Latex allergens in glove-powdering slurries

Exposure to airborne glove powder contaminated with latex allergens is known to provoke respiratory symptoms in latex-sensitized individuals. In the commonly used wet-powdering process in glove manufacturing, powder is applied by dipping gloves in a cornstarch suspension, a slurry. The slurry is a potential source of allergen contamination of the powder. The protein and latex allergen contents in five different slurries and in extracts from the corresponding latex gloves were measured using the BCA assay and the IgE antibody inhibition assay (EAI assay). Latex allergens were found in all slurries and gloves. No correlation between the values of protein contents and allergen contents was found. Wet powdering of gloves induces a risk of latex protein contamination of the cornstarch.     

Assessment of latex allergy in a healthcare population: are the available tests valid?

BACKGROUND: Latex allergy can cause serious, preventable work-related health problems in healthcare workers who are a high risk group for this form of allergy. Type I hypersensitivity can produce life-threatening systemic effects, and involves an allergen-specific immunoglobulin (IgE) response to proteins found in latex. The estimated prevalence of latex 'allergy' in healthcare workers varies widely (2.8% - 18%), and studies do not always distinguish between those who are positive in an assay for latex-specific IgE and those with clinical allergy. OBJECTIVE: To assess the performance of four in-vitro methods and three skin testing methods for detecting latex-specific IgE in a group of UK healthcare workers. Test results were compared with reported clinical symptoms defined by questionnaire. METHODS: Skin prick testing was carried out on volunteers using three reagents: (a) stallergenes commercial latex extract (Cedex, France); (b) an in-house latex glove extract; and (c) a fresh glove piece. Specific IgE levels were determined using Pharmacia AutocapTM (Uppsala, Sweden), Pharmacia UnicapTM (Uppsala, Sweden), DPC Immulite(R) (Los Angeles, USA) and Hycor HytecTM (Irvine, California, USA) methods. Each volunteer completed a questionnaire detailing latex exposure and allergic history. RESULTS: In vitro methods for detecting specific IgE to natural rubber latex were positive in 3.6%, to 43.6% of the same population. Skin prick tests positivity varied between 2. 9% and 14.3% with different extracts. From the subjects tested 9.1% reported symptoms which could be consistent with type I allergy, although none had been given a pre-existing diagnosis of latex allergy, and 43.6% of volunteers reported symptoms consistent with type IV hypersensitivity or irritant dermatitis. Contingency tables and chi-squared analysis revealed no correlation between most methods. No correlation was shown between symptoms consistent with type I allergy and any in vitro or skin testing method for latex-specific IgE. CONCLUSIONS: A wide variation between testing procedures was found, and no method could be correlated with reported symptoms of type I allergy. At least one in vitro specific IgE assay produced a high percentage of positive results at variance with the clinical symptoms in volunteers. A clinical history is essential in establishing type I hypersensitivity to latex and test results should not be used in isolation. The incidence of clinical sensitization may be seriously over-estimated if only laboratory parameters are used.     

Outcome of a latex avoidance program in a high-risk population for latex allergy – a five-year follow-up study

BACKGROUND: Children with a shunted hydrocephalus are at highest risk for developing an immediate type allergy to latex. Limited data are available for preventive or therapeutical approaches. OBJECTIVE: To evaluate the effectiveness of latex avoidance, with special regard to status of sensitization and compliance. METHODS: In 1995, 131 children with a shunted hydrocephalus were screened for sensitization to latex by skin prick test and determination of specific IgE. Patients and parents were instructed on latex-avoiding strategies. Hospital physicians, family doctors and dentists were advised to perform further surgical and other medical interventions under latex-free conditions. In 2000, 100 of these 131 patients were re-evaluated according to the same testing procedures. Special attention was directed at the extent prophylaxis had been performed. RESULTS: In 1995, 30/100 patients re-evaluable in 2000 proved sensitized to latex, 70 had negative testing results. In 2000, 64/70 patients were still negative, six had meanwhile developed latex-specific IgE. Seven out of thirty subjects with former positive testing had changes within the same RAST-class, 20 showed a decline of at least one RAST-class, whereas in three cases an increase of latex-specific IgE was found. However, only 34 patients, mainly those being already sensitized, had thoroughly followed both medical and private prophylaxis. Within this group, 16 subjects (47.1%) had improved and another nine (26.5%) were still negative. Only three (8.8%) already previously sensitized patients presented with a further increase of latex-specific IgE. Medical prevention contributed more to the outcome than home prevention. No statistically significant correlation with latex-avoidance was observed, however, in previously unsensitized subjects. Underlying disease, atopy, number of operations, and age did not prove as significant variables. CONCLUSION: Secondary prevention results in a decrease of specific IgE in latex-sensitized patients with hydrocephalus. This is due to medical more than home prophylaxis. Sensitization obviously occurs mainly in early childhood, thus primary prevention remains to be the main target.     

