Molecular characteristics of cockroach allergens

Cockroaches, commonly found in urban dwellings worldwide, have long been considered vectors of various infectious diseases and cockroach allergens are one of the major etiologic risk factors for IgE-mediated allergic respiratory illness throughout the world. A high prevalence of cockroach hypersensitivity in atopic （20-55 %） and asthmatic （49-60 %） populations has been documented. Cockroach allergens with molecular weights ranging from 6 to 120 kD have been identified by various standard immunochemical techniques. This article covers the characteristics of major cockroach allergens that have been purified, sequenced, cloned, and produced as recombinant proteins. Cellular ＆ Molecular Immunology. 2005;2（3）： 177-180.     

Environmental assay for cockroach allergens

A sandwich ELISA was developed to measure the concentration of cockroach allergen in the environment. The assay was based on a monospecific rabbit antibody preparation reactive with determinants shared by the important allergens, Per a I and Bla g I, from American and German cockroaches. The sensitivity was 0.2 ng Lowry protein of Per a I equivalents per milliliter, corresponding to 1 ng of Per a I equivalents per gram of dust (Per a I eq/gm). The assay did not react with noncockroach-allergen sources. Dust samples from 73 households in a cockroach-infested area were assayed. The concentration in these samples varied from below detection to 200,000 ng of Per a eq/gm of dust. Three commercial cockroach-allergen extracts all contained the allergen. The assay will be valuable for studies of the clinically relevant cockroach-allergen exposure levels and for assessment of efficacy of allergen-avoidance measures. Furthermore, the assay could be used for sanitary documentation in bakeries, restaurants, etc.     

Specific IgE and IgG antibody-binding patterns to recombinant cockroach allergens

BACKGROUND: The specificity of serum antibody responses to different cockroach allergens has not been studied. OBJECTIVE: We sought to quantitate serum IgE and IgG antibodies to a panel of purified cockroach allergens among cockroach-sensitized subjects. METHODS: IgE antibodies to recombinant cockroach allergens (rBla g 1, rBla g 2, rBla g 4, rBla g 5, and rPer a 7) were measured in sera containing IgE antibodies to Blattella germanica extract (n = 118) by using a streptavidin CAP assay and a multiplex flow cytometric assay. Specific IgG antibodies were determined by using radioimmunoprecipitation techniques. RESULTS: Specific IgE antibodies measured by means of CAP assay and multiplex assay were strongly correlated ( r = 0.8, P < .001). The sum of IgE antibodies (in international units per milliliter) against all 5 allergens equated to IgE antibodies to cockroach extract. Although the prevalence of IgE antibodies was highest for rBla g 2 (54.4%) and rBla g 5 (37.4%), patterns of IgE antibody binding were unique to each subject. Surprisingly, only 16% of cockroach-sensitized subjects with IgE antibodies to house dust mite exhibited IgE antibody binding to cockroach tropomyosin (rPer a 7). Specific IgE antibodies were associated with increased IgG antibody levels, although detection of IgG in the absence of IgE was not uncommon. CONCLUSION: The techniques described offer a new approach for defining the hierarchy of purified allergens. IgE antibodies directed against 5 allergens constitute the majority of the IgE antibody repertoire for cockroach. Such distinct patterns of IgE-IgG responsiveness to different cockroach allergens highlight the complexity of B-cell responses to environmental allergens.     

Identification and characterization of important cockroach allergens

Allergens extracted from American and German cockroach species have been identified as significant sensitizing agents in the induction/exacerbation of asthma. In the present study, gel-filtration fractions of saline extracts of American cockroach (Periplaneta americana) whole bodies (AWBE fraction 2) and German cockroach (Blattella germanica) whole bodies (GWBE fraction 2) were used to identify and characterize important cockroach allergens by immunoprinting. In addition, allergens from AWBE and GWBE fractions 2 were additionally fractionated by chromatofocusing on polybuffer exchanger. Immunoprinting studies demonstrated several important acidic allergens in cockroach whole body extracts. All but one allergen had an acid isoelectric point (pH 2.80 to 5.20). Two allergens, one that focused at pH 3.50 and another allergen (or group of isoallergens) that focused between pH 4.15 to 4.55 were reactive with most sera obtained from cockroach-sensitive subjects. Chromatofocusing and subsequent skin test and RAST studies of AWBE and GWBE confirmed the presence of significant cockroach allergens with isoelectric points within the zone of pH 3.75 to 4.50. RAST-inhibition studies demonstrated the similarity of these allergens between AWBE and GWBE. Collectively, these observations identify the presence of several acidic cockroach allergens presumably shared between AWBE and GWBE.     

