Structure, Immunogenicity, and IgE Cross-Reactivity among Walnut and Peanut Vicilin-Buried Peptides.

Vicilin-buried peptides (VBPs) from edible plants are derived from the N-terminal leader sequences (LSs) of seed storage proteins. VBPs are defined by a common α-hairpin fold mediated by conserved CxxxCx(10-14)CxxxC motifs. Here, peanut and walnut VBPs were characterized as potential mediators of both peanut/walnut allergenicity and cross-reactivity despite their low (∼17%) sequence identity. The structures of one peanut (AH1.1) and 3 walnut (JR2.1, JR2.2, JR2.3) VBPs were solved using solution NMR, revealing similar α-hairpin structures stabilized by disulfide bonds with high levels of surface similarity. Peptide microarrays identified several peptide sequences primarily on AH1.1 and JR2.1, which were recognized by peanut-, walnut-, and dual-allergic patient IgE, establishing these peanut and walnut VBPs as potential mediators of allergenicity and cross-reactivity. JR2.2 and JR2.3 displayed extreme resilience against endosomal digestion, potentially hindering epitope generation and likely contributing to their reduced allergic potential.

Successful treatment of neurocysticercosis with albendazole desensitization.

BACKGROUND: Neurocysticercosis is a growing public health problem in the United States. Albendazole is a mainstay of medical therapy for neurocysticercosis, and here we present a case of hypersensitivity to albendazole leading to life-threatening disease progression. OBJECTIVE: To report the first successful albendazole desensitization protocol. METHODS: An oral albendazole 12-step desensitization protocol was developed, starting with 0.001 mg and progressing at 15 minutes intervals. Dosage for each subsequent step was as follows: 0.003 mg, 0.01 mg, 0.03 mg, 0.1 mg, 0.3 mg, 1 mg, 3 mg, 10 mg, 30 mg, 100 mg, 300mg. RESULTS: The patient rapidly improved from a symptomatic standpoint, and repeat MRI showed a dramatic improvement in lesions. CONCLUSIONS: This successful desensitization protocol to albendazole can be of value to other patients with history suggestive of IgE-mediated allergy needing treatment for parasitic infections.

The COMPARE Database: A Public Resource for Allergen Identification, Adapted for Continuous Improvement.

Motivation: The availability of databases identifying allergenic proteins via a transparent and consensus-based scientific approach is of prime importance to support the safety review of genetically-modified foods and feeds, and public safety in general. Over recent years, screening for potential new allergens sequences has become more complex due to the exponential increase of genomic sequence information. To address these challenges, an international collaborative scientific group coordinated by the Health and Environmental Sciences Institute (HESI), was tasked to develop a contemporary, adaptable, high-throughput process to build the COMprehensive Protein Allergen REsource (COMPARE) database, a publicly accessible allergen sequence data resource along with bioinformatics analytical tools following guidelines of FAO/WHO and CODEX Alimentarius Commission. Results: The COMPARE process is novel in that it involves the identification of candidate sequences via automated keyword-based sorting algorithm and manual curation of the annotated sequence entries retrieved from public protein sequence databases on a yearly basis; its process is meant for continuous improvement, with updates being transparently documented with each version; as a complementary approach, a yearly key-word based search of literature databases is added to identify new allergen sequences that were not (yet) submitted to protein databases; in addition, comments from the independent peer-review panel are posted on the website to increase transparency of decision making; finally, sequence comparison capabilities associated with the COMPARE database was developed to evaluate the potential allergenicity of proteins, based on internationally recognized guidelines, FAO/WHO and CODEX Alimentarius Commission.

The clinical implications of selective IgA deficiency.

Selective IgA deficiency (SIgAD) is the most common primary immunodeficiency but does not always result in clinical disease. This may in part be due to the definition based on serum IgA, while most IgA is secreted at mucosal surfaces, not amenable to measurement. Clinical complications include increased risk of sinopulmonary infections with bacteria and viruses, gastrointestinal infections with a predilection for Giardia lamblia, a myriad of autoimmune diseases including systemic lupus erythematosus, hyper- and hypo-thyroidism, Type 1 diabetes, celiac disease, and rarely, malignancy. SIgAD must be differentiated from IgA deficiency that may be seen with IgG2 or IgG4 deficiency, specific antibody deficiency, or as an early manifestation prior to a diagnosis of common variable immunodeficiency. Secondary IgA deficiency is increasingly recognized and may be due to medications such as anti-epileptics, or antibiotics with disruption of the microbiome which can influence IgA levels, infections or malignancies. Patients with SIgAD should be monitored at regular intervals and educated to be aware of particular complications. There is a rare chance of development of anti-IgA IgE antibodies in patients with complete deficiency, which can result in anaphylaxis if blood products with IgA are administered. Prophylactic antibiotics may be indicated in some cases, and very rarely, supplemental IgG infusions.

