[Latex allergens: review of current knowledge].

Both health care workers and spina bifida patients are at risk to develop type I latex allergy since allergenic proteins of natural rubber latex are present in a variety of latex products. Natural latex contains more than 250 polypeptides and approximately 60 of them show IgE-binding characteristics. A multitude of these latex allergens has been identified, and their sensitization potency for both risk groups has been determined.

Can a threshold limit value for natural rubber latex airborne allergens be defined?

Background: Recent studies have shown that systemic or respiratory occupational responses to latex can be induced by inhalation of latex aeroallergens.

Objective: Our objectives were to study the relationship between exposure to different latex aeroallergen levels and type I allergic reactions in subjects with occupational contact with latex and to assess a threshold value for latex airborne allergens required for sensitization and symptom elicitation.

Methods: We screened 145 subjects working in 32 hospitals or operating rooms with different latex aeroallergen levels.

Relation between occupational asthma case history, bronchial methacholine challenge, and specific challenge test in patients with suspected occupational asthma.

Inhalative methacholine challenge (MC) was performed in 229 subjects presumed to suffer from occupational asthma due to exposure to airborne latex allergens (n = 62), flour (n = 28), isocyanates (n = 114), or irritants in hairdressers' salons (n = 25). They were also subjected to specific challenges with the occupational agents they were exposed to, completed a questionnaire using an abbreviated version of the ATS-DLD, and were interviewed by an experienced physician. Bronchial hyperresponsiveness in MC was defined by the results obtained in a previous study with 81 healthy volunteers.

[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.

Comparison of the binding potential of various diisocyanates on DNA in vitro.

Inhalation of diisocyanate vapors is associated with immediate-type hypersensitivity reactions and direct toxic responses. The genotoxic effects of diisocyanates have not been clarified. The aim of this study was to examine the changes in DNA following in vitro exposure to three most commonly used diisocyanates (toluene diisocyanate, TDI; methylenediphenyl-4,4'-diisocyanate, MDI; and hexamethylene diisocyanate, HDI) and to compare their binding potential using melting behavior of DNA and electrophoresis studies in DNA.

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.

No evidence for the influence of HLA class II in alleles in isocyanate-induced asthma.

Isocyanates are one of the main causes of occupational asthma. The aim of this investigation was to study the possible genetic background of isocyanate-induced asthma under consideration of the atopy status and different lung function parameters. We investigated the human leukocyte antigen (HLA) genes DRB1,3,4,5, DQB1, and DQA1 in 55 isocyanate-exposed patients with workplace-related dyspnea (32 asthmatics, 23 nonasthmatics) and 90 nonexposed controls.

Cross-reactivity between natural rubber latex and food allergens.

Immediate-type hypersensitivity to latex is a growing problem, especially among health care workers (HCWs) and patients requiring long-term catheterization and multiple operations. The responsible allergens are latex proteins, which are found in raw latex, as well as in various latex-containing products. More than 200 polypeptides can be discerned in latex sap and of these, 60 proteins showed reactivity with IgE antibodies from patients with latex allergy.

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.

Changes in high molecular weight DNA fragmentation following human blood exposure to styrene-7,8-oxide.

Styrene-7,8-oxide (S7,8O) is the major in vivo metabolite of styrene and is a genotoxic agent potentially carcinogenic to humans. It is known to cause DNA strand breaks and adducts. We studied high molecular weight DNA fragmentation in white blood cells following incubation of blood with S7,8O from individuals with no previous exposure to this compound.

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.

Differentiation between cosensitization and cross-reactivity in wheat flour and grass pollen-sensitized subjects.

Background: To diagnose baker's asthma, occupational sensitization to wheat flour should be distinguished clearly from influences of cosensitization such as it may exist in pollinosis patients. To define the route of sensitization, the cross-reactivity between wheat flour and grass pollen allergens was investigated.

Methods: Two groups of atopic individuals with or without professional contact to wheat flour were screened by skin prick test for their sensitization to wheat flour and grass pollen and, in the case of hints for cosensitization, by Enzyme Allergo Sorbent Test (EAST).

Latex allergen elimination in natural latex sap and latex gloves by treatment with alkaline potassium hydroxide solution.

