Profilin cross-reactive panallergen causes latex sensitization in the pediatric population allergic to pollen.

BACKGROUND: Component-resolved diagnostics (CRD) has been demonstrated to be an excellent new tool for improving the current diagnosis of allergies, and it allows differentiation between polysensitization and cross-reactivity. OBJECTIVE: To demonstrate the role of cross-reactive pollen allergens in pediatric patients living in areas with large amounts of airborne grass pollen grains who are sensitive to grass pollen and latex. METHODS: Serum samples were obtained from 106 children between 3 and 14 years of age diagnosed with allergies to pollen based on clinical history, skin prick tests, and specific immunoglobulin E (IgE). None of them had allergy symptoms to latex or fruits. From these 106 children, 56 patients revealed positive results to Phleum-specific major allergens but not to cross-reactive allergens. The other 50 patients who showed positive specific IgE to Phleum-specific major allergens and to cross-reactive pollen allergens also showed positive results to latex allergens. CRD was carried out by specific IgE quantification using a fluoro-enzyme immunoassay (ImmunoCAPT System). RESULTS: Results demonstrated a positive significant relationship between the specific IgE to Hev b 8 and Phl p 12 and also between the specific IgE to Hev b 8 and latex extract in the group of patients sensitized to species-specific and cross-reactive Phleum allergens. Positive significant relationships were also found between profilin and avocado or peach sensitizations. No other latex allergens gave positive results. CONCLUSION: The apparent sensitization to latex in pediatric patients allergic to grass pollen is caused by the cross-reactive profilin panallergen; however, it is appears not to be clinically relevant.

Fungi Sensitization in Spain: Importance of the Alternaria alternata Species and Its Major Allergen Alt a 1 in the Allergenicity.

Prevalence of allergy to fungi is around 3-10%. The most prevalent species involved in sensitizations are Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum, and Penicillium notatum. Our main objective was to estimate the prevalence of fungal sensitization and its variation across Spain. Following the ICH-GCP, we recruited 1156 patients from 15 allergy departments in Spain. Hospitals were selected by bioclimatic areas. Patients underwent a skin prick test (SPT) with fungi, pollens, house dust mites, and animal dander. Specific IgE to Alternaria alternata and Alt a 1 was assessed in patients with positive SPT to fungi. Of the 233 patients (20.2%) sensitized to at least one of the five fungi tested, 162 (69.5%) were sensitized to Alternaria alternata and Alt a 1, of whom 113 (69.8%) were children; 181 (77.7%) were also polysensitized to other allergens. Alternaria alternata and Alt a 1 sensitization was present in 25.4% of patients in the Continental area, 12.0% in the Mediterranean area, 7.0% in the Semidesertic area, and 2.3% in the Oceanic area. Prevalence of sensitization to the other tested sources was 63.8% to pollens, 60.5% to house dust mite, and 38.1% to animal dander. We concluded that the prevalence of fungal allergy is increasing. Fungi are still the fourth source of allergen sensitization. Alternaria alternata sensitization is the most prevalent in allergic patients to fungi. Alt a 1 is present in almost 90% of the patients sensitized to Alternaria alternata.

Sensitivity to bee venom antigen phospholipase A2: association with specific HLA class I and class II alleles and haplotypes in beekeepers and allergic patients.

Bee venom hypersensitivity is a clinical entity of outstanding importance because bee stings are a leading cause of mortality worldwide. Individuals with immediate-type bee venom hypersensitivity, beekeepers, and healthy controls were examined for HLA-DRB1, DQB1, and DQA1 alleles by sequence-specific oligonucleotide probe typing. Defined hypersensitivity to bee venom antigen phospholipase A2 (vbPLA2) is significantly associated with the presence of susceptible HLA class II alleles: DRB1*0101 (RR = 2.7, p < 3 x 10(-3)), DRB1*0103 (RR = 21.2, p < 7.5 x 10(-11)), DQA1*0101 (RR = 1.2, p < 38.52 x 10(-10)), and DQB1*0501 (RR = 4, p < 2.18 x 10(-10)). Some HLA class I alleles were also associated with risk to bee venom allergy: A*01 (RR = 2.4, p < 7.5 x 10(-4)), B*57 (RR = 35.1, p < 3.5 x 10(-7)), and B*5901 (p < 3.5 x 10(-5)), but they are probably of secondary significance. Three- (DRB1*0103-DQA1*0101-DQB1*0501) (RR = 21.24, p < 7.5 x 10(-11)) and five-loci (A*01-B*59-DRB1*0103-DQA1*0101-DQB1*0501) (p < 2.3 x 10(-6)) extended haplotypes are also significantly carried by vbPLA2 allergic patients. When HLA allele frequencies from patients are compared with those from beekeepers, only HLA-DRB1*0103 (RR = 11.7, p < 8.5 x 10(-5)) and HLA-DQA1*0101 (p < 0.02) were significantly increased in the former. These observations emphasize the importance of the DRB1*0103-DQA1*0101-DQB1*0501 haplotype as a strong candidate for susceptibility to vbPLA2 hypersensitivity, at least in our region.