Latex allergy: a model for therapy

Biomedical applications of natural rubber latex from the rubber tree Hevea brasiliensis

The past decades have witnessed tremendous progress in biomaterials in terms of functionalities and applications. To realize various functions such as tissue engineering, tissue repair, and controlled release of therapeutics, a biocompatible and biologically active material is often needed. However, it is a difficult task to find either synthetic or natural materials suitable for in vivo applications. Nature has provided us with the natural rubber latex from the rubber tree Hevea brasiliensis, a natural polymer that is biocompatible and has been proved as inducing tissue repair by enhancing the vasculogenesis process, guiding and recruiting cells responsible for osteogenesis, and acting as a solid matrix for controlled drug release. It would be extremely useful if medical devices can be fabricated with materials that have these biological properties. Recently, various types of natural rubber latex-based biomedical devices have been developed to enhance tissue repair by taking advantage of its biological properties. Most of them were used to enhance tissue repair in chronic wounds and critical bone defects. Others were used to design drug release systems to locally release therapeutics in a sustained and controlled manner. Here, we summarize recent progress made in these areas. Specifically, we compare various applications and their performance metrics. We also discuss critical problems with the use of natural rubber latex in biomedical applications and highlight future opportunities for biomedical devices produced either with pre-treated natural rubber latex or with proteins purified from the natural rubber latex.

Latex Allergy: Current Status and Future Perspectives

Allergy to natural rubber latex (NRLA) from Hevea brasiliensis is a relevant public health issue, in particular in healthcare workers and groups at risk. Clinical manifestations of NRLA can range from mild skin disorders to life-threatening systemic reactions. Prevention measures remain the gold-standard treatment for patients suffering from NRLA, but the only etiological therapy able to influence the natural history of NRLA is specific desensitization. This review aims to underline the epidemiological, clinical and diagnostic aspects of NRLA, and carries out a complete and wide-ranging review of the current literature on NRLA management and immunotherapy.

Hand eczema as a risk factor for food allergy among occupational kitchen workers

BACKGROUND

An increasing number of studies in children is highlighting the importance of transdermal routes of exposure to food allergens through damaged skin in the pathogenesis of food allergies. However, data on this in adults are limited. A few case-series studies has documented development of food allergy among kitchen workers with hand eczema after direct contact exposure to foods.

METHODS

To explore the significance of hand eczema as a risk factor for food allergies in adults at the epidemiological level, we performed a cross-sectional web-based questionnaire survey on kitchen workers whose exposures were classed as occupational (cooks and food handlers, n = 1592) or non-occupational (housewives, n = 1915). Logistic regression was used to explore the association between the presence/severity of hand eczema and the risk of food allergy after adjustment for potential confounders.

RESULTS

Current hand eczema and current diagnosed food allergy were more common among occupational kitchen workers (OKW) than among non-occupational kitchen workers (NOKW) (32.3%-vs-29.9% and 9.9%-vs-3.8%, respectively). Current hand eczema was significantly associated with increased risk of current diagnosed food allergy in OKW (adjusted odds ratio 2.4, 95% CI 1.6-3.7). Those with more severe hand eczema were more likely to suffer from allergic symptoms for foods, and diagnosed food allergy.

CONCLUSIONS

This study illustrates a significant public health problem in the adult population, documenting a major impact of hand eczema on the ongoing adult food allergy epidemic.

Latex immunotherapy: evidence of effectiveness

INTRODUCTION

The only etiological and decisive therapy, able to influence the natural history of latex allergy is the specific desensitization.

AIM

To verify the clinical efficacy and immunological changes determined by latex sublingual immunotherapy in allergic patients who underwent this treatment for at least 3 years.

MATERIAL AND METHODS

We enrolled 76 patients (16 males and 60 females, mean age 34 years old) with evidence of a natural rubber latex allergy. To assess the effectiveness of the immunotherapy we performed a latex skin prick test, specific IgE and IgG4 and challenge tests before and after at least 3 years of desensitization.

