Dermatophagoides Pteronyssinus Extract Research Articles

Comparison and Evaluation of Several Dermatophagoides Pteronyssinus Allergen Extracts for Skin Prick Test

To evaluate the significance of several Dermatophagoides pteronyssinus allergen extracts for skin prick test (SPT) in patients allergic to Dermatophagoides pteronyssinus. Two hundred and nineteen patients enrolled in Peking Union Medical College Hospital underwent SPT and serum specific IgE assay to detect the Dermatophagoides pteronyssinus allergen. Three kinds of house dust mite allergen extracts were used for SPT, including the Dermatophagoides pteronyssinus extract prepared by our laboratory (group A), standardized Dermatophagoides pteronyssinus extract (group B), and mixed extracts of Dermatophagoides pteronyssinus and Dermatophagoides farinae (group C). Human serum specific IgE result was regarded as the reference standard for diagnosis of Dermatophagoides pteronyssinus allergy. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of SPT with the extracts of three groups. SPT results showed that the median wheal diameter of group A, group B, and group C was 0.43, 0.35, and 0.28 cm, respectively, with significant difference among three groups (P<0.05). The difference was significant between group A and B (P<0.01) as well as group A and C (P<0.01), but not between group B and C (P>0.05). There was no local urticaria or systemic allergic reactions following the procedure of SPT. Local reaction was observed in 5 patients and delayed reaction was in 2 patients of group A. As for group B and C, local reaction occurred in 3 cases and delayed reaction in 2 cases in each group. The area under ROC curve of SPT with extract in group A, group B, and group C was 0.765, 0.801, and 0.782, respectively. Based on the detection results of serum specific IgE, the sensitivity of SPT in diagnosis of Dermatophagoides pteronyssinus allergy with extract of group A, group B, and group C was 92.4%, 87.0%, and 81.5%, and the specificity was 60.6%, 73.2%, and 74.8%, respectively. The Dermatophagoides pteronyssinus extract for SPT prepared by our laboratory offers good sensitivity and specificity comparable to commercially available allergen extracts, and it may be an appropriate candidate for clinical screening and diagnosis of Dermatophagoides pteronyssinus allergy.

Suppression of histamine- and allergen-induced skin reactions: comparison of first- and second-generation antihistamines

Nonsedating antihistamines (nsAHs) are recommended as first-line therapeutics for the treatment of mast cell-driven disorders, including allergic rhinitis and urticaria. However, their superiority over first-generation AHs (fgAHs) has recently been called into question, mainly because of the lack of supporting head-to-head therapeutic studies. To compare the effects of 3 modem nsAHs with those of the fgAH hydroxyzine on histamine- and allergen-induced skin reactions in a controlled, double-blind, clinical trial. Skin prick tests with histamine and Dermatophagoides pteronyssinus extract were performed before and 4 hours after treatment with hydroxyzine, 25 mg; desloratadine, 5 mg; epinastine, 20 mg; fexofenadine, 120 mg; or placebo. Wheal and erythema development was evaluated by digital photography and planimetric analyses. The nsAHs prevented the development of positive reactions to histamine in only 10% to 20% of all individuals tested (n = 75). In contrast, more than 50% of all hydroxyzine-treated individuals showed negative test reactions to histamine (ie, wheals <7 mm2 in area or <3 mm in diameter). Similar differences, although less pronounced, were detected when comparing the effects of nsAHs with hydroxyzine on D pteronyssinus prick testing in a limited number of D pteronyssinus-sensitized individuals. These results indicate that hydroxyzine is more effective than nsAHs when given as recommended in suppressing histamine-induced or allergic skin reactions. Our results suggest that higher doses of nsAHs than those currently recommended are required for the treatment of skin responses to obtain antihistaminic and antiallergic effects that are equivalent to those of fgAHs.

