SEARCH · PubMed Health

Results for “ALLERGENS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed1991

Airborne dust mite allergens: comparison of group II allergens with group I mite allergen and cat-allergen Fel d I.

The form in which allergens become airborne is important because it may influence both symptoms caused by allergen exposure and methods used to reduce exposure. The group I allergens from dust mites only become airborne during disturbance and fall rapidly, which is in keeping with their being carried on fecal pellets. Their mean size is approximately 20 microns in diameter. By contrast, the cat-allergen Fel d I is airborne on particles varying from greater than 10 to less than 2 microns in diameter, some of which remain airborne even without disturbance. A second group of mite allergens, molecular weight 14,000, are equally important and are associated predominantly with mite bodies. With a monoclonal antibody-based assay and a cascade impactor, we have investigated the form in which group II mite allergens become airborne. The results reveal that these allergens only become airborne during disturbance and that they fall within 15 minutes. However, the mean size of particles carrying group II allergens appears to be slightly smaller than the mean size of particles carrying group I allergens. In addition, the quantities of group II allergen becoming airborne during disturbance (mean, 26 ng/m3) could not be explained by the quantity found in fecal particles. Thus, group II mite allergens become airborne in a form quite distinct from cat allergens and very similar to group I mite allergens; however, it appears unlikely that fecal particles are the main form in which group II allergens become airborne.

Allergens↗

PubMed1992

Monoclonal antibodies against Olea europaea major allergen: allergenic activity of affinity-purified allergen and depleted extract and development of a radioimmunoassay for the quantitation of the allergen.

Several monoclonal antibodies (MAbs) were raised against Olea europaea pollen-extract components. Two of these antibodies, named OL 2 and OL 7, recognize two nonoverlapping, nonrepeating epitopes on the olive-allergen Ole e I, as demonstrated by different techniques. The allergen was purified in a single step by MAb-based affinity chromatography, and the allergen revealed a band at molecular weight 20 kd as well as a minor band at 18 kd on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The contribution of allergen Ole e I to the allergenic activity of O. europaea pollen extracts was determined from the effect of allergen depletion by affinity chromatography on skin reactivity and a histamine-release test. The removal of allergen caused a large reduction in the activity of the preparation in 25 monospecific olive-allergic patients. In agreement, the affinity-purified allergen demonstrated a similar response when it was compared with the whole extract in these assays. The results indicated that Ole e I is by far the most important olive-pollen allergen. A two-site solid-phase radioimmunoassay was developed for the quantitation of the allergen Ole e I in mass units. The assay was based on the MAbs, OL 2 and OL 7, and had a detection limit in the nanogram range. A good correlation was found between allergenic activity, as determined by RAST inhibition, and allergen content in 18 olive-pollen extracts. This result indicates that the assay can be a good alternative to RAST inhibition for the standardization of O. europaea extracts.

Allergens↗

PubMed2001

Recombinant allergens with reduced allergenicity but retaining immunogenicity of the natural allergens: hybrids of yellow jacket and paper wasp venom allergen antigen 5s.

The homologous venom allergen Ag 5s from the yellow jacket (Vespula vulgaris) and paper wasp (Polistes annularis) have 59% sequence identity of their respective 204 and 205 amino acid residues, and they have low degrees of antigenic cross-reactivity in insect allergic patients and in animal models. Hybrids containing different segments of these two vespid Ag 5s were expressed in yeast. Circular dichroism spectroscopy suggests the hybrids to have the secondary structure of natural Ag 5. Inhibition ELISA with human and murine Abs suggests the hybrids to have the discontinuous B cell epitopes of the natural Ag 5 but with an altered epitope density. The hybrids were immunogenic in mice for B and T cell responses to both Ag 5s. The N-terminal region of Ag 5 was found to contain its dominant B cell epitope(s). Hybrids containing 10-49 residues of yellow jacket Ag 5 showed 100- to 3000-fold reduction in allergenicity when tested by histamine release assay with basophils of yellow jacket-sensitive patients. Our findings suggest that hybrids represent a useful approach to map the discontinuous B cell epitope-containing regions of proteins. They also suggest that Ag 5 hybrids may be useful immunotherapeutic reagents in man.

