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Biomedical subjects

M Raulf-Heimsoth

Publications and source records attributed to M Raulf-Heimsoth.

At least 55 records · Page 3Linked to original sources
PubMed1998

Reduction of latex aeroallergens and latex-specific IgE antibodies in sensitized workers after removal of powdered natural rubber latex gloves in a hospital.

BACKGROUND: Respiratory symptoms of natural rubber latex (NRL) allergy in health care workers (HCWs) have been reported in rooms with a detectable allergen load. Preventive measures have been proposed to reduce the risk of NRL sensitization. OBJECTIVES: Eliminating powdered NRL gloves from the workplace and giving NRL-free material to sensitized workers has been among proposed preventive measures. To appraise the success of such procedures among HCWs, a prospective study was carried out. METHODS: Sensitization of HCWs to NRL was determined by skin prick tests and measurements of specific IgE antibodies. NRL allergen concentrations in room air were measured before and after substitution of powdered NRL gloves with powder-free or synthetic gloves in different departments of a hospital and determined by a competitive inhibition immunoassay. RESULTS: The prevalence of HCWs with positive skin prick test responses and NRL-specific IgE-positive HCWs was 8% (n = 7) among the 90 examined staff members before the intervention started. All 7 reported glove-related allergic symptoms. Six of 7 sensitized subjects had a significant decrease of latex-specific IgE antibody concentrations during follow-up examinations in April and September 1997 (P <.003). Within 24 hours after substitution took place, NRL aeroallergen levels (up to 49.9 ng/m3) fell below the detection limit in areas with synthetic gloves or powder-free NRL gloves alike. Use of asthma medication and antiallergic drugs could be discontinued by 2 HCWs with NRL-related respiratory tract symptoms. CONCLUSIONS: Our results demonstrate that elimination of powdered NRL gloves is a useful device in reducing aerogen NRL allergen loads below the detection limit and permitting sensitized or allergic personnel to remain on the job.

Adult↗
PubMed1998

Allergy to Aspergillus-derived enzymes in the baking industry: identification of beta-xylosidase from Aspergillus niger as a new allergen (Asp n 14).

BACKGROUND: Aspergillus-derived enzymes are used in dough improvers in bakeries. Some of these enzymes are identified as causing IgE-mediated sensitization in up to 25% of bakers with workplace-related symptoms. OBJECTIVE: The aim of this study was to compare the frequency of sensitization to Aspergillus xylanase, cellulase, and glucoamylase with the sensitization to alpha-amylase (Asp o 2) and to identify IgE-reactive proteins in enzyme preparations. METHODS: Sensitization to Aspergillus-derived enzymes and cross-reactivity were retrospectively studied by enzyme allergosorbent test (EAST) and EAST-inhibition experiments. IgE-reactive proteins were detected by electrophoretic separation and immunoblotting. Liquid chromatography with electrospray ionization mass spectrometry and Edman degradation of tryptic protein fragments were used for the biochemical identification of an unknown IgE-binding protein. RESULTS: Twenty-three percent of 171 tested bakers had specific IgE to alpha-amylase, 8% reacted to glucoamylase, 13% reacted to cellulase, and 11% reacted to xylanase. Xylanase and cellulase preparations, each containing at least 6 different proteins, showed cross-reactivity in the range of 80%. The main IgE-binding protein in the xylanase preparation recognized in 7 of 8 xylanase-positive subjects was a protein of about 105 kd. This protein was identified as beta-xylosidase by peptide mass spectrometric fingerprinting. The identification was confirmed by matching 12 peptide sequences obtained by N-terminal and mass spectrometric sequencing to this protein. CONCLUSIONS: Beta-Xylosidase from Aspergillus niger is an occupational allergen present in currently used baking additives, which causes sensitization in at least 4% of symptomatic bakers. According to the International Union of Immunological Societies nomenclature, we suggest the term Asp n 14 for this allergen.

Adult↗
PubMed1998

Identification of hevein (Hev b 6.02) in Hevea latex as a major cross-reacting allergen with avocado fruit in patients with latex allergy.

