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Biomedical subjects

M Raulf-Heimsoth

Publications and source records attributed to M Raulf-Heimsoth.

At least 19 recordsLinked to original sources
PubMed2006

Occupational immunoglobulin E-mediated asthma due to Penicillium camemberti in a dry-sausage packer.

A 62-year-old female sausage packer reported progressive work-related asthma, rhinitis and contact urticaria after contact to dry sausages refined by moulds. Whereas skin prick tests with commercial mould extracts were negative, the patient showed weak skin sensitization to a cultivated mould sample from a dry sausage. Specific immunoglobulin E antibodies to various moulds were demonstrated by ImmunoCAP and antibodies to the cultivated mould sample were demonstrated by enzyme allergosorbent test. The mould was identified by pheno- and genotyping as Penicillium camemberti. Five atopic controls did not show sensitization with the same tests. Crossreactivity of P. camemberti and Penicillium notatum was shown by enzyme allergosorbent inhibition tests. Although no challenge tests were considered due to the patient's airway obstruction, a diagnosis of allergic occupational asthma was made. We conclude that immunoglobulin E-mediated allergic occupational asthma due to moulds may occur in dry sausage packers.

Allergens↗
PubMed2006

Allergen concentration in natural rubber latex.

BACKGROUND: Hevea brasiliensis latex serum is commonly used as the in vivo and in vitro reference antigen for latex allergy diagnosis as it contains the full complement of latex allergens. OBJECTIVE: This study quantifies the concentrations of the significant allergens in latex serum and examines its suitability as an antigen source in latex allergy diagnosis and immunotherapy. METHODS: The serum phase was extracted from centrifuged latex that was repeatedly freeze-thawed or glycerinated. Quantitation of latex allergens was performed by two-site immunoenzymetric assays. The abundance of RNA transcripts of the latex allergens was estimated from the number of their clones in an Expressed Sequence Tags library. RESULTS: The latex allergens, Hev b 1, 2, 3, 4, 5, 6, 7 and 13, were detected in freeze-thawed and glycerinated latex serum at levels ranging from 75 (Hev b 6) to 0.06 nmol/mg total proteins (Hev b 4). Hev b 6 content in the latex was up to a thousand times higher than the other seven latex allergens, depending on source and/or preparation procedure. Allergen concentration was reflected in the abundance of mRNA transcripts. When used as the antigen, latex serum may bias the outcome of latex allergy diagnostic tests towards sensitization to Hev b 6. Tests that make use of latex serum may fail to detect latex-specific IgE reactivity in subjects who are sensitized only to allergens that are present at low concentrations. CONCLUSION: Latex allergy diagnostics and immunotherapy that use whole latex serum as the antigen source may not be optimal because of the marked imbalance of its constituent allergens.

Allergens↗
PubMed2006

Airborne exposure to wheat allergens: measurement by human immunoglobulin G4 and rabbit immunoglobulin G immunoassays.

BACKGROUND: Exposure to airborne wheat allergens in the bakery trade is associated with a high risk of occupational allergy and asthma. Control and reduction of allergen exposure require relatively simple but reliable monitoring techniques. We developed new rabbit IgG-based enzyme immunoassays (EIA) for wheat allergens, which might be a convenient alternative for the thus far used human IgG4 inhibition assay. METHODS: The reactivity and specificity of rabbit antibodies were assessed by EIA and immunoblotting, and compared with those of IgE from wheat-sensitized bakers, and with the antibodies used in the IgG4 inhibition EIA. An IgG inhibition and a sandwich EIA were developed for analysis of airborne dust samples. RESULTS: Human IgG4 and rabbit IgG inhibition EIAs had comparable sensitivities, with limits of detection (LOD) between 18 and 88 ng/mL, while the sandwich EIA was much more sensitive (LOD<0.2 ng/mL). Human IgG4 and rabbit IgG reacted in immunoblotting with most of the IgE-binding wheat proteins, although with quantitative differences. All three assays showed a strong reaction with wheat proteins, and some cross-reactivity with rye and barley, but were further highly specific for cereal flour proteins. Concentrations measured with the three EIAs in 432 airborne dust samples were highly correlated (r>0.95) and their absolute values showed less than 10-20% differences. CONCLUSION: The rabbit IgG EIAs are valid substitutes for the human IgG4 inhibition EIA, with important practical advantages. The inhibition EIA is recommended for routine wheat allergen measurements. The sandwich EIA may be used to measure low allergen levels, as in short task-related exposure measurements or in subfractions of airborne dust samples.

