Estimating the Risk of Severe Peanut Allergy Using Clinical Background and IgE Sensitization Profiles.

Background: It is not well-understood why symptom severity varies between patients with peanut allergy (PA). Objective: To gain insight into the clinical profile of subjects with mild-to-moderate and severe PA, and investigate individual and collective predictive accuracy of clinical background and IgE to peanut extract and components for PA severity. Methods: Data on demographics, patient history and sensitization at extract and component level of 393 patients with probable PA (symptoms ≤ 2 h + IgE sensitization) from 12 EuroPrevall centers were analyzed. Univariable and penalized multivariable regression analyses were used to evaluate risk factors and biomarkers for severity. Results: Female sex, age at onset of PA, symptoms elicited by skin contact with peanut, family atopy, atopic dermatitis, house dust mite and latex allergy were independently associated with severe PA; birch pollen allergy with mild-to-moderate PA. The cross-validated AUC of all clinical background determinants combined (0.74) was significantly larger than the AUC of tests for sensitization to extract (0.63) or peanut components (0.54-0.64). Although larger skin prick test wheal size, and higher IgE to peanut extract, Ara h 1 and Ara h 2/6, were associated with severe PA, and higher IgE to Ara h 8 with mild-to-moderate PA, addition of these measurements of sensitization to the clinical background model did not significantly improve the AUC. Conclusions: Models combining clinical characteristics and IgE sensitization patterns can help establish the risk of severe reactions for peanut allergic patients, but clinical background determinants are most valuable for predicting severity of probable PA in an individual patient.

Molecular characterization of recombinant mus a 5 allergen from banana fruit.

Allergy to banana fruit appears to have become an important cause of fruit allergy in Europe. Among five allergens that have been found, beta-1,3-glucanase denoted as Mus a 5 was identified as a candidate allergen for the component-resolved allergy diagnosis of banana allergy. Because of the variations in protein levels in banana fruit, in this study Mus a 5 was produced as a fusion protein with glutathione-S-transferase in Escherichia coli. The recombinant Mus a 5 was purified under native conditions by a combination of affinity, ion-exchange, and reversed phase chromatography. N-terminal sequence was confirmed by Edman degradation and 55 % of the primary structure was identified by mass fingerprint, while the secondary structure was assessed by circular dichroism spectroscopy. IgG reactivity of recombinant protein was shown in 2-D immunoblot with anti-Mus a 5 antibodies, while IgG and IgE binding to natural Mus a 5 was inhibited with the recombinant Mus a 5 in immunoblot inhibition test. IgE reactivity of recombinant Mus a 5 was shown in ELISA within a group of ten persons sensitized to banana fruit. Recombinant Mus a 5 is a novel reagent suitable for the component-resolved allergy diagnosis of banana allergy.

Molecular and immunological characterization of Mus a 5 allergen from banana fruit.

SCOPE: Banana fruit has become an important cause of fruit allergy in the recent years. Among the five registered IUIS allergens, Mus a 1 and Mus a 2 have been characterized in detail. In this study, molecular characterization and evaluation of the allergenic properties of ß-1,3-glucanase from banana (Musa acuminata), denoted as Mus a 5, were performed. METHODS AND RESULTS: The gene of Mus a 5 was cloned and sequenced. The obtained cDNA revealed a novel Mus a 5 isoform with an open reading frame encoding a protein of 340 amino acids comprising a putative signal peptide of 28 amino acid residues. By MALDI-TOF analysis Mus a 5 isolated from banana fruit revealed a molecular mass of 33451±67 Da. Two Mus a 5 isoforms (pI 7.7 and 8.0) were detected by 2D immunoblot with an identical N-terminal sequence. By mass fingerprint, 76 and 83% of the primary structure was confirmed for the two mature Mus a 5 isoforms, respectively. IgE reactivity to Mus a 5 was found in 74% of patients sensitized to banana fruit. Upregulation of basophil activation markers CD63 and CD203c was achieved with Mus a 5 in a concentration-dependent manner. CONCLUSION: Mus a 5 is a functional allergen and a candidate for the component-resolved allergy diagnosis of banana allergy.

Risk of allergic reactions to wine, in milk, egg and fish-allergic patients.

BACKGROUND: European legislators and wine producers still debate on the requirement for labeling of wines fined with potentially allergenic food proteins (casein, egg white or fish-derived isinglass). We investigated whether wines fined with known concentrations of these proteins have the potential to provoke clinical allergic reactions in relevant patients. METHODS: In-house wines were produced for the study, fined with different concentrations of casein (n = 7), egg albumin (n = 1) and isinglass (n = 3). ELISA and PCR kits specific for the respective proteins were used to identify the fining agents. Skin prick tests and basophil activation tests were performed in patients with confirmed IgE-mediated relevant food allergies (n = 24). A wine consumption questionnaire and detailed history on possible reactions to wine was obtained in a multinational cohort of milk, egg or fish allergic patients (n = 53) and patients allergic to irrelevant foods as controls (n = 13). RESULTS: Fining agents were not detectable in wines with the available laboratory methods. Nevertheless, positive skin prick test reactions and basophil activation to the relevant wines were observed in the majority of patients with allergy to milk, egg or fish, correlating with the concentration of the fining agent. Among patients consuming wine, reported reactions were few and mild and similar with the ones reported from the control group. CONCLUSION: Casein, isinglass or egg, remaining in traces in wine after fining, present a very low risk for the respective food allergic consumers. Physician and patient awareness campaigns may be more suitable than generalized labeling to address this issue, as the latter may have negative impact on both non-allergic and allergic consumers.

Community-acquired pneumonia in children.

PURPOSE OF REVIEW: This review highlights recent developments in the diagnosis, etiology, therapy, and prevention of community-acquired pneumonia in children. RECENT FINDINGS: Sensitive new diagnostic methods have increased the detection rate of the causative agent up to 94%. Streptococcus pneumoniae is the most prevalent bacterial pathogen in all ages. Polymerase chain reaction is a rapid and sensitive method for the detection of Chlamydia pneumoniae and Mycoplasma pneumoniae, which have gained greater importance in recent years. During the period covered by this review, two new agents causing pneumonia were extensively studied. Human metapneumonovirus detected in young children is a leading cause of respiratory disease during the first years of life. A novel coronavirus was identified as the causative agent of severe respiratory syndrome, a new respiratory illness that affects adults and children. One multicenter trial concluded that nonsevere pneumonia can be treated with a short course of oral amoxicillin and a multicenter international study showed that children with severe pneumonia have similar outcomes whether treated with oral amoxicillin or parenteral penicillin, but more data are needed to demonstrate the safety and efficacy of such regimens. SUMMARY: The continued evolution of bacterial resistance highlights the need for appropriate use of antibacterials. Improved diagnostic techniques will aid the treatment of children with community-acquired pneumonia. Aggressive vaccination with the pneumococcal conjugate vaccine and other available vaccines as well as the development of new vaccines will aid the prevention of respiratory disease in children.