Immunoglobulin-A Profile in Breast Milk from Mothers Delivering Full Term and Preterm Infants

Recent advances in the care of low-birth-weight and preterm neonates have stimulated research into the best dietetic program to improve their survival and short/long term outcome. Some components of human milk that cannot be included in artificial formulas may be critical for survival. Of these, immunoglobulins are important, and in particular secretory immunoglobulins A (sIgA). The concentration of secretory IgA was measured by immunoblotting (an immunoelectrophoretic technique having high specificity and reliability) in milk from mothers delivering at term (TM) or prematurely (PM). In both groups, IgA concentrations were high very early on but quickly decreased during the first week of lactation. The early IgA mean concentration was higher in PM than in TM but, because of high variability in PM milk, the difference rarely reached statistical significance. This variability during lactation reflects the important role of human milk in supplying immunological factors to cope with the gastrointestinal absorption of high molecular weight proteins in the first days of life. Immunological protection is particularly critical for a preterm baby, so it is important to promote feeding with its own mother's milk if possible, paying strict attention to the timing of milk collection.

Molecular characterization of allergens in raw and processed kiwifruit

BACKGROUND

The prevalence of allergy to kiwifruit is increasing in Europe since the last two decades. Different proteins have been identified as kiwifruit allergens; even though with geographic differences, Act d 1, a cysteine protease protein of 30 kDa, and Act d 2, a thaumatin-like protein of 24 kDa, are normally considered the most important. The aim of this study was (i) to identify at molecular level the sensitization pattern in a group of well-characterized patients allergic to kiwifruit and (ii) to assess the role of technological treatments on kiwifruit allergenic potential.

METHODS

The differences in the pattern of antigenicity between fresh and processed kiwifruit were evaluated by both immunoelectrophoretic techniques and clinical tests.

RESULTS

In the group of patients included in this study, three proteins were identified as major allergens in fresh kiwifruit, as the specific sensitization was present in ≥50% of the subjects. These proteins corresponded to actinidin (Act d 1), pectin methyl aldolase (Act d 6), and thaumatin-like protein (Act d 2). Kiwellin (Act d 5) and proteins of Bet v 1 family (Act d 8/act d 11) were also recognized as minor allergens. Immunoreactivity was totally eliminated by industrial treatments used for the production of kiwifruit strained derivative.

CONCLUSIONS

In this group of allergic children, the technological treatments used in the production of kiwifruit strained product reduced drastically the allergenic potential of kiwifruit.

Biochemical and immunochemical evidences supporting the inclusion of quinoa (Chenopodium quinoa Willd.) as a gluten-free ingredient

To date, the only acceptable therapeutic approach for celiac disease (CD) is a strict elimination from the diet of gluten-containing foods, but this diet does not always guarantee an adequate nutritional intake. Pseudocereals are receiving considerable attention as interesting alternatives for the formulation of gluten-free products, and quinoa grains arise as nutritive substitutes of conventional cereals. The aim of this study was the characterization of different quinoa samples corresponding to 11 quinoa varieties, using polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) and immunoblotting techniques to assess their suitability for celiac subjects. Some of these varieties were grown in Italy to assess if the reproduction in a new habitat can guarantee the retention of the "safe" protein pattern. None of the quinoa varieties studied presented protein bands with electrophoretic mobility comparable with those of wheat gliadins, the toxic protein for celiac subjects. All the quinoa samples showed a low binding affinity for both specific anti-gliadin antibodies and IgAs from celiac subjects, confirming that quinoa can be considered as a safe ingredient for celiac patients. However, reliable varieties should be previously selected since the immuno cross-reactivity with anti-gliadin antibodies can vary significantly.

Characterization of the sensitization profile to lupin in peanut-allergic children and assessment of cross-reactivity risk

BACKGROUND

Case reports of allergy to lupin, due to primary sensitization or cross-reactions with other legumes, are increasing as a consequence of the augmented use of lupin flour in bakery, pasta formulations and other food items. The main allergens that have been associated with the sensitization to lupin are α- and β-conglutins and, to a lesser extent, γ- and δ-conglutin, but no conclusive data are available so far. The aim of this study was to characterize the sensitization pattern to lupin in a group of 12 Italian children allergic to peanut and identify the specific lupin proteins involved in the cross-reactivity with peanut.