Environmental exposure to cockroach allergens: analysis with monoclonal antibody-based enzyme immunoassays

Quantitative two-site monoclonal antibody (MAb)-based enzyme-linked immunoassays for two cockroach (CR) allergens, Bla g I and Bla g II, have been developed and used to measure allergen levels in house-dust samples. Dust collected from the CR-infested homes of two patients with asthma from Charlottesville, Va., demonstrated wide variation in the levels of Bla g I, depending on the location of dust collection. Dust from kitchen floors and cabinets contained 50-fold more allergen (mean, 10,755 U/gm of dust) than dust from bedrooms and upholstered furniture (mean, 204 U/gm). One hundred forty-five dust samples were collected from the bedrooms and living rooms of 22 children with asthma and 16 control subjects without asthma living in Atlanta, Ga. Twenty-seven of the 38 homes (17/22 children with asthma; 10/16 control subjects) had detectable Bla g I (4 to 1340 U/gm of dust). Bla g II levels were assayed in 40 kitchen, bedroom, and living room samples from homes in Wilmington, Del. Highest levels of Bla g II were detected in kitchen-floor dust (300 U/gm of dust). Additionally, approximately 20% of homes with no visual evidence of CR infestation had significant levels of Bla g II in at least one dust sample (greater than 4 U/gm of dust). Our results demonstrate that CR may be an occult allergen in homes. The kitchen appears to be the primary site of CR-allergen accumulation, but significant CR-allergen levels can also be found at other sites in the home. The MAb-based assays can be used for quantitation of environmental exposure to CR allergens.(ABSTRACT TRUNCATED AT 250 WORDS)     

HLA-DRB1*01 alleles are associated with sensitization to cockroach allergens

BACKGROUND: Sensitization to cockroach allergens is an important epidemiologic risk factor for asthma, particularly among African Americans living in urban environments. A recent genome screen in the Hutterites, a white founder population, identified a linkage between an HLA-linked marker and sensitization to cockroach allergens. OBJECTIVE: Our purpose was to determine whether alleles at one or more HLA loci are associated with sensitization to cockroach allergens in ethnically diverse populations. METHODS: Alleles at 14 HLA region loci were studied in the Hutterites. On the basis of these results, selected loci were examined in 54 African Americans with cockroach sensitization (cases) and 65 African Americans without cockroach sensitization (controls). Sensitivity to cockroach allergens was assessed in both samples by skin prick test to purified cockroach allergens (Periplaneta americana and Blatella germanica). RESULTS: Significant associations between cockroach allergies and DRB1*0101 (P(corrected) =.0066), DQA1*0101 (P(corrected) =.0012), and DQB1*0501 (P(corrected) =.00096) were detected in the Hutterites. In the African American sample, the most significant association was with the DRB1*0102 allele (P(corrected) =.0088, odds ratio 16.4, 95% confidence interval 2.0, 131). The DRB1*0101 allele was infrequent in the African American sample (frequency 0.06) and the DRB1*0102 allele was absent in the Hutterites. DRB1*0101 and DRB1*0102 are closely related alleles that differ from nearly all other DRB1 alleles at 3 amino acids in the 1 peptide binding domain of the HLA-DR molecule. CONCLUSIONS: The DRB1*0101 allele in the Hutterites and the DRB1*0102 allele in African Americans confer risk for cockroach sensitization. Elucidating this interaction at the molecular level may allow for more targeted treatment and prevention of atopic asthma in inner-city populations.     

