Palatability of hydrolysates and Other substitution formulas for cow's milk-allergic children: a comparative study of taste, smell, and texture evaluated by healthy volunteers.

BACKGROUND: Hydrolyzed formulas used to feed infants with cow's milk-allergy can be classified as soy based, extensively hydrolyzed (casein, whey and mixed), and amino-acid based. Their unsatisfactory taste is reported by parents and physicians. OBJECTIVE: The aim of this study was to ascertain the palatability of these formulas in a double-blind taste test. MATERIALS AND METHODS: Fifty healthy volunteers performed a randomized-order double-blind test with 12 different milks. The taste, smell, smell, and texture of each formula were evaluated o n scales ranging from 1 (worst) t o 5 (best). The Pearson correlation coefficient between the peptide weight of each formula and the score obtained for each evaluated attribute was calculated. RESULTS: The soy formulas and rice formula had the best taste scores, followed by the whey hydrolysates; the mixed hydrolysates and the casein hydrolysates had the lowest taste scores. Individually the most palatable formula was mixed hydrolysate 1, by total score. We found a statistically significant correlation between peptide weight, reflecting the degree of hydrolysis of each formula, and the scores obtained for taste, texture, and overall palatability. CONCLUSION: The palatability of formulas is determined by the amount of bitter peptides obtained through hydrolysis. Flavorings and sweeteners may also contribute to palatability. Further studies are needed in order to determine how to modify the organoleptic properties of these products with the purpose of improving their palatability.

Food allergy and intolerance in children and adolescents, an update.

Epidemiological surveys demonstrate that rapid increase in allergic diseases is a real phenomenon. In developed countries they are about the commonest chronic diseases, reaching between 15% and 30% of the population. Adverse reaction to food can be divided into toxic reaction and non-toxic reactions. The non-toxic reactions are divided into non-immune mediated and immune mediated, these are considered food allergic reactions. We showed our experience in a 4 y survey, individualized by food allergens during the first two years of life. In Spain egg white protein is the most common allergen followed by cow's milk and peanuts. These three food items represent half of the sensitizations in children under 2 y of age. After 4 y sensitivities to vegetable allergens such as nuts, fruits and legumes are most frequent. The diagnosis of food allergy is still problematic, even in the case of atopy or IgE mediated hypersensitivity. There is a lack of standardized diagnostic procedures; the only test accepted as 'gold standard' for confirmation of food allergy and in general for food intolerance, is a properly performed double blind placebo-controlled oral food challenge. Negative results should be always followed by an open food challenge. This test should only be conducted in patients with a good medical condition and in a clinic or hospital setting, and only if trained personal and equipment for treating systemic anaphylaxis are present. Contraindications to a challenge test are limited to those situations that can be hazardous for the patient in relationship to the studied food. The treatment of food allergy and intolerance is avoiding the implicated food as long as necessary, until tolerance appears. Prevention of food allergy is the first goal of every pediatric allergologist. Controlled trials of food allergy prevention have been performed only in high allergic risk children.

Food allergies in Spain: causal allergens and diagnostic strategies.

A correct diagnosis of food allergy in the child is based on a careful medical history, together with the demonstration of specific IgE for the involved foods. However, before establishing an elimination diet, the "food-symptoms" relationship must be proven through a controlled challenge test.

Immunosuppressive properties of mesenchymal stem cells: advances and applications.

