ENEA, a peach and apricot IgE-binding protein cross-reacting with the latex major allergen Hev b 5

Peach and apricot can cause allergic reactions with symptoms ranging from mild to very severe, including anaphylaxis. Sometimes subjects allergic to fruits of the Prunus genus have been reported to be also allergic to rubber latex products. The objective of this study is the characterization of a newly identified peach and apricot protein showing similarities with the allergens Hev b 5 from rubber latex and Man e 5 from manioc. This protein has been named ENEA on the basis of the single letter amino acid code of the first four N-terminal residues of the isolated molecule. It has been found in very variable amounts in different peach cultivars and batches. ENEA was isolated from peach pulp extracts by chromatographic separations and identified by direct protein sequencing. At that time, the full length sequence was available only for the homologous protein of the taxonomically closely related apricot, which was produced as a recombinant molecule in Escherichia coli. The following availability of the full length sequence of peach ENEA revealed a very high identity (97%) with the apricot homolog. Similarly to Hev b 5 and to Man e 5, the structural characterization indicated that ENEA is an intrinsically disordered protein. The immunological properties, investigated by dot blotting, the ABA system and the FABER test, showed that ENEA is recognized by specific IgE of allergic patients. In a selected population of 31 patients reporting allergic reactions to peach fruit and/or IgE positive to Hev b 5, 28 and 27 subjects resulted co-sensitized to rENEA and Hev b 5 in the ABA and ISAC test, respectively. In a random population of 3305 suspected allergic patients, analyzed with the FABER test, 17 of them were sensitized to rENEA and 10 of them were also positive to Hev b 5. In addition, both the natural molecule from peach and the recombinant protein of apricot partially inhibited the IgE binding to Hev b 5. In conclusion, a new peach and apricot IgE-binding protein, cross-reacting with the major latex allergen Hev b 5, has been identified. Its variable concentration in the fruit might explain some occasionally occurring allergic reactions. The apricot molecule has recently been registered by the WHO/IUIS Allergen Nomenclature Sub-Committee with the allergen name Pru ar 5. The recombinant form of apricot ENEA, now available, will contribute to allergy diagnosis.

Work-related asthma among professional cleaning women

The job of cleaning has developed dynamically as a working service, and women constitute the majority of all professional cleaning workers. Cleaners are at an increased risk of work-related asthma (WRA). This study characterizes work-related respiratory symptoms reported by female cleaners, evaluates any associated factors of WRA, and shows diagnostic management of medical certification. The study group comprised 50 professional cleaning women referred to our Occupational Diseases Department due to suspicion of occupational asthma (OA). A questionnaire, skin prick tests, serum specific IgE antibodies, and specific inhalant challenge were performed in all of the participants. Work-related asthma was recognized in 46% of symptomatic cleaners, of whom 15 were considered as having work-exacerbated asthma (WEA) and 8 as having OA. Sensitization to latex and disinfectants played an important role as a causative agent in OA of cleaners.

[Predisposition to latex allergy undetected on preoperative evaluation: a case report]

A 70-year-old man was scheduled to undergo laparoscopic total gastrectomy for stomach cancer. He had no history of atopy, fruit allergies, or frequent exposure to natural rubber. Preoperative latex-specific IgE antibodies were negative. Anesthesia was induced, and the surgery was started uneventfully. Soon after the surgeon had begun to manipulate the intestine, the blood pressure suddenly dropped to 27/21 mmHg. Facial flushing was also observed. Anaphylactic shock caused by latex was strongly suspected, and surgery was immediately halted. The surgical gloves were changed to latex-free ones, and adrenaline was administered. The blood pressure was gradually normalized within 30 min, and the facial flushing mostly disappeared. Postoperative laboratory examination revealed that serum tryptase had increased to 34.4 microg l-1, 40 minutes after the onset of anaphylaxis, and decreased to 19.4 microg l-1, 24 hours than later. Latex-specific IgE antibodies and a prick test with latex were both positive. Consequently, the diagnosis of latex-induced anaphylactic reaction was confirmed. Because even detailed questioning and examination does not always identify such a predisposition, avoiding contactwith latex products is more rational exhaustively checking every preoperative patient for latex allergy

Profile of latex sensitization and allergies in children and adolescents with myelomeningocele in São Paulo, Brazil

BACKGROUND

Latex allergy is an important cause of occupational allergy. In many countries the prevalence of latex allergy is still high and the profile of latex sensitization is unknown.

OBJECTIVES

To evaluate the frequency of sensitization and allergy to latex in children and adolescents with myelomeningocele and to identify associated risk factors.

METHODS

The study included 55 children and adolescents with myelomeningocele followed at a specialized center. In addition to a standard questionnaire and skin prick tests (SPTs) to aeroallergens and total latex, the patients underwent determination of total and specific serum IgE to latex and recombinant allergens.

RESULTS

We observed a prevalence of 25% for latex sensitization and of 20% for latex allergy. Twenty-four patients (43.6%) were atopic and the average age for the first reaction to latex was 44.5 months. Cutaneous reactions were the most frequently reported reactions (72.7%). Specific immunoglobulin (Ig) E to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of patients allergic to latex. Multivariate analysis showed current asthma, atopy, and having undergone 4 or more operations to be risk factors for latex sensitization.

CONCLUSIONS

Our study documented a high prevalence of sensitization and allergy to latex in patients with myelomeningocele. Specific IgE to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of children and adolescents with myelomeningocele who are allergic to latex. A history of current asthma, atopy, and having undergone 4 or more operations were independent risk factors for latex allergy.

Risk factors associated with asthma phenotypes in dental healthcare workers

BACKGROUND

Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors.

METHODS

A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed.

RESULTS

The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89).

CONCLUSION

Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics.

Evaluation and comparison of commercially available latex extracts for skin prick tests

BACKGROUND

Crude latex extracts are commonly used in skin prick tests (SPT) for the diagnosis of natural rubber latex (NRL) allergy. Nevertheless, variations in protein and allergen composition between latex extracts from different manufacturers can hamper a correct diagnosis.

