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Current Trend in Immunotherapy for Peanut Allergy

Joo Chan C, Richardo T, Lim RLH

Int Rev Immunol, 2018;37(6):279-290.
PMID: 30638084 DOI: 10.1080/08830185.2018.1509967

Peanut allergy is a hypersensitivity reaction with symptoms varying from mild to severe anaphylaxis, tends to be lifelong and very few are able to outgrow this allergy. The prevalence of peanut allergy is highest among the Western countries and over the past decade, a 3.5 fold increase in prevalence of peanut allergy was reported among children in the United States. Increasing prevalence has also been observed among the Asian countries. As with other food allergies, peanut allergy reduces quality of life for the affected individuals and the social and economy burden of healthcare for peanut allergy is substantial. To date, there is no effective treatment for peanut allergy and disease management is by avoidance or relieve of symptoms via administration of epinephrine. Peanut allergy is a type-1 hypersensitivity reaction due to specific IgE production by activated T-helper type 2 (TH2) cells. Studies on various immunotherapy routes such as oral immunotherapy (OIT), sublingual immunotherapy and epicutaneous immunotherapy trials using peanut have shown the ability to induce desensitisation, shifting the allergen-specific cytokine production away from a TH2 respond. In the recent years, lactic acid bacteria probiotics have been reported to down-regulate allergy due to its inherent immunomodulatory properties. Wild-type probiotic in combination with peanut proteins or recombinant probiotics harbouring peanut allergens have been explored for OIT due to its ability to down-regulate allergen-specific-IgE production and the TH2 responses, while increasing the beneficiary population of TH1 regulatory T cells (Treg). This review discusses the current strategies in immunotherapy for peanut allergy.

Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/immunology
Lactococcus lactis harbouring Ara h 2.02 alleviates allergen-specific Th2-associated responses in sensitized mice

Chan CJ, Yong YS, Song AAL, Abdul Rahim R, In LLA, Lim RLH

J Appl Microbiol, 2020 Mar;128(3):862-874.
PMID: 31758869 DOI: 10.1111/jam.14524

AIM: To study the prophylactic effect of recombinant Lactococcus lactis (rLl) harbouring Ara h 2.02 peanut allergen, in sensitized and challenged mice.
METHODS AND RESULTS: Ara h 2.02 cDNA was cloned into pNZ8048 for heterologous expression in L. lactis. The purified recombinant allergen showed IgE binding comparable with native Ara h 2. Balb/c mice were fed with either recombinant (rLl), nonrecombinant L. lactis (Ll) or NaHCO3 (Sham) prior to sensitization and challenged with rAra h 2.02, whereas the baseline group was only fed with Ll. Allergen-specific immunoglobulin and splenocyte cytokines responses were determined for each mouse. Mice fed with either Ll or rLl showed significant alleviation of IgE and IgG1 compared to the Sham group. Despite no significant decrease in Th2 (IL-4, IL-13, IL-6) or increase in Th1 (IFN-γ) cytokines, both groups showed lower IL-10 level, while the IL-4 : IFN-γ ratio was significantly lower for rLl compared to Ll group.
CONCLUSIONS: Oral administration of rLl harbouring Ara h 2.02 demonstrated alleviation of Th2-associated responses in allergen-challenged mice and a possible added allergen-specific prophylactic effect.
SIGNIFICANCE AND IMPACT OF THE STUDY: Ara h 2.02 coupled with the intrinsic properties of probiotic L. lactis as a delivery vehicle can be explored for the development of a commercially scalable vaccine.

Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/immunology
Appraisal of latex glove proteins in the induction of sensitivity to multiple latex allergens

Yeang HY, Chow KS, Yusof F, Arif SA, Chew NP, Loke YH

J Investig Allergol Clin Immunol, 2000 Jul-Aug;10(4):215-22.
PMID: 11039838

Six Hevea brasiliensis latex protein allergens, Hevb 1, Hev b 2, Hev b 3, Hev b 4, and two variants of Hev b 7 (7b and 7c), were purified from Hevea latex, while a seventh protein, Hev b 5, was prepared in recombinant form. The presence of these proteins in glove extracts was indicated by their respective antibodies in the serum of rabbits immunized against the extracts. The relative propensities of IgE binding to the individual latex allergens were compared using sera from latex-allergic patients. IgE recognition of Hev b 4, Hev b 7b, Hev b 5 and Hev b 2 was most frequently encountered, with 75, 61, 31 and 28%, respectively, of the patient sera reacting. Sensitivity to multiple latex proteins was common, and out of the 31 seropositive patients, 23 (74%/ ) had IgE against at least two latex allergens, while 12 (39%) had IgE specific for at least three allergens. Statistical analysis of the data suggested that many patients might have acquired sensitivity to Hev b 2, Hev b 4 and Hev b 7b from a common source. (e.g., from latex products). On the other hand, sensitivity to Hev b 5 and to Hev b 7c were interrelated. It is plausible that sensitivity to these two proteins might have been acquired from sources other than latex products (e.g., from certain foods).

Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/metabolism
Fulltext Association between house dust mite (HDM) sensitisation and asthma control using skin prick test and HDM antigen specific IgE levels in saliva of Malaysian children

Teo, Keat Seong, Cheah, Cheong Wooi, Mak, Joon Wah

International e-Journal of Science, Medicine & Education, 2015;9(2):3-12.
MyJurnal

Background: Sensitisation to house dust mite (HDM) has been regarded as a major risk factor for development of asthma. This study was carried out to investigate the profiles of HDM sensitisation among Malaysian children with asthma.
Material and Methods: The association between HDM sensitisation and control and severity of asthma was investigated. The salivary HDM specific IgE levels were quantified in different grades of control and severity of asthma in 125 unselected asthmatic children aged 5-12 years old attending the asthma follow-up clinic in Hospital Tuanku Ja’afar Seremban. An additional 29 non-asthmatic patients were selected as control. The skin prick test to assess sensitisation to Dermatophagoides pteronyssinus (DP) and Dermatophagoides farinae (DF) was performed on all the participants. A questionnaire regarding the control and severity of asthmatic symptoms of the subject was administered. Saliva was collected by voluntary spitting and ELISA was used to quantify the IgE specific to HDM antigen.
Results: There was a significant association between sensitisation to DP and DF and the control of asthma. The association between DP sensitisation and severity of asthma just failed to reach a significant level although there is a clear trend for this. Significant association was found between DF sensitisation and severity. The HDM specific IgE in the saliva was significantly higher in asthmatic patients compared to non-asthmatic patients. There was no significant difference between the specific IgE levels in patients with different severity status of asthma.
Conclusion: Salivary IgE levels may not be an appropriate indicator of the patients’ asthmatic condition in this study. However, it can be concluded that there is significant association between the sensitisation of HDM and the control and severity of asthma.
Study site: Asthma clinic, Hospital Tuanku Jaafar, Seremban, Negeri Sembilan, Malaysia

Matched MeSH terms: Immunoglobulin E
Fulltext Comparison of serum specific IgE with skin prick test in the diagnosis of allergy in Malaysia

Asha'ari ZA, Suhaimi Y, Yusof RA, Rushdan I, Maraina CH

Med J Malaysia, 2011 Aug;66(3):202-6.
PMID: 22111441 MyJurnal

We compared a newer serum specific IgE (SSIgE) test with skin prick testing (SPT) in the diagnosis of allergy in Malaysia. Ninety newly diagnosed allergic patients were enrolled for both tests. Using SPT as a clinical gold standard, the sensitivity, specificity, positive, and negative predictive values (PPV, NPV) were calculated for SSIgE for each of the common allergens tested. The highest positive results for both SPT and SSIgE were for house dust mite and cat. Compared to SPT, SSIgE showed better sensitivity but poorer specificity, low PPV and good NPV in all the allergens tested. Significant positive correlation was seen between the diameter of wheal and flare of SPT and the SSIgE results.