Mesenchymal stem cells (MSCs) have been isolated from a variety of tissues, such as bone marrow, skeletal muscle, dental pulp, bone, umbilical cord and adipose tissue. MSCs are used in regenerative medicine mainly based on their capacity to differentiate into specific cell types and also as bioreactors of soluble factors that will promote tissue regeneration from the damaged tissue cellular progenitors. In addition to these regenerative properties, MSCs hold an immunoregulatory capacity, and elicit immunosuppressive effects in a number of situations. Not only are they immunoprivileged cells, due to the low expression of class II Major Histocompatibilty Complex (MHC-II) and costimulatory molecules in their cell surface, but they also interfere with different pathways of the immune response by means of direct cell-to-cell interactions and soluble factor secretion. In vitro, MSCs inhibit cell proliferation of T cells, B-cells, natural killer cells (NK) and dendritic cells (DC), producing what is known as division arrest anergy. Moreover, MSCs can stop a variety of immune cell functions: cytokine secretion and cytotoxicity of T and NK cells; B cell maturation and antibody secretion; DC maturation and activation; as well as antigen presentation. It is thought that MSCs need to be activated to exert their immunomodulation skills. In this scenario, an inflammatory environment seems to be necessary to promote their effect and some inflammation-related molecules such as tumor necrosis factor-α and interferon-γ might be implicated. It has been observed that MSCs recruit T-regulatory lymphocytes (Tregs) to both lymphoid organs and graft. There is great controversy concerning the mechanisms and molecules involved in the immunosuppressive effect of MSCs. Prostaglandin E2, transforming growth factor-ß, interleukins- 6 and 10, human leukocyte antigen-G5, matrix metalloproteinases, indoleamine-2,3-dioxygenase and nitric oxide are all candidates under investigation. In vivo studies have shown many discrepancies regarding the immunomodulatory properties of MSCs. These studies have been designed to test the efficacy of MSC therapy in two different immune settings: the prevention or treatment of allograft rejection episodes, and the ability to suppress abnormal immune response in autoimmune and inflammatory diseases. Preclinical studies have been conducted in rodents, rabbits and baboon monkeys among others for bone marrow, skin, heart, and corneal transplantation, graft versus host disease, hepatic and renal failure, lung injury, multiple sclerosis, rheumatoid arthritis, diabetes and lupus diseases. Preliminary results from some of these studies have led to human clinical trials that are currently being carried out. These include treatment of autoimmune diseases such as Crohn's disease, ulcerative colitis, multiple sclerosis and type 1 diabetes mellitus; prevention of allograft rejection and enhancement of the survival of bone marrow and kidney grafts; and treatment of resistant graft versus host disease. We will try to shed light on all these studies, and analyze why the results are so contradictory.

A comparative analysis of the cross-reactivity in the polcalcin family including Syr v 3, a new member from lilac pollen.

BACKGROUND: Polcalcins are pollen-specific allergens with two EF-hand calcium-binding sites that exhibit strong cross-reactivity. Our objective was to isolate and express the cDNA coding of the EF-hand calcium-binding allergen from lilac pollen and to study cross-reactivity with other polcalcins from related and nonrelated pollen sources with different specific antibodies and sera from two different populations. METHODS: Specific cDNA was amplified by PCR, cloned and expressed in Escherichia coli. Purification was achieved by gel permeation and ion exchange chromatographies. ELISA titration and inhibition assays were performed using the recombinant forms of Syr v 3, Ole e 3, Che a 3 and Phl p 7 with sera from two Spanish regions with different sensitization profiles, as well as Phl p 7- and Ole e 3-specific polyclonal rabbit antisera, and an Ole e 3-specific monoclonal antibody. RESULTS: Syr v 3 displays two EF-hand consensus sites and 8863 Da of theoretical molecular mass. The allergen consists of 80 residues with identities ranging from 66 to 87% with polcalcins included in this study. Syr v 3, Ole e 3, Che a 3 and Phl p 7 showed a similar IgG- and IgE-binding capacity although differences at quantitative level were observed depending on the population of patients' sera. CONCLUSION: Syr v 3 is a polcalcin with structural and antigenic similarities to the members of this family. Diagnosis of polcalcin-sensitized patients could be performed whatever polcalcin used, whereas for immunotherapy, primary sensitization to a particular allergenic source should be considered.

Allergy and parasites reevaluated: wide-scale induction of chronic urticaria by the ubiquitous fish-nematode Anisakis simplex in an endemic region.