OBJECTIVES

To analyze the heterogeneity of proteins and allergens in latex extracts from 7 different manufacturers and to assess its relevance in the diagnosis of latex allergy.

METHODS

Seven latex SPT extracts were analyzed for protein content using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The 4 major allergens Hev b 1, Hev b 3, Hev b 5, and Hev b 6.02 were also quantified using enzyme immunoassay. All commercial extracts were tested for their in vitro allergenic capacity using microarray inhibition assays and for their ability to induce biological reactivity in latex-allergic patients undergoing SPT.

RESULTS

The protein content of the extracts varied widely from 8.0 microg/mL to 526.5 microg/mL. SDS-PAGE revealed broad differences in protein profiles between the extracts. Marked variability in the contents of all 4 major allergens was observed, and Hev b 3 and Hev b 5 were undetectable in some extracts. Microarray inhibition assays and SPT demonstrated relevant differences in allergenic capacity between the extracts.

CONCLUSIONS

The marked heterogeneity in protein and allergen content of latex extracts from different manufacturers could explain the broad spectrum of SPT results recorded. Our findings suggest that the extracts used for the diagnosis of latex allergy should be improved and standardized.

Internalization of sapovirus, a surrogate for norovirus, in romaine lettuce and the effect of lettuce latex on virus infectivity

Noroviruses are the leading cause of food-borne outbreaks, including those that involve lettuce. The culturable porcine sapovirus (SaV) was used as a norovirus surrogate to study the persistence and the potential transfer of the virus from roots to leaves and from outer to inner leaves of lettuce plants. Treatment of lettuce with SaV was done through the roots of young plants, the soil, or the outer leaves of mature plants. Sampling of roots, xylem sap, and inner and outer leaves followed by RNA extraction and SaV-specific real-time reverse transcription (RT)-PCR was performed at 2 h and on postinoculation days (PID) 2, 5, 7, 14, and/or 28. When SaV was inoculated through the roots, viral RNA persisted on the roots and in the leaves until PID 28. When the virus was inoculated through the soil, viral RNA was detected on the roots and in the xylem sap until PID 14; viral RNA was detected in the leaves only until PID 2. No infectious virus was detected inside the leaves for either treatment. When SaV was inoculated through the outer leaves, viral RNA persisted on the leaves until PID 14; however, the virus did not transfer to inner leaves. Infectious viral particles on leaves were detected only at 2 h postinoculation. The milky sap (latex) of leaves, but not the roots' xylem sap, significantly decreased virus infectivity when tested in vitro. Collectively, our results showed the transfer of SaV from roots to leaves through the xylem system and the capacity of the sap of lettuce leaves to decrease virus infectivity in leaves.

Molecular allergens in the diagnosis of latex allergy

BACKGROUND

Molecular allergens enable the definition of sensitization profiles in allergic patients.

AIM

To validate the most helpful allergens for the diagnosis of latex allergy in different clinical situations.

METHODS

130 patients suspected to be allergic to latex with positive IgE against natural rubber latex (NRL) have been studied: 97 were confirmed as latex allergic (among which 55 professionally exposed to latex and 35 with a peranaesthetic anaphylactic shock) and 33 were only sensitized to latex without clinical allergy. Each serum was tested for IgE against 9 recombinant latex allergens and bromelain using Phadia ImmunoCAP 250.

RESULTS

rHev b 6.01, 6.02, 2 and 5 were the major allergens in the allergic population. An excellent correlation (94%) was observed between IgE against rHev b 6.01 and latex prick test positivities. IgE against rHev b 1, 3 and 5 were more frequent and their levels significantly higher in patients with peranaesthetic anaphylactic shock. Among the asymptomatic patients (29/33 allergic to pollen), NRL IgE positivity is explained by the presence of anti-rHev b 8 and/or anti-carbohydrate IgE.

CONCLUSIONS

rHev b 6.01 and rHev b 5 specific IgE are of major interest to confirm latex allergy diagnosis. rHev b 5 is particularly useful in case of monosensitization where clinical symptoms and latex skin prick tests may be discordant, rHev b1 and rHev b 3 are interesting to document multi-operated and peranaesthetic latex allergy. Finally, rHev b 8 is a helpful marker to highlight latex/pollen cross-reactivity which improves the specificity of the serological tests.

Latex allergy: Position Paper

Correct management of latex allergy is essential to ensure adequate care of patients who are allergic to latex, which is ubiquitous in the health care setting. In this Position Paper, the Latex Committee of the Spanish Society of Allergology and Clinical Immunology provides guidelines for the management of latex allergy.

Cucumber anaphylaxis in a latex-sensitized patient

We report the case of a 76-year-old woman who experienced dizziness, vomiting, dyspnea, thoracic erythema, and vaginal itching within 5 minutes of eating cucumber. She had been diagnosed 3 months earlier with papaya urticaria and latex sensitization. The results of skin prick tests were positive for cucumber, watermelon, papaya, and latex and negative for melon and profilin extracts. ImmunoCAP for latex-specific serum immunoglobulin (Ig) E was positive. Cucumber-specific serum IgE was negative. Immunoblot analysis using patient serum revealed a 30- to 32-kDa protein band in the cucumber (peel) and papaya extracts. Immunoblot inhibition with latex extract demonstrated inhibition of the band in both extracts. Immunoblot inhibition with cucumber-papaya and papaya-cucumber revealed inhibition of the same band in the cucumber and papaya extracts, respectively. We present a case of IgE-mediated allergy to cucumber and papaya. Our results strongly suggest that the allergen(s) implicated are associated with latex sensitization. To our knowledge, this is the first report of cucumber-latex and cucumber-papaya cross-reactivity.

Latex anaphylaxis caused by a Swan-Ganz catheter

A 78-year-old woman visited the division of cardiovascular disease in our hospital. She underwent a cardiac catheter examination, and a Swan-Ganz catheter was inserted. Several minutes later, she developed anaphylactic shock. She had no past history of latex allergy, but did have a banana allergy. Skin prick tests showed a positive reaction to an extract of latex gloves and an extract of the balloon of a Swan-Ganz catheter. Anaphylactic shock caused by the latex balloon of a Swan-Ganz catheter was diagnosed. It is necessary to pay attention to not only latex allergy but also fruit allergies with a cross-reactivity to latex.