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.     

Molecular and immunological characterization of Can f 4: a dog dander allergen cross‐reactive with a 23 kDa odorant‐binding protein in cow dander

Background Dog dander is an important cause of respiratory allergy but its content of allergenic components is still incompletely known. While Can f 1, 2, 3 and 5 have been studied in detail, only fragmentary information is available on the lipocalin Can f 4. Objective To purify, clone and characterize dog dander allergen Can f 4. Methods Can f 4 was purified from dog dander extract by size exclusion, ion exchange and reverse phase chromatography. A cDNA encoding Can f 4 was cloned and used to produce recombinant Can f 4 in Escherichia coli. A 23 kDa protein from cow dander, displaying cross‐reactivity with Can f 4, was purified and identified by amino acid sequencing and mass spectrometry. IgE antibody binding to dog and cow dander extract and to individual dog allergens among 37 dog allergic subjects and 44 pollen allergic controls was studied using ImmunoCAP. Results A dog genome segment containing the Can f 4 gene was bioinformatically identified and enabled the cloning of Can f 4 cDNA. Recombinant Can f 4 displayed close immunological and biochemical similarity to purified natural Can f 4 and bound IgE antibodies from 13/37 (35%) sera of dog allergic subjects. Can f 4 reactive sera showed IgE binding to a 23 kDa protein present in cow dander extract, related to a family of odorant‐binding proteins. The dog and cow proteins shared 37% sequence identity and their cross‐reactivity was demonstrated by IgE inhibition experiments. Conclusion Recombinant Can f 4 brings the panel of available dog allergens closer to completion and will be important in component‐resolved diagnostics in allergy to animal epithelial allergens. Cite this as: L. Mattsson, T. Lundgren, P. Olsson, M. Sundberg and J. Lidholm, Clinical & Experimental Allergy, 2010 (40) 1276–1287.     

Increase of allergen‐specific immunoglobulin E antibodies from 1973 to 1994 in a Finnish population and a possible relationship to Helicobacter pylori infections1

Background The prevalence of atopic diseases – hayfever, asthma and eczema – has increased over the past decades. The increase may be associated with decreased rates of infections such as measles, hepatitis A, tuberculosis, toxoplasmosis, and, as recently suggested, Helicobacter pylori gastritis. Objective Since the increase of atopy has been mainly based on clinical studies, we wanted to study the prevalence of allergen‐specific Immunoglobulin (Ig)E antibodies in two cross‐sectional, adult population‐based serum samples two decades apart. Since the sera had been tested for H. pylori antibodies, we also had a chance to look for a possible relationship between these two findings. Methods We determined the prevalence rate of allergen‐specific serum IgE antibodies against birch and timothy pollen, and cat and dog epithelium allergens by the radioallergosorbent test in a 15–54‐years‐old Finnish population using 326 sera collected in 1973 and 319 sera collected in 1994 from randomly selected subjects. Results From 1973 to 1994 allergen‐specific IgE prevalence rates and IgE antibody levels rose. In 1994, the prevalence rate of positive findings in 15–24‐year‐old population had increased from 11 to 38% (3.5‐fold increase, P = 0.0001, OR 5.12, CI 95% 2.32–11.3). In older 10‐year age groups similar trends did not reach significance, but the overall change was significant with all three cut‐off levels of allergen‐specific IgE analysed. The percentage of IgE‐positive persons rose mainly in the subgroup with no H. pylori antibodies. In 1994 21% of the H. pylori‐negative subjects had IgE antibodies compared with 5% of the H. pylori‐positive subjects (in 1973 11% in both subgroups). Conclusions IgE‐based evidence for an increase in IgE‐mediated allergy was uncovered. The increase occurred mainly in the subgroup with no antibodies to H. pylori, which support the hypothesis that H. pylori could be one of the microbes counteracting atopy.     

Altered Expression of Substance P and NK1R in CCR3+ and CD123+HLA-DR− Basophils Under Airway Allergic Conditions