BACKGROUND: The ubiquitous fish-nematode Anisakis simplex produces acute urticaria or angioedema in the course of gastro-allergic anisakiasis. We studied the relationship between this nematode and chronic urticaria (CU), as well as the clinical usefulness of measuring specific IgG4 in A. simplex-sensitized patients with CU. METHODS: First, the prevalence of sensitization to A. simplex was estimated in 135 consecutive CU patients and the result was compared with known data about sensitization in a healthy population. Then, clinical response to a 2-month diet without fish was analyzed in 76 CU patients. The improvement rate in patients with and without sensitization to A. simplex was compared. Finally, the improvement rate, other clinical data and specific immunoglobulins in sensitized patients with and without detectable specific IgG4 were compared. RESULTS: a) The A. simplex sensitization rate in CU patients was 52.6 % compared with a known prevalence of between 16 and 20 % in our region. b) Of 65 sensitized patients, 52 experienced clinical improvement after the diet compared with only three of 11 patients without sensitization to A. simplex (p = 0.001). c) Of 43 patients with detectable specific IgG4, 38 showed clinical improvement compared with only 14 of 22 patients without detectable IgG4 (p = 0.02). Eight of nine patients with previous fish-associated cutaneous symptoms had detectable specific IgG4 compared with 15 of 32 patients who reported no previous fish-associated symptoms or acute urticaria (p = 0.03). CONCLUSIONS: Our results indicate that A. simplex is a possibly widespread etiologic agent able to induce CU. This parasite model constitutes the first report that associates an infectious agent with CU on a large scale. The detection of IgG4 antibodies reflects a previous acute parasitic infection and a temporary diet without fish improves symptoms in most patients with detectable specific IgG4.

Specific IgE to recombinant vegetal panallergen (rBet v 2) and fruit allergy in pollinic patients.

The presence of IgE antibodies to the allergens rBet v 1 and rBet v 2 was investigated in patients with known sensitization to ryegrass (Lolium perenne) and/or olive (Olea europaea) pollen, by comparing a group of 10 patients who had allergic symptoms after ingestion of fruits (A) with a group of 17 patients who had only seasonal respiratory symptoms (B). There was no significant difference between the two groups for total IgE. All patients showed specific IgE to both L. perenne and O. europaea. No specific IgE binding to rBet v 1 was detected in any patient. The incidence of the presence of IgE antibodies to rBet v 2 was 90% in the group with fruit allergy (A) and 35% in group B. We found a significant association between presence of IgE antibodies to rBet v 2 and fruit allergy (P = 0.007). Specific IgE values to O. europaea pollen were higher in the fruit-allergy group than the group without fruit allergy (P = 0.032). In conclusion, pollen-allergic patients with specific IgE to birch pollen profilin show a significantly elevated frequency of fruit allergy.

[Anisakis and anisakiosis]. / Anisakis y anisakiosis.

The nematode Anisakis simplex (AS) is a world wide distributed parasite that infects consumers of raw or undercoocked parasitized fish. The clinical manifestation of Anisakiosis depend on the site in the digestive tract in which larva lodges. The symptoms develops as a result of the inflammation when the larvae penetrates the gastric mucous. Most of asymptomatic subjects show high levels of specific IgE to AS. Diagnosis of AS allergy is not simple, due to cross-reactivity with other allergens. In childhood is more difficult to make a right diagnosis than in adult population. Most of positive prick test to AS correspond to children with positive prick tests to other allergens. Cross-reactivity between this parasite and other parasites with a higher prevalence in childhood, is the cause of a false diagnosis. The secretor-excretory antigen shows a better specificity, recognizing the true parasitized patients. This antigen could be used as indicator of parasitization. To follow prevention rules AS, avoid consumption of raw fish unless frozen for 48 hours or ingestion of fresh fish always cooked for more than 20 minutes at least at 60 C.

[Latex allergy]. / Alergia al látex.

Latex allergy has become an increasing cause of morbility in the last few years and is now recognized as an international health problem. The prevalence of latex sensitization among the general population is less than 1 %. The groups at highest risk include healthcare workers, rubber industry workers, patients with a history of multiple surgical procedures, particularly children with spina bifida and urogenital abnormalities, atopic individuals, and patients with certain fruit allergies (especially kiwi, avocado, chestnut and banana). The molecular and immunological characteristics of several natural latex allergens have been identified. Symptoms range from contact urticaria to anaphylaxis. Diagnosis is based on clinical history and is confirmed by skin prick tests. Measurement of serum specific IgE to latex can also be useful. The best treatment is latex avoidance and substitution by other materials. However, because latex products are ubiquitous in medical and nonmedical devices of daily use, a latex-free environment is not easy to achieve. In some patients, immunotherapy could be an alternative.