Comparison of Three Methods of Protein Extraction from Dermatophagoides Pteronyssinus for Two-dimensional Electrophoresis

To explore an effective method of Dermatophagoides pteronyssinus protein extraction suitable for two-dimensional electrophoresis (2-DE) analysis. The extracts of Dermatophagoides pteronyssinus were prepared with Coca's solution, lysis buffer of 2-DE, and Trizol reagent, respectively. Bicinchoninic acid (BCA) assay was used to determine the total protein concentration of the samples. The efficiency of different protein extraction methods were evaluated with 2-DE analysis. The concentrations of extracted protein by methods of Coca's solution, lysis buffer, and Trizol reagent were 0.63 g/L, 0.90 g/L, and 0.80 g/L, respectively. The 2-DE analysis results showed that some protein spots in low molecular weight (LMW) range could be detected with the Coca's solution method. With the lysis buffer of 2-DE method, more protein spots in LMW range could be detected, while the medium molecular weight (MMW) protein spots were absent. Several MMW protein spots (174-178 kD and 133 kD) and more LMW protein spots were detected with Trizol reagent method. Among Coca's solution, lysis buffer of 2-DE, and Trizol reagent, the concentration of extracted protein of Dermatophagoides pteronyssinus by lysis buffer of 2-DE is the highest. However, most protein components of Dermatophagoides pteronyssinus purified mite bodies can be extracted by Trizol reagent, which may generally reflect the whole profile of Dermatophagoides pteronyssinus allergens.

Inhibition of skin inflammation and atopic dermatitis by topical application of a novel ceramide derivative, K112PC-5, in mice

PC-9S (N-Ethanol-2-mirystyl-3-oxo-stearamide) is a synthetic ceramide and has been known to be effective in atopic and psoriatic patients. K112PC-5 (2-Acetyl-N-(1,3-dihydroxyisopropyl)-tetradecanamide) is a novel ceramide derivative of PC-9S. In the present study, we examined the effect of K112PC-5 on macrophage and T lymphocyte function in primary macrophages and splenocytes, respectively, as well as the effect of topical application of K112PC-5 on skin inflammation and atopic dermatitis (AD) in mouse models. K112PC-5 inhibited lipopolysaccharide-induced nitrite generation in mouse peritoneal macrophages in a dose-dependent manner. However, K112PC-5 did not affect concanavalin A-induced proliferation, interleukin (IL)-2 secretion and IL-4 secretion in mouse splenocytes. In addition, K112PC-5 significantly suppressed the increase in phorbol ester-induced ear thickness in BALB/c mice. Further study demonstrated that topical application of K112PC-5 also inhibited AD induced by extracts of dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae, in NC/Nga mice. Taken together, these results showed that K112PC-5 exerted an anti-inflammatory effect both in vitro and in vivo and proved to be beneficial in an animal model of AD. Our results suggest that K112PC-5 might be beneficial as a topical agent for the treatment of AD.

Anti-inflammatory modulation of chronic airway inflammation in the murine house dust mite model

Asthma affects 300 million people worldwide and continues to be a major cause of morbidity and mortality. Disease relevant animal models of asthma are required for benchmarking of novel therapeutic mechanisms in comparison to established clinical approaches. We demonstrate that chronic exposure of mice to house dust mite (HDM) extract results in allergic airway inflammation, that can be significantly attenuated by therapeutic intervention with phosphodiesterase 4 inhibition and corticosteroid treatment. Female BALB/c mice were administered intranasally with HDM ( Dermatophagoides pteronyssinus) extract daily for five weeks, and therapeutic intervention with anti-inflammatory treatment (dexamethasone 1 mg/kg subcutaneous once daily, prednisolone 10 mg/kg orally twice daily, fluticasone 3, 10 and 30 μg intranasally twice daily, roflumilast 10 mg/kg orally twice daily and intranasally 10 and 30 μg twice daily) was initiated after three weeks of exposure. Chronic HDM extract exposure resulted in significant airway inflammation, demonstrated by bronchoalveolar lavage cell infiltration and lung tissue inflammatory gene expression by TaqMan low density array. Chronic steroid treatment significantly inhibited these parameters. In addition, roflumilast caused a significant reduction in airway inflammatory cell infiltration. We have demonstrated that chronic HDM-induced allergic inflammation can be significantly ameliorated by steroid treatment, and that phosphodiesterase 4 inhibition modulates inflammatory cell infiltration. Therefore, the murine HDM model may be a useful tool for evaluating new targets for the treatment of asthma.