BACKGROUND: Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified. OBJECTIVE: The purpose of this study was to investigate the cross-reactivity of a latex major allergen, hevein, with avocado proteins. METHODS: Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients' sera containing IgE antibodies to both hevein and avocado. RESULTS: The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of hevein-specific IgE antibodies in subjects of both groups (P < .001). Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to avocado. Competitive RAST inhibition with 42 sera showed that IgE binding to avocado could be completely inhibited in 27 (64%) sera by preincubation with hevein. By contrast, the degrees of inhibition of IgE to hevein by avocado extract ranged from 0% to 36% (n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested. CONCLUSION: Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy.

Adolescent↗
PubMed1998

Latex allergens.

Explore the source record for details and available documents.

Allergens↗
PubMed1998

Analysis of T-cell reactive regions and HLA-DR4 binding motifs on the latex allergen Hev b 1 (rubber elongation factor).

BACKGROUND: The rubber elongation factor in Hevea rubber (Hev b 1) is one of the important latex-allergenic proteins inducing the production of specific IgE antibodies in latex-exposed subjects. In addition, Hev b 1 induces lymphocyte proliferation responses. A study about detailed T-cell epitope analysis of major latex allergens has not been published yet. OBJECTIVE: The aim of this study was to define the T-cell reactive regions on the latex allergen Hev b 1. METHODS: Nine overlapping peptides with 19 or 17 amino acid lengths representing the complete sequence of Hev b 1 were used for T-cell epitope mapping. Peripheral blood mononuclear cells (PBMCs) of latex-sensitized patients and healthy subjects were isolated and stimulated with the synthetic peptides to determine the specific proliferation response. The examined patients were sensitized to latex by occupational exposure (n=14) and suffered from rhinitis, conjunctivitis, contact urticaria and/or asthma. Two control groups of non-sensitized subjects were studied, one occupationally exposed to latex (n=4), the other one not exposed to latex (n=4). RESULTS: Positive proliferation response induced by one or more peptides was detected in 10 of the latex-sensitized patients and in two of the latex-exposed non-sensitized subjects. Each patient exhibited an individual epitope reactivity pattern. The whole protein was found to be immunogenic, but the intensity of lymphocyte responses induced by the peptides was different. The majority of the patients' PBMCs (more than 66%) responded to the peptides 31-49 and 91-109. Using the peptide selection of Stille's algorithms, three epitopes were predicted covering region 38-74 and two others covering region 82-104; the two peptides 31-49 and 91-109 are part of these regions. A strong HLA-DR4Dw4 (DRB1*0401)-binding motif according to published DR4w4 binding motifs was predicted in the region of 102-110 including peptide 91-109 to which the majority of tested HLA-DR4-positive patients responded. CONCLUSIONS: Our data indicate that the whole 14 kDa protein Hev b 1 is immunogenic having regions that demonstrate individual and varying PBMC stimulation. Experimental data of T-cell reactive regions based on PBMC-stimulation complement the information on T-cell epitope prediction. In addition, the Hev b 1 molecule contains a HLA-DR4Dw4 (DRB1*0401)-binding motif.

Adult↗
PubMed1998

Baker's asthma due to the enzyme xylanase -- a new occupational allergen.

The asthmatic baker showed IgE-mediated sensitization to xylanase of Aspergillus niger used as a baking additive. Inhalative challenge with approximately 0.5 microg of the enzyme resulted in an immediate-type asthmatic reaction. This case, as well as a preliminary screening of symptomatic bakers, shows that xylanase is a further relevant type I-sensitizer in the baking industry.

Administration, Intranasal↗
PubMed1998

Results of wearing test with two different latex gloves with and without the use of skin-protection cream.