Allergens↗

PubMed1998

Immunization with purified natural and recombinant allergens induces mouse IgG1 antibodies that recognize similar epitopes as human IgE and inhibit the human IgE-allergen interaction and allergen-induced basophil degranulation.

Molecular characterization of allergens by recombinant DNA technology has made rapid progress in the recent few years. In the present study we immunized mice with aluminum hydroxide-adsorbed purified recombinant major timothy grass pollen allergens (rPhl p 1, rPhl p 2, rPhl p 5), dog albumin, a major animal dander allergen, and proteins with low (beta-lactoglobulin) or no (ribulose diphosphate carboxylase) allergenic potential in humans. Allergens that bind high levels of IgE in humans (Phl p 1, Phl p 5, dog albumin) induced high IgE and IgG1 levels in mice, whereas proteins with little or no allergenic activity in humans failed to induce significant IgE and IgG1 levels in mice. Continuous immunization for a period of 27 wk resulted in the production of mouse IgG1 Abs that recognized recombinant allergen fragments/epitopes defined by IgE Abs of allergic patients. As a consequence, allergen-specific mouse Abs strongly inhibited human IgE binding to the allergens and suppressed the allergen-induced histamine release from human basophils. In summary, our data indicate that 1) the allergenic potency of a protein may be related to its overall immunogenicity and 2) prolonged immunization with single purified recombinant allergens induces protective IgG Abs. The presented experimental in vivo/in vitro system allows the evaluation of Ag preparations (e.g., recombinant allergens) to be used for immunotherapy in humans.

Allergens↗

PubMed1980

Location of the allergenic monomer in warm-polymerized acrylic dentures. Part I: Causes of denture sore mouth, incidence of allergy, different allergens and test methods on suspicion of allergy to denture material - a survey of the literature. Case report, allergenic analysis of denture and test casting.

In the literature dealing with causes of denture sore mouth (D.S.M.) a review is given of some possible allergenic factors in acrylic dentures and of testing procedures, as well as of the incidence of allergy. A report is presented of a patient with D.S.M., the cause of which was allergy to the denture material. Skin tests showed that the surface of the upper denture in contact with the hard palate was allergenic, but not the vestibular surface in contact with the cheeks. The lingual surfaces of the lower denture were not allergenic (the other surfaces were not investigated at this sitting). It could not be ruled out that the resin might be inhomogeneous as regards the allergenic factor. The allergenic properties were verified with test castings in the form of discs made under similar conditions to those for the palatal surface. A test casting made in the same way as the vestibular side of the upper denture showed allergenic properties before polishing. The absence of allergenic properties at this point of the denture could be explained by means of another experiment with a test casting in which the allergenic properties disappeared after polishing of the surface of the resin. The working theory was set up that both the palatal and vestibular surfaces of the denture are allergenic, but that this is eliminated by polishing of the latter. The theory was tested in Part III. It was ruled out that the impression material and insulating material could be allergenic. This study is continued in Parts II and III.

Acrylic Resins↗

PubMed2003

Allergen microarray: comparison of microarray using recombinant allergens with conventional diagnostic methods to detect allergen-specific serum immunoglobulin E.