Matched MeSH terms: Immunoglobulin E/blood*
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: Immunoglobulin E/blood*
Nuclear magnetic resonance structure and IgE epitopes of Blo t 5, a major dust mite allergen

Chan SL, Ong TC, Gao YF, Tiong YS, Wang de Y, Chew FT, et al.

J Immunol, 2008 Aug 15;181(4):2586-96.
PMID: 18684949

A high incidence of sensitization to Blomia tropicalis, the predominant house dust mite species in tropical regions, is strongly associated with allergic diseases in Singapore, Malaysia, and Brazil. IgE binding to the group 5 allergen, Blo t 5, is found to be the most prevalent among all B. tropicalis allergens. The NMR structure of Blo t 5 determined represents a novel helical bundle structure consisting of three antiparallel alpha-helices. Based on the structure and sequence alignment with other known group 5 dust mite allergens, surface-exposed charged residues have been identified for site-directed mutagenesis and IgE binding assays. Four charged residues, Glu76, Asp81, Glu86, and Glu91 at around the turn region connecting helices alpha2 and alpha3 have been identified to be involved in the IgE binding. Using overlapping peptides, we have confirmed that these charged residues are located on a major putative linear IgE epitope of Blo t 5 from residues 76-91 comprising the sequence ELKRTDLNILERFNYE. Triple and quadruple mutants have been generated and found to exhibit significantly lower IgE binding and reduced responses in skin prick tests. The mutants induced similar PBMC proliferation as the wild-type protein but with reduced Th2:Th1 cytokines ratio. Mass screening on a quadruple mutant showed a 40% reduction in IgE binding in 35 of 42 sera of atopic individuals. Findings in this study further stressed the importance of surface-charged residues on IgE binding and have implications in the cross-reactivity and use of Blo t 5 mutants as a hypoallergen for immunotherapy.

Matched MeSH terms: Immunoglobulin E/metabolism; Immunoglobulin E/chemistry*
The effects of exclusion of dietary egg and milk in the management of asthmatic children: a pilot study

Yusoff NA, Hampton SM, Dickerson JW, Morgan JB

J R Soc Promot Health, 2004 Mar;124(2):74-80.
PMID: 15067979 DOI: 10.1177/146642400412400211

Current understanding of the use of exclusion diets in the management of asthma in children is limited and controversial. The aim of this study was to examine the effects of excluding eggs and milk on the occurrence of symptoms in children with asthma and involved 22 children aged between three and 14 years clinically diagnosed as having mild to moderate disease. The investigation was single blind and prospective, and parents were given the option of volunteering to join the 'experiment' group, avoiding eggs, milk and their products for eight weeks, or the 'control' group, who consumed their customary food. Thirteen children were recruited to the experimental group and nine to the control group. A trained paediatrician at the beginning and end of the study period assessed the children. A seven-day assessment of food intake was made before, during and immediately after the period of dietary intervention in both groups. A blood sample was taken from each child for determination of food specific antibodies and in those children who could do so, the peak expiratory flow rate (PEFR) was measured. Based on the recommended nutrient intake (RNI), the mean percentage energy intake of the children in the experimental group was significantly lower (p < 0.05) in the experimental group. After the eight-week study period and compared with baseline values, the mean serum anti-ovalbumin IgG and anti-beta lactoglobulin IgG concentrations were statistically significantly reduced (p < 0.05) for both in the experimental group. In contrast, the values for anti-ovalbumin IgG in the control group were significantly increased and those for anti-beta lactoglobulin IgG were practically unchanged. The total IgE values were unchanged in both groups. Over the study period, the PEFR in those children in the experimental group able to perform the test was significantly increased, but no such change was noted in the children in the control group who could do the test. These results suggest that even over the short time period of eight weeks, an egg- and milk-free diet can reduce atopic symptoms and improve lung function in asthmatic children.
Study site: Outpatient Department, Royal County Hospital and the Frimley Children’s Centre, United Kingdom

Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/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: Immunoglobulin E/blood*
Component-resolved diagnosis (CRD): Is it worth it? frequency and differentiation in rhinitis patients with mite reactivity

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

Iran J Allergy Asthma Immunol, 2014 Aug;13(4):240-6.
PMID: 24659159

Component-resolved diagnosis (CRD) using microarray technology has recently been introduced with the aim to improve diagnosis of allergy. The aim of this study was to compare performance of this allergen microarray to those of an established extract-based skin prick testing (SPT).45 patients with allergic rhinitis were studied (16 children and 29 adults). SPT to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis extracts and allergen microarray ImmunoCAP ISAC were carried out for all patients. Forty out of 45 patients demonstrated positive SPT to all mite extracts tested. These 40 patients were considered to be mite-allergic based on the positive SPT results. The remaining 5 patients with negative SPT to any mite extracts were classified as non-mite allergic. Comparatively, based on the microarray results, only 34 mite-allergic patients had detectable serum IgE to at least one of the mite allergen components tested whereas 6 patients with positive SPT to mite extracts showed no detectable IgE reactivity to any of the components tested. One non-mite allergic patient had a positive test- Blo t 5. Der p 10-positive patients also reacted to other cross-reactive tropomyosin from anisakis (Ani s 3) (25%), cockroach (Bla g 7) (50%) and shrimp (Pen m 1) (75%). CRD is a reliable tool for the diagnosis of allergy to mites. Der p 10 might be a useful indicator to identify a subset of mite-allergic patient that have additional sensitization due to cross-reactivity and thus allows selection of patients for immunotherapy.

Matched MeSH terms: Immunoglobulin E/blood
Impacts of Thermal Treatments on Major and Minor Allergens of Sea Snail, Cerithidea obtusa (Obtuse Horn Shell)

Misnan R, Salahudin Abd Aziz N, Mohamad Yadzir ZH, Bakhtiar F, Abdullah N, Murad S

Iran J Allergy Asthma Immunol, 2016 Aug;15(4):309-316.
PMID: 27921412

Snail is one of the worst causes of food allergy. Thus, the aim of this study was to identify the major and minor allergens of the local marine snail (Cerithidea obtusa) and subsequently to investigate the impacts of heat treatment on the IgE-binding activity of snail allergens. Proteins from raw and heat-treated snails (boiled, roasted and fried) were extracted and then resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblotting of all extracts were then performed using sera from patients with snail allergy. The results showed that the raw extract contains numerous protein bands between 12 to>250 kDa. Some thermostable proteins, predominantly the 33 and 42 kDa bands, remained detected in all cooked extracts with decreasing intensities from boiled to roasted to fried extracts, while the majority of thermolabile bands denatured after heating. Boiled snail had more protein bands compared to roasted and fried snails. Immunoblotting of raw extract demostrated 19 IgE-binding bands ranging from 15 to 240 kDa. The thermostable bands of 33 and 42 kDa and a thermolabile of 30 kDa band were identified as the major allergens of this snail. The cooked extracts yielded less allergenic bands. The boiled extract yielded approximately 14 IgE-binding bands with some smeared bands at high molecular weight regions. The roasted extract had lesser IgE-binding bands and the majority appeared as smears, while the IgE-reactivity in the fried extract was less visible and appeared as weak smears. This study indicated that both raw and cooked snails played a crucial role in snail allergenicity, as this species of snail contains both thermostable and thermolabile major allergens. The degree of snail allergenicity was revealed in the order: raw> boiled > roasted> fried. Thus, the results would facilitate in the development of effective diagnosis and management strategies of snail allergy in this country.

Matched MeSH terms: Immunoglobulin E/immunology*
Fulltext Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn)

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

Asian Pac J Trop Biomed, 2012 Jan;2(1):50-4.
PMID: 23569834 DOI: 10.1016/S2221-1691(11)60189-5

OBJECTIVE: To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn).
METHODS: Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools.
RESULTS: SDS-PAGE of the raw extract showed 23 protein bands (15-250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients' sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase.
CONCLUSIONS: It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.