Air Pollutants, Occupational↗
PubMed2006

IgE reactivity to latex allergens among sensitized healthcare workers before and after immunotherapy with latex.

BACKGROUND: New IgE sensitizations to proteins in allergen extracts have been shown to occur during allergen-specific immunotherapy (IT). METHODS: Twenty-four healthcare workers (HCWs) -- patients included in a latex IT study -- were analysed, 16 in active treatment and eight in placebo. Sera were obtained at baseline and after 6 months of IT and analysed with immunoblotting and CAP System with eight single recombinant latex allergens (rHev b 1, 3, 5, 6.01, 8, 9, 10, 11, and a mix of rHev b1, 5, 6.01 and 8). RESULTS: After IT with latex, three patients in the active treatment group had new IgE sensitizations, one to Hev b 5, one to Hev b 11 and another to Hev b 6.01. No other significant variation in mean of specific IgE to latex or recombinant allergens were observed in patients who received placebo or active treatment. A significant (P = 0.012) negative correlation (-0.72) was observed between maximal tolerated dose and specific IgE to Hev b 6.01 at baseline. After IT, immunoblot analysis demonstrated a significant increase in IgE binding in a band of approximately 22 kDa (P = 0.032) that may correspond to Hev b 6.01. New or more intense bands appeared in seven patients of the active group, while in three subjects a reduction was observed. CONCLUSIONS: Hev b 6.01 seems to be the most relevant latex allergen in HCWs. New or more intense IgE binding to latex allergenic components occurs during latex immunotherapy. However, the levels of specific IgE against these new components are low and do not seem to have clinical relevance.

Allergens↗
PubMed2006

In vitro hymenoptera venom allergy diagnosis: improved by screening for cross-reactive carbohydrate determinants and reciprocal inhibition.

BACKGROUND: Immunoglobulin (Ig) E-double positivity for honeybee (HB) and yellow jacket (YJ) venom causes diagnostic difficulties concerning therapeutical strategies. The aim of this study was to clarify the cause and relation of the cross-reactivity in patients with insect venom allergy. METHODS: For this purpose, 147 patients with suspected stinging insect allergy and CAP-FEIA-double positivity were investigated for specific sIgE to additional cross-reactive carbohydrate determinant (CCD)-containing allergens: timothy grass pollen, rape pollen, natural rubber latex (NRL), bromelain, and horseradish peroxidase (HRP). Sera with sIgE to NRL were further investigated with the commercially available recombinant latex allergens. Reciprocal inhibition assays with both venoms and HRP were performed. RESULTS: About 36 of 147 (24.5%) patients had sIgE to both venoms only. However, 111 of 147 (75.5%) additionally reacted to CCD-carrying allergens. 89 of 111 CCD-reactive sera had NRL-sIgE. In cases where inhibition experiments were performed, the NRL-sIgE binding was completely abolished in the presence of HRP. Only nine of 61 sera were positive for at least one recombinant latex allergen; all of them were negative in history and NRL-skin prick test. In 43 sera containing sIgE to CCD, HRP inhibition revealed unequivocal results: In 28 of 43 (65%) an HRP-inhibition >70% of sIgE to one venom occurred, pointing out the relevant venom. In three of 43 sIgE proved to be entirely CCD-specific. CONCLUSIONS: Our data indicate that in cases of IgE positivity to both insect venoms supplementary screening tests with at least one CCD-containing allergen should be performed; HRP being a suitable tool for this test. In addition, subsequent reciprocal inhibition is an essential diagnostic method to specify cross-reacting sIgE results.

Adolescent↗
PubMed2005

Identification of an obeche (Triplochiton scleroxylon) wood allergen as a class I chitinase.