RESULTS

We observed a reduction in the mean diameter of the wheal area at the skin prick test and a decrease in latex specific IgE while no significant changes of latex IgG4 values were found. Moreover a reduction of symptoms and scores at the provocation tests were remarked.

CONCLUSIONS

Although the primary prevention (which still remains the gold standard treatment for patients suffering from the latex allergy) sublingual immunotherapy can be offered with efficacy in addition to symptomatic treatment to selected patients.

Occupational Latex Allergy: the Current State of Affairs

PURPOSE OF REVIEW

Allergy to natural rubber latex (NRL) reached epidemic proportions during the nineties and led to intense preventive efforts. The aim of this review was to provide a comprehensive compilation of the current status of occupational NRL allergy.

RECENT FINDINGS

Recent advances led to the characterization of 15 NRL allergens and the development of assays for measuring the allergen content of NRL materials and specific IgE antibodies against NRL allergen components. Preventive measures aimed at reducing workplace exposure to NRL allergens were associated with decreasing incidence rates of NRL allergy. However, a pooled analysis of epidemiological surveys published during the last 10 years provided prevalence estimates of NRL sensitization and allergy similar to those derived from studies conducted before 2003. Substantial progress has been made in the understanding and prevention of NRL allergy, although the disease may still remain a worldwide cause of concern.

Surgery-Related Contact Dermatitis: A Review of Potential Irritants and Allergens

Surgical procedures utilize an increasing number of medical products including antiseptics, anesthetics, gloves, suture materials, tissue adhesives, topical antibiotics, and bandages. Many of these products have irritant potential. Allergic contact dermatitis has also been reported. This review covers preoperative, operative, and postoperative exposures that may result in contact dermatitis. Testing with standard patch panels such as T.R.U.E. Test and the North American Contact Dermatitis Group 65 allergen series does not evaluate for all relevant contactants. A thorough understanding of potential exposures is vital to effectively evaluate a patient with surgery-related contact dermatitis. A systematic approach is needed to ensure that standard patch panels and supplementary patches adequately address each encountered contactant.

[Latex allergy in a paediatric hospital. Characteristics and risk factors]

INTRODUCTION

The prevalence of latex sensitisation varies according to the population studied. There are various risk factors that increase latex sensitisation, such as genetic risk, atopy, and multiple surgeries.

OBJECTIVE

To characterise patients referred to an Immunology Unit with suspected latex allergy, and to analyse their clinical features and risk factors.

PATIENTS AND METHOD

A retrospective, descriptive study was conducted on children suspected of latex allergy. Their medical records were reviewed in order to assess symptoms with contact or exposure to latex materials. Known risk factors to latex sensitisation, such as pathologies requiring repeated surgery (spina bifida, myelomeningocele, scoliosis and nephro-urological alterations), atopy (rhinitis, asthma, atopic dermatitis) were investigated. A prick test and/or specific IgE to latex were also performed. A multivariate logistic regression model was performed to find associations between symptoms triggered by exposure to latex with underlying diseases and other risk conditions.

RESULTS

A total of 106 patients were enrolled in the study, of whom 50 were evaluable. At diagnosis 96% of patients were older than five years. Most of the risk factors described were observable in these patients, such as multiple surgeries, neurological and nephro-urological malformations, surgery before one year-old, and repeated bladder catheterisation. After latex exposure, mucous cutaneous manifestations were the most common (52%), followed by respiratory symptoms (36%). All patients were sensitised and allergic to latex.

CONCLUSION

Latex allergy is a significant problem in children with risk factors. The results shown in this study raise important challenges for preventive measures and awareness.

Latex sensitization and risk factors in female nurses in Thai governmental hospitals

OBJECTIVES

Exposure to latex allergens in latex gloves can cause occupational health problems in nurses, yet latex gloves are still widely used in Thai hospitals. Therefore, we conducted a study to determine the prevalence of latex sensitization in nurses and identify risk factors associated with sensitization.