Evaluation of two commercial enzyme immunoassays for the diagnosis of Helicobacter pylori infection.

Sera from 65 patients with upper gastrointestinal tract symptoms and proven Helicobacter pylori infection, and from 42 negative controls were tested with two commercial EIAs (GAP test, BioRad; and ECP test, Biometra) and two non-commercial EIAs, one performed with whole sonicated cells and the other with acid extract of Helicobacter pylori as antigen. The GAP assay showed a sensitivity of 83.1% and a specificity of 47.6%. The ECP assay showed a sensitivity of 87.7% and a specificity of 61.9%. For both non-commercial EIAs these figures were 87.7% and 88.1%, respectively. Independent of the interpretive criteria established by the manufacturers, receiver operating characteristic curves were plotted for better evaluation of the four methods. Both commercial tests showed a lower probability of yielding a correct diagnosis than the non-commercial tests (p less than 0.05). Although commercial EIAs are convenient for the diagnosis of Helicobacter pylori infection, the accuracy of the two commercial tests evaluated in this study was lower compared to that of the two non-commercial EIAs.

[Prevention of food allergy]. / Prevención de la alergia alimentaria.

The occurrence of allergic diseases depends on genetic and environmental factors. Genetic factors determine individual risk and these persons should undergo early detection. However, the methods currently available (mainly clinical history and IgE in umbilical cord blood) have poor predictive value so their use in the general population is not practical. In contrast, the feeding habits of newborns and infants can influence the development of food allergies in children at risk. Therefore, several modes of action have been proposed, based mainly on prolonging breast-feeding (with the mother avoiding allergenic foods) and delaying the introduction of complementary foods considered to be a risk. Use of cow milk protein hydrolysates may have a preventive effect similar to that of breast-feeding, but their administration is not problem-free. The preventive effect of partial hydrolysates or soybean formulas is even more questionable.

Serum CD23 is not altered in gastroallergic anisakiasis, but correlates with the production of specific IgE and the amount of polyclonal stimulation.

BACKGROUND: Previous studies have shown elevated serum levels of the cytokines IL-4 and sCD23 in atopic patients and parasitic disease. Gastroallergic anisakiasis is an acute parasitic disease, accompanied by IgE-mediated clinical symptoms and an important increase of specific and total IgE. METHODS: Sixteen patients with acute urticaria/angioedema due to parasitism by Anisakis simplex after intake of raw or undercooked fish were selected, and serum samples were taken in the emergency room within 24 h (day 0; n=16), after 1 month (n=16), and after 6 months (n=10). Serum samples were studied for specific IgE against A. simplex, total IgE, sCD23, and IL-4. RESULTS: Mean values for sCD23 did not change in the observation period. Only 4/16 serum samples showed measurable IL-4 levels. Specific IgE and total IgE levels were found to be elevated after 1 month; after 6 months, they fell to nearly basal values. There was a positive correlation between sCD23 and specific IgE at day 0 and follow-up (r=0.55-0.69, P<0.026); a positive correlation between sCD23 and total IgE (r=0.54-0.62, P<0.056). Basal sCD23 could moderately predict the percentual increment of total IgE in the first month (r=0.56, P<0.038). CONCLUSION: Thus, it seems that interindividual variability of sCD23 is an important factor, with higher values predisposing to more production of unrelated IgE, independently of the parasite's action.

Are Ca2+-binding motifs involved in the immunoglobin E-binding of allergens? Olive pollen allergens as model of study.

