Background In 2009, we reported a novel form of delayed anaphylaxis to red meat that is related to serum IgE antibodies to the oligosaccharide galactose-α-1,3-galactose (alpha-gal). Most of these ...patients had tolerated meat for many years previously. The implication is that some exposure in adult life had stimulated the production of these IgE antibodies. Objectives We sought to investigate possible causes of this IgE antibody response, focusing on evidence related to tick bites, which are common in the region where these reactions occur. Methods Serum assays were carried out with biotinylated proteins and extracts bound to a streptavidin ImmunoCAP. Results Prospective studies on IgE antibodies in 3 subjects after tick bites showed an increase in levels of IgE to alpha-gal of 20-fold or greater. Other evidence included (1) a strong correlation between histories of tick bites and levels of IgE to alpha-gal (χ2 = 26.8, P < .001), (2) evidence that these IgE antibodies are common in areas where the tick Amblyomma americanum is common, and (3) a significant correlation between IgE antibodies to alpha-gal and IgE antibodies to proteins derived from A americanum ( rs = 0.75, P < .001). Conclusion The results presented here provide evidence that tick bites are a cause, possibly the only cause, of IgE specific for alpha-gal in this area of the United States. Both the number of subjects becoming sensitized and the titer of IgE antibodies to alpha-gal are striking. Here we report the first example of a response to an ectoparasite giving rise to an important form of food allergy.
For the 301 with positive results (>0.35 IU/ml) the sera were further assayed for 112 purified allergens using ISAC, and compared with results for IgE in patients with peanut allergy or with EoE.
Little is known regarding the epidemiology of sIgG4 to CM or other foods in the general population. ...the diagnostic utility of IgG4 assays is unclear.
The icosahedral RV capsid is composed of viral proteins (VP) 1-4, and antibodies directed against epitopes on exterior regions of VP1-3 are a major component of the humoral response to infection.
Methods ImmunoCAP for specific IgE antibodies to cow's milk and IgG4 antibodies to cow's milk components Bos d 4 (alpha-lactalbumin), Bos d 5 (beta-lactoglobulin), Bos d 6 (bovine serum albumin; ...BSA), and Bos d 8 (caseins) were performed on sera collected before and after treatment with either cow's milk elimination diet or fluticasone.
Methods Quantitative assays for IgE to eight allergens were carried out on 963 sera from 19-year-olds in a population-based cohort in northern Sweden, and associations with questionnaire data from ...ages 7, 12, and 19 on asthma symptoms, diagnosis, and treatment were tested.
Tick bites are known to induce IgE production to alpha-gal. Elevated alpha-gal IgG1 compared to natural alpha-gal IgG2 production has been reported in alpha-gal IgE+ subjects. We here report further ...investigation of the relationship between alpha-gal IgG and both reactions to red meat and exposure to ticks. Methods: IgG from serum was absorbed onto recombinant Protein G-Sepharose and incubated with radiolabeled allergen. The radioactivity of bound allergen was measured using a gamma counter. A control curve was generated in parallel to assign unitage. Additional testing of serum immunoglobulins was performed via ImmunoCAP and nephelometry. Results: Alpha-gal IgG was measured in a Northern Sweden cohort and in subjects presenting to allergy clinics in Virginia with delayed reactions to red meat. Alpha-gal IgG was significantly higher in alpha-gal IgE+ subjects versus alpha-gal IgE- subjects, and longitudinal serology in several alpha-gal IgE+ subjects demonstrates parallel alpha-gal IgE and IgG response trends. Among the alpha-gal IgE+ subjects, alpha-gal IgG was higher in those with alpha-gal IgE:total IgE ratios >25%, but was not related to reported severity to red meat. Compared to the alpha-gal IgE- subjects in Virginia, alpha-gal IgG was lower in the group from Northern Sweden, where alpha-gal IgE-mediated hypersensitivity is absent and ticks are rare. Conclusions: Alpha-gal IgG is strongly related to alpha-gal IgE and is significantly lower in prevalence and titer in subjects without tick exposure. The absence of a relationship between alpha-gal IgG and severity of reactions to red meat suggests that the alpha-gal syndrome may not be a suitable candidate for conventional immunotherapy.
Conclusions Patients with delayed anaphylaxis to red meat present a novel disease with late onset, delayed expression, no immediate symptoms of food allergy, and a very high incidence of previous ...exposure to ticks.
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