The cat lipocalin Fel d 7 and its cross-reactivity with the dog lipocalin Can f 1.

We investigated the prevalence of sensitization to the cat lipocalin Fel d 7 among 140 cat-sensitized Swedish patients and elucidated its allergenic activity and cross-reactivity with the dog lipocalin Can f 1. Sixty-five of 140 patients had IgE to rFel d 7 whereof 60 also had IgE to rCan f 1. A moderate correlation between IgE levels to rFel d 7 and rCan f 1 was found. rFel d 7 activated basophils in vitro and inhibited IgE binding to rCan f 1 in 4 of 13 patients, whereas rCan f 1 inhibited IgE binding to rFel d 7 in 7 of 13 patients. Fel d 7 and Can f 1 showed high similarities in protein structure and epitopes in common were found using cross-reactive antisera. Fel d 7 is a common allergen in a Swedish cat-sensitized population that cross-reacts with Can f 1, and may contribute to symptoms in cat- but also in dog-allergic patients.

Red meat allergic patients have a selective IgE response to the α-Gal glycan.

Galactose-α-1,3-galactose (α-Gal) is a mammalian carbohydrate with significance in a novel type of food allergy. Patients with IgE against α-Gal report severe allergic symptoms 3-6 h after consumption of red meat. We investigated whether IgE from red meat allergic patients recognizes other mammalian glycans than α-Gal or glycans from the plant kingdom and insects of importance in allergy. We found that none of the 24 red meat allergic patients investigated had an IgE antibody response against the other abundant mammalian glycan N-glycolylneuraminic acid or against cross-reactive carbohydrate determinants from plant or venom sources (nCup a 1, nArt v 1, and MUXF3). Deglycosylation of an α-Gal-containing protein, bovine thyroglobulin, significantly reduced the IgE response. In conclusion, we show that red meat allergic patients have a selective IgE response to the α-Gal glycan found in red meat. Other common glycans reactive in allergic disease are not targets of red meat allergic patients' IgE.

Bronchial inflammation and hyperresponsiveness in well controlled asthma.

BACKGROUND: Little research has been devoted to the characteristics of bronchial inflammation in patients with stable, well controlled asthma. OBJECTIVE: The aim of this study was to assess the degree and type of airway inflammation and to investigate the relationship between inflammation and bronchial hyperresponsiveness in patients with well controlled asthma. METHODS: A cross-sectional study was conducted in 84 adult patients (43 men, mean age 43 years) with documented well controlled asthma. Induced sputum samples were obtained and cell types determined by differential cell count. Spirometry and methacholine challenge testing were performed. Asthma Control Questionnaire (ACQ) was used to assess symptoms. Patients were included if their ACQ score was < 0.75. RESULTS: A total of 59 patients had persistent bronchial inflammation: 28 cases were considered eosinophilic, 28 neutrophilic, and 3 mixed. Median (range) percentage of eosinophils was 4% (0-64) in patients testing positive to methacholine challenge (n = 66) and 1% (0-3) in those testing negative (n = 18) (P = 0.003). A positive correlation was found between eosinophil percentage and the methacholine dose/response ratio (r = 0.477, P = 0.0001). The geometric mean (95% CI) of the methacholine PC20 was 1.74 mg/mL (1.04-2.93) in patients with eosinophilic inflammation and 4.14 mg/mL (2.5-6.84) in those with neutrophilic inflammation (P = 0.03). CONCLUSIONS: Inflammation and bronchial hyperresponsiveness persist in most patients with well controlled asthma. CLINICAL RELEVANCE: The study demonstrates that eosinophilic or neutrophilic inflammation persisted in most well controlled asthma patients despite the fact that their condition was controlled and therefore, measurement of bronchial inflammation seems essential to achieve proper asthma control.