The effect of enantiomers of beta-agonists on myofibroblast-derived vascular endothelial growth factor and other matrix components in the presence of dust-mite extract

Beta(2)-adrenergic receptor agonists have been shown to modulate airway epithelial cell and smooth muscle release of cytokines and growth factors transforming growth factor (TGF) beta, associated with remodeling, is known to up-regulate the synthesis of vascular endothelial growth factor (VEGF) and stimulate differentiation of fibroblasts to the myofibroblast phenotype. VEGF and fibronectin can promote angiogenesis and (S)-albuterol can induce VEGF secretion from normal human lung fibroblasts (NHLF). We hypothesize that (S)-albuterol could stimulate myofibroblast secretion and expression of VEGF and fibronectin in the presence of Dermatophagoides pteronyssinus extract. Cultured NHLFs were stimulated with IL-1beta, TGF-beta, D. pteronyssinus, and treated with (R)- and (S)-enantiomers of albuterol. VEGF and fibronectin and basic fibroblast growth factor (bFGF) were measured by ELISA and mRNA. VEGF secretion by fibroblasts was twofold higher with 10(-7) M of (R) relative to (S) (p < 0.05). Myofibroblast secretion of VEGF was increased twofold over fibroblasts, but there was no difference between enantiomers. (S)-albuterol at 10(-8)-10(-4) M caused an increase in VEGF mRNA that paralleled VEGF secretion relative to 10(-8)-10(-4) M. Fibronection secretion by myofibroblasts but not fibroblasts was increased by 10(-5) M of (S) relative to (R) in the presence of recombinant interleukin 1 (rhIL-1)beta and D. pteronyssinus (S)-albuterol at 10(-6) M increased bFGF. The 10(-6) M of (S)-albuterol, but not (R)-albuterol, may promote angiogenesis. Increased fibronectin or bFGF by (S)-albuterol could enhance matrix deposition and remodeling in a subset of asthmatic patients.

A Mite Antigen, Der P1, Activates Dendritic Cells (DCs) and Stimulates Th2 Polarization through a Toll-like Receptor (TLR)-4 Pathway