BACKGROUND: The availability of recombinant allergens and recent advances in biochip technology led to the development of a novel test system for the detection of allergen-specific IgE. OBJECTIVE: To test the performance of this allergen microarray in a serological analytical study. METHODS: Standard allergens contained in grass pollen (Phl p 1, Phl p 2, Phl p 5 and Phl p 6) and tree pollen (Bet v 1 and Bet v 2) were used as a model system. The detection of allergen-specific serum IgE using microarrays was compared with standard test systems: CAP/RAST and an in-house ELISA. In order to test the analytical sensitivity of the assays, geometric dilutions of a serum pool containing high levels of pollen-specific IgE from allergic individuals were tested in each system. To assess the analytical specificity, the sera of 51 patients with presumptive allergic symptoms were collected before diagnosis. Thereafter, the results for grass/tree-pollen-specific IgE were compared. RESULTS: The microarray has a good dynamic range similar to the CAP/RAST system. Microarray and ELISA showed comparable analytical sensitivity exceeding the CAP/RAST system. With respect to the analytical specificity, no significant cross-reactivity of the allergens was observed. For two of the allergens tested, weak positive signals were detected in the microarray test system, whereas they were not detectable by CAP/RAST. CONCLUSION: A good correlation of presently used methods to detect serum IgE and the novel microarray test system was observed. As a next step, a careful validation of this method for a multitude of allergens and a thorough clinical evaluation has to be provided. Microarray testing of allergen-specific IgE can be presumed to be the method of choice for a prospective component-resolved diagnosis of Type I allergy, and the basis for the design and monitoring of a patient-tailored specific immunotherapy in the future.

Allergens↗

PubMed2001

Cross-reactivity studies of a new group 2 allergen from the dust mite Glycyphagus domesticus, Gly d 2, and group 2 allergens from Dermatophagoides pteronyssinus, Lepidoglyphus destructor, and Tyrophagus putrescentiae with recombinant allergens.

BACKGROUND: Dust mites are important inducers of allergic disease. Group 2 allergens are recognized as major allergens in several mite species, including Dermatophagoides pteronyssinus, Lepidoglyphus destructor, and Tyrophagus putrescentiae. No allergens have thus far been characterized on the molecular level from the dust mite Glycyphagus domesticus. OBJECTIVE: We sought to examine the cross-reactivity among group 2 allergens of G domesticus, L destructor, T putrescentiae, and D pteronyssinus. METHODS: A group 2 allergen from G domesticus, Gly d 2, was cloned and expressed as a recombinant protein. Cross-reactivity between Gly d 2 and 3 other group 2 allergens, Lep d 2, Tyr p 2, and Der p 2, was studied by using individual sera and a serum pool RAST-positive to G domesticus, L destructor, T putrescentiae, and D pteronyssinus. Recombinant allergens were used as inhibitors of IgE binding in immunoblotting experiments. Molecular modeling on the basis of the Der p 2 structure was carried out for Gly d 2, Lep d 2, and Tyr p 2. RESULTS: Two cDNAs encoding isoforms of Gly d 2 were isolated, but only the Gly d 2.02 isoform was used in this study. Sixteen of 17 subjects had IgE to Gly d 2. The protein sequence of Gly d 2 revealed 79% identity to Lep d 2 and 46% and 41% identity to Tyr p 2 and Der p 2, respectively. Extensive cross-reactivity was demonstrated among Gly d 2, Lep d 2, and Tyr p 2, but little cross-reactivity was found between these allergens and Der p 2. According to the tertiary structure of Der p 2 and 3-dimensional models of Gly d 2, Lep d 2, and Tyr p 2, differences reside mainly in surface-exposed residues. CONCLUSION: Gly d 2 showed high sequence homology to Lep d 2. Cross-reactivity was observed between Gly d 2, Lep d 2, and Tyr p 2, but only limited cross-reactivity was demonstrated between these 3 allergens and Der p 2.

Allergens↗

PubMed2005

Cord blood house dust mite allergen in newborns: relationship to maternal blood levels of allergen and allergen specific IgG and IgE.

BACKGROUND: House dust mite allergen has previously been detected in the cord blood of some newborns but not others. The factors that affect the presence and levels in cord blood of this and possibly other allergens are unknown. OBJECTIVE: To test the hypothesis that the levels of maternal allergen and allergen specific IgG affect the presence and levels of newborn allergen. METHODS: Enzyme-linked immunosorbent assays were used to measure the levels of house dust mite allergen Der p 1 and Der p 1 specific IgG and IgE in paired blood samples from 98 mothers and full-term newborns. RESULTS: Der p 1 was detected in 27 mothers and 12 newborns. None of the 71 mothers who lacked Der p 1 had Der p 1-positive newborns. When present, cord blood Der p 1 levels correlated with and were approximately one third of Der p 1 levels in maternal blood. Cord blood Der p 1 levels also tended to correlate with maternal blood levels of Der p 1 specific IgG but showed little, if any, correlation with maternal blood levels of Der p 1 specific IgE. CONCLUSIONS: When detectable, the levels of an allergen in the blood of newborns correlate with the levels of that allergen in the blood of their mothers and tend to be related to maternal levels of allergen specific IgG.