A total of 109 subjects reporting symptoms indicating type I hypersensitivity reactions to natural rubber latex (NRL) gloves was included in this study, and 66 of them had latex-specific IgE antibodies. They underwent provocation tests by wearing two types of NRL gloves with high (n=103) and low (n=75) allergen contents. The first glove type caused positive skin reactions in 30% of IgE-positive and in 3% of IgE-negative subjects. After application of a commercially available skin protection (barrier) cream, the frequencies of positive skin responses in wearing tests increased to 41% and 7%, respectively. The gloves with low allergen content did not cause hypersensitivity without skin-protection cream but induced responses in 5% of IgE-positive subjects when this cream was applied. Corresponding findings were obtained in intraindividual comparisons of test results, which were possible in 69 cases. Of all wearing-test responders, 92% had latex-specific IgE antibodies. Our results demonstrate that high allergen contents in latex gloves frequently elicit skin responses in NRL-sensitized subjects, and that skin-protection creams may favor the uptake of allergens from gloves, thus increasing allergic reactions. The stipulation of a legally binding threshold limit value (TLV) for allergens in NRL products is urgently needed. This TLV should not be set above 2 microg allergen/g rubber.

Adult↗
PubMed1998

Analysis of lymphocyte subpopulations in cerebrospinal fluid and peripheral blood in patients with multiple sclerosis and inflammatory diseases of the nervous system.

We analysed different subsets of lymphocytes from peripheral blood (PB) and cerebrospinal fluid (CSF) by flow cytometry in order to determinate alterations in patients with multiple sclerosis (MS) in acute relapse and viral inflammatory neurological disease (IND). We found increased levels of adhesion molecules (LFA-1 and beta1 integrin) in the CSF of patients with MS and IND compared to NIND. CD4+/CD8+ ratio was significantly higher in CSF of MS as compared with all groups analysed and compared with PB. We detected a significantly higher expression of the interleukin-2 receptor in PB of MS patients when compared with other groups. In patients with IND a significant higher expression of the interleukin-2 receptor was found in the CSF compared with MS and NIND. Our findings indicate that the activation of T lymphocytes primarily occurs in the peripheral immune compartment in MS and the increase of adhesion molecules in CSF is related to inflammatory disorders and not only to MS.

CD4-CD8 Ratio↗
PubMed1998

Acute exposure to hair bleach causes airway hyperresponsiveness in a rabbit model.

Ammonium persulphate (APS) and hydrogen peroxide (H2O2) are used as oxidants in many industrial processes and are the main constituents of standard hair bleaching products. In a previous study, it was demonstrated that aerosols of APS induce alterations in airway responsiveness. The present study examined whether exposure for 4 h to a hair bleach composition (containing APS, potassium persulphate and H2O2) or H2O2 could induce airway hyperresponsiveness and/or an obstructive ventilation pattern in a rabbit model. Exposure to the aerosols altered neither baseline airway resistance, dynamic elastance, slope of inspiratory pressure generation nor arterial blood pressure and blood gas measurements. Similarly to APS, hair bleach aerosols containing > or =10.9 mg x m(-3) persulphate (ammonium and potassium salt) in air and > or =1.36 mg x m(-3) H2O2 in air caused airway hyperresponsiveness to acetylcholine after 4 h of exposure. Aerosolized H2O2 (> or =37 mg x m(-3) in air) did not influence airway responsiveness to acetylcholine. The results demonstrate that hair bleaching products containing persulphates dissolved in H2O2 cause airway hyperresponsiveness to acetylcholine in rabbits.

Aerosols↗
PubMed1998

[Quantification of inhaled exposure to alpha-amylase in 2 bakeries].