BACKGROUND: Wood dust is known to cause allergic occupational asthma and obeche (Triplochiton scleroxylon) is a prominent exponent in this field. However, the knowledge about wood allergens is still limited. The aim of this study was to identify and characterize obeche wood allergens. METHODS: Obeche extracts were prepared from freshly ground in comparison to 7 years stored wood dust and investigated by Sodium dodecyl sulfate-polyacrylamid gel electrophoresis, enzyme-linked allergosorbent test and immunoglobulin (Ig)E-immunoblot. Allergens were detected by specific IgE of seven obeche allergic patients' sera and protein analysis was performed by mass spectrometry. Cross-reactivity was demonstrated by ImmunoCAP-inhibition with sera of seven obeche and four latex-allergic patients. RESULTS: Obeche extracts showed different protein pattern and IgE-binding capacities depend on the age of the wood dust. A 38 kDa protein was identified as major obeche wood allergen, detected by six of seven (85%) obeche allergic patients' sera and was entitled as Trip s 1. Trip s 1 is homologous to plant class I chitinases and exhibited enzyme activity demonstrated by chitinolysis. Co-recognition or cross-reactivity of Trip s 1 according to structural similarity was seen in sera of latex allergic patients. IgE inhibition studies with obeche as solid phase and Trip s 1 and latex hevein as inhibitor demonstrated that Trip s 1 was a more effective inhibitor in obeche as well as in latex allergic patients' sera. CONCLUSIONS: Trip s 1 is a new obeche wood allergen of the plant class I chitinase family. This finding may explain the dominant role of obeche in sensitization against wood dust.

Adult↗
PubMed2004

Comparison of wheat and rye flour skin prick test solutions for diagnosis of baker's asthma.

BACKGROUND: Skin prick tests (SPTs) play an important role in the diagnosis of baker's asthma and in the investigation of sensitization frequencies in field studies. It was the aim of our study to compare different SPT solutions for wheat and rye flour sensitization and to assess the validity of test results. METHODS: Skin prick tests with wheat and rye flour were performed in parallel with extracts from different companies and compared with the results of bronchial challenge tests with both flours (69 rye flour and 51 wheat flour challenge tests). Additionally, specific immunoglobulin E (sIgE) to wheat and rye flour were tested. SPT solutions were analysed for protein content and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Skin prick test solutions for diagnosis of wheat and rye flour sensitization from three companies differed in protein concentrations and composition with the consequence of widely differing SPT results. Sensitivity of SPTs in comparison with allergen-specific bronchial challenge as a gold standard was between 40 and 67%, specificity was between 86 and 100%, the positive predictive value (PPV) ranged from 81 to 100% and the negative predictive value (NPV) from 44 to 70%. These numbers were only marginally affected by using a combination of challenge test result and sIgE value as a more specific gold standard. CONCLUSION: Improvement and standardization of SPT extracts for wheat and rye flour is highly recommended.

Adult↗
PubMed2004

Cross-reactivity between obeche wood (Triplochiton scleroxylon) and natural rubber latex.

BACKGROUND: Several studies have shown that allergy to natural rubber latex is associated with cross reactivity to other plants. We have investigated a possible cross reactivity with a tree belonging to the Sterculiaceae family, Tryplochiton scleroxylon, in a patient allergic to obeche wood, that began to suffer symptoms of allergy in contact with latex. METHODS: Determinations of specific IgE by CAP to obeche, natural rubber latex (NRL) and recombinant allergens of latex were done. Immunoblotting was performed to study allergens detected by serum of our patient. CAP-inhibition methods were used to study cross-reactive between NRL and obeche wood. RESULTS: In obeche extract, 4 bands were found of an apparent molecular weight of 18, 38, 75 and 199 kDa. In NRL extract the allergens have a molecular weight around 18, 21, 32, 38, 60, 70 and 199 kDa. IgE to latex was almost completely inhibited (96%) by the obeche extract in CAP-inhibition studies. Using obeche extract as inhibitor, IgE binding to native hevein (nHevb 6.02) was reduced by 25%. CONCLUSIONS: The results obtained in CAP-inhibition demonstrate the existence of cross-reactivity between proteins in NRL and obeche wood. In our patient, a band of apparent molecular weight of 38 kDa could be the most important allergen.

Adult↗
PubMed2004

Characterization of B- and T-cell responses and HLA-DR4 binding motifs of the latex allergen Hev b 6.01 (prohevein) and its post-transcriptionally formed proteins Hev b 6.02 and Hev b 6.03.