Clinical significance of cross-reactivity between tobacco and latex

BACKGROUND

Allergen cross-reactivity between tobacco and other species of Solanaceae family (tomato, potato, aubergine and egg plant) have been reported. We have recently studied IgE response to tobacco in asthmatic patients sensitised to Lolium perenne (Perennial rye grass pollen) and have found that 30% of the tobacco responsive patients also have latex sensitisation.

OBJECTIVE

The aim of our study was to investigate the possibility of cross-reactivity between tobacco and latex in asthmatic patients with IgE response to latex.

METHODS

A study was performed on tobacco and latex exposure in 15 patients who suffered from asthma and latex sensitisation and who were randomly chosen from our database of latex-sensitive patients. To identify tobacco and latex as possible allergens that might cause clinical specific responses, all these patients were tested with prick-tests, specific IgE to tobacco, latex and related allergens, bronchial challenge, and patch tests with tobacco, latex and nicotine. Immunological response was evaluated with immunoblotting, immunoblotting-inhibition and EAST-inhibition tests.

RESULTS

Positive prick and bronchial challenge with specific IgE>0.35 kU/L to tobacco was demonstrated in 11 asthmatics who were also sensitised to rye grass. Tobacco IgE level was related with sensitisation to latex (p<0.002), but not to other vegetables belonging to the Solanaceae family. EAST-inhibition and immunoblotting-inhibition showed the existence of cross-reactivity between tobacco and latex.

CONCLUSIONS

Cross-reactivity exists between latex and tobacco allergens. Smoker patients with IgE response to tobacco may be a risk population for latex sensitisation.

Allergenicity of latex rubber products used in South African dental schools

BACKGROUND

Latex sensitisation is recognised as a health problem among health care workers (HCWs) using latex products. The aim of this study was to quantify specific latex allergens in latex devices used in South African academic dental schools. The current study also compared the total protein content and the levels of specific allergens in these products.

METHODS

Fourteen latex examination gloves (powdered and non-powdered) and five dental rubber dams, representing 6 brands, from five dental academic institutions were analysed for latex allergens and total protein. Total protein content was determined using the BioRad DC protein assay kit and natural rubber allergen levels using a capture enyme-linked immunosorbent assay (ELISA) specific for Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02.

RESULTS

Hev b 6.02 was found in higher concentrations than other natural rubber latex (NRL) allergens in the products analysed. Hev b 5 content ranged from 0 to 9.2 microg/g and Hev b 6.02 from 0.09 to 61.5 microg/g of sample. Hev b 1 levels were below the detection limit (DL) for 79% of the samples (15/19). Dental dams showed higher allergen levels (median 80.91 microg/g) than latex gloves (median 11.34 microg/g). Powdered rubber samples also showed higher allergen levels (median 40.54 microg/g) than non-powdered samples (median 5.31 microg/g). A statistically significant correlation was observed between total protein and total allergen (r=0.74, p<0.001) concentrations.

CONCLUSION

NRL allergen concentrations differ significantly by product and brand. This study has demonstrated that NRL allergens in latex-containing products used in South African dental institutions are present at sufficiently high levels to pose an allergic health risk.

A hospital-based screening study of latex allergy and latex sensitization among medical workers in Taiwan

BACKGROUND AND PURPOSE

Natural rubber latex is the most important occupational allergen among medical workers, and remains a significant occupational health issue in Taiwan. We conducted this large-scale hospital-based screening study to understand the incidence of latex allergy and latex sensitization among medical workers in Taiwan over the past 5 years.

METHODS

1253 medical workers were enrolled in this study. Subjects were interviewed using a screening questionnaire. Skin prick testing with commercial latex extract was performed for 1139 of the subjects.

RESULTS

152 subjects (12%) had positive latex skin prick test, suggesting that they had been sensitized to latex proteins. Seventy nine subjects (6%) had immediate allergic reactions to latex products. The prevalence of contact hand dermatitis from latex gloves was 35%. The intensive care unit and medical laboratory department accounted for the highest prevalence of allergy among all hospital departments. Most subjects developed immediate latex allergy by 9000 h of total latex exposure. The prevalence of positive latex skin prick test increased with increasing duration of latex exposure.

CONCLUSIONS

Latex allergy continues to be an important occupational allergy among medical workers in Taiwan. The addition of a routine screening examination in medical employees' health check-ups will help in the early identification of sensitized cases and facilitate preventive strategies.

Allergen specific nasal challenge to latex in children with latex allergy: clinical and immunological evaluation

There are no data concerning the significance of allergen specific nasal challenge to latex (ASNCL) in the pediatric population and the effect of mometasone furoate nasal spray (MFNS), topic corticosteroid exerting a potent anti-inflammatory activity in children with latex allergic rhinitis. The aims of this study are: to investigate the clinical and immune pathological effects of ASNCL in children with latex allergy; to study the effects of MFNS pre-medication on the clinical and immune pathological effects of ASNCL in children with latex allergy. Thirteen children: 6 male and 7 female, mean (SD) age 9.6 (2.9) years, with latex allergy and seven children: 3 male and 4 female, mean (SD) age 9.9 (3.8) years, without latex allergy underwent ASNCL. Nasal symptoms were recorded, nasal lavage fluid was collected to measure tryptase, eosinophil cationic protein (ECP), interleukin-5, interferon-gamma levels, and spirometric test was performed for each patient without or with premedication with MFNS. ASNCL induced a clinical allergic response and increased tryptase levels only in children with latex allergy. No serious adverse events occurred after ASNCL. MFNS premedication reduced both tryptase and ECP levels only in children with latex allergy. ASNCL is a simple, reliable and useful tool to make or confirm the diagnosis of nasal symptoms due to latex; it allows us to study both clinical symptoms and local immunological changes. MFNS premedication before an ASNCL may prevent some immunological responses induced by ASNCL without clinical allergic modifications.