METHODS

The immunochemical cross-reactivity among peanut and lupin was evaluated by both in vitro immunoblotting and in vivo fresh food skin prick test (FFSPT).

RESULTS

The results showed that β-conglutin was recognized by cutaneous IgEs from 7/12 peanut-allergic children in FFSPT and serum IgEs from 5/12 in immunoblotting, while 4/12 and 8/12 patients tested positive to γ-conglutin in FFSPT and immunoblotting, respectively. No significant immunoreactive responses were observed to α- and δ-conglutins under non-reducing conditions, but they were bound in FFSPT by the sera of 5/12 and 3/12 patients, respectively.

CONCLUSION

In this group of allergic children, β-conglutin has been identified as the major lupin allergen involved both in vitro and in vivo cross-reactivity with peanut proteins. The role of γ-conglutin in the cross-reactivity between lupin and peanut proteins was also relevant and clear, despite the observed unspecificity of the immunoblotting responses.

Severe anaphylaxis to sheep's milk cheese in a child desensitized to cow's milk through specific oral tolerance induction

Specific oral tolerance induction to food (SOTI) is a new promising treatmentfor persistent IgE-mediatedfood allergy. Our paper reports a case of a 5-year-old girl with cow's milk allergy, who developed severe anaphylaxis after the ingestion of a croissant containing sheep's milk ricotta cheese, even though she had been previously desensitized to cow's milk through SOTI. The sheep's milk specific allergen causing the severe allergic reaction (a derivative of alpha-casein of 54,1kDa) was identified by SDS-PAGE and immunoblotting. We conclude that SOTI is a species-specific procedure and the induced tolerance to cow's milk doesn't necessarily provide protection against milk of other mammals. Therefore, children desensitized to cow's milk through SOTI should strictly avoid the intake of milk of other mammals, until tolerance to those kinds of milk is documented by an oral food challenge.

Children monosensitized to pine nuts have similar patterns of sensitization

BACKGROUND

Several cases of pine nut allergies and anaphylaxis have been reported in the literature, but only few pine nut allergens have been characterized. The aim of this research is to identify through immunoelectrophoretic techniques the major pine nut allergens in a group of children monosensitized to pine nuts.

METHODS

We studied five children with pine nut allergies and no other sensitization to food except to pine nuts, confirmed by in vivo (prick test, prick-to-prick) and in vitro tests (specific IgE determinations [CAP-FEIA]). The protein profile of pine nuts was analyzed by Sodium Dodecyl sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE). Immunoblotting was performed after incubation of membranes with the sera from the children included in the present study.

RESULTS

Immunoblotting (SDS-PAGE) demonstrated five similar bands between 6 and 47 kDa in all the subjects studied.

CONCLUSION

These bands should be considered the potential allergens for pine nut allergic children.

Biochemical and immunochemical characterization of different varieties of amaranth (Amaranthus L. ssp.) as a safe ingredient for gluten-free products

Celiac disease is a food intolerance triggered by the ingestion of gluten-containing cereals; the only therapy is a strict gluten-free diet for life. In recent years, amaranth flour has received considerable attention as an interesting source for the formulation of gluten-free products due to its high nutritional value and low content of prolamins, the toxic proteins for celiacs. The aim of this study was to characterize 40 amaranth varieties using both SDS-PAGE/immunoblotting and ELISA to assess their possible tolerance by celiac subjects. All of the amaranth samples studied showed similar binding affinities for both specific anti-gliadin antibodies and human IgAs. In most amaranth grains, the content of gluten-like proteins measured by ELISA was <20 ppm. The molecular characterization of amaranth proteins suggests that amaranth is safe for celiacs to consume. It is recommended that the most suitable amaranth varieties are those having the lowest content of proteins cross-reacting with anti-gliadin antibodies.

Molecular insight into IgE-mediated reactions to sesame (Sesamum indicum L.) seed proteins

BACKGROUND

Food allergy is becoming a major public health concern in recent times. Several sesame seed allergenic proteins have been identified. However, sensitization toward these proteins does not follow a common and unique pattern of clinical reactivity, as shown by the differential geographic recognition of single proteins.