MATERIALS AND METHODS

A questionnaire, providing information on personal characteristics, ill-health, working conditions and symptoms related to latex product use, was administered to 363 female nurses working in two tertiary hospitals in southern Thailand. Latex sensitization was confirmed using a solid phase immunoassay to detect anti-latex IgE antibodies. Total glove protein levels were determined by using a modified Lowry method and latex aeroallergens by a competitive inhibition immunoassay.

RESULTS

The overall prevalence of latex sensitization was 4.4%. Respiratory symptoms related to latex glove use were significantly associated with latex sensitization (OR = 5.5, 95% CI: 1.57-19). Total glove protein levels ranged 87.8-250.8 μg protein/dm(2). The prevalence of latex sensitization was higher (6.6% vs. 2.2%) in the hospital where gloves with higher protein levels (82-438 μg/g vs. 86-170 μg/g) were used. Furthermore, latex sensitization prevalence increased from 3% to 5% with increased average departmental aeroallergen concentrations.

CONCLUSIONS

Latex sensitization prevalence in Thai nurses was higher than previously reported. Respiratory exposure seems to play an important role, in addition to dermal exposure. If latex gloves cannot be replaced by non-latex alternatives, replacement with gloves with lower protein content should be considered.

Latex hypersensitivity among allergic Egyptian children: relation to parental/self reports

BACKGROUND

Latex allergy is one of the major health concerns and allergic reactions to latex may be serious and fatal.

PURPOSE

In this study, we sought to determine the frequency of latex hypersensitivity in a group of allergic Egyptian infants and children and its relation to the history provided by the patients or caregivers.

METHODS

We consecutively enrolled 400 patients with physician diagnosed allergic diseases. The study measurements included clinical evaluation for the site and duration of allergy, history suggestive of latex allergy, family history of allergy, and skin prick testing (SPT) using a commercial latex extract.

RESULTS

The study revealed that 16/400 (4%) patients had positive SPT; 11 of them only had positive history of sensitivity to latex. Positive latex SPT was reported in 3.4% (11/326) of patients with bronchial asthma, 5.9% (7/118) of patients with skin allergy, and 4.5% (2/44) of patients with allergic rhinitis. SPT was positive in 7.4% (4/54) of patients with concomitant respiratory and skin allergy. Latex SPT was more specific than sensitive (97.69% and 77.77%, resp.) with a negative predictive value of 99.47%.

CONCLUSION

Although underrecognized, latex is an important allergen in the pediatric age group with a sensitization frequency of 4% among allergic children. It was observed to be especially associated with multiple allergic diseases coexisting in the same patient. Pediatric allergologists should educate their patients on latex allergy and encourage the use of latex-free products.

Immunological treatments for occupational allergy

Although avoidance of occupational triggers remains the primary step in the management of work-related allergies, immunological treatments (including biological agents and specific immunotherapy) can be regarded as potential therapeutic options for IgE-mediated diseases; for example, many studies with allergen-specific immunotherapy have been carried out on latex allergy, showing overall favorable results, at least with sublingual immunotherapy. On the other hand, only few case reports have suggested the efficacy of immunotherapy in baker's asthma as well as in laboratory animal-induced asthma. The new technologies, including component-resolved diagnosis and recombinant allergens, are expected to improve the quality and efficacy of specific immunotherapy in the future. Also the use of omalizumab may represent a suitable therapeutic choice in very selected cases of occupational allergy, as well as an approach to reduce side effects of venom immunotherapy in subjects with previous severe reactions to the treatment.

Ten years incidence of natural rubber latex sensitization and symptoms in a prospective cohort of health care workers using non-powdered latex gloves 2000-2009

OBJECTIVES

To assess the incidence of sensitization and gloves-related symptoms in 10-year follow-up in a group of health care workers (9,660 person-years) using non-powdered latex gloves from 2000 to 2009 and to examine related factors.

MATERIALS AND METHODS

We studied 2,053 health care workers in Trieste Hospitals by means of skin prick test for latex extract, patch tests and medical examinations. We report the incidence of latex sensitization among workers using non-powdered latex gloves.