Natural rubber latex allergy and dental practice

Natural rubber latex (NRL) allergy is a significant clinical problem with potentially life-threatening complications. Oral health care professionals must be able to screen for NRL allergy and refer patients or staff to a specialist for definitive diagnosis. Protocol for its management must be developed and incorporated into daily practice. Practitioners must be able to recognize and treat NRL exposure emergencies. Knowledge of the availability of substitute products and an adequate fresh stock of such products in dental practice can minimise the risk of adverse NRL sensitivity.

Priming-like effect and successful desensitization after anaphylactic shock by latex sublingual immunotherapy

The present report deals with some unusual events observed restarting allergy vaccine in a case of anaphylactic shock which occurred giving the maximum scheduled dose (25 drops) of rush sublingual immunotherapy (SLIT) to latex. Restarting SLIT by usual (not rush) scheme we observed long-lasting fall of reactivity threshold. The maximum tolerable dose was reduced to 2 drops, a dose fivefold smaller than the one well tolerated during previous rush phase (10 drops). We have excluded a possible nocebo effect and proved that the reduced tolerance was real by double blind placebo-controlled challenge test. We have considered this effect in some ways similar to priming effect. SLIT was continued with two drops every day. After about twenty months we could demostrate a significant reduction of skin reactivity by end-point technique and an improved response to the controlled exposition to latex by use-tests. In the same time the tolerance to vaccine was improved to three drops. The better safety profile allowed us to restart and continue with SLIT also in the reported case of anaphlicatic shock by latex vaccine and, after about two years, to induce valuable hyposensitization. Latex SLIT is confirmed as a safe and effective method.

Percutaneous reactivity to natural rubber latex proteins persists in health-care workers following avoidance of natural rubber latex

BACKGROUND

Long-term avoidance of natural rubber latex [Hevea brasiliensis (Hev b)] is currently recommended for health-care workers (HCWs) with established natural rubber latex (NRL) allergy. Percutaneous sensitivity to eight Hev b NRL allergens was evaluated in HCWs in 2000. To date, no studies have evaluated the longitudinal effects of NRL avoidance on percutaneous sensitivity to NRL allergens.

OBJECTIVE

The aims of this study were to evaluate changes in percutaneous reactivity to non-ammoniated latex (NAL) and NRL allergens in HCWs 5 years after a recommendation to avoid NRL and to evaluate factors that predict the persistence of in vivo sensitivity to NAL and NRL allergens.

METHODS

Skin prick testing was performed with NAL, seven NRL allergens (Hev b 1, 2, 3, 4, 6.01, 7.01, and 13), and recombinant Hev b 5 (rHev b 5) in 34 HCWs who were initially evaluated in 2000 for occupationally related NRL allergy. Serial 10-fold dilutions of NAL and NRL allergens were employed in skin testing. Sera from the HCWs were assayed for latex and enhanced latex (rHev b 5-enriched allergosorbent)-specific IgE antibodies using the ImmunoCAP assay.

RESULTS

The prevalence of work-related symptoms significantly decreased between 2000 and 2005 with avoidance of NRL (P<0.05). A >/=100-fold reduction in percutaneous sensitivity to Hev b 2 and Hev b 7 was less likely in those with prior history of systemic reactions to NRL (P=0.0053), reported history of reaction to cross-reactive foods (P=0.014), continued local reactions to NRL gloves (P<0.0001), or high NRL glove exposure since the initial study (P=0.0075). The diagnostic sensitivity and specificity of the latex-specific IgE serology was 54% and 87.5%, respectively, in comparison with NAL skin tests. The addition of rHev b 5 to the ImmunoCAP (enhanced latex) allergosorbent altered the diagnostic sensitivity and specificity of the ImmunoCAP to 77% and 75%, respectively.

CONCLUSION

While symptoms may resolve quickly with NRL avoidance therapy, detectable IgE indicating continued sensitization remains beyond 5 years, and thus continued avoidance of NRL should be recommended.

Natural rubber latex and hymenoptera venoms share ImmunoglobinE-epitopes accounting for cross-reactive carbohydrate determinants

BACKGROUND

Epidemiological data on the prevalence and risk factors of latex sensitization have suggested a significant association between latex sensitization and the presence of one or more positive skin prick test responses to aeroallergens, food allergens and to one or more insect venoms. Xylose and core 3-fucose are typical complex glycans in plants and are foreign to mammals. Plant N-glycans and insect N-glycans may cross-react in humans.

OBJECTIVE

The aim of our study was to investigate whether there are cross-reactive IgE-binding structures in natural rubber latex (NRL) and hymenoptera venoms and to examine their nature.

METHODS

Hundred and twenty-five consecutive patients with insect venom allergy were screened for coincidental latex-specific IgE. IgE-binding components in the venoms from Apis mellifera and/or vespula species and in NRL extracts were characterized by IgE-immunoblotting to the natural allergen sources and determination of specific IgE to recombinant allergens. Cross-reactive components were investigated by inhibition experiments. The involvement of carbohydrates in the constitution of cross-reactive IgE-epitopes was further examined by specific IgE-binding to cross-reactive carbohydrate determinants (CCD) in bromelain and horseradish peroxidase as well as by periodate treatment.

RESULTS

NRL glove extracts inhibited patients' serum IgE-binding to venom allergens. Vice versa, the IgE-binding to latex glove extracts could be inhibited by pre-incubation with the insect venoms. Specific IgE-binding to recombinant latex allergens was absent, whereas the cross-reactive IgE-epitopes were sensitive to periodate treatment and specific IgE to CCD (MMXF and MUXF type) could be detected.

CONCLUSION

Insect venoms and NRL share IgE-binding CCD that may be responsible for positive serological test results to NRL in patients with insect venom allergy. This copositivity occurs frequently (13.6%) among venom-allergic individuals and did not elicit clinical symptoms upon contact to latex in the patients examined. In contrast, true cosensitization to insect venoms and NRL allergens can occur and may not be missed.

Occupational allergy to latex among loom tuners in a textile factory

BACKGROUND

Occupational allergy to latex is generally reported from occupational groups such as health care workers; however, few reports derive from other occupational settings.

