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At least 19 recordsLinked to original sources

PubMed2001

Final report on the safety assessment of Peanut (Arachis hypogaea) Oil, Hydrogenated Peanut Oil, Peanut Acid, Peanut Glycerides, and Peanut (Arachis hypogaea) Flour.

Peanut (Arachis Hypogaea) Oil is the refined fixed oil obtained from the seed kernels of Arachis hypogaea. Hydrogenated Peanut Oil, Peanut Acid, and Peanut Glycerides are all derived from Peanut Oil. Peanut Flour is a powder obtained by the grinding of peanuts. The oils and glycerides function in cosmetic formulations as skin-conditioning agents. The acid functions as a surfactant-cleansing agent, and the flour functions as an abrasive, bulking agent and/or viscosity-increasing agent. In 1998, only Peanut Oil and Hydrogenated Peanut Oil were reported in use. When applied to the skin, Peanut Oil can enhance the absorption of other compounds. Hepatic changes were noted at microscopic examination of rats fed diets containing 15% edible Peanut Oil for 28 days, although no control group was maintained and the findings were also noted in rats fed fresh corn oil. United States Pharmacopeia (USP)-grade Peanut Oil was considered relatively nonirritating when injected into guinea pigs and monkeys. Technical-grade Peanut Oil was moderately irritating to rabbits and guinea pigs and mildly irritating to rats following dermal exposure. This same oil produced reactions in < or = 10% of 50 human males. Peanut Oil was not an ocular irritant in rabbits. Peanut Oil, either "laboratory expressed" or extracted using a food-grade solvent, was not carcinogenic to mice. Peanut Oil exerted anticarcinogenic activity when tested against known carcinogens. Peanuts are the food most likely to produce allergic and anaphylactic reactions. The major allergen is a protein that does not partition into Peanut Oil, Hydrogenated Peanut Oil, Peanut Acid, and Peanut Glycerides. Aflatoxins can be produced in stored agricultural crops such as peanuts, but do not partition into the oils, acids, or glycerides. Manufacturers were cautioned to make certain that the oils, acids, and glycerides are free of aflatoxins and protein. Formulators were cautioned that the oils, acids, or glycerides may enhance penetration and can affect the use of other ingredients whose safety assessment was based on their lack of absorption. The available studies on Peanut Oil supported the conclusion that Peanut Oil, Hydrogenated Peanut Oil, Peanut Acid, and Peanut Glycerides are safe for use in cosmetic formulations. Peanut (Arachis Hypogaea) Flour, however, is sufficiently different from the above ingredients such that its safety can not be supported by studies using the oil. The additional data needed for Peanut (Arachis Hypogaea) Flour are (1) concentration of use; (2) chemical specifications (i.e., aflatoxin and protein levels); (3) method of preparation; and (4) contact urticaria and dermal sensitization at concentration of use. Although data on aflatoxin levels are sought, it is expected that concentrations of aflatoxin should comply with U.S. government stipulations. Absent the additional data, it was concluded that the available data are insufficient to support the safety of Peanut (Arachis Hypogaea) Flour for use in cosmetic products.

Administration, Cutaneous↗

PubMed2000

The psychological burden of peanut allergy as perceived by adults with peanut allergy and the parents of peanut-allergic children.

BACKGROUND: Peanut-allergic patients are affected by a condition which forces them and their families to exercise extreme dietary vigilance and experience constant uncertainty throughout their lives. OBJECTIVE: To compare the quality of life and family relations of children and adults with a peanut allergy to that of children and adults with a rheumatological disease. METHODS: Patients with a confirmed diagnosis of peanut allergy or a rheumatological disease completed (for children less than 18 years, by proxy) self-report questionnaires regarding the impact of their condition on their quality of life and family relations. A vertical visual analogue scale and the Impact on Family Questionnaire (IFQ) served as outcome measures. RESULTS: One hundred and fifty-three peanut-allergic children were compared with 69 children with a rheumatological disease while 37 peanut-allergic adults were compared with 42 adults with a rheumatological disease. The parents of peanut-allergic children, compared to the parents of children with a rheumatological disease, reported that their children had significantly more disruption in their daily activities. Furthermore, the parents of peanut-allergic children reported more impairment in the familial-social dimension of the IFQ. Conversely, adults with a chronic rheumatological disease reported more disruption in their family relations than peanut-allergic adults. CONCLUSION: Given the considerable disruption in daily activities and family relations reported by the parents of peanut-allergic children, accurate diagnosis of peanut allergy is essential. Our work should make health care professionals dealing with children with confirmed peanut allergy more aware of the support that these families may require. Furthermore, we hope to motivate food industries to offer more 'peanut free' products to decrease the dietary restrictions of these patients while minimizing their potential for accidental ingestion.

