IgE antibodies against bovine serum albumin in a case of eosinophilic gastroenteritis

[Update on meat allergy. α-Gal: a new epitope, a new entity?]

The association between the carbohydrate galactose-[alpha]-1,3-galactose (α-Gal) and anaphylaxis was first documented after severe hypersensitivity reactions to cetuximab, a chimeric mouse-human IgG1 monoclonal antibody approved for targeted therapy of carcinomas of colon, as well as of the head and neck region. α-Gal is a ubiquitous glycan moiety expressed on cells and tissue of non-primate mammals. Since this epitope is not expressed in humans, it is very immunogenic for them. α-Gal is located on the Fab portion of cetuximab and thus on the murine part of the chimera. The anaphylactic reactions to the antibody were mediated by IgE specific for α-Gal. Anti-α-Gal-IgE were first detected in sera of patients from the southeastern U.S. and reacted with a wide range of mammalian allergens. The geographic distribution prompted investigations of sensitization routes apart from the ingestion of red meat, such as tick bites und parasitic infections. Anti-α-Gal-IgE seems to be of clinical relevance for allergy to red meat and for the pork-cat syndrome. It is also associated with a novel form of delayed anaphylaxis, which appears more than 3 hours following the ingestion of red meat (beef, pork and lamb), a phenomenon which is still to be elucidated. For most of these patients conventional skin prick tests with commercial reagents proved insufficient for diagnosis.

Delayed anaphylaxis, angioedema, or urticaria after consumption of red meat in patients with IgE antibodies specific for galactose-alpha-1,3-galactose

BACKGROUND

Carbohydrate moieties are frequently encountered in food and can elicit IgE responses, the clinical significance of which has been unclear. Recent work, however, has shown that IgE antibodies to galactose-alpha-1,3-galactose (alpha-gal), a carbohydrate commonly expressed on nonprimate mammalian proteins, are capable of eliciting serious, even fatal, reactions.

OBJECTIVE

We sought to determine whether IgE antibodies to alpha-gal are present in sera from patients who report anaphylaxis or urticaria after eating beef, pork, or lamb.

METHODS

Detailed histories were taken from patients presenting to the University of Virginia Allergy Clinic. Skin prick tests (SPTs), intradermal skin tests, and serum IgE antibody analysis were performed for common indoor, outdoor, and food allergens.

RESULTS

Twenty-four patients with IgE antibodies to alpha-gal were identified. These patients described a similar history of anaphylaxis or urticaria 3 to 6 hours after the ingestion of meat and reported fewer or no episodes when following an avoidance diet. SPTs to mammalian meat produced wheals of usually less than 4 mm, whereas intradermal or fresh-food SPTs provided larger and more consistent wheal responses. CAP-RAST testing revealed specific IgE antibodies to beef, pork, lamb, cow's milk, cat, and dog but not turkey, chicken, or fish. Absorption experiments indicated that this pattern of sensitivity was explained by an IgE antibody specific for alpha-gal.

CONCLUSION

We report a novel and severe food allergy related to IgE antibodies to the carbohydrate epitope alpha-gal. These patients experience delayed symptoms of anaphylaxis, angioedema, or urticaria associated with eating beef, pork, or lamb.

Bovine serum albumin contained in culture medium used in artificial insemination is an important anaphylaxis risk factor

OBJECTIVE

To analyze the cause of the anaphylactic reaction after a standard artificial insemination process in a patient diagnosed with asthma.

DESIGN

Case report.

SETTING

Residencia Sanitaria Virgen de la Arrixaca (Murcia, Spain) and University of the Basque Country (Vitoria, Spain).

PATIENT(S)

A 30-year-old woman with a previous medical history compatible with respiratory allergy who suffered an anaphylactic reaction after an artificial insemination with spermatozoids in capable medium (Upgraded B2 INRA medium; Laboratories CCD, Paris, France).

INTERVENTION(S)

Cutaneous tests and specific IgE levels to inhalant allergens, grass and Olea pollens, and insemination medium were performed.

MAIN OUTCOME MEASURE(S)

Specific IgE levels to mammal epithelia and bovine serum albumin (BSA).

RESULT(S)

Skin prick tests were positive for inhalant allergens such as mites, cat, dog, horse, and rabbit epithelia, grasses and Olea pollens, and the insemination medium. The beta-lactamic tests were negative. The determination of specific IgE demonstrated positive values to mammal epithelia and mammal serum albumins including BSA.

CONCLUSION(S)

We report a case of an anaphylactic reaction to the BSA included in the insemination culture medium induced by a subclinical sensitivity to serum albumins of mammal epithelia. A previous testing with the medium is recommended and specific testing might be needed in women who have a history of animal epithelium allergies.

[Distinct clinical presentations of a single medical entity: eosinophilic enteritis]

Eosinophilic enteritis is a rare disease characterized by eosinophilic infiltration of different wall layers of the gastrointestinal tract, from the esophagus to the rectum, by eosinophilic cells. The most frequently affected structures are the stomach and small intestine. The pathogenesis of eosinophilic enteritis is not well understood and is often related to a personal or familial history of atopy. Clinical symptoms depend on the affected layers. Thus malabsorptive syndrome, intestinal strictures or ascites depend on a mucosal, muscular or serosa layer infiltration, respectively. We present three cases of eosinophilic gastroenteritis with distinct clinical presentations.