OBJECTIVE

To evaluate the sensitization profiles of 18 Italian individuals who experienced clinical symptoms after sesame seed consumption, including 4 anaphylactic reactions.

METHODS

Using an in vitro approach, we adopted a 2-dimensional electrophoretic technique combined with immunoblotting analyses by using sera from 18 Italian sesame-allergic patients.

RESULTS

We showed the prevalent and almost exclusive reactivity of the sesame 11S globulin. We shed light on the active role of the basic subunit of this globulin family. The limited accessibility of this polypeptide chain, unless the interchain disulphide bonds are cleaved, may be one of the reasons for its structural/functional stability and, thus, great potential for induction of IgE reactivity.

CONCLUSIONS

These results confirmed previous findings on the reactivity of the basic subunit of 11S globulin in various legume species. Moreover, this experimental approach proved to be useful for the noninvasive screening of specific reactivities in sensitized patients.

IgE-mediated cross-reactivity among leguminous seed proteins in peanut allergic children

The immunological cross-reactivity among major protein- and oil-crops, including lupin, lentil, pea, peanut, kidney bean and soybean, has been studied by a combination of in vitro and in vivo experimental approaches: SDS-PAGE separations of legume protein extracts and immuno-blot revelations with 12 peanut-sensitive subjects' sera, Immuno-CAP and Skin Prick tests on the same subjects. The immuno-blotting data showed a wide range of IgE-binding responses both displayed by one subject towards different plant extracts and among subjects. Differences were both quantitative and qualitative. The prevalent responses of most subjects' sera were seen with peanut polypeptides, as expected, as well as with various polypeptides of the other legumes, the most recurrent of which were the basic subunits of the 11S globulins. The distribution of in vivo responses generally paralleled those obtained by in vitro approaches with strong responses elicited by peanut, lentil and pea protein extracts, especially by most sensitive subjects, thus providing a consistent overall set of results. In this work, the comparison of various approaches has allowed us to get an overall broad picture of the immunological cross-reactivities among proteins of widely used different seed species and to hypothesize the role of most conserved specific polypeptides.

Respiratory allergy induced by exclusive polysensitization to serum albumins of furry animals

In this report we describe un unusual case of exclusive allergic sensitization to furry animals, as a possible study model to speculate about different modalities ofsensitization to allergens of common and less common mammalian species. A 27-year-old woman referred in our Allergological Centre for the occurrence of conjunctival and severe respiratory symptoms after contact with several animals such as cats, dogs, rabbits, horses, cows etc. Patient underwent clinical and anamnestic evaluation including a detailed information on the modality of exposure to different furry animals. Skin-prick-test (SPT) was performed with our routine panel of commercial standardized extracts (Lofarma Laboratories, Milan, Italy). Some animal allergenic extracts (rabbit, horse, rat, mouse, cavia, cow and hamster) have been tested by SPT one week after the routine SPT A blood sample was taken for measurement of total IgE and specific IgE (CAP System, Phadia, Uppsala, Sweden) as well as Immunoblotting procedures. The results of in vivo and in vitro procedures revealed allergic sensitization only to animal-derived allergens. Total IgE were 59.3 kU/L. Immunoblotting showed a specific IgE-mediated sensitization of the patient to cow's, rabbit's and horse's serum albumins (SA). In conclusion, our case report confirms the role of SA as cross-reacting agent in allergic sensitization to furry animals. This finding suggests to perform SPTs to several furry animal allergens in all individuals with high level of allergic sensitization to common pets (cats and/or dogs) in order to identify allergy to other animals and consequently to avoid future exposures at risk.

Analytical aspects of diterpene alkaloid poisoning with monkshood

A sensitive and specific method for aconitine extraction from biological samples was developed. Aconitine, the main toxic alkaloid from plants belonging to Aconitum species (family Ranunculaceae), was determined in plant material by an external standard method, and by a standard addition calibration method in biological fluids. Described here is one fatal case and five intoxications of accidental aconitine poisoning following the ingestion of aconite mistaken for an edible grass, Aruncus dioicus (Walt.) Fernald, "mountain asparagus", and Cicerbita alpina (L.) Wallroth. The aconitine content in urine was in the range 2.94 microg/mL (dead patient)-0.20 microg/mL (surviving patients), which was almost two to four times higher than that in plasma.