Adolescent↗

PubMed2004

Dog allergen (Can f 1) and cat allergen (Fel d 1) in US homes: results from the National Survey of Lead and Allergens in Housing.

BACKGROUND: Exposures to dog and cat allergens are believed to play important roles in the etiology of asthma; however, the levels of these allergens have never been assessed in a representative sample of US homes. OBJECTIVE: The objective of this study was to estimate and characterize exposures to Can f 1 (dog allergen) and Fel d 1 (cat allergen) in US homes. METHODS: Data were obtained from the National Survey of Lead and Allergens in Housing, a nationally representative survey of 831 US homes. Vacuumed-collected dust samples from the bed, bedroom floor, living room floor, and living room sofa were analyzed for concentrations of Can f 1 and Fel d 1 (micrograms of allergen per gram of dust). RESULTS: Although a dog or cat had lived in only 49.1% of homes in the previous 6 months, Can f 1 and Fel d 1 were detected in 100% and 99.9% of homes, respectively. Averaged over the sampled sites, geometric mean concentrations (microg/g) were 4.69 for Can f 1 and 4.73 for Fel d 1. Among homes with an indoor dog and cat, respectively, geometric mean concentrations were 69 for Can f 1 and 200 for Fel d 1. Among homes without the indoor pet, geometric mean concentrations were above 1.0. The independent predictors of elevated concentrations in homes without pets were all demographic variables that were also linked to a higher prevalence of pet ownership. CONCLUSIONS: Can f 1 and Fel d 1 are universally present in US homes. Levels that have been associated with an increased risk of allergic sensitization were found even in homes without pets. Because of the transportability of these allergens on clothing, elevated levels in homes without pets, particularly among demographic groups in which pet ownership is more prevalent, implicate the community as an important source of these pet allergens.

Allergens↗

PubMed2005

[Development of Allergen Database for Food Safety (ADFS): an integrated database to search allergens and predict allergenicity].

Allergy has been one of the most common chronic health problems in recent years, and the introduction of recombinant proteins into foods and other products has raised public concern about the induction of allergy. Prediction of food allergenicity is very important but still unsatisfactory. By using an enormous amount of data produced by genomic, functional, and structural studies, bioinformatics can provide useful insights into allergenicity. We have developed a web server database system which is comprised of allergenic proteins for food safety and homology search tools, "Allergen Database for Food Safety (ADFS)". Since ADFS includes the sequences of known allergens and B-cell epitopes, a potential allergenicity of a novel protein in food should be detected by homology search. The database contains allergens classified into 8 categories (pollen, mite, animal, fungus, insect, food, latex, and others), together with the public database accession numbers of their genes, and their epitope and 3D-structure information. Users can easily search allergens with keywords and amino acid sequences through the graphical interfaces.

Allergens↗

PubMed2005

Allergen-specific nasal IgG antibodies induced by vaccination with genetically modified allergens are associated with reduced nasal allergen sensitivity.