RationaleExposure to mite is implicated in the development and exacerbation of asthma and other allergic diseases. Therefore, we investigated whether a mite allergen, Der p 1, directly stimulates DCs and promotes allergic responses.MethodsWe cultured mouse bone marrow-derived DCs with Dermatophagoides pteronyssinus (DP) extract or purified natural Der p 1. Cell surface expression of co-stimulatory molecules and cytokine production were analyzed by FACS and by ELISA, respectively. Der p 1-stimulated DCs were also co-cultured with allogeneic CD4+ T cells, and T cell production of cytokines was analyzed.ResultsBoth DP extract and purified Der p 1 activated DCs, as shown by increased expression of co-stimulatory molecules (CD40, CD80, and CD86) and by IL-6 production. Heat treatment of Der p 1 abolished DC expression of co-stimulatory molecules and IL-6 production; proteinase K treatment of Der p 1 abolished IL-6 production. These treatments did not affect the ability of lipopolysaccharide (LPS) to stimulate DCs. When stimulated with Der p1 or LPS, DCs from TLR4-deficient mice produced less IL-6 compared to DCs from wild-type mice. Der p 1 treatment also downregulated TLR 4 expression in DCs from wild-type mice. When allogenic CD4+ T cells were incubated with Der p 1-treated DCs, the T cells showed enhanced production of IL-4, IL-5, and IL-13 and reduced production of IFN-γ. Heat treatment of Der p 1 abolished this Th2-driving effect.ConclusionDer p 1 activates DCs and facilitates CD4+ T cell production of Th2 cytokines through a TLR4-dependent mechanism. This effect is likely mediated by Der p 1 protein itself and not by LPS contamination. RationaleExposure to mite is implicated in the development and exacerbation of asthma and other allergic diseases. Therefore, we investigated whether a mite allergen, Der p 1, directly stimulates DCs and promotes allergic responses. Exposure to mite is implicated in the development and exacerbation of asthma and other allergic diseases. Therefore, we investigated whether a mite allergen, Der p 1, directly stimulates DCs and promotes allergic responses. MethodsWe cultured mouse bone marrow-derived DCs with Dermatophagoides pteronyssinus (DP) extract or purified natural Der p 1. Cell surface expression of co-stimulatory molecules and cytokine production were analyzed by FACS and by ELISA, respectively. Der p 1-stimulated DCs were also co-cultured with allogeneic CD4+ T cells, and T cell production of cytokines was analyzed. We cultured mouse bone marrow-derived DCs with Dermatophagoides pteronyssinus (DP) extract or purified natural Der p 1. Cell surface expression of co-stimulatory molecules and cytokine production were analyzed by FACS and by ELISA, respectively. Der p 1-stimulated DCs were also co-cultured with allogeneic CD4+ T cells, and T cell production of cytokines was analyzed. ResultsBoth DP extract and purified Der p 1 activated DCs, as shown by increased expression of co-stimulatory molecules (CD40, CD80, and CD86) and by IL-6 production. Heat treatment of Der p 1 abolished DC expression of co-stimulatory molecules and IL-6 production; proteinase K treatment of Der p 1 abolished IL-6 production. These treatments did not affect the ability of lipopolysaccharide (LPS) to stimulate DCs. When stimulated with Der p1 or LPS, DCs from TLR4-deficient mice produced less IL-6 compared to DCs from wild-type mice. Der p 1 treatment also downregulated TLR 4 expression in DCs from wild-type mice. When allogenic CD4+ T cells were incubated with Der p 1-treated DCs, the T cells showed enhanced production of IL-4, IL-5, and IL-13 and reduced production of IFN-γ. Heat treatment of Der p 1 abolished this Th2-driving effect. Both DP extract and purified Der p 1 activated DCs, as shown by increased expression of co-stimulatory molecules (CD40, CD80, and CD86) and by IL-6 production. Heat treatment of Der p 1 abolished DC expression of co-stimulatory molecules and IL-6 production; proteinase K treatment of Der p 1 abolished IL-6 production. These treatments did not affect the ability of lipopolysaccharide (LPS) to stimulate DCs. When stimulated with Der p1 or LPS, DCs from TLR4-deficient mice produced less IL-6 compared to DCs from wild-type mice. Der p 1 treatment also downregulated TLR 4 expression in DCs from wild-type mice. When allogenic CD4+ T cells were incubated with Der p 1-treated DCs, the T cells showed enhanced production of IL-4, IL-5, and IL-13 and reduced production of IFN-γ. Heat treatment of Der p 1 abolished this Th2-driving effect. ConclusionDer p 1 activates DCs and facilitates CD4+ T cell production of Th2 cytokines through a TLR4-dependent mechanism. This effect is likely mediated by Der p 1 protein itself and not by LPS contamination. Der p 1 activates DCs and facilitates CD4+ T cell production of Th2 cytokines through a TLR4-dependent mechanism. This effect is likely mediated by Der p 1 protein itself and not by LPS contamination.