METHODS

Two male subjects working as loom tuners in a textile manufacturing plant developed severe allergic reactions during the cutting and weaving of elastic bands, initially not suspected to contain latex constituents. Clinical evaluation and lung function tests were supplemented by skin prick testing, specific IgE evaluation and basophil activation assays with extracted elastic bands.

RESULTS

Both workers presented with rhinitis, episodes of tight chest and itchy eyes. Initial spirometry was normal with no significant reversibility; however, a histamine challenge test was positive in one worker. Skin prick testing to a battery of common inhalant allergens was negative; however, raised IgE levels were detected to latex using ImmunoCAP. On further testing, the specific IgE response was directed mainly to the major latex allergens rHev b 5, rHev b 6.01, rHev b 6.02 and nHev b 13. Basophils of the two workers, but not the unaffected control subjects, were strongly activated by extracts of the elastic and the cutting dust material.

CONCLUSIONS

Workers are at high risk of becoming sensitised to latex allergens when exposed to excessive dust produced by loom tuning machines. Latex sensitisation should therefore be considered in workers developing unexplained work-related allergic reactions (including asthma) associated with unlabelled materials in the textile industry.

Prevalence of latex allergy in spina bifida: genetic and environmental risk factors

AIM OF STUDY

To evaluate the prevalence of latex allergy in a population of children with spina bifida (SB) and to assess the role of early exposure to latex products and others risk factors.

INTRODUCTION

SB is related with an higher incidence of latex allergic reactions. These patients received repeated surgical procedures, implant of latex-containing materials and catheterization.

MATERIALS AND METHODS

Eighty consecutive subjects affected with SB besides answering a questionnaire, underwent a skin-prick test (SPT) to latex and the determination of the specific serum IgE (RAST CAP) to latex. 40% (32/80) of the patients showed a latex sensitization with specific IgE > 0.7 kU/I but only twelve of the 32 sensitized patients (40%) suffered from clinical reactions to latex (urticaria, conjunctivitis, angioedema, rhinitis, bronchial asthma). Number of surgical procedures, but particularly early exposure to latex and familiarity for allergy are correlated with latex allergy (p < 0.01).

CONCLUSION

Latex allergy in SB children is multifactorial situation related with a disease-associated propensity for latex sensitization, early exposure and number of surgical procedures. Prophylactic measures to avoid the exposure, not only in the sanitary environment, through the institution of latex-safe routes and every day, prevent potentially serious allergic reactions.

Immunological and allergenic responses induced by latex fractions of Calotropis procera (Ait.) R.Br

Immunological and allergenic responses against the latex of Calotropis procera were investigated in mice by oral and subcutaneous routes. The latex was fractionated according to water solubility and molecular size of its components. The fractions were named as non-dialyzable latex (NDL) corresponding to the major latex proteins, dialyzable latex (DL) corresponding to low molecular size substances and rubber latex (RL) which was highly insoluble in water. Anti-sera against these fractions were assayed for total IgG and IgA titration by ELISA and IgE and IgG(1) were quantified by passive cutaneous anaphylaxis (PCA) in rats and mice, respectively. None of the fractions induced antibodies level increases when mice received latex fractions by oral route and thus, did not develop allergy. Nonetheless, anti-sera of mice sensitized with NDL and RL by subcutaneous route displayed considerable immunological response while DL did not. IgG level augmented consistently against NDL and RL while IgA response was detected only to NDL. NDL and RL induced very strong PCA reactions suggesting that both fractions would contain latex substances involved in allergy. Furthermore, protein analysis of NDL and RL suggests that RL still retain residual proteins abundantly found in NDL that could explain its similar allergenic effect. No IgG(1) reaction was detected in any of the anti-sera tested. According to the results, the proteins of latex of Calotropis procera can provoke allergy by subcutaneous route. The NDL has previously shown to display anti-inflammatory and analgesic activities by intraperitoneal injection. It should be relevant to determine whether NDL could induce such activities when assayed by oral route since it was ineffective to induce allergy by this way.

Generation of Allergen-Enriched Protein Fractions of Hevea brasiliensis Latex for in vitro and in vivo Diagnosis

BACKGROUND

The latex of Hevea brasiliensis trees contains a complex proteome that includes a range of allergenic proteins. Current latex extracts that are used for the diagnosis of latex allergy still lack important allergens. We aimed to devise a production process for an improved reagent that would ideally contain the complete latex allergome.

METHODS

Latex C-serum was fractionated by ammonium sulfate precipitation, and B- and C-serum proteins were then separated by anion exchange chromatography. Proteins eluting within defined salt concentration ranges were pooled into six final fractions. Fractions were evaluated by two-dimensional electrophoresis and subsequent IgE immunoblot for their spectrum of allergens. The presence of the most important latex allergens in the fractions was checked by Western blot analyses. Each fraction was further evaluated by skin prick test (SPT).

RESULTS

Reproducibility of the preparation method was demonstrated with two batches of latex. Comparison of latex B- and C-serum to the six fractions showed a remarkable increase in the number of detectable allergens in the fractions. The presence of the latex allergens Hev b 1-8 and Hev b 13 in the fractions was demonstrated. In SPTs, the fractions produced wheal-and-flare reactions comparable to commercial latex extracts.

CONCLUSIONS

This method provides reproducible latex protein fractions of high allergen content for the diagnosis of latex allergy.

In silico identification of potential new latex allergens

BACKGROUND

Allergy to latex of Hevea brasiliensis is a frequent problem. In spite of the significant progress of research, the identity and cross-reactivity of some latex allergens are unknown.

OBJECTIVE

To identify, among the fully characterized latex proteins, those with a higher probability to be allergenic.

METHODS

We used in silico techniques (amino acid sequence comparison and molecular modelling) to identify potential new allergens among the known proteins of H. brasiliensis.

RESULTS

Cu/Zn superoxide dismutase, heat shock protein and calmodulin of H. brasiliensis show highly significant (E < 10(-9)) amino acid sequence homologies with known allergens.