RESULTS

The incidence of latex sensitization, rhinitis, asthma, urticaria, irritant and allergic contact dermatitis were 1.0; 0.12; 0.21; 0.72; 2.39 and 2.50 cases per 1,000 person-years, respectively. Respiratory symptoms and urticaria were positively related with latex sensitization (OR = 8.0; 95 % CL 1.27-48.6), with common allergic respiratory symptoms (OR = 4.19; 95 % CL 1.04-16.8) and with familial atopy (OR = 4.47; 95 % CL 1.1-17.9).

CONCLUSION

The incidence of latex sensitization and latex-related symptoms were very low but subjects with allergic symptoms related to common allergens are at higher risk. The use of non-latex gloves is suggested for them.

Omalizumab beyond asthma

INTRODUCTION

Omalizumab has been demonstrated to be a successful therapy in the management of asthma through reduction of patient's symptoms and use of inhaled corticosteroids. The effect of omalizumab is achieved by immunoglobulin E (IgE) blockage and other secondary mechanisms resulting from this blockage. Because other diseases have an important IgE mediation in their physiopathology, the question arises as to if omalizumab would be useful in the treatment of other IgE-mediated diseases.

OBJECTIVE

We present an overview of the experimental studies and clinical reports evaluating the use of omalizumab in diseases different to asthma including atopic dermatitis, urticaria, eosinophilic gastrointestinal disorders, idiopathic anaphylaxis, latex allergy, hymenoptera venom allergy, and other IgE diseases.

METHODS

We reviewed the literature using PUBMED, EMBASE, and LILACS for publications which used omalizumab in the treatment of patients with allergic diseases or any other diseases. Complete articles published in English, Spanish or Portuguese were included.

CONCLUSION

There is not enough evidence to support the regular use of omalizumab in IgE diseases other than asthma. However, some experimental and clinical investigations indicate that omalizumab could be a therapeutic option in several allergic diseases like atopic dermatitis, urticaria, and eosinophilic gastrointestinal disorders. More control studies are needed in each IgE disease to evaluate the efficacy and safety of omalizumab in IgE mediated diseases.

Latex immunotherapy: state of the art

OBJECTIVE

Latex allergy remains a significant problem, especially among certain professional categories, and specific immunotherapy has been suggested as a suitable therapeutic option. The objective of the this article is to review the available literature on clinical trials of specific immunotherapy in latex allergy.

DATA SOURCES

Literature databases (PubMed, Embase, Google Scholar) were searched for latex immunotherapy clinical trials.

STUDY SELECTIONS

Clinical trials (either open or randomized controlled) using subcutaneous or sublingual immunotherapy with latex extracts were selected. Only articles published in English in peer-reviewed journals were considered. Case reports quoted in the clinical trials were also described, when pertinent.

RESULTS

Eleven clinical trials (3 with subcutaneous and 8 with sublingual immunotherapy) were identified. Two of the 3 randomized trials of subcutaneous immunotherapy reported some benefit in adults but a remarkable occurrence of side effects. Concerning sublingual immunotherapy (SLIT), there were 6 randomized placebo-controlled (1 in children), 1 randomized open, and 1 open trials. All but 1 trial reported positive results, and the safety profile was overall superior to injection immunotherapy. The overall quality of the study was moderate, and the number of subjects studied was low.

CONCLUSION

Although guidelines do not consider allergy to latex as an accepted indication to desensitization, SLIT can be offered, in addition to symptomatic treatment, to selected patients, when avoidance measures are not feasible or effective.