Frequencies of circulating CD4+CD25+CD127low cells in atopics are altered by bronchial allergen challenge

Recent studies in rodents revealed that regulatory T cells (T reg cells) with CD4+CD25+ phenotype can exert suppressive effects on experimentally-induced allergic airway inflammation and airway hyper-reactivity. It is unclear however, whether modulations of bronchoconstriction responses in human subjects might be related to T reg cells. We report here for the first time the changes in frequency of circulating lymphocytes with putative T reg cell phenotype (CD4+CD25+CD127low) in relation to bronchoconstriction phenotype following an intrabronchial allergen challenge. Thirty-one house dust mite sensitive patients were challenged with Dermatophagoides pteronyssinus extract (Dp). Eleven isolated early responders (IER) were compared with nine dual (early and late) responders (DR) and to 11 non-responders (NR). Frequencies of peripheral blood CD4+CD25+CD127low lymphocytes were assessed in all groups of patients by using three-parameter flow cytometry before, and six and 24 h, after allergen inhalation. At baseline, frequencies of CD4+CD25+CD127low lymphocytes were not statistically different among NR, IER and DR. When all individuals were analyzed together, a statistically significant decrease in frequency of CD4+CD25+CD127low lymphocytes was observed 6 h after the bronchial challenge. Interestingly, such a pattern was found consistently only in NR, while IER and DR displayed varying responses resulting in a trend similar to that of NR. Twenty-four hours after the bronchial challenge, frequencies of CD4+CD25+CD127low lymphocytes in all groups tended to return to baseline values. Our data indicate that bronchial allergen inhalation in sensitive patients (predominantly in those who did not develop significant bronchoconstriction) is associated with a decrease of proportion of peripheral lymphocytes with regulatory T cell phenotype.

Differences in Skin Prick Test Reactivity Between Body and Faecal Extracts of Dermatophagoides pteronyssinus in Two Spanish Cities

Differences in Skin Prick Test Reactivity Between Body and Faecal Extracts of Dermatophagoides pteronyssinus in Two Spanish Cities

Safety and efficacy of the ultra-rush immunotherapy with extracts of Dermatophagoides pteronyssinus in children

Purpose :Immunotherapy is accepted as the only treatment of allergic disease that can modify the natural course of the disease and ameliorate symptoms. This study aimed to evaluate the safety and efficacy of ultra-rush therapy using Dermato phagoides extracts in children. Methods :Of children older than four years who had visited Bundang CHA Pediatric Allergy Clinic, those showing positive reactions only to Dermatophagoides in the skin prick test and to the nasal provocation test were included. In all, 11 and 12 patients respectively preferred conventional and ultra-rush immunotherapy. We elevated allergen concentrations diluted to 1,000:1 of the end strength by 2-3 times with 30-minute intervals and checked oxygen saturation, pulse rate, blood pressure, and systemic reactions every 15 minutes. Immunotherapy effectiveness was valued by changes in nasal provocation test scores before and after immunotherapy. Results : The average ages of patients in the conventional and ultra-rush immunotherapy groups were 8.3±2.3 and 9.2± 2.8 years, respectively. Systemic reactions were observed in six in the ultra-rush group (50%) without anaphylaxis and one (9%) in the conventional group. The average scores in the nasal provocation test before and after treatment in the conven tional group were 8.2±1.5 and 4.6±2.1, respectively (P=0.043). In the ultra-rush immunotherapy group, the scores changed from 6.2±2.2 to 3.7±2.5 (P=0.017). Conclusion : Ultra-rush immunotherapy using Dermatophagoides in children is effective for treating allergic disease but can induce systemic effects rather than conventional immunotherapy. (Korean J Pediatr 2008;51:868-873)

Bronchial Challenge Test in Asthmatics Sensitized to Mites: Role of Particle Size in Bronchial Response