CONCLUSION

On the basis of our data, Cu/Zn superoxide dismutase, heat shock protein and calmodulin are the most probable allergens among fully characterized proteins of H. brasiliensis, and could potentially explain, at least in part, the multiple cross-reactivities of latex with vegetable foods and other plant-derived products. Consequently, we think that the above proteins should be particularly considered in the future laboratory and clinical research.

Latex allergen sensitization and risk factors due to glove use by health care workers at public health units in Florianopolis, Brazil

BACKGROUND

Natural rubber latex allergy is a "new" illness whose prevalence has reached epidemic proportions in highly exposed populations such as health care professionals.

OBJECTIVE

The aim of the study was to evaluate the frequency of reactions to latex and risk factors due to glove use in health care workers (HCW) in Florianopolis, Santa Catarina, Brazil.

METHODS

We evaluated latex-related allergy in 260 HCW by means of a questionnaire, skin prick tests (SPT) and serum latex specific IgE antibody levels. The subjects were divided into two groups depending on level of exposure to latex gloves. Comparisons were made between the different variables and a risk score was calculated using logistic regression analysis.

RESULTS

Glove-related symptoms were observed in 57% of 140 HCW. Significant differences between HCW and control groups were found for the following symptoms: contact dermatitis (P < .0001), cutaneous rash (P < .0001), asthma or allergic rhinitis (P < .0001), symptoms associated with toy balloons (P < .0001), airborne glove powder causing latex allergen reaction (P < .0001), food allergy (P < .0001), fruit allergy (P < .0001) and multiple surgical interventions (P = .0052). Contact dermatitis and anaphylaxis were the main problems, with a high risk factor for the development of latex allergy. Logistic regression analysis showed a significant positive association between the risk of latex allergy and those subjects who reported more than 4 positive answers on the questionnaire (including SPT) (odds ratio 6.8; 95% confidence interval 0.7-60.3). No latex-related allergy symptoms were reported by the control group. Serological latex specific immunoglobulin (Ig) E antibody levels were negative for both groups.

CONCLUSION

It is essential to recognize which professionals are sensitized to latex in order to provide appropriate treatment and to establish adequate prevention.

Allergy to cassava: a new allergenic food with cross-reactivity to latex

Patients who are allergic to latex (Hevea brasiliensis) may exhibit cross-hypersensitivity with foods. We present a case of anaphylaxis due to cassava in a patient suffering from pollinosis, latex allergy, and latex-fruit syndrome. We performed sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with cassava, avocado, chestnut, banana, kiwi, and latex extracts in order to analyze the protein bands and their molecular weights, and identify immunoglobulin (Ig) E-binding bands. Immunoblot inhibition and enzyme-linked immunosorbent assay (ELISA) inhibition were performed with latex in order to assess cross-reactivity. Cassava exhibited numerous protein bands, 5 of which were IgE-binding (89.75, 46.28, 26.68, 21.38, and 19.49 kd). These cassava IgE-binding bands were 100% inhibited by preincubation of the patient's serum with latex extract. The ELISA inhibition between latex and cassava was 23%. Our results confirm cassava as another food with clinical cross-reactivity in patients suffering from latex allergy.

Inhibition of Calotropis procera latex-induced inflammatory hyperalgesia by oxytocin and melatonin

The latex of the wild growing plant Calotropis procera produces inflammation of the skin and mucous membranes upon accidental exposure. On local administration it elicits an intense inflammatory response due to the release of histamine and prostaglandins that is associated with hyperalgesia. In the present study we have evaluated the anti-inflammatory and antinociceptive activity of oxytocin and melatonin against rat paw edema induced by dried latex (DL) of C procera and compared it with that against carrageenan-induced paw edema. Aqueous extract of DL of C procera or carrageenan (1%) was injected into the subplantar surface of the rat paw and the paw volume was measured at 0, 1, 2, 3, 4, 6, 10, and 24 hours. The associated hyperalgesic response and functional impairment were also evaluated concomitantly by dorsal flexion pain test, motility test, and stair climbing ability test. The inhibitory effect of oxytocin and melatonin on edema formation and hyperalgesic response was compared with dexamethasone. DL-induced edema formation was maximum at 2 hours and was associated with decreased pain threshold and functional impairment. Treatment with melatonin significantly attenuated the edematous response while both oxytocin and melatonin increased the pain threshold and improved functional parameters. Both oxytocin and melatonin significantly inhibited the hyperalgesia associated with DL-induced paw edema. Oxytocin was found to be as effective as melatonin in ameliorating the hyperalgesic response. However, it was found to be less effective than melatonin in attenuating edema formation.

Sublingual desensitization in children with congenital malformations and latex allergy

The frequency of latex allergy in children requiring multiple surgery ranges from 16.7% to 65%. The aim of this study was to investigate the safety and efficacy of latex desensitization in a group of 10 patients with a history of multiple surgical procedures and clinically manifested allergy to latex. We selected 10 children (female-male ratio = 5:5), aged 4-16 yr (mean +/- s.d.: 9 +/- 4), with a history of multiple surgical procedures, adverse reactions to latex and positive skin test to latex and/or specific immunoglobulin E (IgE). Latex allergy diagnosis was confirmed by specific provocation tests (cutaneous, sublingual, mucous, conjunctival tests). Rush (4-day) sublingual desensitization was performed with increasing doses of latex extract (ALK Abellò) under patients' tongue until the highest dose of 500 microg of latex. A maintenance therapy (10 drops of undiluted solution three times a week) was recommended. During the 2-yr follow-up mean values of specific IgG4 and IgE, eosinophilic cationic protein and total IgE did not show significant variations. Patients did not manifest any adverse effect during the rush phase and only two patients manifested mild local symptoms during the maintenance therapy. All the challenges showed a reduction in terms of percentage of positivity and mean scores. All the patients showed a reduction of the mean individual score (p < 0.001). Furthermore patients who needed dental examination or surgery underwent such procedures without the occurrence of symptoms. Our preliminary results show sublingual desensitization to latex can be an important therapeutic tool in the management of young allergic patients requiring multiple operations.