PurposeTo explore expression of SP and NK1R in basophils of allergic asthma (AA), allergic rhinitis (AR) and AR combined with AA (ARA), and influence of allergens and immunoglobulin E (IgE) mediated mechanisms on SP and NK1R expression.MethodsExpression of SP and NK1R was detected by flow cytometry, NK1R mRNA expression was detected by real time quantitative polymerase chain reaction (qPCR), and mouse AR and AA models were employed for in vivo study.ResultsSP⁺ and NK1R⁺ cells increased in CCR3⁺ and CD123⁺HLA-DR⁻ granulocytes of AA. PPE elevated proportions of SP⁺ cells in CCR3⁺ and CD123⁺HLA-DR⁻ granulocytes, whereas ASWE and HDME augmented SP⁺ cells in CD123⁺HLA-DR⁻ granulocytes of AR and ARA patients. ASWE, HDME and PPE increased proportions of NK1R⁺ cells in CCR3⁺ PBMC and CD123⁺HLA-DR⁻ granulocytes of AR patients. OVA, Der p1, IL-33, IL-37, IgE and SP enhanced NK1R expression on KU812 cells. NK1R expressing basophils were increased in blood of OVA sensitized and challenged AR and AA mice. FcεRI-KO AA mice seemed to have less NK1R⁺ basophils than WT AA mice in their blood.ConclusionCCR3⁺ and CD123⁺HLA-DR⁻ cells are likely involved in AA and AR via SP and NK1R. IgE-related mechanism may participate in upregulation of NK1R expression.     

Presentation of allergen in different food preparations affects the nature of the allergic reaction – a case series

BACKGROUND: Characterization of fatal and non-fatal reactions to food indicates that the majority of reactions are due to the ingestion of prepared foods rather than the non-processed allergen. In an ongoing study that used a double-blind placebo-controlled food challenge to investigate peanut allergy and clinical symptoms, the observed reaction severity in four of the first six subjects was greater than anticipated. We hypothesized that this was due to differences in the composition of the challenge vehicle. OBJECTIVE: The aim was to investigate whether the severity of observed challenge reactions would be repeated on re-challenge with a lower fat challenge vehicle. METHODS: Peanut-allergic subjects were re-challenged with a lower fat recipe after reacting more severely than was anticipated to an initial peanut challenge. Similar challenge vehicle recipes were used, the only difference being the lower fat content (22.9% compared with 31.5%). The peanut content of the two recipes was analysed using RAST inhibition studies and ELISA tests. RESULTS: Three of four subjects reacted to much smaller doses of peanut protein on re-challenge (mean dose equivalence - 23 times less peanut) with the lower fat recipe. RAST inhibition showed that neither recipe altered epitope recognition. The higher fat recipe required twice as much peanut to cause 50% inhibition. ELISA detected far lower levels of peanut in the higher fat recipe (220 000 parts per million (p.p.m.)) than in the lower fat recipe (990 000 p.p.m.). CONCLUSION: The fat content of a challenge vehicle has a profound effect on the reaction experienced after allergen ingestion. This is another factor to be considered in assessing the risk of certain foods to food-allergic consumers and adds another dimension to clinical, research and regulatory practice.     

Determination of the allergenic activity of birch pollen and apple prick test solutions by measurement of β‐hexosaminidase release from RBL‐2H3 cells. Comparison with classical methods in allergen standardization

BACKGROUND: A murine in vitro model of the allergic type I reaction was set up to determine the biologic activity of extracts without involvement of human beings. It is based on beta-hexosaminidase release from passively sensitized RBL cells after allergen challenge. The intended application of this RBL cell assay in the field of quality control of allergenic extracts requires its comparison with established methods. METHODS: The activity of five standardized birch-pollen prick test solutions was determined in parallel by RBL assay, direct IgE binding, IgE-binding inhibition, major allergen content, histamine-release assay, and skin testing. RESULTS: The RBL cell-release assay corresponded well to other methods if a reagin raised against natural birch-pollen extract was used for passive sensitization. However, in the case of a reagin against recombinant Bet v 1, only a decreased activity was observed, presumably because a reduced number of epitopes were recognized by the monospecific reagin. In contrast to standardized birch-pollen extracts, nonstandardized apple extracts showed poor activity in all assays. CONCLUSIONS: This murine model might be a useful tool in the quality control of allergenic extracts. It combines properties of assays based on standardized antisera and of assays that consider IgE cross-linking properties.     

Time trends (1980–1987) of ten selected informative morphogenetic variants in a newborn population

The annual prevalence rates of ten selected informative morphogenetic variants (IMVs) were studied in 31,194 newborn infants over a period of 8 years (1980-1987). Two of them (preauricular sinus and ocular hypertelorism) revealed a highly significant decrease by logistic regression analysis. The other eight presented a stable pattern or small fluctuations which did not reach statistical significance. These data may serve as valuable baseline rates for monitoring IMVs in a specific newborn population. Their potential informative value as indicators of altered morphogenesis and their power for monitoring programs of environmental teratogenicity should be carefully verified.     