BACKGROUND: We have performed a double-blind, placebo-controlled injection immunotherapy study with genetically modified derivatives of the major birch pollen allergen, Bet v 1 (Bet v 1-trimer, Bet v 1-fragments). OBJECTIVE: To investigate whether vaccination with genetically modified allergens induces allergen-specific antibodies in nasal secretions and to study whether these antibodies affect nasal allergen sensitivity. METHODS: A randomly picked subgroup of patients (n = 23; placebo, n = 10; trimer, n = 10; fragments, n = 3) was subjected to an extensive analysis of serum samples and nasal lavage fluids and to nasal provocation testing. Bet v 1-specific IgG(1-4) and IgA antibodies were determined in serum samples obtained before and after vaccination, after the birch pollen season, and 1 year after start of vaccination as well as in nasal lavage fluids obtained after the birch pollen season and 1 year after start of vaccination by ELISA. Nasal sensitivity to natural, birch pollen-derived Bet v 1 was determined by active anterior rhinomanometry after the birch pollen season and 1 year after start of vaccination. RESULTS: Vaccination with genetically modified Bet v 1 derivatives, but not with placebo, induced Bet v 1-specific IgG1, IgG2, and IgG4, and low IgA antibodies in serum, which also appeared in nasal secretions, but no IgG3 antibodies. The levels of therapy-induced Bet v 1-specific IgG4 antibodies in nasal secretions were significantly (P < .05) associated with reduced nasal sensitivity to natural, birch pollen-derived Bet v 1 as objectively determined by controlled nasal provocation experiments. CONCLUSION: Our data demonstrate that vaccination with genetically modified allergens induces IgG antibody responses against the corresponding natural allergen not only in serum but also in mucosal fluids, where they may protect against allergen-induced inflammation.

Adult↗

PubMed2006

Gene gun immunization with clinically relevant allergens aggravates allergen induced pathology and is contraindicated for allergen immunotherapy.

Gene gun immunization has been associated with the induction of a heterologous type of immune response characterized by a T(H)1-like immune reaction on the cellular level, i.e. generation of IFN-gamma secreting CD8(+) T-cells, yet a T(H)2 biased serology as indicated by high IgG1:IgG2a ratios and induction of IgE. Nevertheless, gene gun immunization using the model molecule beta-galactosidase has been argued to prevent IgE induction and to promote T(H)1 cells with respect to allergy DNA immunization. In our current study, we evaluated the potential of gene gun immunization to prevent type I allergic reactions comparing beta-galactosidase with two clinically relevant allergens, and further investigated the effect of gene gun immunization on relevant lung parameters. BALB/c mice were immunized with plasmids encoding the birch pollen allergen Bet v 1, the grass pollen allergen Phl p 5, or the model molecule beta-galactosidase, either by gene gun or intradermal injection followed by sensitization and intranasal provocation with the respective allergen. IgG1 and IgG2a antibody titers were determined by ELISA. IgE levels were evaluated in a rat basophil release assay. The severity of eosinophilia was determined in bronchoalveolar lavages, and the overall infiltrate was analyzed by histology on lung paraffin sections. Gene gun immunization induced a T(H)2-biased immune reaction, which did not prevent from production of IgE after subsequent sensitization. This T(H)2 effect was influenced by the nature of the antigen, with a more pronounced T(H)2-bias for the allergens Bet v 1 and Phl p 5 compared to beta-galactosidase. Gene gun immunization with all three antigens promoted eosinophil influx into the lung and did not alleviate lung pathology after intranasal provocation. In contrast to needle injection of plasmid DNA, which triggers a clearly T(H)1-biased and allergy-preventing immune response, gene gun application fails to induce anti-allergic reactions with all tested antigens and is therefore contraindicated for allergen-specific immunotherapy.

Allergens↗

PubMed1998

Effects of adjuvants on the immune response to allergens in a murine model of allergen inhalation: cholera toxin induces a Th1-like response to Bet v 1, the major birch pollen allergen.