Although major house dust mite allergen (Der p 1) is carried mainly on large particles (>10 microm), standard bronchial challenge tests (BCT) use nebulizers that deliver smaller particles (sizes from 1 to 5 microm) and may therefore not reflect actual domestic exposure. The objective of this study was to evaluate the influence of particle size of Dermatophagoides pteronyssinus extract on bronchial response. Specific BCT were performed with different mass median aerodynamic diameters (MMAD): 1.1, 5.6, and 9.7 microm. Each of the 19 mite-sensitized patients underwent mite BCT three times, once with each nebulizer. IL-5 levels were assessed in induced sputum and blood samples. The PD(20) for Der p 1 differed substantially with particle size, with less Der p 1 (11.2 ng) needed to produce a PD(20) with the largest particles (9.7 microm), compared to 18.1 ng for the 5.6 microm particles and 142.5 ng for the 1.1 microm particles (p < 0.0001). Large particles also induced an early phase response significantly more often than small particles (100% vs. 63%). Although the late phase reaction (LPR) frequency was similar with all three particle sizes, lower mean oral corticosteroid doses were needed to treat LPR with the largest particles (23 mg), compared to the smaller particles, with 34 mg for the 5.6 microm particles and 51 mg for the 1.1 microm. The 1.1 microm particles produced a significantly greater increase in IL-5 concentrations in sputum and blood compared to the larger particles. Large particles clearly play a role in the immediate bronchial response in asthmatics sensitized to mites and, therefore, should be included in pharmacological studies in humans.

Enzymatic Activity of Dermatophagoides pteronyssinus Extracts after Acidic Treatment

Background: Mite extracts contain potent enzymes. These enzymes, especially Der p 1, may affect the bronchial homeostasis and the amplification of the allergic response. The objectives of this study were to determine how depigmentation affects the enzymatic activity of allergen extracts of Dermatophagoides pteronyssinus and to verify if these depigmented extracts retain their in vitro allergenic properties. Methods: Four native extracts were manufactured from 4 different batches of raw material of D. pteronyssinus. Once extracted, native extracts were reconstituted and modified by adding increasing quantities of 2 M HCl to the solution and dialyzed against double-distilled water. The enzymatic activity of these 8 extracts (4 native and 4 depigmented) was evaluated using in vitro methods. The allergenic potency was evaluated by human specific IgE and IgG ELISA inhibition experiments. The major allergen content (Der p 1 and Der p 2) was measured with monoclonal antibodies. Results: Protease, phosphatase, lipase and glycosidase activity was detected in native extracts. After depigmentation, all the enzymatic activities showed a significant decrease. SDS-PAGE reveals the same protein profile in both types of extracts. The results of ELISA inhibition confirmed that depigmented extracts preserved their antigenic and allergenic capacity. Der p 2 levels increased in depigmented extracts, while the detection capacity of Der p 1 decreased. Conclusions: The depigmentation process significantly reduced the enzymatic activity of these mite extracts, while preserving their allergenicity and antigenicity. No significant differences were observed in the antigenic profile of native and depigmented extracts.

Double-blind placebo-controlled study of treatment with a depigmented and glutaraldehyde-polymerised extract of dermatophagoides pteronyssinus and D. farinae

Double-blind placebo-controlled study of treatment with a depigmented and glutaraldehyde-polymerised extract of dermatophagoides pteronyssinus and D. farinae

Evolution of quality of life in patients treated with therapeutic vaccine containing depigmented and polymerized allergen extracts of dermatophagoides pteronyssinus and D. farinae in allergic asthmatic patients

Evolution of quality of life in patients treated with therapeutic vaccine containing depigmented and polymerized allergen extracts of dermatophagoides pteronyssinus and D. farinae in allergic asthmatic patients

Evaluation of skin sensitivity in dogs bearing allergic dermatitis to standardized allergenic extract of house dust and storage mites