Analytical Aspects of Diterpene Alkaloid Poisoning with Monkshood

A sensitive and specific method for aconitine extraction from biological samples was developed. Aconitine, the main toxic alkaloid from plants belonging to Aconitum species (family Ranunculaceae), was determined in plant material by an external standard method, and by a standard addition calibration method in biological fluids. Described here is one fatal case and five intoxications of accidental aconitine poisoning following the ingestion of aconite mistaken for an edible grass, Aruncus dioicus (Walt.) Fernald, “mountain asparagus”, and Cicerbita alpina (L.) Wallroth. The aconitine content in urine was in the range 2.94 μg/mL (dead patient) – 0.20 μg/mL (surviving patients), which was almost two to four times higher than that in plasma.

A method for the analysis of milk and egg allergens for the atopy patch test

The patch test with food antigens (atopy patch test, APT) has been reported as a more specific method than prick or RAST for the early detection of cow's milk and/or egg sensitizations in children. Standardization of APT extracts is a major issue on the road towards full clinical exploitation of this assay. Here, we used sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to characterize sensitivity and specificity of commercial preparations of APT for milk and egg allergies, which are expected to improve the reliability of this test, when compared with fresh food allergen sources. We found that: (i) SDS-PAGE is an appropriate technique for quality control of APT and (ii) commercial milk and egg APT are equivalent to fresh food preparations in terms of allergen content. Clinical trials aimed at characterizing sensitivity and specificity of APT in the diagnosis of food allergy in children will benefit from this technique.

Analysis of food supplements containing iodine: a survey of Italian market

Iodine is an essential nutrient for humans as a critical constituent of thyroid hormones; both iodine deficiency and excess have adverse consequences for the thyroid gland. The aims of this research were to compare claimed concentrations of iodine with measured ones in various iodine-supplemented products, estimate the amount of iodine ingested by Italian consumers who use these products, and compare the calculated intakes to the Recommended Daily Allowance and tolerable Upper Level. A convenience sample of 43 food supplements was analyzed for iodine concentration. Analytical values resembled those declared in the label in fewer than half of the examples; in four cases, the maximal daily dose was higher than the tolerable upper level for iodine of 600 microg/day. Labeling of iodine-rich food supplements appears to be unreliable and caution should be exercised in the consumption of food supplements rich in iodine as there is a risk of exceeding the established safe upper level of daily intake.

Evaluation of the residual antigenicity of dairy whey hydrolysates obtained by combination of enzymatic hydrolysis and high-pressure treatment

Dairy whey was hydrolyzed for 15 min with five food-grade enzymes (Alcalase, Neutrase, Corolase 7089, Corolase PN-L, and Papain) at atmospheric pressure (0.1 MPa) and in combination with high pressure (HP) at 100, 200, and 300 MPa, applied prior to or during enzymatic digestion. The peptide profile of the hydrolysates obtained was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and their residual antigenicity was assessed by immuno-blotting with anti-beta-lactoglobulin monoclonal antibodies and the sera from pediatric patients allergic to cow's milk proteins. Moreover, to evaluate the presence of residual trace amounts of casein in bovine whey hydrolysates, immunoblotting with anti-cow's milk protein polyclonal antibodies was performed. SDS-PAGE analysis showed that HP treatment increased hydrolysis by the proteases assayed, especially when it was applied during the enzymatic digestion. Positive reactions at the band corresponding to beta-lactoglobulin were detected for Corolase PN-L and Corolase 7089 hydrolysates, except for those obtained under 300 MPa by the last protease. However, the immunochemical reaction was lower in the hydrolysis products obtained under HP than in those obtained at atmospheric pressure and after the HP treatment. On the contrary, no residual immunochemical reactivity associated with beta-lactoglobulin was observed in the hydrolysates obtained by Alcalase and Neutrase under HP, and none was observed in any of the hydrolysis products obtained by Papain. The presence of traces of casein was not significant. These results suggest that HP combined with selected food-grade proteases is a treatment that can remove the antigenicity of whey protein hydrolysates for their use as ingredients of hypoallergenic infant formulae.