Adolescent↗

PubMed2003

Characterization of lymphocyte responses to peanuts in normal children, peanut-allergic children, and allergic children who acquired tolerance to peanuts.

Comparing lymphocyte responses to allergenic and nonallergenic foods could reveal the differences between pathogenic and normal immune responses to foods. Defining the cytokine-producing phenotypes of peanut-specific lymphocytes from peanut-allergic children, children who outgrew peanut allergy, and children who have always tolerated peanuts may be useful for understanding the mechanisms of food tolerance. Investigating immune responses against foods is hindered, however, by the fact that circulating food antigen-specific lymphocytes are very rare. In a novel approach we used carboxyfluorescein succinimidyl ester to detect peanut-specific lymphocytes by flow cytometry. We confirmed that these cells are indeed peanut specific by cloning. Peanut-allergic donors show Th2 polarization of cytokine production by peanut-specific cells (IFN-gamma (low), TNF-alpha (low), IL-4 (high), IL-5 (high), IL-13 (high)). Conversely, nonallergic children and children who have outgrown their allergy show Th1 skewing to peanut antigens (IFN-gamma(high), TNF-alpha (high), IL-4 (low), IL-5 (low), IL-13(low)), similarly to nonallergenic food antigens (beta-lactoglobulin, OVA). This finding suggests that peanut antigens do not intrinsically induce Th2 skewing, but that the type of response depends upon the donor's allergic status. In conclusion, food allergic status is characterized by a Th2 response whereas Th1-skewed responses underlie oral tolerance.

Adolescent↗

PubMed1999

Exposure to peanuts in utero and in infancy and the development of sensitization to peanut allergens in young children.

This study attempted to determine the underlying factors that may influence the development of peanut sensitization in young children in South Africa. One of our objectives was to ascertain whether the consumption of peanuts or peanut-containing foods during pregnancy and lactation by mothers from atopic families impacted upon the development of an allergic response to peanuts in the child. Forty-three children between the ages of 0 and 3 yr participated in this study. There were 25 peanut-sensitized subjects and 18 control subjects (children sensitized to milk and/or egg, but not to peanuts). A significant association was found between peanut sensitization and sensitivity to soya (p=0.0002), wheat (p=0.03), and cod fish. We found that mothers who consumed peanuts more than once a week during pregnancy were more likely to have a peanut-allergic child than mothers who consumed peanuts less than once a week (odds ratio=3.97, 98% confidence interval 0.73-24). Peanuts or peanut butter was introduced into the child's diet from a significantly younger age in the peanut-allergic subjects (p<0.03). There was a positive correlation in the peanut-allergic subjects between age of introduction of peanuts and age at the onset of symptoms (r=0.63). Exclusive breast feeding did not protect against the development of peanut sensitization. Peanut allergy is associated with an increased risk of sensitization to other foods. It is more likely to occur if mothers eat peanuts more frequently during pregnancy and introduce it early to the infant's diet. These features highlight potentially avoidable factors that might prevent sensitization.

Animals↗

PubMed2000

A murine model of peanut anaphylaxis: T- and B-cell responses to a major peanut allergen mimic human responses.