Boiling and Frying Peanuts Decreases Soluble Peanut (Arachis Hypogaea) Allergens Ara h 1 and Ara h 2 But Does Not Generate Hypoallergenic Peanuts.

Peanut allergy continues to be a problem in most developed countries of the world. We sought a processing method that would alter allergenic peanut proteins, such that allergen recognition by IgE from allergic individuals would be significantly reduced or eliminated. Such a method would render accidental exposures to trace amounts of peanuts safer. A combination of boiling and frying decreased recovery of Ara h 1 and Ara h 2 at their expected MWs. In contrast, treatment with high pressures under varying temperatures had no effect on protein extraction profiles. Antibodies specific for Ara h 1, Ara h 2, and Ara h 6 bound proteins extracted from raw samples but not in boiled/fried samples. However, pre-incubation of serum with boiled/fried extract removed most raw peanut-reactive IgE from solution, including IgE directed to Ara h 1 and 2. Thus, this method of processing is unlikely to generate a peanut product tolerated by peanut allergic patients. Importantly, variability in individual patients' IgE repertoires may mean that some patients' IgE would bind fewer polypeptides in the sequentially processed seed.

Medical Complications of Tattoos: A Comprehensive Review.

Tattoos are defined as the introduction of exogenous pigments into the dermis in order to produce a permanent design. This process may occur unintentional or may be deliberately administered for cosmetic or medical reasons. Tattoos have been around for over 5000 years and over time have evolved to represent a common cosmetic practice worldwide. Currently, adverse reactions are relatively rare and generally unpredictable and predominantly include immune-mediated reactions and skin infections. Along with better healthcare standards and more stringent public health mandates such as the provision of disposable needles, major infectious complications related to hepatitis and human retroviral infections have decreased significantly. When they do occur, skin infections are most frequently associated with Staphylococcus aureus or Streptococcus pyogenes. The aim of this study is to review the types and rates of medical complications of permanent tattoos. PubMed search and search dates were open ended. Acute local inflammation is the most common complication, but infections, allergic contact dermatitis, and other inflammatory or immune responses that are not well-characterized may occur. As many patients with immune reactions to tattoos do not react on skin or patch testing, it is postulated that the antigens contained in dyes or pigments are such small molecules that they need to be haptenized in order to become immunogenic. Red ink is associated more frequently with long-term reactions, including granulomatous and pseudolymphomatous phenomena or morphea-like lesions and vasculitis. Exacerbation of preexisting psoriasis, atopic dermatitis, and pyoderma gangrenosum may occur after tattooing. There is no well-defined association between cancer and tattoos. The treatment of tattoo-related complications may include local destructive measures (cryotherapy, electro-surgery, dermabrasion, chemical destruction, ablative laser destruction), surgical excision, and thermolysis of the pigment using Q-switched laser therapy.

Allergenic properties and differential response of walnut subjected to processing treatments.

The aim of this study was to investigate changes in walnut allergenicity after processing treatments by in vitro techniques and physiologically relevant assays. The allergenicity of walnuts subjected to high hydrostatic pressure and thermal/pressure treatments was evaluated by IgE-immunoblot and antibodies against walnut major allergen Jug r 4. The ability of processed walnut to cross-link IgE on effector cells was evaluated using a rat basophil leukaemia cell line and by skin prick testing. Susceptibility to gastric and duodenal digestion was also evaluated. The results showed that walnuts subjected to pressure treatment at 256 kPa, 138 °C, were able to diminish the IgE cross-linking capacity on effector cells more efficiently than high pressure treated walnuts. IgE immunoblot confirmed these results. Moreover, higher susceptibility to digestion of pressure treated walnut proteins was observed. The use of processed walnuts with decreased IgE binding capacity could be a potential strategy for walnut tolerance induction.

Conformational epitope mapping of Pru du 6, a major allergen from almond nut.