Cockroach allergen detection and cockroach allergens of allergic Thai patients

Hybridomas secreting monoclonal antibodies (MAb) specific to American cockroach (Periplaneta americana) were produced through a fusion of immune splenocytes of a BALB/c mouse immunized with crude cockroach (CR) extract and mouse myeloma cells. Two hybridomas namely 38G6 and 3C2 were established. These specific hybridomas secreted IgG1 monoclonal immunoglobulins with antigenic specificities to CR protein components of over 207 to 72 kDa and 45 to 40 kDa, respectively. The monoclonal antibodies were applied to select their specific epitopes out of the crude CR extract using affinity chromatography. A Prausnitz-Kustner test revealed that these epitopes were allergens which caused wheals and flares of the skin of a guinea-pig previously sensitized with a pool of serum samples from CR allergic patients. The monoclonal antibodies were also used in a capture ELISA to detect specific IgE in serum samples of allergic Thai patients. It was found that 72% and 76% of the patients had IgE antibodies to the epitopes of MAb 38G6 and MAb 3C2, respectively, indicating that the two epitopes are major CR allergens among the CR allergic Thai patients. An antibody-sandwich ELISA was developed for quantitative detection of CR allergens using the two monoclonal antibodies as a capture reagent and rabbit polyclonal antibodies to crude CR extract as a detection reagent. The assay could detect allergenic epitopes contained in as little as 122 pg of crude cockroach extract, and has high potential for direct measurement of the marker allergens in extracts of environmental samples.     

HLA-DQ/human CD4-restricted immune response to cockroach allergens in transgenic mice

We investigated the immune response to the German cockroach (Blattella germanica), and one of its major antigens, Blattella germanica group 5 (Bla g 5), in a double-transgenic, double-knockout mouse expressing human HLA-DQ8, HLA-DQ6 and CD4 molecules in the absence of mouse class II and mouse CD4. Transgenic mice were primed and challenged with CR extract or individual synthetic peptides representing Bla g 5. Strong T-cell responses to CR extract were detected in both HLA-DQ/hCD4+ transgenic mice. The responses were two times lower in mice expressing HLA-DQ molecule in the context of mouse CD4. Under similar treatment, no responses were found in the double-knockout Abetadegrees/mCD4degrees mice and in mice expressing human CD4 molecule alone. HLA-DQ/hCD4+ mice produced primarily interleukin (IL)-5, IL-10, and IL-13. Minimal amounts of IL-4 were detected only in HLA-DQ6/ hCD4+ mice. Interferon (IFN)-gamma production was low in both transgenic mouse, suggesting a predominantly T-helper 2 (Th2)-type response. Cockroach allergen extract immunized HLA-DQ8/hCD4+ mice recognized only one of the 20 peptides of Bla g 5 while HLA-DQ6/hCD4+ mice responded primarily to three peptides. Primed with individual peptides, both HLA-DQ/hCD4+ mice responded maximally to peptides 10 (residues 91-110) and 17 (residues 161-180). In addition, HLA-DQ6/hCD4+ mice responded to peptide 16 (residues 151-170). Thus, peptides 10 and 17 contained the major HLA-DQ-restricted hCD4+ T-cell epitopes and could be recognized by both HLA-DQ8 and HLA-DQ6 transgenic mice. Transgenic mice represent a new tool for investigating the immune responses to cockroach allergen. Our results suggest that therapeutic strategies aimed at developing antagonist peptides might be a useful treatment (immunotherapy) for allergic asthma.     

Cloning of the American cockroach Cr-PII allergens: Evidence for the existence of cross-reactive allergens between species

Background: Previously, we have identified the 28 and 32 kd proteins as additional important allergens from the American cockroach (Periplaneta americana) Cr-PII allergenic fraction. Objective: The aim of this study was the cloning of P. americana Cr-PII allergens. Methods: A λgt22A cDNA library constructed from P. americana mRNA was packaged into Escherichia coli Y1090 (r^–), and clones recognized by murine anti-Cr-PII monoclonal antibodies and human IgE antibodies were isolated, sequenced, and subcloned into pET 21 and expressed in E. coli BL21(DE3). Results: Six Cr-PII–positive clones recognized by human IgE antibodies were isolated. Two clones, C6 and C17, were sequenced, and we found encoding proteins of 228 and 274 amino acids with no cysteine or any potential N-glycosylation site, with predicted masses of 25.8 and 31.14 kd, respectively. Both molecules contain internal repeated sequences with a 94% identity between them. C6 and C17 showed 59% and 77.3% skin reactivities, respectively, on 22 cockroach-sensitive atopic patients. Both clones were found to have 28.9% to 31.8% identities to ANG12 protein, a precursor of the African malaria mosquito (Anopheles gambiae) and 82.7% to 85.1% identity to a nucleotide sequence of the German cockroach (Blattella germanica) Bla g Bd90K allergen. The anti-C6 and anti-C17 antibodies were able to recognize Cr-PII, recombinant proteins, five commercial American extracts, and two German cockroach extracts. Moreover, the binding of anti-C6 and anti-C17 antibodies to recombinant protein can be inhibited by B. germanica crude extract. Furthermore, Northern blot analyses have shown that B. germanica mRNAs could be detected by both cDNA probes. Conclusion: Our findings provide the first evidence of antigenic cross-reactivity between P. americana and B. germanica allergens on molecular levels. The results will be a great aid in facilitating the epitope mapping and improving diagnostic and therapeutic reagents for both cockroach species. (J Allergy Clin Immunol 1998;101:832-40.)J Allergy Clin Immunol 1998;101:832-40.     