BACKGROUND: Multiple immunoglobulin E (IgE)-binding proteins in natural rubber latex extracts have been identified. In the case of Hev b 6 a differentiation was made between the precursor protein prohevein (Hev b 6.01) and its two post-transcriptionally formed proteins, the N-terminal hevein (Hev b 6.02) and the C-terminal domain (Hev b 6.03). All three components act as independent allergens. The aim of this study was a detailed analysis of the T-cell responses and the IgE-binding capacity of Hev b 6.01, Hev b 6.02 and Hev b 6.03 by using these allergens as recombinant maltose-binding fusion (MBP) proteins and the usage of synthetic modified hevein peptides. METHODS: Latex-allergic health care workers (HCWs) suffering from rhinitis, conjunctivitis, contact urticaria and/or asthma with increased specific IgE-antibodies to latex were tested for their IgE-binding capacity and T-cell reactivity (by proliferation response) to the recombinant MBP-rHev b 6.01, MBP-rHev b 6.02, MBP-rHev b 6.03, to native Hev b 6.02, to modified hevein peptides and wheat germ agglutinin (WGA). For testing of the human leucocyte antigen (HLA) class II restriction of MBP-rHev b 6.01 induced peripheral blood mononuclear cell (PBMC) responses, monoclonal antibodies against HLA-DR, HLA-DP or HLA-DQ were added. RESULTS: Seventeen of 18 (94%) serum samples from latex-allergic HCWs had increased levels of specific IgE to MBP-rHev b 6.01, 16 (89%) to MBP-rHev b 6.02 and 13 (72%) to MBP-rHev b 6.03. A significant difference existed between the specific IgE-values of MBP-rHev b 6.02 and MBP-rHev b 6.03 (P < 0.01). Proliferation responses of PBMC of the same 18 latex-allergic patients were positive for MBP-rHev b 6.01 and MBP-rHev b 6.03 in 83 and 67% of the tested PBMC suspension, whereas the proliferation responses induced with MBP-rHev b 6.02 or native Hev b 6.02 were very low (5.6 and 22.2%). Sera from nine additional latex-allergic patients showed specific IgE binding to the native Hev b 6.02, but none of these sera showed specific IgE binding to the modified Hev b 6.02-peptides [whereby all eight cysteine residues were substituted by serine (C --> S) or by alanine (C --> A)]. Proliferation responses induced by the modified Hev b 6.02 peptides were not significantly different from that induced by Hev b 6.02. Potential HLA-DR4Dw4(DRB1*0401)-restricted T-cell epitopes of Hev b 6.01 predicted by two computer algorithms were only found in the Hev b 6.03-part of Hev b 6.01. CONCLUSION: In the Hev b 6.01 precursor the regions responsible for IgE binding and those for inducing the T-cell proliferation responses are settled in different parts of the protein. The Hev b 6.02 domain is responsible for IgE binding and carries discontinuous B-cell epitopes whereas Hev b 6.03 is a better inducer of a proliferation response and contains HLA-DR4-binding motifs.

Adult↗
PubMed2003

Molecular cloning, purification, and IgE-binding of a recombinant class I chitinase from Hevea brasiliensis leaves (rHev b 11.0102).

BACKGROUND: Class I chitinase in natural rubber latex (NRL) has been assumed to be an important allergen, especially concerning its cross-reactivity with fruits like avocado and banana. OBJECTIVES: The present study aimed to produce a recombinant latex class I chitinase from Hevea brasiliensis leaves and to study its immunoglobulin (Ig)E-binding reactivity. METHODS: A class I chitinase-specific complementary DNA from H. brasiliensis leaves was synthesized, subcloned, sequenced and overexpressed in fusion with the maltose-binding protein (MBP) in Escherichia coli. The IgE-binding reactivity of this protein was studied by the Pharmacia CAP System and by immunoblot experiments using sera from latex-allergic patients. RESULTS: The rHev b 11.0102 was found to have a length of 295 amino acid residues and contains an N-terminal hevein-like domain with a 56% homology to hevein. Analysis by the CAP method revealed the presence of rHev b 11.0102-specific IgE antibodies in 17 of 58 sera (29%) of IgE-mediated latex-allergic subjects tested. Immunoblot analysis of the MBP-rHev b 11.0102 fusion protein and the MBP carrier protein as a negative control confirmed the IgE-reactivity of rHev b 11.0102. CONCLUSION: Due to its IgE-reactivity rHev b 11.0102 represents an allergen of intermediate prevalence in NRL. Its property to cross-react with certain fruits makes it an important supplement in the diagnostic panel of recombinant NRL allergens.

Adolescent↗
PubMed2002

Bioaerosol exposure during refuse collection: results of field studies in the real-life situation.