Matched MeSH terms: Immunoglobulin E/immunology
Fulltext Identification of major and minor allergens of black tiger prawn (Penaeus monodon) and king prawn (Penaeus latisulcatus)

Sahabudin S, Misnan R, Yadzir ZH, Mohamad J, Abdullah N, Bakhtiar F, et al.

Malays J Med Sci, 2011 Jul;18(3):27-32.
PMID: 22135598 MyJurnal

BACKGROUND: Prawns and shrimp are a frequent cause of seafood allergy mediated by IgE antibodies. Penaeus monodon and Penaeus latisulcatus, commonly known as black tiger prawn and king prawn, respectively, are among the most frequently consumed prawns in Malaysia. The aim of this study was to identify the IgE-binding proteins of these 2 prawn species.
METHODS: Raw and boiled prawn extracts were prepared and then resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE-immunoblotting was then performed using sera from patients with positive skin prick tests to the raw prawn extracts.
RESULTS: SDS-PAGE analysis of the raw extracts of both prawn species revealed 23 protein bands; the boiled extracts yielded fewer protein bands. The bands in the range of 40 to 100 kDa were sensitive to heat and therefore were not found in the boiled extracts. Immunoblot of raw extracts of black tiger prawns and king prawns yielded 14 and 11 IgE-binding proteins, respectively, with molecular weights of between 15 and 200 kDa. Proteins at 36, 42, and 49 kDa were detected as the major allergens in both species of prawns. A protein of 75 kDa was also identified as a major allergen in black tiger prawns. Other potential allergens were also observed at various molecular masses.
CONCLUSION: Proteins of 36, 42, and 49 kDa were identified as the major allergens of both species of prawns. The 36 and 42 kDa proteins are hypothesised to be tropomyosin and arginine kinase, respectively. A high molecular weight protein of 75 kDa was found to be an additional major allergen in black tiger prawns.
KEYWORDS: Penaeus; allergens; allergy and clinical immunology; hypersensitivity; immunoblotting; tropomyosin

Matched MeSH terms: Immunoglobulin E
Cord IgE and ECP levels of Malay neonates

Yadav A, Naidu R

Allergol Immunopathol (Madr), 2013 Nov-Dec;41(6):364-8.
PMID: 23276420 DOI: 10.1016/j.aller.2012.08.007

Cord IgE and ECP levels are major atopic markers implicated in early childhood allergy development. Most epidemiological studies to date have not utilised current technology to establish baseline cord IgE levels, further aggravated by lack of data in this region. This study also attempts to identify a relationship between cord IgE and ECP levels as a mean to improve sensitivity for early prediction of atopy.

Matched MeSH terms: Immunoglobulin E/blood*
Fulltext Crystal structure and epitope analysis of house dust mite allergen Der f 21

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: Immunoglobulin E
Fulltext Laboratory detection of strongyloidiasis: IgG-, IgG4 - and IgE-ELISAs and cross-reactivity with lymphatic filariasis

Norsyahida A, Riazi M, Sadjjadi SM, Muhammad Hafiznur Y, Low HC, Zeehaida M, et al.

Parasite Immunol., 2013 May-Jun;35(5-6):174-9.
PMID: 23448095 DOI: 10.1111/pim.12029

Enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of IgG, IgG4 and IgE antibodies against Strongyloides stercoralis. A commercial ELISA (IVD Research, USA) was also used, and the sensitivities and specificities of the four assays were determined. Serum samples from 26 patients with S. stercoralis infection and 55 patients with other infections or no infection were analysed. Sensitivities of the IgG4 , IgG, IgE and IgG (IVD) assays were 76.9%, 84.6%, 7.7% and 84.6%, respectively, while the specificities were 92.7%, 81.8%, 100% and 83.6%, respectively. If filariasis samples were excluded, the specificities of the IgG4 -ELISA and both IgG-ELISAs increased to 100% and 98%, respectively. A significant positive correlation was observed between IgG- and IgG4 -ELISAs (r = 0.4828; P = 0.0125). IgG- and IgG- (IVD) ELISAs (r = 0.309) were positively correlated, but was not significant (P = 0.124). Meanwhile there was no correlation between IgG4 - and IgG- (IVD) ELISAs (r = 0.0042; P = 0.8294). Sera from brugian filariasis patients showed weak, positive correlation between the titres of antifilarial IgG4 and the optical densities of anti-Strongyloides IgG4 -ELISA (r = 0.4544, P = 0.0294). In conclusion, the detection of both anti-Strongyloides IgG4 and IgG antibodies could improve the serodiagnosis of human strongyloidiasis. Furthermore, patients from lymphatic filariasis endemic areas who are serologically diagnosed with strongyloidiasis should also be tested for filariasis.

Matched MeSH terms: Immunoglobulin E/blood*
Fulltext Serodiagnosis and early detection of Strongyloides stercoralis infection

Arifin N, Hanafiah KM, Ahmad H, Noordin R

J Microbiol Immunol Infect, 2019 Jun;52(3):371-378.
PMID: 30482708 DOI: 10.1016/j.jmii.2018.10.001

Strongyloidiasis is a major neglected tropical disease with the potential of causing lifelong infection and mortality. One of the ways for effective control of this disease is developing improved diagnostics, particularly using serological approaches. A serological test can achieve high diagnostic sensitivity and specificity, has the potential for point-of-care translation, and can be used as a screening tool for early detection. More research is needed to find clinically important antibody biomarkers for early disease detection, mapping, and epidemiological surveillance. This article summarizes human strongyloidiasis and the available diagnostic tools for the disease, focusing on describing the current antibody assays for strongyloidiasis. Finally, prospects of developing a more effective serodiagnostic tool for strongyloidiasis are discussed.

Matched MeSH terms: Immunoglobulin E/blood
Fulltext Diagnostic Potential of an IgE-ELISA in Detecting Strongyloidiasis

Ahmad H, Balachandra D, Arifin N, Nolan TJ, Lok JB, Hayat Khan A, et al.

Am J Trop Med Hyg, 2020 12;103(6):2288-2293.
PMID: 32996454 DOI: 10.4269/ajtmh.20-0265

Strongyloides stercoralis infection is prevalent worldwide and can cause lifelong infection in immunocompetent individuals, and potentially death in immunosuppressed patients. The diagnosis is hindered by the low sensitivity of microscopic examination, thus making serology an important complementary test to improve the detection rate. However, there were reports that some Strongyloides-infected individuals were negative with specific IgG and IgG4 assays, and other helminth infections were positive with commercial Strongyloides IgG-ELISAs. Thus, there is a need to develop better serodiagnostic methods for strongyloidiasis. We investigated the diagnostic potential of IgE-ELISAs using Strongyloides larval lysate. Sera from two groups infected with Strongyloides served as the positive reference, that is, 1) positive by commercial IgG-ELISAs and IgG4 rapid test, and stool samples positive by microscopy and/or PCR (group IA; n = 20); and 2) negative by IgG-ELISAs and IgG4 rapid test, but stool samples were PCR positive (group IB sera; n = 11). Sera from another two groups served as negative reference (controls), that is, 1) infected with other parasites (group II; n = 73) and 2) healthy donors (group III; n = 22). Results showed a 100% diagnostic sensitivity in detecting sera from groups IA and IB. The latter group of individuals probably had early infection because their IgG and IgG4 assays were negative. The optical density values of group IB sera were also significantly lower than those of group IA (P < 0.003). The IgE-ELISA was 100% specific when tested against sera from groups II and III. This study highlights the diagnostic potential of IgE-ELISA using larval lysate to detect strongyloidiasis, especially those with probable early infection.