One- and two-dimensional electrophoretic identification of IgE-binding polypeptides of Lupinus albus and other legume seeds

The prevalence of food allergies in the world population requires integrated approaches to identify new potential allergens, especially those of plant origin. The aim of this work was the allergen in vitro analysis of Lupinus albus seed proteome, a promising food protein source, and the assessment of IgE cross-reactivities with other more diffused legume species. A combination of one- and two-dimensional gel electrophoresis and immunoblotting analyses with specific IgGs for band identification and lupin-sensitized patients' circulating IgEs for allergenicity studies has been used. Two lupin proteins, namely, conglutin gamma and 11S globulin basic subunits, strongly reacted with all patients' sera. Also, cross-reactivities with the homologous polypeptides of other legume species were observed. Otherwise, no reaction at all was detected with a 2S-type lupin protein. This global electrophoretic approach has allowed the identification of a new potential lupin allergen and confirmed the cross-reactivity among the legume 11S globulin basic subunits.

Identification of the basic subunit of Ara h 3 as the major allergen in a group of children allergic to peanuts

BACKGROUND

Several proteins have been identified as peanut allergens; among them, Ara h 1 (7S globulin) and Ara h 2 (2S globulin) are usually considered the major allergens.

OBJECTIVE

To identify the major allergens in a group of children selected for their specific pattern of immunoreactivity.

METHODS

We identified the dominant allergen by using (1) amino acid sequencing of the bands that show the strongest IgE immunoreactivity in 1-dimensional electrophoresis and immunoblotting and (2) specific animal IgGs raised against the dominant immunoreactive band to pinpoint the allergen(s) in peanut proteins separated by 2-dimensional electrophoresis and immunoblotting. To confirm these data, we further examined the peanut proteome using serum samples from the children with the unusual immunoreactivity.

RESULTS

We found a group of children with marked peanut allergy who are specifically sensitized to the basic subunit of Ara h 3 (11S globulin family).

CONCLUSION

That the dominant immunoreactivity in these patients is in a basic subunit of Ara h 3 was unexpected, because previous studies had indicated that Ara h 3 was only a minor peanut allergen and that the identified allergenic epitopes occurred mainly in the acidic Ara h 3 subunit.

Two-dimensional electrophoresis and western-blotting analyses with anti Ara h 3 basic subunit IgG evidence the cross-reacting polypeptides of Arachis hypogaea, Glycine max, and Lupinus albus seed proteomes

The allergenicity of seed storage proteins, the major components of edible legume seeds, may cause serious reactions in both children and adult population. Updated methodologies for evaluation of the activity of these proteins are needed. In this paper we used two-dimensional (2D) electrophoretic techniques to investigate the immuno-cross-reactivities of anti Ara h 3 basic subunit IgG to the seed proteomes of three legume species, namely, peanut, soybean, and lupin. The seed proteins, extracted with two different procedures, were separated by 2D electrophoresis, and the electrophoretic maps were analyzed by Western blot. In peanut proteome the antibodies strongly reacted with the 23 kDa polypeptides, corresponding to Ara h 3 basic isoforms, the antigen they were raised to, and three unidentified acidic polypeptides near 45 kDa. Remarkable cross-reactivities with lupin and soybean Ara h 3 homologous polypeptides and nonrelated proteins, namely, lupin conglutin gamma and soybean Bg7S, were detected. Therefore, these proteins may be regarded as new putative allergens. The present findings show the potentiality of 2D electrophoresis in the identification of food allergens and open the way to the traceability of the new cross-reacting proteins in the food chain.