Immunohistochemical Detection of 13(R)-hydroxyoctadecadienoic Acid in Atherosclerotic Plaques of Human Carotid Arteries Using a Novel Specific Antibody

13-Hydroxyoctadecadienoic acid (13-HODE) is a major component of oxidized low density lipoprotein (OxLDL), which has been shown to have a crucial role in atherogenesis. Of the 13-HODE stereoisomers, 13(S)-HODE and 13(R)-HODE, little is known about the latter in contrast to the former. To detect 13(R)-HODE in atherosclerotic lesions, we prepared a mouse monoclonal antibody against 13(R)-HODE. Competitive enzyme-linked immunosorbent assay clarified the selective reaction of a clone mAb 13H1 with both free and bovine serum albumin-conjugated forms of 13(R)-HODE but not other oxidized lipids including 13(S)-HODE. Immunohistochemical analysis revealed the colocalization of 13(R)-HODE immunoreactivity with the OxLDL marker oxidized phophatidylcholine immunoreactivity in vascular endothelial cells, macrophages and migrating vascular smooth muscle cells in atherosclerotic plaques of human carotid arteries. The present results provide in vivo evidence for the formation of 13(R)-HODE in atherosclerotic lesions of carotid arteries.     

Suppression of gastric acid increases the risk of developing Immunoglobulin E‐mediated drug hypersensitivity: human diclofenac sensitization and a murine sensitization model

Background Hypersensitivity reactions towards non‐steroidal anti‐inflammatory drugs (NSAID) are common, although true allergies are detectable only in a subgroup of patients. The current study was prompted by a case observation, where a patient experienced generalized urticaria following his second course of diclofenac and proton pump inhibitor medication, and was found to have diclofenac‐specific IgE. During recent years, our group has been investigating the importance of gastric digestion in the development of food allergies, demonstrating anti‐acid medication as a risk factor for sensitization against food proteins. Objective Here, we aimed to investigate whether the mechanism of food allergy induction described can also be causative in NSAID allergy, using diclofenac as a paradigm. Methods We subjected BALB/c mice to several oral immunization regimens modelled after the patient's medication intake. Diclofenac was applied with or without gastric acid suppression, in various doses, alone or covalently coupled to albumin, a protein abundant in gastric juices. Immune responses were assessed on the antibody level, and functionally examined by in vitro and in vivo crosslinking assays. Results Only mice receiving albumin‐coupled diclofenac under gastric acid suppression developed anti‐diclofenac IgG1 and IgE, whereas no immune responses were induced by the drug alone or without gastric acid suppression. Antibody induction was dose dependent with the group receiving the higher dose of the drug showing sustained anti‐diclofenac titres. The antibodies induced triggered basophil degranulation in vitro and positive skin tests in vivo. Conclusion Gastric acid suppression was found to be a causative mechanism in the induction of IgE‐mediated diclofenac allergy. Cite this as: A. B. Riemer, S. Gruber, I. Pali‐Schöll, T. Kinaciyan, E. Untersmayr and E. Jensen‐Jarolim, Clinical & Experimental Allergy, 2010 (40) 486–493.     

Apolipoprotein(a): structural and functional consequences of mutations in kringle type 10 (or kringle 4–37)

The size polymorphism of Lp(a) is well recognized. It is now apparent that there is an additional polymorphism resulting from mutations occurring at the kringle level. One of these mutations involves a trp72 to arg substitution in apo(a) kringle type 10 and is attended by a defective binding of Lp(a) to immobilized lysine/fibrin. Other mutations affecting the other amino acids of the "lysine-binding pocket" may have similar functional consequences and may be important at the clinical level in terms of thrombogenesis.     

Cytotoxicity of the β-carboline alkaloids harmine and harmaline in human cell assays in vitro

beta-Carboline alkaloids are natural products widely distributed in plants and also found in alcoholic beverages, well-cooked foods and tobacco smoke. Various authors have reported genotoxic activities of several carboline in prokaryotic and eukaryotic cells that have been attributed to their abilities to intercalate into DNA. But studies on the genotoxic and on the cytotoxic potencies in human cells in vitro are not found in the literature. In the present study the toxicities of one full aromatic beta-carboline alkaloid (harmine) and one dihydro-beta-carboline alkaloid (harmaline) were evaluated by means of two in vitro human cell assays: the cytochalasin-B blocked micronucleus (CBMN) assay and the viability/colony formation assay with four different human cultured non-transformed (CCD18Lu) and transformed (HeLa, C33A and SW480) cells. Neither alkaloid was able to induce micronuclei levels above that of control levels in a wide range of doses tested; although, harmine at the highest concentrations assayed induced apoptotic as well as necrotic cells. Harmine produced a good viability of all cell lines assayed (control and tumor) while harmaline significantly reduced the viability of transformed and non-transformed cell lines in a dose-dependent manner. Harmine displayed a dose-dependent inhibitory effect on cell proliferation against all human carcinoma cells, but the SW480 transformed cell line showed a higher sensitivity. These results suggested that harmine was identified as a useful inhibitor of tumor development.