allergen of Loligo edulis (white squid) by immunoblotting using sera from patients with squid allergy. The aim of this present study was to further identify this major allergen using a proteomics approach. The major allergen was identified by a combination of two-dimensional electrophoresis (2-DE), immunoblotting, mass spectrometry and bioinformatics tools. The 2-DE gel fractionated the cooked white squid proteins to more than 50 different protein spots between 10 to 38 kDa and isoelectric point (pI) from 3.0 to 10.0. A highly reactive protein spot of a molecular mass of 36 kDa and pI of 4.55 was observed in all of the patients' serum samples tested. Mass spectrometry analysis led to identification of this allergen as tropomyosin. This finding can contribute to advancement in component-based diagnosis, management of squid allergic patients, to the development of immunotherapy and to the standardization of allergenic test products as tools in molecular allergology.

Matched MeSH terms: Allergens/immunology*
Fulltext Identification of tropomyosin and arginine kinase as major allergens of Portunus pelagicus (blue swimming crab)

Rosmilah M, Shahnaz M, Zailatul HM, Noormalin A, Normilah I

Trop Biomed, 2012 Sep;29(3):467-78.
PMID: 23018510

Crab is an important source of food allergen. Tropomyosin represents the main crab allergen and is responsible for IgE cross-reactivity between various species of crustaceans. Recently, other new crab allergens including arginine kinase have been identified. However, information on allergens of the local Portunidcrab is not available. Thus, the aim of this study was to identify the major allergens of Portunus pelagicus (blue swimming crab) using the allergenomics approach. Raw and cooked extracts of the crab were prepared from the crab meat. Protein profile and IgE binding pattern were demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from 30 patients with crab allergy. The major allergens of the crab were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry analysis of the peptide digests. The SDS-PAGE of raw extract revealed approximately 20 protein fractions over a wide molecular weight range, while cooked extract demonstrated fewer protein bands. The raw extract also demonstrated a higher number of IgE reactive bands than the cooked extract. A heat-resistant protein of 36 kDa has been identified as the major allergen in both raw and cooked extracts. In addition, a heat-sensitive protein of 41 kDa was also recognized as a major allergen in raw crab. The 2-DE gel profile of the raw extract demonstrated about >100 distinct proteins spots and immunoblotting of the 2-DE profile demonstrated at least 12 different major IgE reactive spots with molecular masses between 13 to 250 kDa and isoelectric point (pI) values ranging from 4.0 to 7.0. The 36 and 41 kDa proteins were identified as the crab tropomyosin and arginine kinase, respectively by mass spectrometry. Therefore, this study confirmed that tropomyosin and arginine kinase are the major allergens of the local Portunid crab, P. pelagicus.

Matched MeSH terms: Allergens/immunology*
Identification of the major allergens of Indian scad (Decapterus russelli)

Misnan R, Murad S, Jones M, Taylor G, Rahman D, Arip M, et al.

Asian Pac J Allergy Immunol, 2008 Dec;26(4):191-8.
PMID: 19317337

The purpose of this study was to characterize major allergens of Indian scad (Decapterus russelli) which is among the most commonly consumed fish in Malaysia. Raw and cooked extracts of the fish were prepared. Protein profiles and IgE binding patterns were produced by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from subjects with fish allergy. The major allergens of the fish were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry of the peptide digests. The SDS-PAGE of the raw extract revealed 27 protein fractions over a wide molecular weight range, while the cooked extract demonstrated only six protein fractions. The 1-DE immunoblotting detected 14 IgE-binding proteins, with a molecular weight range from 90 to < 6.5 kDa. Three protein fractions with molecular weights of approximately 51, 46 and 12 kDa were identified as the major allergens of this fish. The approximately 12 kDa band was a heat-resistant protein while the approximately 51 and 46 kDa proteins were sensitive to heat. The 2-DE gel profile of the raw extract demonstrated > 100 distinct protein spots and immunoblotting detected at least 10 different major IgE reactive spots with molecular masses as expected and isoelectric point (pI) values ranging from 4.0 to 7.0. A comparison of the major allergenic spot sequences of the 12 kDa proteins with known protein sequences in databases revealed extensive similarity with fish parvalbumin. In conclusion, this study demonstrated that a parvalbumin which is similar to Gad c 1 is the major allergen of Indian scad. Interestingly, we also detected heat-sensitive proteins as major allergenic components in our fish allergy patients.