Tolerance of heat-treated kiwi by children with kiwifruit allergy

Kiwifruit allergy is increasing among children but whether heating affects clinical tolerance to kiwifruit is unknown. To assess tolerance to heated kiwifruit in children allergic to fresh kiwifruit. In this prospective trial, 20 children (median age 9.4 yr) with a history of immediate allergic reactions to fresh kiwifruit underwent double-blind placebo-controlled food challenges with steam-cooked (100 degrees C for 5') and industrially homogenised kiwifruit. Skin prick tests with a commercial kiwifruit allergen, raw kiwifruit and double-blind placebo-controlled food challenge with 25 g of fresh kiwifruit were used to confirm the history. Specific kiwifruit IgE to native and homogenized fruit were identified by immunoblotting. Fresh kiwifruit induced positive skin prick wheals in all children (confirmed during challenge in 19 patients). Commercial skin prick test elicited a positive response in five children, steam-cooked kiwifruit in five, and the homogenised kiwifruit preparation in none. UniCAP determinations were positive for kiwifruit in three patients. All children's sera showed specific IgE at immunoblotting with raw kiwifruit and one with the homogenised preparation (major allergens identified: Act c 1 and Act c 2). There was no clinical reactivity following challenge with homogenised kiwifruit but one child reacted to cooked kiwifruit challenge. Industrial heat treatment and homogenisation can make kiwifruit safe for children who are allergic to this increasingly popular fruit. This has dietary implications for children who are allergic to several fruit and vegetable proteins.

Characterization of bovine serum albumin epitopes and their role in allergic reactions

OBJECTIVE

This review provides updated information on conformational and sequential epitopes identified in bovine serum albumin (BSA) and summarizes available data about the role of structural modifications on BSA antigenicity/allergenicity.

DATA SOURCES

Data on beef allergy and BSA antigenicity are reported, with reference both to the basic literature and to clinical results obtained by our group.

RESULTS AND DISCUSSION

BSA is an important allergen involved in milk and beef allergy. The presence of conformational epitopes has been suggested by indirect evidence, while at least one sequential epitope has been experimentally identified. The role of structural modifications on BSA antigenicity is discussed as well as the increased tolerance observed in allergic subjects consuming beef as strained (homogenized) and freeze-dried derivatives.

CONCLUSION

Study of the molecular characteristics of a known major allergen allows the identification of technological processes that may be capable of improving the tolerance of allergic subjects to a specific food. Even though any hoped for reduced allergenicity must be verified under medical supervision, the use of new products could obviate the need to avoid important foods such as meat in childhood.

Ochratoxin A in conventional and organic cereal derivatives: a survey of the Italian market, 2001–02

Ochratoxin A is a mycotoxin produced mainly by Penicillium verrucosum and Aspergillus ochraceus. Although typically considered a cereal contaminant, it has also been detected in dried fruit, nuts, meat and derivatives. To estimate the quantity of ochratoxin A that might be ingested by Italian consumers from these foods, 211 cereal derivatives (flours and bakery products) were analysed by high-performance liquid chromatography. Products were from conventional and organic agriculture and from integrated pest management agriculture. All commercial flours and derivatives examined contained ochratoxin A at concentrations very much below the legal limit (3 microg kg(-1)): the highest value, 0.816 microg kg(-1), was detected in a sample of spelt whole flour from organic agriculture. In many samples, the ochratoxin content was below the limit of detection; only rarely did values exceed 0.5 microg kg(-1). In baby foods, four samples were above the particularly restrictive Italian legal limit of 0.5 microg kg(-1). Although some significant differences were found between samples from conventional and organic agriculture when some product categories were examined (namely, baby foods as semolina and rice creams), no important difference was found between the two types of agricultural practice when all types of cereal derivatives were considered together.

Evaluation by SDS-Page and immunoblotting of residual antigenicity in gluten-treated wine: a preliminary study

Hydrolyzed gluten could be a suitable alternative to animal proteins in the wine clarification process, but the residual proteins could constitute a risk for subjects suffering from celiac disease or allergy to cereals. The aim of this study was to investigate possible traces of gluten in treated wine and to assess its antigenicity in commercial products. The presence of gluten in treated wine was evaluated by an electrophoretic method [sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE)] and its immunoreactivity was evaluated by immunoblotting. No traces of protein were found in untreated samples. A small quantity of protein was detected in treated wine but this produced no significant immunochemical reaction. In an experimental clarification process, a protein fraction was detectable in untreated samples and in the first stages of the clarification process. However, there was no significant gluten-associated immunochemical reaction in clarified wine samples, confirming strong binding between the clarifying agent and the phenolic fraction. In conclusion, the clarifying process strongly reduced the amount of protein material, at least in red wines. Under the most restrictive tests of the presence of gluten in the product, the predictable residue of gluten in wine was safe for celiac subjects. For allergic subjects the data are less conclusive because there is no known limit for allergic reactions, but clear labeling of the method of treating the wine should also protect this group of consumers.