BACKGROUND: Baker's asthma and baker's rhinitis are among the most frequent occupational diseases. A major cause is the high exposure to flour dust in the workplace and to allergenic enzymes like alpha-amylase from Aspergillus oryzae (allergen name: Asp o 2). METHODS: To quantify allergen exposure in the workplace, 31 personal dust samples in a conventional small bakery (six workers) and in a biobakery (seven workers) were collected. Using a recently developed two-site enzyme-linked immunosorbent assay based on monoclonal antibodies to alpha-amylase from Aspergillus oryzae, the allergen content of these dust samples was determined. RESULTS: Dust exposure in the biobakery was in the range between 3.5 and 12 mg/m3 (median: 5.2 mg/m3) and in the conventional bakery between 0.9 and 118 mg/m3 (median 8.5 mg/m3). 23 out of 31 exposure measurements showed values higher than 4 mg/m3 (threshold limit value for inhalable dust). In the biobakery, no fungal alpha-amylase could be detected. 15 out of 17 samples taken in the conventional bakery contained fungal alpha-amylase in the range between 0.2 and 88 ng per mg dust. The geometric mean of alpha-amylase exposure in this bakery was 13 ng Asp o 2/m3, and the maximum exposure was 4.8 micrograms/m3. In four cases, fungal alpha-amylase was detected although exposure to dust was below the threshold limit of 4 mg/m3. CONCLUSIONS: This study in two German bakeries shows that preventive measures to reduce contact to allergens have not been sufficiently realised. Relevant alpha-amylase exposure occurred at low dust levels illustrating that dust measurements are not adequate to control alpha-amylase exposure. For fungal alpha-amylase an additional threshold limit should be established.

Aspergillus oryzae↗
PubMed1997

Development of a two-site enzyme-linked immunosorbent assay for alpha-amylase from Aspergillus oryzae based on monoclonal antibodies.

A two-site monoclonal antibody ELISA was developed to quantify the allergen Asp o 2 (alpha-amylase from Aspergillus oryzae). Two mAbs recognizing distinct epitopes were selected, enriched by in vitro production in a modular minifermenter and affinity-purified. The first antibody was bound to microtiter plates which were then incubated with samples containing the allergen. Bound allergen was detected using a biotinylated second antibody and peroxidase-polymer-labelled streptavidin. The assay had a sensitivity of 0.6 ng/ml and did not react to high concentrations of wheat and rye flour or yeast proteins. The mAb ELISA will be useful in individual or epidemiological studies of baker's asthma to assess workplace allergen concentrations and the efficacy of allergen exposure prevention. It can be used as a standard assay for the quantification of alpha-amylase and the establishment and control of threshold limits in European bakeries.

Allergens↗
PubMed1997

[Exposure testing with powdered gloves in 60 health care workers with latex allergy].

BACKGROUND AND OBJECTIVE: Type 1 sensitization to natural rubber latex occurs in up to 22% of health care workers. Most sensitizations are due to the use of powdered latex gloves. Work place-associated exposure tests were performed to ascertain how frequently persons who developed breathing difficulties, rhinitis/conjunctivitis or obstructive respiratory tract illness when using powdered latex gloves are allergic to latex. PATIENTS AND METHODS: 60 persons (48 women and 12 men; mean age 29 +/- 7 years) with type 1 sensitization to natural rubber latex were studied. The past history was obtained through a questionnaire specially designed for those with latex allergy. Diagnostic measures included prick tests with different latex allergens, measuring the concentrations of total and latex-specific IgE and exposure trials, related to the work place, with powdered vinyl and latex gloves. RESULTS: The prick tests with various latex allergens produced significant skin reactions in 59 subjects, 58 had latex-specific IgE antibodies (0.47 kU/l- > 100 kU/l). Exposure tests with powdered latex gloves produced rhinitis in 55 and conjunctivitis in 38 persons, urticaria in 3 and cough in 19. Whole-body plethysmography demonstrated a significant rise in respiratory tract resistance in 13, a reduction in 1-second expiratory volume of at least 20% in 15. Abnormal values in both tests were noted in 8 subjects. CONCLUSION: The breathing difficulty reported by all subjects was in most cases due not to bronchial obstruction but to obstructed nasal breathing. In cases with breathing difficulty on exposure to latex gloves a latex allergy should be considered as the cause. Powdered latex gloves present a danger to health care personnel and should no longer be used.

Adult↗
PubMed1997

A longitudinal study of circulating lymphocyte subsets in the peripheral blood during the acute stage of Guillain-Barré syndrome.