BACKGROUND: Several Ca2+-binding proteins, which possess EF-hand sites with a high sequence similarity, have been found to be able to induce Type-I allergy. OBJECTIVE: To study whether the common EF-hand sequential motifs can be involved in the IgE-reactivity of these proteins, thus being responsible of a degree of cross-reactivity among different Ca2+-binding proteins. METHODS: Two olive pollen allergens, Ole e 3 and Ole e 8, have been used in the study. Parvalbumin and calmodulin were included in immunological analyses. Sera from patients allergic to olive pollen, as well as Ole e 3- and Ole e 8-specific rabbit antisera were used in indirect enzyme-linked immunosorbent assay (ELISA), ELISA inhibition assays and immunoblotting. Conformational analyses (circular dichroism spectra and thermal stability) and specific immunodetection assays were performed in the presence and the absence of Ca2+. Chemical breakdown and high-performance liquid chromatography (HPLC) was used to obtain fragments from Ole e 3 containing a single EF-hand motif. RESULTS: Thirty-four (17%) and 16 (8.2%) out of 195 sera from patients allergic to olive pollen contained specific IgE against Ole e 3 and Ole e 8, respectively. The IgE-binding of 12 allergic sera diminished up to 22% for Ole e 3 and to 82% for Ole e 8, when depleted Ca2+. A pool of these sera recognized the two olive allergens and parvalbumin, but at very different extent. Inhibition of the IgE-binding was only achieved between two olive allergens. No structural relationships between Ole e 3 and Ole e 8 were established when specific polyclonal antisera against both proteins were used. CONCLUSION: EF-hand Ca2+-binding sites can not be considered as general allergenic motifs responsible for the cross-reactivity between Ca2+-binding allergens. Different families of Ca2+-binding allergens have specific epitopes that could be involved in the cross-reactivity among members of the same family.

[The allergenic significance of legumes]. / La importancia alergénica de las legumbres.

Leguminous are a cheap source of protein that are cultivated practically throughout the world. They are the main source of food in developing countries. In the Mediterranean area and Middle East, the most commonly consumed legumes are lentils and chickpea. In the United States, United Kingdom and south-east Asia, the major legumes involved in food allergy are considered to be peanut and soy bean, respectively. The clinical manifestations of the allergy to legumes are similar for all legumes and range from oral allergy syndrome, urticaria, angioedema, rhinitis and asthmatic crises to anaphylaxis and even death. Legumes have a high degree of immunological cross-reactivity. Severals authors have described cross-reactivity among different legumes and between legumes and various vegetables. The allergenicity of legumes is mainly is mainly related to allergens from the storage proteins of seeds. Vicilins from this group of proteins could be an important common allergen in clinical allergy to legumes. Profilins are considered to be a cause of cross-reactivity among fruits, vegetables and some pollens and are believed to be a panallergen. Other panallergens of increasing importance are lipid transfer proteins. Few studies have assessed the long-term clinical course of allergy to legumes. Novel therapeutic agents are being investigated for the treatment of peanut allergy and these could be applied to other legumes.

Vicilin and convicilin are potential major allergens from pea.

BACKGROUND: Allergic reactions to pea (Pisum sativum) ingestion are frequently associated with lentil allergy in the Spanish population. Vicilin have been described as a major lentil allergen. OBJECTIVE: To identify the main IgE binding components from pea seeds and to study their potential cross-reactivity with lentil vicilin. METHODS: A serum pool or individual sera from 18 patients with pea allergy were used to detect IgE binding proteins from pea seeds by immunodetection and immunoblot inhibition assays. Protein preparations enriched in pea vicilin were obtained by gel filtration chromatography followed by reverse-phase high-performance liquid chromatography (HPLC). IgE binding components were identified by means of N-terminal amino acid sequencing. Complete cDNAs encoding pea vicilin were isolated by PCR, using primers based on the amino acid sequence of the reactive proteins. RESULTS: IgE immunodetection of crude pea extracts revealed that convicilin (63 kDa), as well as vicilin (44 kDa) and one of its proteolytic fragments (32 kDa), reacted with more than 50% of the individual sera tested. Additional proteolytic subunits of vicilin (36, 16 and 13 kDa) bound IgE from approximately 20% of the sera. The lentil vicilin allergen Len c 1 strongly inhibited the IgE binding to all components mentioned above. The characterization of cDNA clones encoding pea vicilin has allowed the deduction of its complete amino acid sequence (90% of sequence identity to Len c 1), as well as those of its reactive proteolytic processed subunits. CONCLUSIONS: Vicilin and convicilin are potential major allergens from pea seeds. Furthermore, proteolytic fragments from vicilin are also relevant IgE binding pea components. All these proteins cross-react with the major lentil allergen Len c 1.