The clinical meaning of positive latex sIgE in patients with food/pollen adverse reactions

Natural rubber latex allergy (NRL-A) is an international problem of public health. About 50-60% of NRL-A patients may present adverse reactions after ingestion of cross-reacting vegetable foods. This condition, called "Latex-fruit Syndrome", is a matter of research. The aim of our study is to distinguish between clinical/subclinical latex-fruit syndrome and cross-sensitization to latex and food/pollen allergens on the basis of latex recombinant allergens. We studied 51 patients with food hypersensitivity and serological evidence of NRL sensitization. The subjects underwent an accurate allergological evaluation (skin prick test with latex, food and pollen extracts, specific IgE to latex and recombinant allergens, challenge provocation tests). The patients were divided in two groups: group A) 34 patients with clinical and serological latex and fruit/vegetable allergies; group B) 17 patients allergic to fruits/vegetables and/or pollens, with serological, but not clinical NRL-A. All the latex challenge tests resulted positive in group A patients and only two patients of group B presented positive cutaneous challenge tests. Moreover, specific IgE-antibodies were detected to rHev b 5, to rHev b 6.01, to rHev b 6.02 and to rHev b 8 (and other profilins) of group A patients, while in group B we observed a monosensitization to Hev b8, probably linked to a cross-sensitization to pollens and foods. At the present state of knowledge, we need a multi-parametric approach based on a combination of clinical history, diagnostic tests (CRD) and latex challenge tests to make diagnosis of latex-fruit syndrome.

Randomized, double-blind, placebo-controlled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

BACKGROUND

Natural rubber latex allergy is a common and unsolved health problem. Since the avoidance of exposure is very difficult, immunotherapy is strongly recommended, but before its use in patients, it is essential to prove the efficacy and safety of extracts.The aim of the present randomised, double-blind, placebo-controlled clinical trial was to assess the efficacy and tolerability of latex sublingual immunotherapy in adult patients undergoing permanent latex avoidance.

METHODS

Twenty-eight adult latex-allergic patients (5 males and 23 females), with mean age of 39 years (range 24-57) were randomized to receive a commercial latex-sublingual immunotherapy or placebo during one year, followed by another year of open, active therapy. The following outcomes were measured at baseline and at the end of first and second year of follow-up: skin prick test, gloves-use score, conjunctival challenge test, total and specific IgE, basophil activation test, and adverse reactions monitoring.

RESULTS

No significant difference in any of the efficacy in vivo variables was observed between active and placebo groups at the end of the placebo-controlled phase, nor when each group was compared with their baseline values at the end of the two year-study. An improvement in the average percentage of basophils activated was observed. During the induction phase, 4 reactions in the active group and 5 in the placebo group were recorded. During the maintenance phase, two patients dropped out due to pruritus and to acute dermatitis respectively.

CONCLUSION

Further studies are needed to evaluate latex-sublingual immunotherapy, since efficacy could not be demonstrated in adult patients with avoidance of the allergen.

TRIAL REGISTRATION NUMBER

ACTRN12611000543987.

Latex medical gloves: time for a reappraisal

Many hospitals have implemented policies to restrict or ban the use of devices made of natural rubber latex (NRL) in healthcare as precautionary measures against the perceived risk of NRL allergy. Changes in glove technology, progress in measuring the specific allergenic potential of gloves and a dramatic decrease in the prevalence of NRL allergies after interventions and education prompted us to revisit the basis for justifiable glove selection policies. The published Anglophone literature from 1990 to 2010 was reviewed for original articles and reviews dealing with the barrier and performance properties of NRL and synthetic gloves and the role of glove powder. The review shows that NRL medical gloves, when compared with synthetic gloves, tend to be stronger, more flexible and better accepted by clinicians. The introduction of powder-free gloves has been associated with reductions in protein content and associated allergies. Recently, new methods to quantify clinically relevant NRL allergens have enabled the identification of gloves with low allergenic potential. The use of low-protein, low-allergenic, powder-free gloves is associated with a significant decrease in the prevalence of type I allergic reactions to NRL among healthcare workers. Given the excellent barrier properties and operating characteristics, dramatically reduced incidences of allergic reactions, availability of specific tests for selection of low-allergen gloves, competitive costs and low environmental impact, the use of NRL gloves within the hospital environment warrants reappraisal.