Gastro-Intestinal Exposure to Latex Antigens Induce Allergic Responses in Mice

BACKGROUND

Natural rubber latex (NRL) has emerged as a major cause of respiratory allergy among specific exposed groups of individuals. Since latex allergens are dispersed in the environment it is conceivable that latex proteins are both inhaled and ingested. The mechanism of latex allergy and the immune responses following reexposure of latex allergens by the intranasal route was studied in a murine model of latex allergy developed by intragastric sensitization with NRL.

METHODS

BALB/c mice were sensitized intragastrically ('ig'), intranasally ('in') or 'ig' followed by 'in' challenge with NRL allergens. The cellular and humoral immune responses, lung function and histological changes were determined.

RESULTS

Peripheral blood eosinophilia was observed in the 'ig' and 'ig/in'-NRL-sensitized animals in comparison to normal controls (p < 0.05). The 'ig' group showed a marked increase over control mice in serum total IgE, NRL-specific IgG and IgG subclasses (p < 0.05). Increased levels of IL-4, IL-5, IL-10, and IL-13 were detected in 'ig'-NRL-sensitized mice. Intranasal exposure with NRL after 'ig' sensitization further enhanced the cytokine levels. A tendency towards enhanced stimulation was determined in 'ig'-sensitized mice; a significant difference was shown in the 'ig/in'-group (p < 0.05). Increased airway hyperreactivity was found in 'ig'-NRL-sensitized-mice (15.1 +/- 2.5 vs. 8.9 +/- 1.7 cm H2O x ml(-1) x s, p < 0.05). Mucus secretion from jejunal epithelium and eosinophilic infiltration into the jejunal lamina propria were observed in the 'ig'-NRL-sensitized-mice.

CONCLUSIONS

The results demonstrate that intragastric NRL sensitization did not induce specific tolerance, and additional intranasal exposure with latex allergens resulted in systemic allergic manifestations in the murine model.

Differential expression of allergens on the internal and external surfaces of latex surgical gloves

BACKGROUND

Differences in latex allergen sensitization profiles have been described between children undergoing repeated surgical interventions and health care workers. The purpose of this study was to determine whether such sensitization profiles are associated with differences in the expression of latex allergen between the internal and external surfaces of surgical gloves.

METHODS

Extracts were obtained from whole surgical gloves as well as from their external and internal surfaces. The extracts were centrifuged, filtered, concentrated, dialyzed and lyophilized. The protein profile of the extracts was analyzed using hydrophobic interaction chromatography (HIC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblotting was performed using sera from two patients with confirmed latex allergy. Latex recombinant allergen-specific IgE in these two patients was determined using a fluorescence enzyme immunoassay (FEIA) method. Latex allergen quantification was determined on both glove surfaces using an ELISA method.

RESULTS

HIC and SDS-PAGE showed qualitative and quantitative differences in proteins between the internal and external glove surfaces, with the former being much richer in proteins. Immunoblotting of glove extracts using sera from two latex-allergic health workers showed differences between glove surface extracts. ELISA quantification of latex allergens demonstrated that the internal glove surface had high amounts of Hev b 5 and Hev b 6.02 whereas the external surface showed Hev b 1, Hev b 3, and Hev b 6.02.

CONCLUSIONS

Our results reveal substantial differences in the composition of latex allergen profiles between the internal and external surfaces of surgical latex gloves, which may suggest a relationship between latex allergen localization and sensitization routes in different risk groups.

Specific immunotherapy with standardized latex extract versus placebo in latex-allergic patients

BACKGROUND

Allergy to natural rubber latex proteins continues to be an important medical problem among health care professionals, but also in multioperated children. Clinical manifestations range from urticaria to angioedema, rhinoconjunctivitis, bronchial asthma and anaphylactic shock.

METHODS

The aim of this study was to investigate the efficacy and safety of a 12-month latex-specific immunotherapy in sensitized patients, most often health care workers. Twenty-three patients with latex rhinoconjunctivitis (20 of whom also had asthma) were included in this randomized, double-blind, placebo-controlled trial (11 in the active group, 12 in the placebo group). Treatment efficacy was assessed by means of symptom and medication scores. Conjunctival provocation tests and quantitative skin prick tests were also performed.

RESULTS

The clinical index (derived by combining changes from baseline of six efficacy variables during the treatment period) did not differ significantly between treatment groups. Change from baseline of rhinitis, conjunctivitis, skin symptoms, asthma symptoms, medication score and cutaneous reactivity were not significantly different between the two groups. A nonsignificant difference in conjunctival reactivity was observed in favor of the active group (p = 0.09). Systemic reactions were much higher in the specific immunotherapy than in the placebo group.

CONCLUSIONS

The present study failed to show a significant improvement of symptoms and medication scores, probably because of the low level of symptoms at baseline and the low maintenance dose of therapy, even if allergen-specific conjunctival reactivity decreased in the active group. Moreover, the incidence of systemic reactions was very high in the active group.

Effects of established allergen sensitization on immune and airway responses after secondary allergen sensitization

BACKGROUND

Spreading of sensitization with clinical manifestation of allergy is often observed in atopic individuals.

OBJECTIVE

To investigate the effects of an established primary allergen sensitization on immune responses and airway inflammation/reactivity on secondary allergen sensitization and airway challenges in a murine model.

METHODS

Balb/c mice were primarily sensitized intraperitoneally with ovalbumin or PBS, followed by systemic sensitization and airway challenges with latex extract as a secondary, unrelated allergen. Purely sham-sensitized animals were included as controls. In a second set of experiments, the primary and secondary allergens were switched.

RESULTS

Sensitization with ovalbumin before sensitization with latex resulted in increased production of total and latex-specific (Hev b 3-specific) IgE and IgG(1), and enhanced secretion of T(H)2-cytokines by spleen mononuclear cells cultured with mitogen compared with single latex-sensitized mice. Furthermore, airway challenges of double-sensitized mice (ovalbumin + latex) with latex caused a significant increase in airway reactivity compared with purely latex-sensitized and challenged animals. These effects were dependent on dosing and timing of the primary sensitization in relation to the secondary sensitization and independent of the primary allergen used.