Isolation and characterization of relevant allergens from boiled lentils.

BACKGROUND: Lentils seem to be the most common legume implicated in pediatric allergic patients in the Mediterranean area. However, no lentil allergen has been isolated and characterized. OBJECTIVE: We sought to purify and characterize relevant IgE-binding proteins from boiled lentil extracts. METHODS: IgE-binding proteins from crude and boiled lentil extracts were detected with a pool of sera from patients with lentil allergy. Allergens were isolated by gel-filtration chromatography followed by cation- and anion-exchange chromatography or by reverse-phase HPLC. Their characterization included N-terminal amino acid sequencing, complex asparagine-linked glycan detection, specific IgE immunodetection with 22 individual sera from allergic patients, and immunoblot and CAP inhibition assays. RESULTS: Heat treatment of lentils produced substantial changes in the SDS-PAGE patterns of whole extracts, mainly a strong increase of 12- to 16-kd bands and a decrease of 25- to 45-kd components. Major IgE-binding proteins from the boiled lentil extract were located in the 12- to 16-kd and 45- to 70-kd ranges. Two allergens of 16 kd, proteins L1 and L2, and another one of 12 kd, protein L3, were purified. N-terminal sequencing indicated that all 3 were related and allowed their identification as gamma-vicilin subunits. Protein L1 was recognized by 68% of the individual sera tested and inhibited 64% of the IgE binding by commercial lentil CAPs. A second type of allergen of 66 kd, named protein H, was also isolated and identified as a seed-specific biotinylated protein. Protein H reacted with 41% of the individual sera and produced 45% inhibition in CAP inhibition assays. CONCLUSIONS: Two different types of allergens have been identified in boiled lentils. Those of 12 to 16 kd, called Len c 1, correspond to gamma-vicilin subunits, and those of 66 kd, designated Len c 2, correspond to seed-specific biotinylated protein. Homology with proteins from other legume species can explain potential cross-reactions among these foods.

Tomato allergy in children and young adults: cross-reactivity with latex and potato.

BACKGROUND: Several studies have shown that allergy to natural rubber latex is associated with cross-reactivity to certain foods such as tomato and potato. The objective was to investigate the clinical and immunologic differences between a group of patients with clinical allergy to tomato and latex and another which had only clinical allergy to tomato. We also aimed to assess, in vitro, the relationship of tomato and latex allergens, which could explain the cross-reactivity. METHODS: Forty patients with histories of adverse reactions to tomato and IgE-mediated hypersensitivity were enrolled in the study. Tomato, latex, and potato components were analyzed by SDS-PAGE immunoblotting. CAP and immunoblot inhibition were used to study allergen cross-reactivity. RESULTS: Patients from group A had a mean age of 13.2 years, and in group B the mean age was 21.7 years. In group B, 9/10 patients belonged to the latex-fruits syndrome. All patients of both groups tolerated potato. Immunoblotting patterns obtained with patients' sera from pool A showed IgE-binding bands to tomato ranging from 44 to 46 kDa and a triple band at 67 kDa. For latex, there was a strong binding at 44 kDa, and potato showed a strong band of 44 kDa and a 67-kDa triple band. In pool B, the binding to the band of 44 kDa in latex and tomato was more intense than in pool A. In pool A, immunoblot inhibition with potato allergen showed an intense inhibition of the three allergens (potato, latex, and tomato); with latex, inhibition was partial and with tomato, a complete inhibition of tomato and latex was observed, and a partial inhibition of potato. In pool B, the inhibition pattern followed a similar tendency to pool A. The CAP inhibition confirmed the high rate of cross-reactivity between tomato, potato, and latex. CONCLUSIONS: In our study, tomato, potato, and latex showed a common band of 44-46 kDa probably corresponding to patatin. This protein could be implicated in the high cross-reactivity between tomato, latex, and potato observed in the immunoblot and CAP inhibition.