The objective of the study was to evaluate whether allergenic extracts of five house dust and storage mite species standardized for humans might be used for the diagnosis of canine atopic dermatitis (CAD). Extracts of Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) and Tyrophagus putrescentiae (Acaridae) were evaluated by intradermal testing in 20 healthy dogs (control) and 25 dogs with allergic dermatitis. A significant difference in the response was observed between the two groups (p&lt;0.05). Only one dog (5%) in the control group reacted to the intradermal test, whereas 14 dogs (56%) in the allergic group were positive for at least one extract (odds ratio = 24.2). Most of the positive reactions observed in the allergic group occurred against the extracts of T. putrescentiae or L. destructor, each inducing reactions in 10 dogs (40%). D. farinae, D. pteronyssinus e B. tropicalis extracts induced reactions in 7 (28%), 3 (12%) and 3 (12%) dogs, respectively. The allergenic extracts standardized for humans evaluated in the present study may be used as a tool to complement the diagnosis of the disease, as well as to select potential allergen candidates for allergen-specific immunotherapy.

Distinctive immunoglobulin E anti‐house dust allergen‐binding specificities in a tropical Australian Aboriginal community

There is evidence that the specificity of the IgE binding in allergy tests can vary for different populations. We aimed to examine the allergenic specificity of IgE binding in sera from house dust mite (HDM)-atopic subjects in a tropical Australian Aboriginal community. Sera shown to contain IgE antibodies to an HDM extract of Dermatophagoides pteronyssinus were examined for IgE binding to a panel of nine purified HDM allergens from this mite species by quantitative microtitre assays. IgG antibody binding (IgG1 and IgG4) was also measured. The IgE-binding activity in the sera from the Aboriginal community was not directed to the expected major groups 1 and 2 HDM allergens but instead to the group 4 amylase allergen. There was also little IgE binding to the potentially cross-reactive tropomyosin (Der p 10) or arginine kinase (Der p 20) allergens. The IgG4 antibody was rarely detected and limited to the Der p 4 allergen. IgG1 antibody binding was frequently measured to all the allergens regardless of an individual's atopic status, whereas in urban communities it is restricted to the major allergens and to atopic subjects. The high IgE anti-HDM response of Australian Aboriginals predominantly bound Der p 4 and not the Der p 1 and 2 allergens, showing a distinctive allergy that could affect the disease outcome and diagnosis.

Effect of Dermatophagoides pteronyssinus on expression of monocyte chemotactic protein 1 (MCP-1)/IL-6/IL-8 in the human monocytic cell line, THP-1 (96.26)

Abstract RATIONALE: The house dust mite, Dermatophagoides pteronyssinus (DP) is a major source of allergens implicated in the pathogenesis of allergic disorders; they include asthma, allergic rhinitis, and atopic dermatitis. Monocyte chemotactic protein 1 (MCP-1/CCL2)/IL-6/IL-8 plays a pivotal role in mediating the infiltration of various cells into the skin of atopic dermatitis and psoriasis. METHODS: The aim of this study was to investigate the effect of DP extract (DpE) on expression of MCP-1/IL-6/IL-8 mRNA and protein and the signal transduction leading to MCP-1/IL-6/IL-8 expression induced by DpE in the human monocytic cell line, THP-1. The mRNA and protein expression of MCP-1/IL-6/IL-8 was measured by performing RT-PCR and ELISA. RESULTS: DpE-stimulated cells showed elevated MCP-1/IL-6/IL-8 expression in a time and dose-dependent course. MCP-1/IL-6/IL-8 expression induced by DpE is strongly inhibited by PP2, an inhibitor of Src, rottlerin, an inhibitor of protein kinase C δ (PKC δ) PD98059, an inhibitor of MEK and SB202190, an inhibitor of p38 mitogen-activated protein kinase (MAPK). CONCLUSIONS: These results indicate that DP increases MCP-1/IL-6/IL-8 expression and transduces the signal through extracellular signal-regulated kinases (ERK1/2) in human monocytes.

