Anafilaxia a alfa-gal: um relato de caso paraibano / Alpha-gal anaphylaxis: a case report from Paraíba, Brazil

O presente relato apresenta um caso de anafilaxia tardia ao carboidrato alfa-gal em um adolescente da cidade de Belém, na Paraíba, Brasil. O paciente desenvolveu reação tardia à ingesta de carne e vísceras de animais. Ele mora em fazenda e tem contato próximo com animais potencialmente contaminados por carrapatos. Essa causa de reação alérgica é nova, e estudos começaram a atribuí-la a casos antes ditos idiopáticos. A anafilaxia é uma reação potencialmente fatal, que deve ser prontamente diagnosticada e tratada. Sendo assim, a descoberta de seu fator desencadeante é um dos principais itens que direcionam o tratamento. No Brasil, nenhum caso de anafilaxia por alfa-gal foi antes descrito na literatura local.

This report presents a case of late anaphylaxis to alpha-gal carbohydrate in a teenager living in the city of Belém, Paraíba, Brazil. The patient developed a late reaction to eating meat and offal of animals; he lives on a farm and has close contact with animals potentially contaminated by ticks. This cause of allergic reaction is new, and studies have started to attribute it to cases previously said to be idiopathic. Anaphylaxis is a potentially fatal reaction that must be promptly diagnosed and treated. Thus, the discovery of its triggering factor is one of the main items that guide treatment. In Brazil, no case of alpha-gal anaphylaxis had been described in the local literature.

A novel Australian tick Ixodes (Endopalpiger) australiensis inducing mammalian meat allergy after tick bite

Tick-induced mammalian meat allergy has become an emergent allergy world-wide after van Nunen et al. first described the association between tick bites and the development of mammalian meat allergy in 2007. Cases of mammalian meat allergy have now been reported on all 6 continents where humans are bitten by ticks, in 17 countries

Tick-induced allergies: mammalian meat allergy, tick anaphylaxis and their significance

Serious tick-induced allergies comprise mammalian meat allergy following tick bites and tick anaphylaxis. Mammalian meat allergy is an emergent allergy, increasingly prevalent in tick-endemic areas of Australia and the United States, occurring worldwide where ticks are endemic. Sensitisation to galactose-α-1,3-galactose (α-Gal) has been shown to be the mechanism of allergic reaction in mammalian meat allergy following tick bite. Whilst other carbohydrate allergens have been identified, this allergen is unique amongst carbohydrate food allergens in provoking anaphylaxis. Treatment of mammalian meat anaphylaxis involves avoidance of mammalian meat and mammalian derived products in those who also react to gelatine and mammalian milks. Before initiating treatment with certain therapeutic agents (e.g., cetuximab, gelatine-containing substances), a careful assessment of the risk of anaphylaxis, including serological analysis for α-Gal specific-IgE, should be undertaken in any individual who works, lives, volunteers or recreates in a tick endemic area. Prevention of tick bites may ameliorate mammalian meat allergy. Tick anaphylaxis is rare in countries other than Australia. Tick anaphylaxis is secondarily preventable by prevention and appropriate management of tick bites. Analysis of tick removal techniques in tick anaphylaxis sufferers offers insights into primary prevention of both tick and mammalian meat anaphylaxis. Recognition of the association between mammalian meat allergy and tick bites has established a novel cause and effect relationship between an environmental exposure and subsequent development of a food allergy, directing us towards examining environmental exposures as provoking factors pivotal to the development of other food allergies and refocusing our attention upon causation of allergy in general.

Histologic Characteristics and Mechanical Properties of Bovine Pericardium Treated with Decellularization and alpha-Galactosidase: A Comparative Study

BACKGROUND: Bioprostheses for cardiovascular surgery have limitations in their use following as calicification. alpha-galactosidase epitope is known as a stimulant of immune response and then shows a progressing calcification. The objective of this study was to evaluate histologic characteristics and mechanical properties of decellularization and treated with alpha-galactosidase. MATERIALS AND METHODS: Bovine pericardial tissues were allocated into three groups: fixation only with glutaraldehyde, decellularization with sodium dodesyl sulfate and decellularization plus treatment with alpha-galactosidase. We confirmed immunohistological characteristics and mechanical properties as fatigue test, permeability test, compliance test, tensile strength (strain) test and thermal stability test. RESULTS: Decellularization and elimination of alpha-gal were confirmed through immunohistologic findings. Decellularization had decreased mechanical properties compared to fixation only group in permeability (before fatigue test p=0.02, after fatigue test p=0.034), compliance (after fatigue test p=0.041), and tensile strength test (p=0.00). The group of decellularization plus treatment with alpha-galactosidase had less desirable mechanical properties than the group of decellularization in concerns of permeability (before fatigue test p=0.043) and strain test (p=0.001). CONCLUSION: Favorable decellularization and elimination of alpha-gal were obtained in this study through immunohistologic findings. However, those treatment including decellularization and elimination of alpha-gal implied the decreased mechanical properties in specific ways. We need more study to complete appropriate ioprosthesis with decellularization and elimination of alpha-gal including favorable mechanical properties too.

The Characteristics of Porcine Cornea as a Xenograft

PURPOSE: To investigate the feasibility, in terms of both physical and immunological aspects, of using porcine cornea as a xenograft in humans. METHODS: Corneal diameter, thickness and axial length were compared in 30 porcine and human control eyes. The histological characteristics and the distribution of the xenonatural antibody were also evaluated. In addition, changes in antigenecity were investigated by cultivating individual corneal cells. RESULTS: The mean values of the porcine corneal diameter (14.2+/-0.3 mm) and the thickness (867.2+/-23.8 mm) were larger than those of human, but, on the contrary, the axial length (20.2+/-0.74 mm) and the refractive power (40.4+/-0.9D) were not. The lymphocytes existed in the normal porcine limbus, and the distribution of alpha-gal was confined. However, in the cell culture, the expression of alpha-gal was prominent in both stromal (39.0+/-28.4%) and endothelial cells (87.1+/-4.4%) at the second passage. The expression of class II major histocompatibility antigen was comparable to that of human. CONCLUSIONS: Physical, optical, histological, and immunological characteristics suggest the possibility of using porcine cornea as a xenograft in humans.