Guanine, mite, and cockroach allergens in Costa Rican homes

Previous studies of schoolchildren in Costa Rica have shown an asthma prevalence of 23% and a high level of sensitization, particularly to mite allergens. As a continuation of these studies, some 400 dust samples were collected from various places in Costa Rica, and parts of these were analyzed for specific mite and cockroach allergens, as well as for the number of mites and amount of guanine. Guanine was quantified by a diazo, as well as an HPLC method, which were found to be highly correlated. The concentrations of guanine by the diazo method, Der p 1, Der f 1, and the number of mites were higher in bed dust than in bedroom floor dust, and it was possible to quantify mite allergens and guanine in almost all bed-dust samples. The mean levels were 2–3 times higher than the proposed risk level for elicitation of symptoms in mite-sensitive asthmatics. Bed and bedroom floor dust contained more guanine and mite allergen in humid (>2000 mm rain) than in drier places (P&0.05), but the number of mites in bed and bedroom floor dust was higher in less humid places (P=0.01). The guanine content in bedroom floor dust was higher in areas with a temperate climate than in areas with a warmer climate (P<0.001, Bartlett's chi square [BCS]), as was the number of mites (P<0.01, Kruskal-Wallis [KW], 0.04, BCS) and the Der p 1 concentration (P<0.01, BCS; P=0.02, KW). The Der f 1 concentration in bedroom floor dust was higher in a warmer than in a temperate climate (P<0.001, BCS). More guanine and mites were found in urban than in rural bed dust (P<0.03, KW). Dust samples from the metropolitan area (temperate climate) of Costa Rica contained higher levels of guanine (P<0.01) and Der p 1 (P<0.07) than the coastal areas, but very little Der f 1. In these samples, guanine and Der p 1 allergen were closely related, and 2 μg of the allergen was equivalent to 0.49 mg of guanine. Two-thirds of bed and floor samples collected on cotton filters contained Bla g 2 allergen at mean levels of 1.6 and 2.1 units/g dust, respectively. Cockroach allergen was, however, absent in all bed samples from the metropolitan area, but did occur in very high concentrations in the coastal bed dust samples collected with tighter polyester filters. In conclusion, the concentration of guanine and Der p 1 was very high in the bed dust of Costa Rican homes. Some factors, such as humidity, small houses for large families, and type of bedding, probably favored the heavy mite infestation, which is probably related to the widespread occurrence of bronchial asthma in this country.     

Two new types of allergens from the cockroach,Periplaneta americana

Periplaneta americana cockroach is an important source of inhalant indoor allergen resource, and there are more than twenty IgE‐binding components identified in P. americana, but only nine allergens were characterized. Our knowledge about cockroach allergens remains poor. In this work, two novel allergen proteins Per a 11 (alpha‐amylase) and Per a 12 (chitinase) with molecular weight around 55 and 45 kDa, respectively, were purified and characterized from the midgut of cockroaches. Their primary sequences were determined by Edman degradation, mass spectrometry, and cDNA cloning. Sera from 39 and 30 of 47 (83.0% and 63.8%) patients reacted to Per a 11 and Per a 12 on immunoblots, respectively. The allergenicity of Per a 11 and Per a 12 was further confirmed by competitive ELISA, basophil activation test (BAT), and skin prick test (SPT). They appear to be of importance for the allergic reactions induced by cockroach and have a potential for component‐based diagnosis of allergy.     