To determine the bioaerosol exposure of refuse collectors, field measurements were performed under real working conditions within the framework of a research project. Influencing variables such as different types of refuse, community structure, collection interval and season were taken into account. Overall, 1612 samples were taken in towns of Westfalia, Germany. With workplace levels on a scale of 10(3) to less than 10(4) CFU/m3 for the loader, the results show a surprisingly low total fungi concentration in comparison with earlier studies. Total bacteria concentrations, in contrast, were largely on a scale of 10(4) CFU/m3, with 10(5) CFU/m3 being registered sporadically, especially in apartment-block districts. Endotoxin levels were high especially in the summer months, occasionally reaching values of more than 50 EU/m3, whereas they were normally below 10 EU/m3 in autumn and winter. Inside the cab, the exposure level for the entire spectrum was at least one power of ten lower. The factors believed to account primarily for the low total fungi concentration were workplace hygiene, the prevailing 1-week collection interval, and the low in-process exposure time resulting from the effective deployment of automatic lifting devices. In contrast, the type of refuse was not found to have a significant influence.

Aerosols↗
PubMed2002

Comparison of IgE antibody concentrations to pyromellitic dianhydride-modified laminin and human serum albumin in sera of exposed workers with respiratory complaints.

BACKGROUND: Acid anhydrides are used in a variety of industrial branches because of their highly reactive anhydride groups. Adverse effects of anhydride exposure include toxic/irritative effects as well as IgE- and IgG-mediated respiratory disorders. It was the aim of this study to examine the usefulness of conjugates of pyromellitic dianhydride (PMDA) and laminin, a respiratory tract protein, for the in vitro diagnosis of sensitization to PMDA. METHODS: Sera of PMDA-exposed workers (n = 9) and nonexposed controls (n = 8) were tested with an enzyme allergosorbent test (EAST). Human laminin and human serum albumin (HSA) were derivatized with PMDA and used as solid-phase in a commercial assay. RESULTS: Seven out of 9 exposed workers revealed elevated IgE antibody concentrations (>0.35 kU/l) against laminin-PMDA whereas 5 of 9 subjects had elevated IgE antibody concentrations to HSA-PMDA. All 9 workers had elevated IgE antibody concentrations in at least one of the two tests. Of the 4 workers who complained of shortness of breath, 3 were positive for laminin-PMDA and 2 for HSA-PMDA. All of the nonexposed subjects were negative (<0.35 kU/l) for laminin-PMDA. CONCLUSION: PMDA-modified laminin could provide an additional diagnostic tool for the detection of sensitization to PMDA.

Benzoates↗
PubMed2002

Interest of two-dimensional electrophoretic analysis for the characterization of the individual sensitization to latex allergens.

BACKGROUND/OBJECTIVE: Latex allergy is a type 1 hypersensitivity reaction that mainly affects high-risk populations such as health care workers, spina bifida-affected or multiply-operated children. Ten molecules have so far been identified and registered as latex allergens (Hev b 1 to Hev b 10). The aim of the present investigation was to identify the major latex allergens by an individual analysis of the IgE response of latex-allergic patients to latex proteins separated by two-dimensional (2-D) gel electrophoresis. MATERIALS AND METHODS: Latex proteins from a sap or a glove extract were separated by 2-D electrophoresis and transferred to a nitrocellulose membrane. Each membrane was incubated with the serum of one latex-allergic patient. The most frequently recognized latex allergens were characterized in sap and glove extracts using monoclonal antibodies or amino acid microsequencing. RESULTS: The one-dimensional screening of 54 patient sera revealed 4 major bands recognized by IgE. The 2-D analysis of the sensitization to latex allergens allows the identification of allergen isoforms and the characterization of an individual response diversity. Hev b 6.01 was recognized by 88.9% of the patients. Protein spots around 14 kD were recognized by 48.1% of the patients and corresponded to Hev b 6.03 as well as other proteins. A not yet characterized doublet of acidic proteins with molecular masses of 43 and 94 kD was recognized by 20.4% of the sera. Only 5.5% of the sera did not recognize any of these 4 major allergens. Hev b 1 is the main protein from the glove extract but was not constantly found in sap extracts. CONCLUSIONS: One-dimensional electrophoretic analysis of the allergen is usually not sufficient to characterize the individual specificity of the IgE response to latex allergens. Latex-glove proteins which are allergens can be absent from the sap extracts and the sensitization to these allergens could be underestimated. Individual 2-D analysis of the sensitization to latex allergens is useful to define the best allergen mixture required for diagnosis and needed for individual therapy monitoring.

Allergens↗