Background In 2009, we reported a novel form of delayed anaphylaxis to red meat, which is related to serum IgE antibodies to the oligosaccharide galactose-alpha-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 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 using biotinylated proteins and extracts bound to a streptavidin ImmunoCAP. Results Prospective studies on IgE antibodies in three subjects following tick bites showed an increase in IgE to alpha-gal of twenty-fold or greater. Other evidence included i) a strong correlation between histories of tick bites and IgE to alpha-gal (χ2=26.8, p<0.001), ii) evidence that these IgE antibodies are common in areas where the tick Amblyomma americanum is common, and iii) a significant correlation between IgE antibodies to alpha-gal and IgE antibodies to proteins derived from A. americanum (rs=0.75, p<0.001). Conclusion The results presented here provide evidence that tick bites are a cause, or 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.

In ages >45 years, the prevalence of COPD according to the BTS guidelines was 8%, and it was 14% according to the GOLD criteria. Fifty percent of elderly smokers had developed COPD. The large majority of subjects having COPD were symptomatic, while the proportion of those diagnosed as having COPD or similar diagnoses was small.

An inverse relationship has been proposed between exposure to high quantities of cat allergen at home and both asthma and cat allergy. First- and second-grade children from Luleå, Kiruna, and Piteå, Sweden participated in an asthma questionnaire study (n = 3,431) and incidence was evaluated over the next 3 years. Skin testing was performed on the children in Luleå and Kiruna (n = 2,149). The strongest risk factor for incident cases of asthma was Type 1 allergy (relative risk [RR], 4.9 [2.9-8.4]), followed by a family history of asthma (RR, 2.83 [1.8-4.5]). Living with a cat was inversely related both to having a positive skin test to cat (RR, 0.62 [0.47-0.83]) and incidence of physician-diagnosed asthma (RR, 0.49 [0.28-0.83]). This effect on incident asthma was most pronounced among the children with a family history of asthma (RR, 0.25 [0.08-0.80]). The evidence also suggests that many of the children exposed to cats at home can develop an immune response that does not include immunoglobulin E. Weaker protective trends were seen with dog ownership. The traditional thinking that not owning cats can provide protection against developing allergy and asthma among those with a family history of allergy needs to be re-evaluated. In a community where cat sensitization was strongly associated with asthma, owning a cat was protective against both prevalent and incident asthma.

Background Time trends for allergic sensitization are poorly known. Aim To compare the trends in prevalence of allergic sensitization and associated risk factors in children. Methods Two cohorts of children (age 7–8 years) were invited to skin prick testing (SPT) ten years apart, 1996 and 2006. Participation rate was 2148 (88%) and 1700 (90%), respectively. The methods were identical and ten common airborne allergens were used. An expanded ISAAC-questionnaire about symptoms and possible risk factors for allergic conditions was completed by the parents. Results The prevalence of any positive SPT increased from 21% in 1996 to 30% in 2006 (p<0.001). The pattern of sensitization remained similar, and sensitization to cat was most common both years, 13% and 19%, respectively. Sensitization to mites and mould were uncommon in both surveys. A family history of allergy was a significant risk factor for a positive SPT both years (OR 1.7). Factors that in 1996 had a protective effect, i.e. rural living and having several siblings, had lost this effect in 2006. The prevalence of most risk factors remained similar, but respiratory infections and smoking among parents decreased significantly. During the same period there was no significant increase in prevalence of current wheeze (11.9% to 12.4%, n.s.) or symptoms of rhinitis or eczema. Conclusion The prevalence of allergic sensitization increased significantly from 1996 to 2006, while no increase in clinical symptoms was found. The parallel decrease in parental smoking and respiratory infections indicate a different influence of environmental factors on allergic sensitization and clinical symptoms, respectively.

Exacerbations are the key drivers in the costs of chronic obstructive pulmonary disease (COPD). The objective was to examine the costs of COPD exacerbations in relation to differing degrees of severity of exacerbations and of COPD. We identified 202 subjects with COPD, defined according to the BTS and ERS criteria. Exacerbations were divided into mild (self-managed), mild/moderate (telephone contact with a health-care centre and/or the use of antibiotics/systemic corticosteroids), moderate (health-care centre visits) and severe (emergency care visit or hospital admission). Exacerbations were identified by sending the subjects a letter inquiring whether they had any additional respiratory problems or influenza the previous winter. At least one exacerbation was reported by 61 subjects, who were then interviewed about resource use for these events. The average health-care costs per exacerbation were SEK 120 (95% C=39-246), SEK 354 (252-475), SEK 2111 (1673-2612) and SEK 21852 (14436-29825) for mild, mild/moderate, moderate and severe exacerbations, respectively. Subjects with impaired lung function experienced more severe exacerbations, which was also reflected in the cost of exacerbations per severity of the disease during the 4 1/2 month study period (ranging from SEK 224 for mild to SEK 13708 for severe cases, median SEK 940). Exacerbations account for 35-45% of the total per capita health-care costs for COPD. In conclusion, costs varied considerably with the severity of the exacerbation as well as with the severity of COPD. The prevention of moderate-to-severe exacerbations could be very cost-effective and improve the quality of life.