Common German cockroach whole body and fecal allergens: immunoprint inhibition studies

Previous studies have established that cockroach allergens are important sensitizing agents in the induction/exacerbation of urban asthma. The present investigation compared saline extracts of German cockroach (Blattella germanica) whole bodies (GWBE) and feces (GFE) as important sources of allergens. Both extracts were tested prior to or following gel filtration on Sephadex G-75 (Fr2). Immunoprinting of unfractionated fecal extract using 10 RAST-positive sera detected a series of allergens with pI values between 4.15-4.55 and a single allergen that focused near the cathode. Multiple allergens were detected in both GWBE-Fr2 and GFE-Fr2. Generally, most RAST-positive sera reacted similarly, although GWBE-Fr2 had more allergenic proteins than GFE-Fr2 with pI less than 4.7 and fewer allergens with pI greater than 4.7. Immunoprint inhibition of GWBE and GFE by GWBE and GFE also demonstrated allergenic similarity, although homologous extracts were more effective inhibitors than heterologous preparations. Collectively, these studies demonstrate the allergenic similarities of cockroach whole body and fecal extracts. Thus fecal material may provide an important source of sensitizing antigen.     

Production and characterization of monoclonal antibodies against major allergens of American cockroach

From several fusion experiments between spleen cells obtained from BALB/c mice immunized with partially purified Cr-PI of American cockroach and NS-1 cells, growth was observed in many wells. Seven stable subclones secreting monoclonal antibodies (mAbs) against Cr-PI, as determined by enzyme-linked immunosorbent assay (ELISA) with high absorbance values and immunoblot analysis, were obtained. All seven mAbs were characterized as IgG1 subclass by immunodiffusion, and reacted strongly with 72 kilodaltons (kD) of Cr-PI which have been identified as a major allergen of American cockroach. Six mAbs were found to have similar epitope specificities against Cr-PI by ELISA. The remaining mAb was found to have different epitope specificities with others. Interestingly, all mAbs did not react with any components of crude extracts of Oriental and German cockroaches as determined by immunoblot analysis and ELISA. A mAb-based double-antibody sandwich ELISA was developed, and the ELISA was dose-dependent and capable of detecting as little as 140 ng of Cr-PI allergen.     

Identification, quantitation, and purification of cockroach allergens using monoclonal antibodies

A panel of murine IgG monoclonal antibodies (MAbs) was raised against German cockroach (CR) (Blattella germanica) extract and selectively screened to identify MAb directed against allergen(s) recognized by IgE antibodies. Sera from 28 CR-allergic patients were used as sources of IgE antibodies to detect allergens "presented" by the MAb. Four clones (10A6, 3G12, 8F4, and 1D4) produced MAb to allergen(s) that bound IgE antibodies. Quantitative radioimmunoassays were used to compare levels of the MAb-defined allergens in CR extracts. MAb 10A6 reacted with a cross-reacting allergen that was detected in 9/14 CR species, including Blattella, Periplaneta, Blatta, Leucophea, and Supella spp, at concentrations of 100 to 10,000 U/ml. In contrast, MAb 3G12, 8F4, and 1D4 were Blattella specific. The allergen defined by MAb 8F4 was purified by MAb affinity chromatography and size-exclusion by high-performance liquid chromatography. It is a 36 kd heat-sensitive protein, isoelectric point, 5.2 to 5.4. Allergen 10A6 was partially purified by isoelectric focusing and high-performance liquid chromatography. It is a heat-stable, acidic protein (isoelectric point 3.15). Based on comparison of their properties with properties of previously described CR allergens, the allergens defined by MAb 10A6 and 8F4 have been provisionally designated Blattella germanica allergen I (Bla g I) and Blattella germanica allergen II (Bla g II), respectively. Assays of six commercial CR skin test extracts demonstrated a 200-fold difference in Bla g I levels (4.7 to 1085 U/ml) and only two extracts that contained detectable Bla g II (248 and 324 U/ml). The results demonstrate that MAb can be used to identify and define CR allergens and that the strategy of the use of MAb as a first step in allergen analysis and purification can be very effective, especially for poorly characterized allergen extracts.     

Analysis of properties and proinflammatory functions of cockroach allergens Per a 1.01s

Cockroaches have been identified as one of the major indoor allergens inducing perennial rhinitis and asthma. Per a 1s are a group of the major allergens from American cockroach. Although Per a 1s are major allergens from American cockroach, factors contributing to the allergenicity of Per a 1s are still poorly defined. To investigate the effects of Per a 1s on the expression of PARs and the release of proinflammatory cytokines from mast cells. Per a 1.0101 and Per a 1.0104 were cloned from American cockroach and then expressed in Eschericia coli. The purified allergens were used to stimulate P815 mast cells, and the expression of protease-activated receptors (PARs) was determined by real-time RT-PCR and flow cytometry. The levels of IL-4 and IL-13 in culture media were detected with ELISA. Sera from 80 and 77.3% of cockroach allergy patients reacted to recombinant Per a (rPer a) 1.0101 and rPer a 1.0104, confirming they are major allergens. Both rPer a 1.0101 and rPer a 1.0104 had no enzymatic activity, but rPer a 1.0101 upregulated the expression of PAR-1 and PAR-2, and rPer a 1.0104 enhanced the expression of PAR-1 and PAR-4 proteins. Both recombinant allergens were able to increase the release of IL-4 and IL-13 from P815 mast cells. This is the first study aiming to investigate functions of group 1 allergens of American cockroach. rPer a 1.0101 and rPer a 1.0104 have the capacity to upregulate the expression of PARs and to enhance Th2 cytokine production in mast cells.     