Assessment of residual immunoreactivity in red or white wines clarified with pea or lupin extracts

Vegetable proteins could be a suitable alternative to animal proteins in the clarification of wine, but their residues could represent a risk for subjects with food allergy or intolerance. The aim of this study was to investigate the presence of specific immunoreactivity in red and white wines treated, as must or wine, with vegetable proteins in the clarification process. The proteins considered were prepared from lupins and peas, which are not included among the allergens listed in annex Illbis of Directive 2003/89/EC. The presence of residual immunoreactivity to specific rabbit anti-lupin and anti-pea polyclonal antibodies in treated wines was assessed by electrophoresis (SDS-PAGE) and immunoblotting. Residual protein was not detectable in red wines clarified with lupin, pea or a mixture of pea and lupin proteins or in white wines clarified with pea proteins. A small number of musts treated with lupin or pea proteins and white wines treated with lupin proteins yielded equivocal results, probably because of the presence of interfering material (e.g., sugar-rich proteins from grape and yeast). The use of bentonite as a secondary clarifying agent is therefore recommended since its combination with vegetable proteins is particularly effective in removing overall protein immunoreactivity.

Evaluation of residual immunoreactivity in red and white wines clarified with gluten or gluten derivatives

Gluten or hydrolyzed gluten could be a suitable alternative to animal proteins in the wine clarification process, but their residues could represent a risk for individuals suffering from coeliac disease or allergic to cereal proteins. The aim of this study was to investigate the presence of gluten in wines treated with gluten or its hydrolysate in the clarification process and to assess its antigenicity in commercial products. The presence of residual immunoreactive gluten was evaluated by electrophoresis (SDS-PAGE) and immunoblotting. Data obtained in several red and white wine samples showed that no residue was detectable in any of the red wines. In white wines, gluten reduced the protein content less completely, but most samples showed no immunoreactivity after the wine had been treated with gluten or its derivatives, either alone or combined with bentonite, silica gel or tannins. The use of gluten derivatives coupled with bentonite was the most effective method of removing immunoreactive protein in white wines. In conclusion, the use of gluten derivatives in wine clarification seems to exclude a risk for subjects susceptible to coeliac disease or gluten allergy. However, it is recommended that wine producers continuously monitor the clarification process in order to protect the most sensitive individuals.

Cross-reactivity between mammalian proteins

BACKGROUND

Cross-reactivity between food allergens occurs when they share part of their amino acid sequence, or when their three-dimensional molecular structure causes them to have a similar capacity to bind specific antibodies.

OBJECTIVES

To review data from our laboratory on cross-reactivity between mammalian proteins (milk and meat allergens).

METHODS

Studies used immunoelectrophoresis (sodium dodecyl sulfate-polyacrylamide gel electrophoresis/polyacrylamide gel electrophoresis and immunoblotting), and animal monoclonal antibodies.

RESULTS

The findings suggest that animal monoclonal antibodies specific for cow's milk proteins are able to recognize the major part of milk proteins from mammals bred in Mediterranean countries (sheep, goat, and buffalo); weak cross-reactivity was observed with milk proteins from mares and donkeys. None of the antibodies used in our studies reacted with proteins from an exotic mammalian species: the camel. Similar cross-reactions were found with human circulating immunoglobulin E from children allergic to milk. With regard to beef allergy, monoclonal antibodies specific for bovine serum albumin cross-reacted only with ovine serum albumin, whereas the number of sera from allergic children able to recognize other mammalian serum albumins depended directly on the closeness of phylogenetic relationship between animal species and inversely on the percent identity with human serum albumin in the main epitopic sequence.

CONCLUSION

An area of heterogeneity between animal and human species in a critical amino acid sequence (epitope) of an allergen can determine the degree of immunogenic activity.