BACKGROUND: Peanut allergy affects 0.6% of the US population. At the present time, allergen avoidance is the only therapeutic option. Animal models of food-induced anaphylaxis would facilitate attempts to design novel immunotherapeutic strategies for the treatment of peanut allergy. OBJECTIVE: The purpose of this study was to develop a murine model of IgE-mediated peanut hypersensitivity that closely mimics human peanut allergy. METHODS: C3H/HeJ mice sensitized orally with freshly ground whole peanut and cholera toxin as adjuvant were challenged orally 3 and 5 weeks later with crude peanut extract. Anaphylactic reactions were determined. T- and B-cell responses to Ara h 1 and Ara h 2, the major peanut allergens, were characterized by evaluating splenocyte proliferative responses and IgE antibody concentrations. Furthermore, IgE antibodies in the sera of patients with peanut allergy and mice were compared for antibody binding to Ara h 2 isoforms and allergenic epitopes. RESULTS: Peanut-specific IgE was induced by oral peanut sensitization, and hypersensitivity reactions were provoked by feeding peanut to sensitized mice. The symptoms were similar to those seen in human subjects. Ara h 1- and Ara h 2-specific antibodies were present in the sera of mice with peanut allergy. Furthermore, these Ara h 2-specific IgE antibodies bound the same Ara h 2 isoforms and major allergenic epitopes as antibodies in the sera of human subjects with peanut allergy. Splenocytes from mice with peanut allergy exhibited proliferative responses to Ara h 1 and Ara h 2. CONCLUSION: This murine model of peanut allergy mimics the clinical and immunologic characteristics of peanut allergy in human subjects and should be a useful tool for developing immunotherapeutic approaches for the treatment of peanut allergy.

2S Albumins, Plant↗

PubMed2003

Relevance of casual contact with peanut butter in children with peanut allergy.

BACKGROUND: Casual skin contact or inhalation of peanut butter fumes is reported and feared to cause allergic reactions in highly sensitive children with peanut allergy but has not been systematically studied. OBJECTIVE: We sought to determine the clinical relevance of exposure to peanut butter by means of inhalation and skin contact in children with peanut allergy. METHODS: Children with significant peanut allergy (recent peanut-specific IgE antibody concentration >50 kIU/L or evidence of peanut-specific IgE antibody and one of the following: clinical anaphylaxis, a reported inhalation-contact reaction, or positive double-blind, placebo-controlled oral challenge result to peanut) underwent double-blind, placebo-controlled, randomized exposures to peanut butter by means of contact with intact skin (0.2 mL pressed flat for 1 minute) and inhalation (surface area of 6.3 square inches 12 inches from the face for 10 minutes). Placebo challenges were performed by using soy butter mixed with histamine (contact), and scent was masked with soy butter, tuna, and mint (inhalation). RESULTS: Thirty children underwent the challenges (median age, 7.7 years; median peanut IgE level, >100 kIU/L; 13 with prior history of contact and 11 with inhalation reactions). None experienced a systemic or respiratory reaction. Erythema (3 subjects), pruritus without erythema (5 subjects), and wheal-and-flare reactions (2 subjects) developed only at the site of skin contact with peanut butter. From this number of participants, it can be stated with 96% confidence that at least 90% of highly sensitive children with peanut allergy would not experience a systemic-respiratory reaction from casual exposure to peanut butter. CONCLUSIONS: Casual exposure to peanut butter is unlikely to elicit significant allergic reactions. The results cannot be generalized to larger exposures or to contact with peanut in other forms (flour and roasted peanuts).

Administration, Inhalation↗

PubMed1998

Peanut allergic subjects' peripheral blood mononuclear cell proliferative responses to crude peanut protein.

BACKGROUND: Peanut allergy is characterized by a high frequency of severe and occasionally fatal reactions. OBJECTIVE: To determine if there are features of the in vitro cellular response that may account for the observed severity of peanut allergy. METHODS: Skin-prick testing (SPT), RAST assay of serum peanut-specific and total IgE and mixed peripheral blood mononuclear cells (PBMC) proliferative responses to crude peanut protein were measured in 44 peanut allergics with varying severity of clinical reactions. PBMC responses of 13 non-peanut allergic controls (six atopic) were also studied. RESULTS: Subjects' PBMCs proliferated more than controls', even without stimulation. Subjects' PBMC proliferative responses did not correlate with clinical severity, SPT weal size or peanut-specific IgE levels. Controls' PBMCs did not respond to peanut. There was no correlation between PBMC response and time since last reaction to peanut. Subjects' PBMCs responded more than controls, to mitogen as well as allergen. Proliferation increased with increasing concentration of peanut protein (P < 0.0001). CONCLUSION: PBMCs of peanut allergics demonstrate a dose-dependent response to peanut which does not correlate with clinical severity, SPT reaction or levels of peanut specific IgE. The response is antigen-specific. Peanut protein is not mitogenic and is not acting as a superantigen. While there are non-specific differences in the PBMC responses of peanut allergic individuals compared with atopic and non-atopic controls, these differences do not explain the unique severity of peanut allergy.