Risk Factors for Sensitization to Anisakis Simplex: A Multivariate Statistical Evaluation

Anisakis simplex is a nematode belonging to the Anisakidae family. The ingestion of third stage larvae in uncooked or undercooked seafood may cause human diseases known as anisakiasis and anisakidosis. A total of 400 (159 atopic and 241 non-atopic) subjects living in an area of southern Italy (Bari district) were consecutively evaluated to identify the association of some factors (sex, age, atopy, consumption of uncooked seafood and sensitization to dust mites) with the risk of Anisakis simplex sensitization. Patients were investigated on history of atopy and allergic diseases and were skin prick tested with commercial allergen extracts of Anisakis simplex, Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae, Glycyphagus domesticus, Euroglyphus maynei, Dermatophagoides pteronyssinus and Dermatophagoides farinae. Our results suggest that atopic subjects have a lower risk of Anisakis allergy than non-atopic subjects and show the association of Anisakis simplex sensitization with the consumption of uncooked seafood (anchovies and squid), increasing age and sensitization to Glycyphagus domesticus.

Sensitization and exposure to house dust and storage mites in high-altitude areas of Ecuador

Few studies have addressed exposure and sensitization to mite allergens in Andean countries. To identify the main mite species in 3 locations at different altitudes in Ecuador and to verify skin test reactivity to various mite species in allergic individuals in Quito, Ecuador. Mattress dust samples were collected in Quito (2,800 m above sea level), Cuenca (2,500 m above sea level), and Guayaquil (sea level). Mite species present in the samples were isolated, identified, and counted. Der p 1 and Der f 1 levels were measured using monoclonal antibody-based enzyme immunoassays. Four hundred thirty-five patients in Quito diagnosed as having allergic rhinitis or asthma underwent skin testing with commercial extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, Tyrophagus putrescentiae, and Lepidoglyphus destructor. In addition, Glycyphagus domesticus, Acarus siro, and Aleuroglyphus ovatus were tested in 362, 262, and 279 patients, respectively. Twenty-one mite species were identified. Large populations of mites were detected above 2,500 m of altitude. All the dust samples contained detectable levels of Der p 1 or Der f 1. Positive skin prick test reactions to D. pteronyssinus, D. farinae, B. tropicalis, L. destructor, T. putrescentiae, A. ovatus, A. siro, and G. domesticus were obtained in 60.9%, 56.8%, 17.0%, 19.3%, 10.6%, 15.8%, 8.8%, and 11.0% of the patients, respectively. Most analyzed mattresses contained several species of mites. Mite allergen levels were high. This study confirms the importance of house dust and storage mite allergens in Ecuador in areas above 2,500 m of altitude, where humidity remains high year round.

Successful management of mite-allergic asthma with modified extracts of Dermatophagoides pteronyssinus and Dermatophagoides farinae in a double-blind, placebo-controlled study

Mite sensitivity is highly prevalent in tropical and subtropical regions, such as the Canary Islands. To evaluate the clinical efficacy and safety of a depigmented polymerized allergen vaccine containing a 50% mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae. Sixty-four patients participated in the study. It was prospective, double-blind, and placebo-controlled, with random allocation of patients to receive active treatment or placebo. The active group received a mixture of modified allergen extracts containing 50% D pteronyssinus and 50% D farinae; the control group received placebo. All individuals were diagnosed with mild/moderate asthma and rhinoconjunctivitis caused by sensitization to D pteronyssinus and D farinae. Bronchial provocation test (BPT) was considered the main outcome to document clinical efficacy. Fifty-four patients completed the study. The active group experienced a significant improvement in BPT (P < .001), whereas the placebo group did not (P = .648). At the end of the study, 20 patients in the active versus 9 in the placebo group (P = .013; odds ratio, 5.71 [1.76, 18.51]) needed more than twice the amount of allergen to obtain a positive BPT. The median improvement in the active group over placebo was 53.76% in total symptom and 58.09% in medication scores. Immunotherapy with a mixture of modified allergen extracts of D pteronyssinus and D farinae is safe and efficacious to treat mite-allergic asthma. This immunotherapy modifies the natural course of the illness because it improves all clinical outcomes measured and prevents the worsening of specific bronchial hyperreactivity.