Latex-allergic patients sensitized to the major allergen hevein and hevein-like domains of class I chitinases show no increased frequency of latex-associated plant food allergy

Allergies to certain fruits such as banana, avocado, chestnut and kiwi are described in 30–70% of latex-allergic patients. This association is attributed to the cross-reactivity between the major latex allergen hevein and hevein-like domains (HLDs) from fruit class I chitinases. We aimed to assess the extent of cross-reactivity between hevein and HLDs using sera from latex-allergic patients with and without plant food allergy. Hevein and HLDs of latex, banana, and avocado chitinases were expressed in Escherichia coli as fusion proteins with the maltose-binding protein and purified by affinity chromatography. IgE binding to these proteins was studied in sera from 59 latex-allergic patients and 20 banana-allergic patients without latex allergy by ELISA and ELISA inhibition. Additionally, 16,408 allergic patients’ sera were tested for IgE binding to hevein, latex chitinase, and wheat germ agglutinin using an allergen microarray. Hevein-specific IgE was detected in 34/59 (58%) latex-allergic patients’ sera. HLDs of latex, banana, and avocado chitinases were recognized by 21 (36%), 20 (34%), and 9 (15%) sera, respectively. In contrast, only one of 20 banana-allergic patients without latex allergy was sensitized to chitinase HLDs. In most tested latex-allergic patients’ sera, IgE binding to hevein was only partially reduced by preincubation with HLDs. Among hevein-sensitized, latex-allergic patients, the percentage of plant food allergy (15/34 = 44%) was equal to latex-allergic patients without hevein sensitization (11/25 = 44%). In the general allergic population, 230 of 16,408 sera (1.4%) reacted to hevein and/or a hevein-like allergen. Of these, 128 sera showed an isolated sensitization to hevein, whereas only 17 bound to latex chitinase or wheat germ agglutinin without hevein sensitization. In conclusion, the IgE response to HLDs is elicited by hevein as sensitizing allergen in most cases. Despite considerable cross-reactivity between these allergens, no correlation between latex-associated plant food allergy and sensitization to hevein or HLDs was found.

Perioperative anaphylaxis

The incidence of immune-mediated anaphylaxis during anesthesia ranges from 1 in 10,000 to 1 in 20,000. Neuromuscular blocking agents are most frequently incriminated, followed by latex and antibiotics, although any drug or substance used may be a culprit. Diagnosis relies on tryptase measurements at the time of the reaction and skin tests, specific immunoglobulin E, or basophil activation assays. Treatment consists of rapid volume expansion and epinephrine administration titrated to symptom severity.

Latex sublingual immunotherapy: can its safety be predicted?

BACKGROUND

Complete avoidance sometimes cannot be possible in latex-allergic health care workers. So far, very few double-blind placebo-controlled studies revealed the efficacy of sublingual latex immunotherapy (SLIT) in those patients.

OBJECTIVE

Our aim was to evaluate the efficacy and safety of latex SLIT in health care workers.

METHODS

30 patients (all health care workers) diagnosed as latex allergic were advised to avoid latex exposure and were given information about the prevention measures and asked to return two months later. 24 patients who were still symptomatic despite prevention measures were informed about the latex SLIT study and asked to participate. However, only 12 gave approval and were randomized to receive sublingual latex extract or placebo. Symptom scores and latex cutaneous provocation test scores were recorded at baseline and at the 6th and 12th months of the study.

RESULTS

Two patients experienced anaphylaxis, 1 patient showed severe bronchial obstruction during dose incremental phase and were excluded from the study. The differences of the symptom and provocation scores between baseline and the 12th month of the treatment were significant in the active group (p = .042, p = .038, respectively). Also the symptom and provocation scores at 12 months were significantly lower in the active group than in the placebo group (p = .035, p = .013, respectively).

CONCLUSION

Latex SLIT can be used as an effective treatment for latex-allergic health care patients having difficulties in applying adequate avoidance measures. However, the risk of systemic reactions should be kept in mind and sufficient precaution measures must be made available.