Gastrointestinal allergy in adults

The prevalence of food allergy reaches 3% in the adult population. Chronic gastrointestinal allergy is a rare entity: 4.2% of food allergies in adults, and represents 3.2% of all intestinal disorders. Non-specific symptoms are the rule but eosinophilic gastrointestinal disorders are the subject of much interest. Endoscopy and biopsies of the gastrointestinal tract help the differential diagnoses. Food allergy is suspected from the patient's history leading to skin tests and laboratory tests identifying a sensitization but allergy is only confirmed by standardized challenges or eviction diets over a sufficiently long period. New types of investigations coupling oral challenges to foods to gastroenterological techniques should be studied further.

Isolation and characterization of a heat-resistant beef allergen: myoglobin

BACKGROUND

Meat allergy is rarely reported. Most of the described cases are sensitizations to bovine serum albumin.

OBJECTIVE

The aim of the study was to describe a case of allergy to a new meat allergen and, after its characterization.

METHODS

A 35-year-old nonatopic female with allergic episodes after ingestion of several types of meat was studied. Skin tests (prick and prick-to-prick); total and specific immunoglobulin E (IgE) determination; sodium dodecyl sulphate-polyacrylamide gel electrophoresis and specific IgE determination by immunoblotting under different conditions were performed. A 17-kDa allergen was semipurified by ethanol fractionation and its amino-terminal sequence was determined. The existence of specific IgE directed to this protein was studied by immunoblot in 80 atopic patients.

RESULTS

The patient showed specific IgE antibodies to a 17-kDa protein. During the isolation of this allergen it was found that a 70-90% (vol/vol) ethanol concentration was able to purify the protein. The characterization revealed that it was a heat-resistant protein without disulfide bonds. N-terminal amino acid sequence (16 residues) showed identity with myoglobin. The study of specific IgE to this allergen among atopic patients showed that it was recognized by about 1% of the subjects.

CONCLUSIONS

We describe a case of meat allergy caused by myoglobin. This is the first described case of monosensitization to this protein.

Eosinophilic Gastroenteritis

There are no evidence-based studies of the treatment of patients with eosinophilic gastroenteritis. Treatment decisions depend on experience gained from observations linking causative entities, principal clinical manifestations, and anticipated natural history of the disease. Because clinical symptoms and organ involvement probably vary with etiology, classification as to the likely cause (eg, food allergy or other dietary intolerance, idiosyncratic drug reaction, occult infection, idiopathic) determines the decisions made about dietary, pharmacologic, and surgical treatment. Elimination of foods and the use of elemental diets, corticosteroids, and mast cell inhibitors (eg, cromolyn sodium, ketotifen), alone or in combination, all have their place, depending on the age of the patient, organ involved, clinical presentation, and clinical urgency. Isolated cases are diagnosed only at surgical exploration for acute abdominal catastrophes; in these instances, further therapy depends on whether resection is done, but most patients remain in remission after surgery. Occult parasitism remains an elusive and unrecognized cause of an unknown number of cases, suggesting that empiric antihelminthic therapy should be tried in some patients. Individual reports of success with nonsystemic steroids and leukotriene inhibitors have been published.

Evaluation of IgE-mediated food hypersensitivities

During the past 25 years the diagnostic assessment of IgE-associated food hypersensitivity has improved substantially. The double-blind placebo-controlled food challenge has become the "gold-standard" against which all other diagnostic approaches can be measured. Having a standard which gives a correct answer almost all of the time, has enabled us to move to more accurate diagnoses in both the clinic and the laboratory. Food allergy has gone from being a medical mystery to being a clear component of allergy evaluation. Histories are obtained from patients which may be used to design food challenges. The role of skin testing and its interpretation has moved from the fringe to having a central role in eliminating foods incriminated as causes of immediate-onset allergic reactions. The material used for skin testing for foods has improved and we have learned when we must use fresh substances to supplement the commercial extracts. Recently the CAP radioallergosorbent test has shown promise in raising the probability of food reactions to the point that for a few foods in specific individuals, challenges may not be needed. Progress in this area will continue. We have been able to clarify which foods have a high probability of producing symptoms and which foods and which constellation of complaints are unlikely to be confirmed. These patterns of food allergic reactions have now been reproduced in many research centers throughout the world giving us confidence in their validity.

Severe anaphylactic reaction to bovine serum albumin at the first attempt of artificial insemination

A 33-year-old woman without history of previous atopic diseases or drug allergies developed a severe anaphylactic reaction with asthma, vomiting, itching, generalized urticaria, and angioedema during artificial insemination with her husband's sperm. The sperm-processing medium contained bovine serum albumin (BSA). Skin prick test and RAST demonstrated an IgE-mediated hypersensitivity to BSA as well as a polyvalent atopic sensitization to pollens, animal danders, cow's milk, beef, pork, and mutton. SDS-PAGE studies indicated serum albumin to be the appropriate allergen with a high degree of cross-reactivity between serum albumin from different animal species. Artificial insemination with fluid containing potential allergens can, therefore, represent an unnecessary risk for atopic females, even in the absence of prior clinical symptoms of allergic diseases. Preoperative testing with the medium is recommended.