Adolescent↗

PubMed2002

High-oleic peanuts are not different from normal peanuts in allergenic properties.

High-oleic peanuts are known for a high content of oleic fatty acid. However, it is not known whether high-oleic peanuts are different from normal chemistry peanuts in levels of allergenicity and end-product adducts (i.e., products cross-linked with proteins). For this purpose, four different peanut cultivars (Florunner, Georgia Green, NC 9, and NC 2) were evaluated and compared with high-oleic peanuts (SunOleic 97R). Adducts such as AGE/CML from Maillard reactions and MDA/HNE from lipid oxidation were determined, respectively, in ELISA, using polyclonal antibodies. Allergenicity was determined based on IgE binding and T-cell proliferation. Results showed that raw high-oleic peanuts were not different from normal peanuts in adduct levels. After roasting, CML and HNE levels remained unchanged, but an increased and similar amounts of AGE adducts were found in all peanuts. MDA also increased but not in high-oleic peanuts. This suggests that high-oleic peanuts are more stable to lipid oxidation than others during heating. Despite this, high-oleic peanuts did not differ from normal peanuts in IgE binding and T-cell proliferation. It was concluded that a high content of oleic fatty acid has no effect on peanut allergenicity and that high-oleic peanuts do not give a higher or lower risk of allergy than normal peanuts.

Aldehydes↗

PubMed1997

Treatment of anaphylactic sensitivity to peanuts by immunotherapy with injections of aqueous peanut extract.

BACKGROUND: Immediate hypersensitivity to peanuts is a frequent cause of anaphylactic reactions and deaths in children and adults. Currently, preventive treatment consists of avoidance, which is difficult because of the widespread and often disguised use of peanuts in the food industry. METHODS: Twelve patients with immediate hypersensitivity to ingestion of peanuts were recruited. Half were treated with injections of peanut extract: a maintenance level of tolerance was first achieved by a rush protocol, then maintained with weekly injections for at least 1 year. The other six were untreated control subjects. All patients underwent double-blind, placebo-controlled, oral peanut challenges initially, after approximately 6 weeks, and after 1 year. RESULTS: All treated patients achieved the maintenance dose of 0.5 ml of 1:100 wt/vol peanut extract by the rush injection protocol. All experienced increased tolerance to double-blind, placebo-controlled peanut challenge and decreased sensitivity on titrated skin prick testing with peanut extract, whereas the threshold to oral peanut challenge and cutaneous reactivity to peanut extract were unchanged in the untreated control subjects. Systemic reactions were common in the treated group both during rush immunotherapy and with maintenance injections. Only three patients remained tolerant of the full maintenance dose. The increased tolerance to oral peanut challenge was maintained in the three subjects who received full maintenance doses, but there was partial (n = 2) or complete (n = 1) loss of protection in the patients who required dose reduction because of systemic reactions. CONCLUSIONS: Injections of peanut extract increase the tolerance of patients with peanut allergy to oral ingestion of peanuts. Injections result in repeated systemic reactions in most patients, even during maintenance injections. For clinical application of this method of treatment, a modified peanut extract is needed.

Administration, Oral↗

PubMed2000

The natural history of peanut allergy in young children and its association with serum peanut-specific IgE.

OBJECTIVES: To observe the nature and frequency of adverse reactions caused by accidental peanut exposure in young children with clinical peanut hypersensitivity and to determine the value of serum peanut-specific IgE levels during follow-up. STUDY DESIGN: Eighty-three children with clinical peanut hypersensitivity diagnosed before their fourth birthdays were contacted yearly to track adverse peanut reactions. Serum peanut-specific IgE levels were determined in 51 of 83 subjects. RESULTS: Fifty-eight percent (31/53) of subjects followed up for 5 years experienced adverse reactions from accidental peanut exposure. Regardless of the nature of their initial reaction, the majority with subsequent reactions (52%, 31/60) experienced potentially life-threatening symptoms. The group with isolated skin symptoms (11/51, 22%) had lower serum peanut-specific IgE levels than the group with respiratory and/or gastrointestinal symptoms (40/51, 78%) (median: 1.25 kU(A)/L vs 11. 65 kU(A)/L, P =.004, Wilcoxon rank sums test). Despite this, there was no threshold level below which only skin symptoms appeared to occur. Four selected subjects had negative double-blind placebo-controlled food challenge responses to peanuts during follow-up. CONCLUSIONS: The majority of children with clinical peanut hypersensitivity followed up for 5 years will have adverse reactions from accidental peanut exposure. Symptoms experienced during subsequent adverse peanut reactions may not be consistent with symptoms reported during initial reactions. Therefore proper education regarding peanut avoidance and treatment of adverse reactions is necessary in all cases of clinical peanut hypersensitivity. Young children who are allergic to peanuts can lose clinical hypersensitivity.