Characterization of a cashew allergen, 11S globulin (Ana o 2), conformational epitope

Both linear and conformational epitopes likely contribute to the allergenicity of tree nut allergens, yet, due largely to technical issues, few conformational epitopes have been characterized. Using the well studied recombinant cashew allergen, Ana o 2, an 11S globulin or legumin, we identified a murine monoclonal antibody which recognizes a conformational epitope and competes with patient IgE Ana o 2-reactive antibodies. This epitope is expressed on the large subunit of Ana o 2, but only when associated with an 11S globulin small subunit. Both Ana o 2 and the homologous soybean Gly m 6 small subunits can foster epitope expression, even when the natural N-terminal to C-terminal subunit order is reversed in chimeric molecules. The epitope, which is also expressed on native Ana o 2, is readily susceptible to destruction by physical and chemical denaturants.

Use of a latex biomembrane for bladder augmentation in a rabbit model: biocompatibility, clinical and histological outcomes

PURPOSE

To investigate histological features and biocompatibility of a latex biomembrane for bladder augmentation using a rabbit model.

MATERIAL AND METHODS

After a partial cystectomy, a patch of a non-vulcanized latex biomembrane (2x4 cm) was sewn to the bladder with 5/0 monofilament polydioxanone sulfate in a watertight manner. Groups of 5 animals were sacrificed at 15, 45 and 90 days after surgery and the bladder was removed. The 5-mum preparations obtained from grafted area and normal bladder were stained with hematoxylin-eosin. Immunohistochemical staining was performed with a primary antibody against alpha-actin to assess muscle regeneration.

RESULTS

No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. Macroscopically, after 90 days, the latex biomembrane was not identifiable and the patch was indistinguishable from normal bladder. A bladder stone was found in one animal (6.6%). On the 90th day, histology revealed continuity of transitional epithelium of host bladder tissue on the patch area. At this time, the muscle layers were well organized in a similar fashion to native bladder muscle layers. The inflammatory process was higher on grafted areas when compared to controls: 15 days--p < 0.0001, 45 days--p < 0.001, and 90 days--p < 0.01. The anti alpha-actin immunoexpression peaked at 45 days, when the graft was observed covered by muscle cells.

CONCLUSION

The latex biomembrane is biocompatible and can be used in models for bladder augmentation in rabbits. It promotes epithelium and muscle regeneration without urinary leakage.

Allergen-related approaches to immunotherapy

Allergic diseases, including asthma, rhinitis and eczema, represent a major health burden worldwide. Mainstay treatments are allergen avoidance where feasible and pharmacotherapy for symptom relief. For selected patients, allergen-specific immunotherapy (SIT) offers the prospect of long lasting clinical efficacy. SIT involves the administration of allergen extract using a standardized regimen, usually subcutaneously or increasingly sublingually. However, application of this potentially curative treatment is restricted, largely due to the risk of serious adverse events, especially in asthmatics and for potent allergens such as peanut, seafood and latex. New insights into immunological mechanisms underlying effective SIT and molecular characterization of allergens and their recognition by the immune system suggest strategies for refinement of SIT. Selective targeting of allergen-specific T cells, especially regulatory T cells, is likely to be pivotal for efficacy. Recombinant allergens lacking IgE reactivity and small T cell epitope-based peptides are being trialled clinically with evidence of efficacy without serious IgE-mediated adverse reactions. Adjuvants, either co-administered or incorporated into a recombinant allergen vaccine to target tolerogenic dendritic cells may also increase efficacy. The safer sublingual route of allergen administration is attracting interest and different allergen forms may be optimal for inducing tolerance by this route. Defined allergen-derived molecules or peptides offer ease of standardization and, coupled with appropriate targeting of immunoregulatory mechanisms, will result in more widespread clinical use of SIT. Adjunct therapies such as anti-IgE antibody and corticosteroids may minimize the likelihood of adverse reactions in those with severe allergic disease who would most benefit from this treatment.