Tree nuts are a widely consumed food. Although enjoyed safely by most individuals, allergic reactions to tree nuts, including almond, are not uncommon. Almond prunin (Pru du 6), an 11S globulin (legumin), is an abundant nut seed protein and a major allergen. Conformational epitope mapping studies of prunin have been performed with a murine monoclonal antibody (mAb) 4C10. This mAb reacts with non-reduced but not reduced prunin in immunoblotting assays, indicating the recognition of a conformational epitope. 4C10 competes with patient IgE, as assessed by ELISA, indicating clinical significance of the epitope. To characterize the 4C10 epitope, hydrogen/deuterium exchange (HDX) monitored by 14.5 T Fourier transform ion cyclotron resonance mass spectrometry (MS) was performed on the native prunin-4C10 complex and on uncomplexed native prunin. Several epitope candidate peptides that differ in deuterium uptake between the complexed and uncomplexed forms were identified. The epitope was further mapped by analyzing chimeric molecules incorporating segments of the homologous soybean allergen, Gly m 6, in immunoassays. These data indicate that the 4C10 epitope overlaps with a subset of patient IgE binding epitopes on almond prunin and further supports HDX-MS as a valid technique for mapping conformational epitopes.

Asthma and pregnancy.

Asthma is probably the most common serious medical disorder that may complicate pregnancy. A third of pregnant women with asthma will experience worsening of their symptoms, a third will see improvement of their symptoms and a third will see no change. The primary goal is to maintain optimal control of asthma for maternal health and well-being as well as fetal maturation. Vital patient education should cover the use of controller medication, avoidance of asthma triggers and early treatment of asthma exacerbations. Proper asthma management should ideally be started in the preconception period. Since smoking is probably the most modifiable risk factor of asthma, pregnant woman should avoid active and passive smoking. Acute asthma exacerbation during the first trimester is associated with an increased risk of congenital malformations. Poorly controlled asthma is associated with low birth weight, preeclampsia, and preterm birth. Medications used for asthma control in the non-pregnant population are generally the same in pregnancy with a few exceptions. Inhaled corticosteroids (ICS) are the preferred controller therapy. Budesonide is the preferred ICS. Long-acting B-agonists (LABA) are the preferred add-on therapy to medium to high dose ICS. Major triggers for asthma exacerbations during pregnancy are viral infections and ICS nonadherence.

Overview of penicillin allergy.

Allergy to penicillin is the most commonly reported antibiotic allergy. However, most patients who report a positive history of a prior reaction to penicillin are not found to be allergic to penicillin upon skin testing. Often, this history is vague or based on a parent's recollection of an event that occurred in the distant past. Avoidance of penicillin based on self-reported allergic history alone often leads to the use of an alternate antibiotic with greater cost or side effect profile. Patients with a negative skin test to both major and minor determinants may generally be given penicillin, with a statistical risk of developing an allergic reaction similar to that observed in the general population. A more cautious approach in these cases where the degree of suspicion is low, an allergic etiology is unproven, or there is a negative skin test, is to do a graded challenge. If the skin test is positive, an alternate antibiotic should be used. If, however, an alternate antibiotic is not available, then desensitization may be performed, but there are limitations to desensitization as well, and tolerance is not permanent. Avoidance of cephalosporins may be recommended in cases of penicillin allergy, but newer generation cephalosporins have demonstrate less cross-reactivity to penicillin than earlier generation ones. Desensitization protocols for cephalosporins are available but not standardized. The mechanisms of antibiotic sensitization are not clearly understood.

Cloning, expression and patient IgE reactivity of recombinant Pru du 6, an 11S globulin from almond.

BACKGROUND: IgE-reactive proteins have been identified in almond; however, few have been cloned and tested for specific patient IgE reactivity. Here, we clone and express prunin 1 and prunin 2, isoforms of the major almond protein prunin, an 11S globulin, and assay each for IgE reactivity. METHODS: Prunin isoforms were PCR-amplified from an almond cDNA library, sequenced, cloned and expressed in Escherichia coli. Reactivity to the recombinant (r) allergens, Pru du 6.01 and Pru du 6.02, was screened by dot blot and immunoblot assays using sera from almond-allergic patients and murine monoclonal antibodies (mAbs). Sequential IgE-binding epitopes were identified by solid-phase overlapping peptide analysis. Epitope stability was assessed by assaying denatured recombinant proteins by immunoblot. RESULTS: IgE reactivity to rPru du 6.01 and rPru du 6.02 was found in 9 of 18 (50%) and 5 of 18 patients (28%), respectively. Four patients (22%) demonstrated reactivity to both isoforms. Murine anti-almond IgG mAbs also showed greater reactivity to rPru du 6.01 than to rPru du 6.02. Both stable and labile epitopes were detected. Six IgE-binding sequential epitope-bearing peptide segments on Pru du 6.01 and 8 on Pru du 6.02 were detected using pooled almond-allergic sera. CONCLUSIONS: rPru du 6.01 is more widely recognized than rPru du 6.02 in our patient population. The identification of multiple sequential epitopes and the observation that treatment with denaturing agents had little effect on IgE-binding intensity in some patients suggests an important role for sequential epitopes on prunins.