Matched MeSH terms: Allergens/immunology*
Identification of the major allergens of Charybdis feriatus (red crab) and its cross-reactivity with Portunus pelagicus (blue crab)

Misnan R, Murad S, Yadzir ZH, Abdullah N

Asian Pac J Allergy Immunol, 2012 Dec;30(4):285-93.
PMID: 23393908

Tropomyosin and arginine kinase have been identified as the major allergens in multiple species of crab. Charybdis feriatus is an important commercial crab in this country.

Matched MeSH terms: Allergens/immunology*
Fulltext Identification of parvalbumin and two new thermolabile major allergens of Thunnus tonggol using a proteomics approach

Rosmilah M, Shahnaz M, Meinir J, Masita A, Noormalin A, Jamaluddin M

Int Arch Allergy Immunol, 2013;162(4):299-309.
PMID: 24193115 DOI: 10.1159/000354544

The longtail tuna (Thunnus tonggol) is widely consumed in Asia. Parvalbumin, the main major allergen of fish, has been well identified in multiple fish species, yet little is known about the allergenic proteins in T. tonggol. Thus, the aim of this study was to characterize the major allergens of T. tonggol using a proteomics approach.

Matched MeSH terms: Allergens/immunology
Identification of major allergens of wildflower honey

Yadzir ZH, Misnan R, Abdullah N, Arip M, Murad S

Southeast Asian J. Trop. Med. Public Health, 2011 Mar;42(2):370-5.
PMID: 21710860

The aim of this study was to identify the major allergens of wildflower honey in local patients with atopic disease. SDS-PAGE revealed ten protein bands of 25 to 110 kDa, with a heavy cluster in region of 40-75 kDa. Immunoblotting demonstrated seven IgE-binding bands of 39 to 110 kDa. The 60 kDa protein had the highest frequency of IgE-binding (100%) followed by 54 kDa protein (95%), thus identified as the major allergens of wildflowerhoney. Our findings indicate that the allergen extract used for diagnosis of honey allergy contains both the 54 kDa and 60 kDa proteins.

Matched MeSH terms: Allergens/immunology*
Fulltext Identification of major allergens of two species of local snappers: Lutjanus argentimaculatus (merah/ red snapper) and Lutjanus johnii (jenahak/ golden snapper)

Rosmilah M, Shahnaz M, Masita A, Noormalin A, Jamaludin M

Trop Biomed, 2005 Dec;22(2):171-7.
PMID: 16883284 MyJurnal

Fish has been recognized as a source of potent allergens both in food and occupational allergy. Lutjanus argentimaculatus (red snapper) and Lutjanus johnii (golden snapper) locally known as merah and jenahak, respectively, are among the most commonly consumed fish in Malaysia. The objective of this study is to identify the IgE-binding proteins and major allergens of these species of fishes. Extracts of both fish species were prepared and fractionated by sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding patterns were then demonstrated by immunoblotting using sera from patients allergic to the fishes. The raw extracts of both fish produced 26 protein bands. Both species of fishes had similar protein profiles. In cooked extracts, several protein bands in the range of about 40 to 90 kD which were present in the uncooked extracts appeared to be denatured and formed high molecular weight complexes. The immunoblotting of golden snapper and red snapper revealed 16 and 15 various IgE-binding bands, in the range of 151 to 12-11 kD, respectively. A 51 kD protein was identified as a major allergen for both fishes. A 46 kD protein was also demonstrated as a major allergen in golden snapper and a 42 kD protein was also seen as a major allergen in red snapper. A heat-resistant protein of ~12 kD which is equivalent in size with fish parvalbumin was demonstrated only as minor allergen for both fishes.

Matched MeSH terms: Allergens/immunology
Fungal DNA, allergens, mycotoxins and associations with asthmatic symptoms among pupils in schools from Johor Bahru, Malaysia

Cai GH, Hashim JH, Hashim Z, Ali F, Bloom E, Larsson L, et al.

Pediatr Allergy Immunol, 2011 May;22(3):290-7.
PMID: 21457336 DOI: 10.1111/j.1399-3038.2010.01127.x

While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO(2) levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29°C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m(2)) was 5.7*10(8) and 0.5*10(8), respectively. The arithmetic mean (CE/m(2)) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m(2)) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m(2) per day) was 9.2*10(6) and 1.6*10(6), respectively. The arithmetic mean (CE/m(2) per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m(2) per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.