Allergens↗

PubMed2003

The predictive value of a positive prick skin test to peanut in atopic, peanut-naïve children.

BACKGROUND: Although allergy testing before food ingestion is generally not recommended, many peanut-naive children undergo prick skin tests (PSTs) to peanut because of atopy. Children with positive PSTs are generally advised to avoid peanuts either indefinitely or until a definitive diagnosis is made through challenge. OBJECTIVE: To describe peanut challenges in atopic, peanut-naive children with PST to peanuts > or = 3 mm and the PST properties in this population. METHODS: Between 1994 and 2001, 47 patients were identified who had a positive peanut PST, no previous peanut ingestion, and had undergone a peanut challenge. RESULTS: Forty-nine percent of the challenges were positive. The mean of the largest wheal diameter (95% confidence interval [CI]) of the PST in children having a negative and positive challenge was 6.3 mm (CI, 5.3 to 7.3) and 10.3 mm (CI, 8.9 to 11.8), respectively. At a PST cutoff of > or = 5 mm, the sensitivity and negative predictive value (95% CI) was 100% (85.2 to 100) and 100% (29.2 to 100), whereas the specificity and positive predictive value (95% CI) was 12.5% (2.7 to 32.4) and 52.3% (36.7 to 67.5), respectively. CONCLUSIONS: We show that 49% of atopic, peanut-naïve children sensitized to peanut developed allergic symptoms during oral provocation with peanut. Although the sensitivity of the PST at > or = 5 mm for the detection of peanut allergy in this study was 100%, our small sample size limits the applicability of this value. Further investigation is needed to determine whether children with wheal diameters of 3 or 4 mm, perhaps coupled with low peanut-specific IgE, could undergo less resource-intensive, accelerated challenges.

Antibody Specificity↗

PubMedDate not supplied

Preparation of peanut butter suspension for determination of peanuts using enzyme-linked immunoassay kits.

Peanuts are one of the 8 most common allergenic foods and a large proportion of peanut-allergic individuals have severe reactions, some to minimal exposure. Specific protein constituents in the peanuts are the cause of the allergic reactions in sensitized individuals who ingest the peanuts. To avoid accidental ingestion of peanut-contaminated food, methods of analysis for the determination of the allergenic proteins in foods are important tools. Such methods could help identify foods inadvertently contaminated with peanuts, thereby reducing the incidence of allergic reactions to peanuts. Commercial immunoassay kits are available but need study for method performance, which requires reference materials for within- and between-laboratory validations. In this study, National Institute of Standards and Technology Standard Reference Material 2387 peanut butter was used. A polytron homogenizer was used to prepare a homogenous aqueous Peanut Butter suspension for the evaluation of method performance of some commercially available immunoassay kits such as Veratox for Peanut Allergen Test (Neogen Corp.), Ridascreen Peanut (R-Biopharm GmbH), and Bio-Kit Peanut Protein Assay Kit (Tepnel). Each gram of the aqueous peanut butter suspension contained 20 mg carboxymethylcellulose sodium salt, 643 microg peanut, 0.5 mg thimerosal, and 2.5 mg bovine serum albumin. The suspension was homogenous, stable, reproducible, and applicable for adding to ice cream, cookies, breakfast cereals, and chocolate for recovery studies at spike levels ranging from 12 to 90 microg/g.

Arachis↗

PubMed1999

Cross-allergenicity of peanut and lupine: the risk of lupine allergy in patients allergic to peanuts.