Ochratoxin A in cereal-based baby foods: occurrence and safety evaluation

Ochratoxin A is a typical cereal contaminant with strong nephrotoxic activity. To estimate the quantity of ochratoxin A that can be taken in by a child in the weaning period, several samples of cereal-based baby foods were analysed. Although most samples analysed contained ochratoxin A in undetectable amounts or below the Italian legal limit of 0.5 microg kg(-1), some irregular products were found. In particular, the analyses of the 119 batches (338 samples) of baby foods considered indicated that: 20 batches (16.8%) contained detectable quantities of ochratoxin A and four of these (3.4% of the total) contained ochratoxin A above the Italian permitted value. All samples coming from agricultural practices based on integrated pest management contained undetectable amounts of ochratoxin A, while approximately 5% of batches coming from conventional and organic agricultural practices were above the legal limit. On the basis of the established provisional tolerable weekly intake (PTWI), there is no significant toxicological risk for a child who occasionally consumes a formula with ochratoxin concentration slightly above the permitted level. However, stricter controls have to be applied to reject the batches containing irregular concentrations of ochratoxin A.

Antigenic determinants of bovine serum albumin

BACKGROUND

Bovine serum albumin (BSA) is one of the most widely studied proteins; its structure is well known and its antigenic characteristics have been described in several papers. The aim of this research was the identification of the BSA antigenic determinants.

METHODS

This study was performed using limited proteolysis and an immunoblotting technique, in which a commercial murine antibody and sera from children sensitized to BSA were used.

RESULTS

Findings suggest amino acids (aa) 524-598 as an epitopic area for human species. The most critical sequence seems to be aa 524-542, even if it must be included in a longer fragment to be recognized by antibodies. Murine IgG antibodies also recognize fragments contained in the first half (NH(2)-terminal portion) of BSA.

CONCLUSIONS

The results presented in this study indicate that the epitopic sites of an antigenic protein can be different when different species are considered, so that data obtained with antibodies from animal species cannot be directly extrapolated to the behavior of human IgEs.

Severe anaphylaxis induced by latex as a contaminant of plastic balls in play pits

BACKGROUND

Latex causes anaphylaxis in specific contexts among children. We present 2 cases that show that severe reactions may occur in everyday circumstances with latex as a contaminant.

OBJECTIVE

Because 2 cases of severe reactions to latex suggested similar circumstances of exposure, we investigated the immediate environment in which episodes occurred.

METHODS

A 5-year-old girl presented to our casualty department with anaphylaxis after playing in a ball pit filled with approximately 10-cm diameter plastic balls in an American-style fast-food outlet. Two months later, a 9-year-old boy had severe anaphylaxis followed by an asthma attack with loss of consciousness while playing in the playpen of a different outlet belonging to the same company. Latex sensitization was confirmed in both cases by means of skin prick testing, latex glove skin prick testing, and 1-glove finger testing. Immunoblotting of elutions from a ball, the natural rubber latex foam pit lining, and its polyvinyl chloride sheet were performed.

RESULTS

In the girl's immunoblot high levels of IgE specific to Hev b 4, Hev b 7, and Hev b 2 were found. The boy's immunoblot showed positivity to Hev b 7. The polyvinyl chloride ball sample showed a high concentration of specific Hevea species allergen similar to that of the foam layer sample.

CONCLUSION

Severe anaphylaxis can result from contact with latex proteins as a contaminant, rather than as a component, of play area ball pits and therefore outside the reported settings. Emergency health care workers should be aware of this kind of risk. A latex-reduced environment might prevent potentially severe reactions in young customers of fast-food outlets.

Pulmonary sequestration in a child with acute myeloid leukemia

The article describes a relatively rare congenital anomaly that was difficult to diagnose in a 10-year-old child with acute nonlymphoblastic leukemia. Just at diagnosis of leukemia, the patient showed a pathologic chest radiograph because of a parenchymal thickening at the right lung apex. The presence of bronchopneumonia was suspected, and broad-spectrum antibiotic therapy was started with subsequent antifungal treatment for persistent fever and concurrent chemotherapy-induced marrow aplasia, which did not favor pulmonary infiltrate recovery. Continuous culture tests, including bronchial swab, proved negative for Koch-Weeks bacillus, fungal organisms, and other pathogens. Computed tomography, however, was suggestive of Aspergillus lung involvement, and apical segmentectomy was performed. The anatomic pathologist suggested the diagnosis of intralobar sequestration. In summary, when pulmonary pathology with an excavation is found in a leukemic child, one must consider the possibility of pulmonary sequestration complicated by an infectious disease.