Based on the fact that type I allergies are frequently elicited by inhalant allergens, we have established a model of aerosol inhalation leading to allergic sensitization in BALB/c mice. Using this model we studied the effects of aluminium hydroxide (Al(OH)3), known to enhance IgE antibody responses, compared with cholera toxin (CT), a potent mucosal adjuvant, on the immune response to birch pollen (BP) and its major allergen Bet v 1. Two groups of BALB/c mice were either systemically immunized with recombinant Bet v 1 in Al(OH)3 and subsequently aerosol exposed to BP allergen, or aerosolized with BP and CT. IgE-mediated skin reactions were only elicited in the mice which had received Bet v 1/Al(OH)3. Allergen-specific serum IgE and IgG1 antibodies dominated in the Al(OH)3 group, IgG2a antibody levels to BP and rBet v 1 were markedly higher in the sera of mice exposed to CT with the allergen. IgA antibodies were only detected in the bronchial lavage of the CT-treated group. Moreover, the latter group displayed consistently higher T cell proliferative responses to BP and interferon-gamma production in vitro. Thus, the systemic immunization with rBet v 1 in Al(OH)3 before inhalation of the BP extract promoted a Th2-like immune response, while CT mixed with the aerosolized BP extract rather induced a Th1-like immune response. In an attempt to reverse these ongoing immune responses we could achieve a shift towards a Th0 response. Immunization with BP extract without adjuvant treatment led to undetectable antibody or cellular immune responses. We conclude from the present study that the induction of an immune response to BP allergen after aerosol inhalation can be directed towards a Th1- or a Th2-like response. Once established, the immune response can be modulated.

Adjuvants, Immunologic↗

PubMed1986

High-performance liquid chromatographic molecular weight determination of allergen extracts. Examination of the influence of the column material on allergenic activity and allergen patterns.

To investigate whether the column material employed in size-exclusion high-performance liquid chromatography (HPLC) influences the allergenic activity and antigen/allergen patterns of allergen extracts, the molecular weights of a mite and a birch pollen allergen extract were determined using a Bio-Sil TSK 250 column with a guard column. The allergenic activities were measured by RAST inhibition and the antigen/allergen patterns were determined by crossed (radio)immunoelectrophoresis. The original extracts and the corresponding eluates after HPLC runs showed the same allergenic activity and the same number of antigen/allergen precipitation lines. Only slight differences in the peak heights of some precipitates were observed.

Allergens↗

PubMed2003

[Exposition and sensitisation to indoor allergens, house dust mite allergen and cat allergens].

The study examined the exposure to biological indoor air agents and their possible role for allergies and respiratory tract illnesses of children. It was conducted as a case control study (atopic vs non-atopic children) at the four surveillance public health departments in Baden-Württemberg in the winter season 1999/2000 and included 379 children of the fourth class. The concentrations of the house dust mite antigens Der F1, Der p1, and Der Gr2 as well as cat allergen Fel d1 were determined in the children's bedrooms on the ground and in the mattress. Specific IgE-antibodies against allergens from house dust, mites and cat were determined in the serum of the children. For mite allergens the following medians ( micro g/g) were estimated in floor dust: Der p1 = 0.6, Der f1 = 2.3, Gr2 = 0.1; in mattresses: Der p1 = 1.2, Der f1 = 3.4, Gr2 = 0.3. The median of Fel d1 in floor dust was 0.2 microg/g, in mattresses 0.1 microg/g. Sensitisation to dust mite allergen was found to be more prevalent than sensitisation to cat. The distribution of sensitisation among the cases and controls is different. Among the cases, more subjects were sensitised to dust mites (32.9 %) and cat (13.1 %). Among the controls, 17.1 % were sensitised to dust mites and 4.1 % to cat. The results showed no direct association between the prevalence of allergies or respiratory tract illnesses and the indoor concentrations of the allergens. Possible reasons for these findings are discussed.

Allergens↗

PubMed1998

Bet v 1, the major birch pollen allergen, and Mal d 1, the major apple allergen, cross-react at the level of allergen-specific T helper cells.