BACKGROUND: Peanut allergy is common, but cross-allergy between legumes is rare. Proteins from Lupinus albus are increasingly eaten in the form of seeds or additives to wheat flour. The risk of cross-allergenicity is still insufficiently known. OBJECTIVE: We sought to study the risk of cross-allergy to lupine in patients allergic to peanut and to study lupine allergenicity. METHODS: Twenty-four patients allergic to peanuts were studied by means of skin prick tests with native lupine flour from Lupinus albus. Double-blind oral challenge tests were performed with lupine flour and peanut in 8 of these patients. Specific IgEs were assayed for peanut, lupine flour, and pollen in 6 sera. RAST inhibition tests for lupine pollen by peanut were performed on 4 of these sera. Peanut and lupine flour immunoblots were carried out for 6 sera, and crossed immunoblot inhibitions for peanut by lupine flour and lupine flour by peanut were carried out for 2 sera. RESULTS: The skin prick test responses with lupine flour were positive in 11 (44%) subjects. The challenge test responses were positive in 7 of 8 subjects at the same doses as with peanut. The major lupine flour allergen (molecular mass, 43 kd) is present in peanuts. The RAST inhibition and immunoblot tests indicated cross-reactivity of peanut with the lupine flour and pollen. CONCLUSIONS: The risk of crossed peanut-lupine allergy is high, contrary to the risk with other legumes. The inclusion of 10% lupine flour in wheat flour without mandatory labeling makes lupine a hidden allergen, presenting a major risk of cross-reaction in subjects already allergic to peanut products. A high sensitizing potential can also be postulated for this legume.

Adolescent↗

PubMed2004

Mixed antibody and T cell responses to peanut and the peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 in an oral sensitization model.

BACKGROUND: Peanut allergy is known for its severity and persistence through life. Several peanut proteins have been identified as allergenic and are indicated as Ara h 1-7. Very little is known about the mechanisms that underlie sensitization to peanut proteins. OBJECTIVE: The purpose of the present study was to reveal the immune responses that are induced against peanut and the peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 during sensitization, including the very early responses. METHODS: Humoral and T cell responses against peanut and the peanut allergens were examined in an early and later stage of sensitization in an established murine model of peanut anaphylaxis. Therefore C3H/HeJ mice were orally exposed to two different doses of peanut extract plus cholera toxin. RESULTS: Oral sensitization to peanut was characterized by an antigen-induced mixed cytokine response in the spleen (IL-4, IL-5, IL-10 and IFN-gamma), which could already be observed 7 days after the onset of exposure. Additionally, polyisotypic humoral responses (IgE, IgG1 and IgG2a) against peanut were found in the serum. Moreover, we demonstrated that these T helper (Th)1/Th2 cytokine and antibody responses were also directed specifically against the major peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6. CONCLUSIONS: This study implicates that both Th1 and Th2 phenomena are involved in the development of peanut allergy in the C3H/HeJ murine model. Furthermore, we show that the present oral model is suitable to examine immune responses to food allergens during different stages of sensitization upon treatment with a whole food extract.

2S Albumins, Plant↗

PubMed1997

An evaluation of the sensitivity of subjects with peanut allergy to very low doses of peanut protein: a randomized, double-blind, placebo-controlled food challenge study.

BACKGROUND: The minimum dose of food protein to which subjects with food allergy have reacted in double-blind, placebo-controlled food challenges is between 50 and 100 mg. However, subjects with peanut allergy often report severe reactions after minimal contact with peanuts, even through intact skin. OBJECTIVE: We sought to determine whether adults previously proven by challenge to be allergic to peanut react to very low doses of peanut protein. METHODS: We used a randomized, double-blind, placebo-controlled food challenge of 14 subjects allergic to peanuts with doses of peanut ranging from 10 microg to 50 mg, administered in the form of a commercially available peanut flour. RESULTS: One subject had a systemic reaction to 5 mg of peanut protein, and two subjects had mild objective reactions to 2 mg and 50 mg of peanut protein, respectively. Five subjects had mild subjective reactions (1 to 5 mg and 4 to 50 mg). All subjects with convincing objective reactions had short-lived subjective reactions to preceding doses, as low as 100 microg in two cases. Five subjects did not react to any dose up to 50 mg. CONCLUSION: Even in a group of well-characterized, highly sensitive subjects with peanut allergy, the threshold dose of peanut protein varies. As little as 100 microg of peanut protein provokes symptoms in some subjects with peanut allergy.

