Galactose-α-1,3-galactose-specific IgE is associated with anaphylaxis but not asthma.

RATIONALE: IgE antibodies to the mammalian oligosaccharide galactose-α-1,3-galactose (α-gal) are common in the southeastern United States. These antibodies, which are induced by ectoparasitic ticks, can give rise to positive skin tests or serum assays with cat extract. OBJECTIVES: To evaluate the relationship between IgE antibodies to α-gal and asthma, and compare this with the relationship between asthma and IgE antibodies to Fel d 1 and other protein allergens. METHODS: Patients being investigated for recurrent anaphylaxis, angioedema, or acute urticaria underwent spirometry, exhaled nitric oxide, questionnaires, and serum IgE antibody assays. The results were compared with control subjects and cohorts from the emergency department in Virginia (n = 130), northern Sweden (n = 963), and rural Kenya (n = 131). MEASUREMENTS AND MAIN RESULTS: Patients in Virginia with high-titer IgE antibodies to α-gal had normal lung function, low levels of exhaled nitric oxide, and low prevalence of asthma symptoms. Among patients in the emergency department and children in Kenya, there was no association between IgE antibodies to α-gal and asthma (odds ratios, 1.04 and 0.75, respectively). In Sweden, IgE antibodies to cat were closely correlated with IgE antibodies to Fel d 1 (r = 0.83) and to asthma (P < 0.001). CONCLUSIONS: These results provide a model of an ectoparasite-induced specific IgE response that can increase total serum IgE without creating a risk for asthma, and further evidence that the main allergens that are causally related to asthma are those that are inhaled.

Prevalence and titer of IgE antibodies to mouse allergens.

BACKGROUND: Positive skin tests to allergens derived from mouse urine have been reported among patients with asthma. Very few data are available detailing the titer of IgE Ab to mouse allergen and how it varies by location and population. OBJECTIVE: To evaluate further the prevalence and titer of IgE Ab to mouse-derived allergens and their relevance to total IgE and asthma. METHODS: IgE Ab to mouse allergens was measured in 1165 sera from diverse populations including children and adults. The results were compared with IgE Ab to other allergens and total serum IgE. RESULTS: Positive results were found in 79 sera, but only 15 had an IgE Ab titer >or=10 IU/mL. Results for IgE Ab to Mus m 1 showed a close quantitative correlation with IgE Ab to mouse allergen (r = 0.93; P < .001). Cohorts in neither Atlanta nor Virginia contained sera in which IgE Ab to mouse was dominant over other allergens or contributed significantly to total IgE. By contrast, among 319 mothers from minority groups in Boston, 11 sera had >or=10 IU/mL. In these sera, specific IgE Ab to mouse made a significant contribution to the total. CONCLUSION: Mouse allergen sensitization may contribute significantly to total IgE and allergy in African American and Hispanic populations from some northern cities. Analysis of the significance of an IgE Ab response should include quantitative comparison with other responses and total IgE. CLINICAL IMPLICATIONS: Significance of rodent infestation and IgE Ab varies dramatically in different populations and areas of the United States.

Sinus computed tomography scan and markers of inflammation in vocal cord dysfunction and asthma.

BACKGROUND: The inappropriate closure of the vocal cords is characteristic of vocal cord dysfunction (VCD). These patients present with wheezing and frequently receive a misdiagnosis of asthma. OBJECTIVE: To demonstrate the ability of computed tomography (CT) scored for the presence and extent of sinus disease and markers of inflammation to distinguish patients with VCD from patients with asthma. METHODS: Comparisons of 13 patients with VCD were made to 77 patients presenting to the emergency room with acute asthma, 31 non-acute asthmatic patients, and 65 nonasthmatic controls. Evaluation consisted of exhaled nitric oxide gas (eNO), circulating eosinophils, and total serum immunoglobulin (Ig)E, as well as the sinus CT scan. RESULTS: Extensive sinus CT changes were present in 23 of 74 acute asthmatic patients, 5 of 29 non-acute asthmatic patients, and 2 of 59 nonasthmatic controls. In addition, absolute eosinophil counts, eNO, and total IgE were significantly elevated among the asthmatic patients. Sinus symptoms reported by questionnaire did not predict sinus CT findings. Among the patients with VCD, none had extensive sinus disease. They also had normal eNO, low IgE, and normal eosinophil count. Five of the patients presenting to the emergency room who were identified as acute asthmatic were identified with VCD by laryngoscopy and were all characterized by the absence of significant inflammation on their sinus CT scan, low IgE, and normal eosinophil count. CONCLUSIONS: Among patients presenting with intermittent or reversible airway obstruction, patients with VCD can be distinguished from asthma by minimum or absence of inflammation in their sinuses as shown by CT scan. Clinical symptom scores are not predictive of presence or extent of sinus disease in most cases.