Activated T cells are implicated in the pathogenesis of Guillain-Barré syndrome (GBS). Blood samples from 16 patients with GBS were studied with flow cytometry during the acute stage of their disease to define circulating lymphocyte populations. During the progressive phase of GBS the T-suppressor/inducer (CD4/CD45RA) subset was decreased (10.3 +/- 4.4%, P < 0.05) and the T-helper/ inducer (CD4/CD29) subset was increased (34.9 +/- 9.2%, P < 0.05) compared to sex and age matched patients with other neurological diseases (OND, 15.5 +/- 5.7% and 27.8 +/- 8.6%, respectively) and healthy controls (16.5 +/- 6% and 28.1 +/- 8.5%, resp.). Within the CD8 population, the activated T-cytotoxic/suppressor (CD8/CD38) subset was increased during the progressive (13 +/- 10.1%, P < 0.05) and plateau phase (16.4 +/- 16.9%, P < 0.01) of GBS compared to OND patients (6.2 +/- 2.3%) and healthy controls (5.8 +/- 2.5%). The proportion of activated T cells (CD3/CD25) was increased during the progressive (9.3 +/- 3.8%, P < 0.05) and plateau phase (11.5 +/- 5.5%, P < 0.01) compared to OND patients (6.6 +/- 2.7%) and healthy controls (5.5 +/- 2.5%). The changes of T cell subsets normalized during the early recovery phase of GBS. 2 patients with serological evidence of antecedent cytomegalovirus (CMV) infection had abnormal high proportions (mean +/- 2 (SD) of healthy controls) of CD8 lymphocytes and correspondingly abnormal low proportions of CD4 lymphocytes during all phases of GBS. In contrast, the CD8 proportions were abnormal low in 3 patients with serological evidence of recent Campylobacter jejuni infection. There was no correlation between the proportions of lymphocyte subsets and the disability score during the maximum of the disease and after half a year. In conclusion, we found further evidence of T cell activation during the acute stage of GBS by the demonstration of an increased proportion of activated CD8+ T cells, which may be directly cytotoxic to Schwann cells. The abnormalities of the CD8 subset in some GBS patients seem to depend on the nature of the preceding infection.

Acute Disease↗
PubMed1997

Characterization and identification of latex allergens by two-dimensional electrophoresis and protein microsequencing.

BACKGROUND: Proteins of natural rubber latex cause IgE-mediated sensitization in 3% to 18% of health care workers and in up to 50% of patients with spina bifida. OBJECTIVE: This study was aimed at the generation of a comprehensive latex protein database by two-dimensional electrophoresis (2-DE). METHODS: Proteins extracted from fresh Hevea brasiliensis latex were separated by 2-DE. IgE-reactive proteins were analyzed by immunoblotting with sera of health care workers with latex allergy. Protein microsequencing and monoclonal antibodies were used to identify the latex allergens. RESULTS: The latex C-serum 2-DE map was very complex and exhibited about 200 distinct polypeptides. The proteins eluted from the latex particles consisted primarily of two groups of acidic proteins located in the 8 to 14 kd and 22 to 24 kd areas of the 2-DE map. Major IgE-reactivity was detected with C-serum proteins in the 56, 45, 30, 20, 14, and <6.5 kd areas of the immunoblots. The 8 to 14 kd particle proteins exhibited distinct IgE reactivity, whereas the 22 to 24 kd proteins were not stained. Seven of the soluble IgE-reactive protein spots showed high homology with enolase, superoxide dismutase, triosephosphate isomerase, proteasome subunit, and chitinase and represent previously undescribed latex allergens; whereas nine protein spots corresponded to known latex allergens, namely prohevein, hevein, prohevein C-domain, and hevamine. As identified by monoclonal antibodies, the IgE-reactive latex particle proteins mainly represent the allergenic rubber elongation factor. CONCLUSIONS: Two-dimensional electrophoresis, followed by immunoblotting and protein microsequencing, can rapidly identify a large number of IgE-binding latex proteins. The 2-DE latex maps generated will provide valuable information for the development of strategies to isolate the relevant latex allergens. Because the novel latex allergens are common plant enzymes, they may also act as cross-reacting proteins in various foods.