BACKGROUND: Food allergy to apple is frequent in individuals allergic to tree pollen. The major allergens of birch, Bet v 1, and apple, Mal d 1, have been cloned and sequenced and display a high degree of sequence identity, leading to IgE cross-reactivity. OBJECTIVE: We sought to investigate cross-reactivity between Bet v 1 and Mal d 1 at the level of allergen-specific T lymphocytes. METHODS: PBMCs of 13 patients allergic to birch pollen with oral allergy syndrome to apple were stimulated with rBet v 1 and rMal d 1, respectively, thereby establishing allergen-specific T-cell lines and T-cell clones. rMal d 1-specific T-cell cultures were tested for reactivity with rBet v 1, and rBet v 1-specific T cells were analyzed for reactivity with apple allergen. Cytokine production patterns in response to specific stimulation were evaluated. A selection of cross-reacting T-cell clones was mapped for epitope specificity by the use of overlapping Bet v 1- derived peptides. RESULTS: Nineteen Mal d 1-specific T-cell clones were produced, 79% of which cross-reacted with Bet v 1. Eight of 18 Bet v 1-specific T-cell clones cross-reacted with Mal d 1. Six peptides representing cross-reactive T-cell epitopes could be identified. The respective fragments from birch and apple displayed approximately 50% amino acid identity. Seventy percent of the cross-reactive T-cell clones revealed a T(H2)-like cytokine production pattern. CONCLUSION: The results indicate that cross-reactivity between apple and birch pollen leading to the clinical oral allergy syndrome occurs not only at the serologic, but also at the cellular level.

Adult↗

PubMed1999

Cockroach allergens and asthma in Brazil: identification of tropomyosin as a major allergen with potential cross-reactivity with mite and shrimp allergens.

BACKGROUND: Cockroaches produce several proteins that induce IgE antibody responses. Although cockroaches are abundant in warm and humid areas, sensitization to cockroach allergens has not been investigated in Brazil. OBJECTIVE: The aims of this study were to investigate the frequency of cockroach allergy among patients with asthma, rhinitis, or both in Brazil and to identify American cockroach allergens. METHODS: Skin tests using cockroach extracts were performed on children and young adults with asthma, rhinitis, or both. A Periplaneta americana complementary (c)DNA library was screened by using IgE antibodies from Brazilian patients allergic to cockroaches. Reactivity of an mAb directed to Dermatophagoides pteronyssinus tropomyosin against cockroach tissue was examined by immunofluorescence. RESULTS: Cockroach allergy was present in 55% and 79% of the patients, as determined by using skin prick tests alone or combined prick and intradermal tests, respectively. Five cDNA clones reacted with IgE antibody and contained the same sequence. A representative clone (1300 bp), pa 12, coded for a protein that reacted with 50% of the sera from patients allergic to cockroaches on plaque immunoassay and showed a high degree of homology to tropomyosins, particularly those from invertebrates. P americana tropomyosin showed 80%, 81%, and 82% sequence identity to tropomyosins from D pteronyssinus, D farinae, and shrimp, respectively, which have been previously defined as important allergens. An mAb directed against D pteronyssinus tropomyosin, which also recognizes shrimp tropomyosin, showed binding to cockroach striated muscle. CONCLUSION: Our results support the recommendation that cockroach extracts should be routinely used for the evaluation of patients with asthma, rhinitis, or both in Brazil. The identification of P americana tropomyosin as an important allergen will make it possible to investigate cross-reactivity among cockroaches, mites, and food derived from invertebrates.

Adolescent↗

PubMed1985

Analysis of allergen-specific IgE responses in 341 allergic patients. Associations between allergens and between allergen groups and clinical diagnoses.

An allergic population of 341 patients was studied using 14 different allergen extracts in skin prick tests and radioallergosorbent tests (RAST) in an attempt to identify important allergen sources in the Sydney area and to examine relationships between these diagnostic methods and a number of clinical parameters. A computer based statistical analysis of the data revealed that: (a) male patients showed a significantly higher frequency of skin test reactivity to extracts of house dust and the house dust mite Dermatophagoides farinae; (b) the incidence of positive prick test reactions declined with age; (c) cross-reactive allergenic determinants were found in taxonomically-related extracts (e.g. between different house dust mites, pollens, and fungi); (d) a clear correlation emerged between relative potency using a histamine standard and RAST score which supports the continued use of histamine as a standard in skin prick testing; and (e) important associations between certain allergens and clinical diagnosis emerged (e.g. positive skin test reactions to house dust mites and epithelia but not pollens were associated with asthma).

Adolescent↗