Effect of walnut (Juglans regia) polyphenolic compounds on ovalbumin-specific IgE induction in female BALB/c mice.

English walnuts are implicated in severe, IgE-mediated food allergy in humans. We sought to determine if polyphenolic compounds extracted from the edible nut could promote IgE production to a coadministered allergen. BALB/c mice were sensitized to ovalbumin (OVA) with or without alum (AL) or polyphenolic-enriched extract via intraperitoneal injection. Serum was analyzed for total IgE and OVA-specific IgE, IgG(1,) and IgG(2a/2b). Coadministration of walnut polyphenolic-enriched extract with antigen and AL increased serum concentrations of antigen-specific IgE and IgG(1). When AL was excluded from the injections, polyphenolic extract tended to enhance OVA-specific IgE and IgG(1) over levels induced by OVA alone, but the increase did not reach significance. Serum IgG(2a/2b) levels were similar between mice receiving OVA/AL and OVA/AL with polyphenolics. Thus, walnut polyphenolic extract enhanced the Th2-skewing effect of an aluminum hydroxide adjuvant. This indicates that walnut polyphenolic compounds may play a role in allergic sensitization of genetically predisposed individuals.

Ellagic acid and polyphenolics present in walnut kernels inhibit in vitro human peripheral blood mononuclear cell proliferation and alter cytokine production.

Tree nuts, including walnuts, are important elicitors of food allergy. We examined the ability of walnut kernel polyphenolics and purified ellagic acid (EA) to modulate cytokine production and cellular proliferation from stimulated human peripheral blood mononuclear cells (PBMC). IL-13 and TNF-alpha production decreased while no change was observed in IL-4 production. Paradoxically, EA and the walnut polyphenolics all significantly and dose-dependently inhibited stimulated [phytohemagglutin (PHA), alpha-CD3, and phorbol myristate acetate (PMA)/ionomycin] PBMC proliferation while simultaneously increasing IL-2 production. When added at time 0 min and 2 h, EA dose-dependently inhibited PHA-induced proliferation. However, at 30 min and 1 h, low doses of EA (10 and 1 muM) significantly increased proliferation above that of PHA alone, although higher doses led to inhibition. Our data do not support the hypothesis that walnut polyphenolics skew a cytokine response toward Th2 in an in vitro environment. However, immunomodulatory effects are present, including an inhibition of cellular proliferation despite no decrease in IL-4 or IL-2.

Macrophage activation syndrome in autoimmune disease.

Macrophage activation syndrome (MAS) is a phenomenon characterized by cytopenia, organ dysfunction, and coagulopathy associated with an inappropriate activation of macrophages. Current diagnostic criteria are imprecise, but the syndrome is now recognized as a form of hemophagocytic lymphohistiocytosis that is characteristically associated with autoimmune diatheses. The diagnosis of incipient MAS in patients with autoimmune disease requires a high index of suspicion, as several characteristics of the disorder may be present in the underlying condition or infectious complications associated with the treatment thereof. Proposed treatment regimens include aggressive approaches that require validation in future controlled studies. This review discusses the major aspects of the pathophysiology, diagnosis, and management of MAS with a focus on the association with autoimmune disease.

Characterization of a cashew allergen, 11S globulin (Ana o 2), conformational epitope.

Both linear and conformational epitopes likely contribute to the allergenicity of tree nut allergens, yet, due largely to technical issues, few conformational epitopes have been characterized. Using the well studied recombinant cashew allergen, Ana o 2, an 11S globulin or legumin, we identified a murine monoclonal antibody which recognizes a conformational epitope and competes with patient IgE Ana o 2-reactive antibodies. This epitope is expressed on the large subunit of Ana o 2, but only when associated with an 11S globulin small subunit. Both Ana o 2 and the homologous soybean Gly m 6 small subunits can foster epitope expression, even when the natural N-terminal to C-terminal subunit order is reversed in chimeric molecules. The epitope, which is also expressed on native Ana o 2, is readily susceptible to destruction by physical and chemical denaturants.