Adult↗
PubMed1997

Isolation and identification of hevein as a major IgE-binding polypeptide in Hevea latex.

BACKGROUND: Polypeptides in Hevea latex are known as the major cause of latex type I sensitivities. So far, only a few of them have been characterized. METHODS: Proteins with a molecular weight lower than 10 kd in fresh Hevea latex were separated by ultrafiltration and further characterized by liquid chromatography on-line-coupled electrospray mass spectrometry. Hevein in this fraction was then purified by preparative reverse-phase high-performance liquid chromatography and characterized by matrix-assisted laser desorption ionization mass spectrometry and protein sequencing. Skin prick tests, enzyme-linked allergosorbent tests, and inhibition immunoblotting were performed to show the allergenicity of the purified hevein. RESULTS: Hevein, a 4.7 kd polypeptide, is the predominant component in the fraction with latex proteins of smaller than 10 kd. Specific IgE antibodies to hevein were detected by enzyme-linked allergosorbent test in 48 of 64 (75%) sera from health care workers allergic to latex and in three of 11 (27%) sera from patients with spina bifida and hypersensitivity reactions to latex. Inhibition immunoblotting demonstrated that the preincubation of 14 sera and a serum pool from patients allergic to latex with purified hevein completely inhibited IgE binding to the 20 kd protein, which has been recently reported to be a major allergen in latex (prohevein). Skin prick testing showed a positive reaction to hevein in 17 of 21 (81%) patients with latex allergy. CONCLUSIONS: The results clearly demonstrate that hevein is an important latex allergen, and the IgE-binding capacity of prohevein in latex is mostly attributed to hevein, the N-terminal domain of prohevein.

Adolescent↗
PubMed1997

On the allergenicity of Hev b 1 among health care workers and patients with spina bifida allergic to natural rubber latex.

BACKGROUND: Recent studies have caused much controversy about the prevalence of IgE antibodies to Hev b 1 among health care workers (HCWs) and patients with spina bifida (SB) who are allergic to latex. This investigation was carried out to verify the results reported. METHOD: Serum samples from 140 patients with SB as well as from 105 HCWs allergic to latex were tested by enzyme allergosorbest test (EAST) and EAST-inhibition assay to evaluate the rate and degree of sensitization to highly purified Hev b 1. RESULTS: Eighty-one percent of patients with SB who were allergic to latex had IgE antibodies against Hev b 1. The prevalence of anti-Hev b 1 antibodies among HCWs allergic to latex was 52.3%. In 15 of 33 serum samples from patients with SB that were randomly tested, the IgE binding to commercial latex allergens could be completely inhibited by Hev b 1; in only six cases was the maximum inhibition of IgE binding to latex by Hev b 1 less than 50%. Testing two monoclonal anti-Hev b 1 antibodies with extracts of five brands of latex gloves revealed a predominant presence of Hev b 1 protein as a monomer or its aggregates. Molecular analysis of human leukocyte antigen-D region genes DRB and DQB1 suggested no statistically significant correlation between the human leukocyte antigen alleles tested and IgE responsiveness to Hev b 1. CONCLUSIONS: Our results indicate that Hev b 1 not only makes significant contributions to the IgE binding to latex, but it is also the unique sensitizer in about 45% of patients with SB who are allergic to latex.

Allergens↗
PubMed1997

Protein and allergen content of various natural latex articles.

Proteins remaining in products made of natural rubber latex are potential sensitizers. In the present work, we quantified the releasable protein and allergen contents in 37 brands of latex gloves and 26 other latex products. Our results demonstrate the presence of widely varied protein and allergen contents in various latex articles and the lack of a correlation between the protein and allergen values. These findings may assist hospital management and medical staff to take effective preventive measures.

Allergens↗