Matched MeSH terms: Immunoglobulin E/immunology*
Fulltext Detection of Strongyloides stercoralis infection among cancer patients in a major hospital in Kelantan, Malaysia

Zueter AM, Mohamed Z, Abdullah AD, Mohamad N, Arifin N, Othman N, et al.

Singapore Med J, 2014 Jul;55(7):367-71.
PMID: 25091885

INTRODUCTION: Strongyloidiasis is one of the most commonly neglected but clinically important parasitic infections worldwide, especially among immunocompromised patients. Evidence of infection among immunocompromised patients in Malaysia is, however, lacking. In this study, microscopy, real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays (ELISAs) were used to detect Strongyloides stercoralis (S. stercoralis) infection among cancer patients in a Malaysian hospital.

METHODS: A total of 192 stool and serum samples were collected from cancer patients who were receiving chemotherapy with or without steroid treatment at a hospital in northeastern Malaysia. Stool samples were examined for S. stercoralis using parasitological methods and real-time PCR. Serology by ELISA was performed to detect parasite-specific immunoglobulin G (IgG), IgG4 and immunoglobulin E (IgE) antibodies. For comparison, IgG4- and IgG-ELISAs were also performed on the sera of 150 healthy individuals from the same area.

RESULTS: Of the 192 samples examined, 1 (0.5%) sample was positive for S. stercoralis by microscopy, 3 (1.6%) by real-time PCR, 8 (4.2%) by IgG-ELISA, 6 (3.1%) by IgG4-ELISA, and none was positive by IgE-ELISA. In comparison, healthy blood donors had significantly lower prevalence of parasite-specific IgG (2.67%, p < 0.05) and IgG4 (2.67%, p < 0.05) responses.

CONCLUSION: This study showed that laboratory testing may be considered as a diagnostic investigation for S. stercoralis among immunocompromised cancer patients.

Matched MeSH terms: Immunoglobulin E/blood
Fulltext Development and evaluation of a sensitive and specific assay for diagnosis of human toxocariasis by use of three recombinant antigens (TES-26, TES-30USM, and TES-120)

Mohamad S, Azmi NC, Noordin R

J Clin Microbiol, 2009 Jun;47(6):1712-7.
PMID: 19369434 DOI: 10.1128/JCM.00001-09

Diagnosis of human toxocariasis currently relies on serologic tests that use Toxocara excretory-secretory (TES) antigen to detect immunoglobulin G (IgG) antibodies to the larvae. In general, however, these assays do not have adequate specificity for use in countries in which other soil-transmitted helminths are endemic. The use of recombinant antigens in these assays, however, is promising for improving the specificity of the diagnosis of toxocariasis. Toward this goal, we developed an IgG4 enzyme-linked immunosorbent assay (ELISA) involving three recombinant antigens: rTES-30USM (previously produced), rTES-26, and rTES-120. The latter two antigens were produced by reverse transcription-PCR cloning; subcloned into glutathione S-transferase (GST)-tagged and His-tagged prokaryotic expression vectors, respectively; and expressed in Escherichia coli. The recombinant proteins were subsequently purified by affinity chromatography using GST and His-Trap resins. The diagnostic potential of each purified recombinant antigen was tested with various immunoglobulin classes (IgG, IgM, and IgE) and IgG subclasses. The IgG4 ELISA was determined to have the highest specificity and was further evaluated using a panel of serum samples. The rTES-26 IgG4 ELISA showed 80.0% (24/30 samples positive) sensitivity, and both the rTES-30USM IgG4 ELISA and rTES-120 IgG4 ELISA had 93.0% (28/30) sensitivity. Combined use of rTES-120 and rTES-30 IgG4 ELISA for the diagnosis of toxocariasis provided 100% sensitivity. The specificities of rTES-26, rTES-30USM, and rTES-120 antigens were 96.2%, 93.9%, and 92.0%, respectively. These results indicate that the development of a diagnostic test using the three recombinant antigens will allow for more-accurate detection of toxocariasis.

Matched MeSH terms: Immunoglobulin E/blood

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