Matched MeSH terms: Allergens/immunology
First report on sensitization to allergens of a house dust mite, Suidasia pontifica (Acari: Saproglyphidae)

Mariana A, Ho TM, Gendeh BS, Iskandar H, Zainuldin-Taib M

Southeast Asian J. Trop. Med. Public Health, 2000 Dec;31(4):722-3.
PMID: 11414419

A species of house dust mite, Suidasia pontifica, was recently shown to produce allergens affecting man. The species may be as important as other allergen producing mite in sensitization and causing allergic symptoms in Malaysians. Surveys conducted demonstrated that 80% of the houses surveyed were positive for this mite with densities ranged from 2 to 50 mites per gram of dust. Colonies of the species has been successfully established and materials from those colonies have been used to produce extracts for studies on sensitization to the mites. A total of 85 suspected allergic rhinitis patients were tested and 74.1% demonstrated positive reactions. Extract of this mite should be considered for routine diagnostic testing and possible immunotherapy.

Matched MeSH terms: Allergens/immunology*
FeNO level and allergy status among school children in Terengganu, Malaysia

Ma'pol A, Hashim JH, Norbäck D, Weislander G, Hashim Z, Isa ZM

J Asthma, 2020 08;57(8):842-849.
PMID: 31155989 DOI: 10.1080/02770903.2019.1614614

Background: Almost one third of the world population suffers from allergic conditions. Respiratory symptoms are common in Malaysian children but there are few studies on fractional exhaled nitric oxide (FeNO), inclusive of field clinical test for asthma among children in Malaysia. The aim was to provide insight on factors related to level of FeNO among students in Terengganu, Malaysia.Methods: In total, 487 randomly selected students from eight secondary schools participated (13-14 years old). A Standardized questionnaire was used to obtained information on doctors' diagnosed asthma, current asthma and respiratory symptoms. FeNO measurement and skin prick test (SPT to common allergen) were conducted.Results: The geometric mean FeNO was 16.7 ppb. Totally, 38.4% of students had elevated FeNO level (>20 ppb) and 40.3% had had positive SPT to house dust mites allergens (HDM), Dermatophagoides pteronyssinus (Der p 1), Dermatophagoides farinae (Der f 1) or Felis domisticus (cat). Male gender, height, parental history of allergy, self-reported allergy, and atopy were associated with FeNO. In particular, a combination of sensitization to HDM or cat and elevated FeNO were associated with doctor-diagnosed asthma and self-reported allergy to food, pollen and cat.Conclusion: Asthma, respiratory symptoms and sensitization to HDM and cat are common among students and presence of elevated FeNO levels indicate ongoing airway inflammation.

Matched MeSH terms: Allergens/immunology*
Expression of a codon-optimised recombinant Ara h 2.02 peanut allergen in Escherichia coli

Lew MH, Lim RL

Appl Microbiol Biotechnol, 2016 Jan;100(2):661-71.
PMID: 26411458 DOI: 10.1007/s00253-015-6953-y

Current diagnostic tools for peanut allergy using crude peanut extract showed low predictive value and reduced specificity for detection of peanut allergen-specific immunoglobulin E (IgE). The Ara h 2.02, an isoform of the major peanut allergen Ara h 2, contains three IgE epitope recognition sequence of 'DPYSPS' and may be a better reagent for component resolve diagnosis. This research aimed to generate a codon-optimised Ara h 2.02 gene for heterologous expression in Escherichia coli and allergenicity study of this recombinant protein. The codon-optimised gene was generated by PCR using overlapping primers and cloned into the pET-28a (+) expression vector. Moderate expression of a 22.5 kDa 6xhistidine-tagged recombinant Ara h 2.02 protein (6xHis-rAra h 2.02) in BL21 (DE3) host cells was observed upon induction with 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG). The insoluble recombinant protein was purified under denaturing condition using nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography and refolded by dialysis in decreasing urea concentration, amounting to a yield of 74 mg/l of expression culture. Matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) and immunoblot analysis confirmed the production of the recombinant 6xHis-rAra h 2.02. The refolded recombinant 6xHis-rAra h 2.02, with or without adjuvant, was able to elicit comparable level of allergen-specific IgE and IgG1 in sensitised Balb/c mice. In addition, the specific IgE antibodies raised against the recombinant protein were able to recognise the native Ara h 2 protein, demonstrating its allergenicity and potential as a reagent for diagnosis and therapeutic study.

Matched MeSH terms: Allergens/immunology*

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