Antigenic proteins in latex products can cause type I allergy. We investigated the effects of potassium hydroxide (KOH) solution on the allergenicity of proteins in natural latex sap and latex gloves by using an EAST competitive inhibition immunoassay and skin prick test. Latex sap was mixed with KOH solution at different concentrations and incubated over various periods of time at room temperature.

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.

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.

Flow-cytometric analysis of T-cell receptor expression in peripheral blood lymphocytes.

Background: Lymphocytes of subjects sensitized to the insect-derived allergen Chi t 1-9 are, in response to the allergen, characterized by an elevated proliferation and increased expression of activation markers such as HLA-DR and CD25 in vitro. A restriction for HLA-DR B1 in monosensitized patients was found.

Objective: The aim of this study was to investigate whether the response to the allergen Chi t 1-9 involves the preferential cell surface expression of a specific alpha/beta T-cell receptor type.

Modulation of airway responsiveness to acetylcholine by nitric oxide in a rabbit model.

Nitric oxide (NO) is an important mediator in the regulation of bronchial muscle tone and airway responsiveness. We investigated the influence of exogenous NO on airway responsiveness to acetylcholine aerosols (ACH) in normal and in hyperresponsive rabbits. White New Zealand rabbits were anesthetized, intubated, and breathed room air spontaneously.

Detection of 8-hydroxydeoxyguanosine, a marker of oxidative DNA damage, in white blood cells of workers occupationally exposed to styrene.

Styrene-7,8-oxide (SO), the major in vivo metabolite of styrene, is a genotoxic compound and a potential carcinogenic hazard to occupationally exposed workers. The aim of the present work was to investigate the ability of styrene exposure to induce formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in white blood cells (WBC) of boatbuilders occupationally exposed to styrene. The study of these adducts was conducted to see if styrene exposure can cause oxidative damage of DNA.

Hexamethylene diisocyanate induction of transient airway hyperresponsiveness in guinea pigs.

The induction of lung injury and the development of airway hyperresponsiveness (AHR) by exposure to hexamethylene diisocyanate (HDI) were studied in a guinea pig model of occupational lung diseases. In addition to an unexposed control group of 16 guinea pigs (A), two groups (B, C) of 8 animals inhaled HDI atmospheres in the range of the threshold limit value (TLV) of 10 ppb for 6 h/day on 5 days/week over a period of 8 weeks. Airway responses to aerosols of 0.

HLA class II antigens DR4 and DQ8 are associated with allergy to hevein, a major allergen of Hevea latex.

In this study we investigated the relationship between HLA class II alleles and the IgE-specific immune response to the 4.7 kDa polypeptide hevein of Hevea brasiliensis, a major latex allergen, 51 individuals with immediate-type latex allergy and 90 controls were examined for the polymorphisms in exon 2 of HLA-DRB1, 3, 4, 5 and DQB1 by sequence-specific oligonucleotide probe typing. 35 (69%) out of 51 latex-sensitized subjects showed positive hevein-specific IgE values.

Lymphocyte proliferation response to extracts from different latex materials and to the purified latex allergen Hev b 1 (rubber elongation factor).

Background: Type I allergy to latex is a growing problem, especially among health care workers. A detailed study of the peripheral blood cell responses to latex allergens has not been reported.

Methods: Peripheral blood mononuclear cells of patients and healthy subjects were isolated and stimulated with protein extracts from latex sap and latex gloves and the purified latex allergen Hev b 1 (rubber elongation factor) at different concentrations to determine the antigen-specific proliferation response.

EAST and CAP specificity for the evaluation of IgE and IgG antibodies to diisocyanate-HSA conjugates.

Sera of 54 symptomatic workers showing sensitization to isocyanate-human serum albumin (HSA) conjugates were subjected to parallel enzyme allergosorbent test (EAST) and CAP measurements to determine IgE antibodies to diphenyl-methane diisocyanate-HSA, toluene diisocyanate-HSA and hexamethylene diisocyanate-HSA. Results of both methods correlated rather well with each other. In comparison to the EAST results, the CAP values were twice as high, and 4, 17 and 13% more frequently positive findings were obtained with the three different antigens.