CONCLUSION

Primary sensitization boosted systemic T(H)2 immune responses and enhanced the development of airway reactivity after sensitization and airway challenges with a secondary, unrelated allergen. This effect of consecutive priming was dependent on the strength of the primary sensitization but independent of the allergen used. The results explain the increased susceptibility toward sensitization spreading in atopic individuals.

CLINICAL IMPLICATIONS

Because sensitization spreading is facilitated by primary sensitization, early prevention measurements or immunotherapy should be considered at this stage of monosensitization.

Latex allergen IgE assays in the assessment of Veterans Affairs health care workers

BACKGROUND

A previous multicenter study of Veterans Affairs health care workers evaluated hospital participants for latex hypersensitivity. Well-defined groups from that study allowed us to explore the diagnostic utility of newer antilatex allergen IgE immunoassays in the present study.

OBJECTIVES

To determine whether an enhanced CAP (ENHCAP) assay or an enzyme-linked immunosorbent assay (ELISA) identifies latex glove symptomatic individuals with antilatex allergen IgE that had not been detected by the CAP assay used in the original study and to determine the specificity of the ENHCAP assay.

METHODS

The ELISA measured IgE antibody to Malaysian nonammoniated natural rubber latex extract (MNA), Hev b1, Hev b5, and Hev b6. Four patient groups were tested: confirmed latex glove allergic, latex glove symptomatic, latex glove sensitized/asymptomatic, and latex glove nonallergic.

RESULTS

The ENHCAP assay and the MNA ELISA were highly concordant with the original CAP assay. In the subgroup with latex glove symptoms that were previously negative by the CAP assay, the ENHCAP assay value was elevated in 7 (11%) of 64 samples, only 3 of which were class 2 or higher. The MNA ELISA result was positive in only 4 (6%) of these 64 samples, and 3 of these were fractionally above the cutoff value for this assay.

CONCLUSIONS

The ENHCAP assay and the MNA ELISA identified a few additional positive individuals in the group that was latex glove symptomatic and originally CAP assay negative. The ENHCAP assay and the MNA ELISA produced only a modest improvement in diagnostic sensitivity over that of the original CAP assay.

Emotion with tears decreases allergic responses to latex in atopic eczema patients with latex allergy

OBJECTIVE

Allergic responses are enhanced by stress, whereas they are reduced by laughter in atopic eczema patients. Emotion with tears decreases plasma IL-6 levels in patients with rheumatoid arthritis. Thus, the effect of emotion with tears on allergic responses in patients with atopic eczema was studied.

METHODS

Sixty patients with atopic eczema having latex allergy viewed both the weather information video and the heart-warming movie, Kramer vs. Kramer. Just before and immediately after viewing each video, allergic responses to latex were measured.

RESULTS

Viewing the weather information video did not cause emotion with tears in any patients, and it failed to modulate allergic responses. In contrast, viewing Kramer vs. Kramer caused emotion with tears in 44 of 60 patients, and it reduced allergic skin wheal responses to latex and latex-specific IgE production in them.

CONCLUSION

Emotion with tears reduced allergic responses, and it may be useful in the treatment of allergic diseases.

IL-25 enhances allergic airway inflammation by amplifying a TH2 cell-dependent pathway in mice

BACKGROUND

A novel IL-17 family cytokine, IL-25, has been reported to induce IL-4, IL-5, and IL-13 production from undefined non-T/non-B cells and then induce T(H)2-type immune responses. However, the roles of IL-25 in inducing allergic airway inflammation remain unknown.

OBJECTIVE

We sought to determine whether IL-25 is involved in causing allergic airway inflammation.

METHODS

We examined the expression of IL-25 mRNA in the lungs of sensitized mice on antigen inhalation. We also examined the effect of IL-25 neutralization by soluble IL-25 receptor on antigen-induced airway inflammation. We then generated IL-25 transgenic mice that express IL-25 specifically in the lung under the control of the Clara cells-10-kd protein promoter and investigated the effect of enforced IL-25 expression on antigen-induced airway inflammation.

RESULTS

IL-25 mRNA was expressed in the lungs of sensitized mice on antigen inhalation, and the neutralization of IL-25 by soluble IL-25 receptor decreased antigen-induced eosinophil and CD4(+) T-cell recruitment into the airways. The enforced expression of IL-25 in the lung itself failed to induce allergic airway inflammation, whereas the expression of IL-25 significantly enhanced antigen-induced T(H)2 cytokine production, eosinophil and CD4(+) T cell recruitment, and goblet cell hyperplasia in the airways. Moreover, IL-25-induced enhancement of allergic airway inflammation was inhibited by the depletion of CD4(+) T cells or by the absence of signal transducer and activator of transcription 6.

CONCLUSION

IL-25 enhances antigen-induced allergic airway inflammation by amplifying a T(H)2 cell-dependent pathway.

CLINICAL IMPLICATIONS

IL-25 might be involved in the enhancement, prolongation, or both of T(H)2 cell-mediated allergic diseases, such as asthma.

Modulation of dendritic cell trafficking to and from the airways

We investigated the fate of latex (LX) particles that were introduced into mice intranasally. Macrophages acquired the vast majority of particles and outnumbered LX particle-bearing airway dendritic cells (DCs) by at least two orders of magnitude. Yet alveolar macrophages were refractory to migration to the draining lymph node (DLN), and all transport to the DLN could be ascribed to the few LX(+) airway DCs. Upon macrophage depletion, markedly greater numbers of DCs were recruited into the alveolar space. Consequently, the number of DCs that carried particles to the DLN was boosted by 20-fold. Thus, a so far overlooked aspect of macrophage-mediated suppression of airway DC function stems from the modulation of DC recruitment into the airway. This increase in DC recruitment permitted the development of a robust assay to quantify the subsequent migration of DCs to the DLN. Therefore, we determined whether lung DCs use the same molecules that skin DCs use during migration to DLNs. Like skin DCs, lung DCs used CCR7 ligands and CCR8 for emigration to DLN, but the leukotriene C(4) transporter multidrug resistance-related protein 1 did not mediate lung DC migration as it does in skin, indicating that pathways governing DC migration from different tissues partially differ in molecular regulation.