Domestic allergens in public places II: dog (Can f 1) and cockroach (Bla g 2) allergens in dust and mite, cat, dog and cockroach allergens in the air in public buildings

Background Sensitization and exposure to indoor allergens are the major risk factors for asthma. It is possible that significant exposure to domestic allergens occurs outside the home. Objectives To investigate the levels of Can f 1 and Bla g 2 in the dust from carpeted floors and upholstered seats in public buildings and public transport and the airborne concentrations of Der p 1, Fel d 1, Can f 1 and Bla g 2 in schools and offices. Methods Can f 1 and Bla g 2 were measured in the dust collected by vacuuming a I m² area of carpet, as well as upholstered seats in five schools, six hotels, four cinemas, six pubs, three buses and two trains. Dust was also collected from the bedroom carpet, living room carpet, mattress and sofa in 20 homes with and 20 homes without a dog in the same area. Personal airborne sampling (2 L/min) was conducted for 8 h in offices (n= 16) and classrooms (n= 9). In addition, airborne samples in schools were collected using a high volume pump (60 L/min) for 1 h in three classrooms immediately after the children vacated the school. Can f 1, Bla g 2, Der p 1 and Fel d 1 were assayed using a two–site monoclonal antibody–based ELISA. Results Can f 1 was detected in all dust samples from public places, ranging from 0.2 to 52.5 μg/g, Significantly higher levels were found in upholstered scats (geometric mean – GM 9.4 μg/g) than in carpets (GM 1.5 μg/g; P < 0.001), and levels of Can f 1 > 10 μg/g were found in 40% of upholstered seats in public places. Can f 1 was significantly higher in upholstered seats in public places than in sofas in homes without a dog (GM 1.8 μg/g; P < 0.001). Detectable levels of Bla g 2 were found in all of the schools (GM 2.4 U/g, range 0.8–4.4 U/g). Bla g 2 concentration greater than 2U/g (provisional threshold level representing risk of sensitization) was measured in 65% of the classrooms sampled. Der p 1 and Bla g 2 were below the detection limit in all airborne samples. However, airborne Fel d 1 and Can f 1 were detected in schools and offices, albeit in low concentrations. Conclusions Upholstered seats from public places constitute a reservoir for the accumulation of dog allergen, and a source of exposure to Can f 1 inside public buildings or on public transport. Exposure to cockroach allergens in schools may be important for cockroach sensitized asthmatic children.     

检测变应性疾病患者特异性IgE探讨三种蟑螂的交叉抗原性

用ELISA法检测变应性疾病患者血清中对三种常见蟑螂:美洲大蠊、黑胸大蠊和德国小蠊变应原的特异性IgE抗体(sIgE),以探讨它们之间可能存在的交叉抗原性及其程度。结果美洲大蠊、黑胸大蠊和德国小蠊sIgE阳性率分别为24.1%、16.7%和14.8%。美洲大蠊与黑胸大蠊间血清学反应符合率为74.5%,美洲大蠊与德国小蠊间血清学反应符合率74.2%,黑胸大蠊与德国小蠊间血清学反应符合率为85.5%。美洲大蠊头部和体部sIgE阳性率分别为17.3%和13.4%;黑胸大蠊头部和体部sIgE阳性率分别为12.1%和9.6%。美洲大蠊头部抗原与其体部抗原间血清学反应符合率为82.5%;黑胸大蠊头部抗原与其体部抗原间血清学反应符合率为88.2%;ELISA交叉抑制实验结果显示,三种蟑螂相互之间均存在较明显的交叉抑制现象。表明三种蟑螂间及美洲大蠊、黑胸大蠊不同部位之间均存在一定程度的交叉抗原性成分,即具有共同的IgE结合组分。