Adult↗

PubMed1997

Systemic allergic reaction following ingestion of undeclared peanut flour in a peanut-sensitive woman.

BACKGROUND: Although peanuts and peanut butter are well recognized as food allergens, few reports describe allergic reactions associated with eating peanut flour. OBJECTIVE: To describe an allergic reaction that occurred in a peanut-sensitive woman who ate undeclared peanut flour that was part of a flavor ingredient contained in a dry soup mixture, and to estimate the amount of peanut protein the patient ingested. METHODS: The patient was interviewed, medical records from her emergency room visit were reviewed, and the manufacturer of the soup mix was investigated to ascertain the proportion of the soup mix constituted by the undeclared peanut flour. RESULTS: Minutes after ingesting the soup, a 33-year-old woman experienced a systemic allergic reaction. She was treated successfully in the emergency room with intravenous fluids, corticosteroids, and diphenhydramine. Investigation of the soup manufacturer revealed that undeclared peanut flour was a component of a flavoring ingredient in the soup. Based on the concentration of peanut flour in the flavoring, we estimated the patient ate approximately 45 mg of peanut protein. CONCLUSIONS: Inadvertent ingestion of peanut flour by peanut-sensitive individuals may lead to systemic allergic reactions.

Adult↗

PubMed2004

Relevance of Ara h1, Ara h2 and Ara h3 in peanut-allergic patients, as determined by immunoglobulin E Western blotting, basophil-histamine release and intracutaneous testing: Ara h2 is the most important peanut allergen.

BACKGROUND: A number of allergenic proteins in peanut has been described and the relative importance of these allergens is yet to be determined. OBJECTIVES: We have investigated the relevance of previously identified peanut allergens in well-characterized peanut-allergic patients by in vitro, ex vivo and in vivo assays. METHODS: Thirty-two adult peanut-allergic patients were included based on careful and standardized patient history and the presence of peanut-specific IgE. The diagnosis peanut allergy was confirmed using double-blind placebo-controlled food challenges in 23 patients. Major peanut allergens Ara h1, Ara h2 and Ara h3 were purified from peanuts using ion-exchange chromatography. IgE immunoblotting was performed and IgE-cross-linking capacity was examined by measuring histamine release (HR) after incubating patient basophils as well as passively sensitized basophils with several dilutions of the allergens. Intracutaneous tests (ICTs) using 10-fold dilution steps of the purified allergens and crude peanut extract were performed. RESULTS: Ara h2 was recognized most frequently (26 out of 32) in all tests and induced both positive skin tests and basophil degranulation at low concentrations, whereas Ara h1 and Ara h3 were recognized less frequently and reacted only at 100-fold higher concentrations as analysed with HR and intracutaneous testing (ICT). Next to the three tested allergens, proteins with molecular weights of somewhat smaller than 15 kDa were identified as a IgE-binding proteins on immunoblot in the majority of the patients (20 out of 32). CONCLUSION: We conclude that Ara h2 is, for our patient group, the most important peanut allergen, and that previously unidentified peanut proteins with molecular weights of somewhat smaller than 15 kDa may be important allergens as well. ICT in combination with basophil-HR and IgE immunoblotting provides insight in the patient specificity towards the individual peanut allergens.

2S Albumins, Plant↗

PubMed1981

Peanut oil is not allergenic to peanut-sensitive individuals.

Ten peanut-sensitive patients were enrolled in a double-blind crossover trial to determine whether ingestion of peanut oil can induce adverse reactions in such individuals. All patients had experienced prior allergic reactions to peanut ingestion, including any of the following: generalized urticaria, angioedema, abdominal cramps, vomiting, diarrhea, bronchospasm, or shock. All patients had elevated levels of serum IgE antibodies to both crude peanut extract and the purified peanut allergen, Peanut-I, by RAST assay; binding values ranged from 2 to 26 times that of negative control serum. All patients demonstrated negative puncture skin tests to both peanut oil and olive oil (control). At 30-min intervals, patients ingested 1, 2, and 5 ml of either oil contained in 1 ml capsules while under constant observation. These quantities exceed the maximum estimated dose of peanut oil that would occur in single meals. Patients returned 2 wk later for ingestion challenge with the remaining oil. No untoward reactions were observed with either peanut oil or olive oil. Peanut oil ingestion does not pose a risk to peanut-sensitive individuals.

Adolescent↗