Value of microarray allergen assay in the management of eosinophilic oesophagitis.

BACKGROUND: Eosinophilic oesophagitis (EoE) is a disorder characterised by oesophageal dysfunction and, histologically, by eosinophilic inflammation. Although treatment, which includes dilatations, oral corticosteroids and restrictive diets, is often effective, choosing the foods to be eliminated from the diet is difficult. OBJECTIVE: Component resolved diagnostic by microarray allergen assay may be useful in detecting allergens that might be involved in the inflammatory process. METHODS: We studied 67 patients with EoE, diagnosed clinically and histologically by endoscopic biopsy. CRD analysis with microarray technology was carried out in the 67 EoE patients, 50 patients with pollen allergy without digestive symptoms, and 50 healthy controls. RESULTS: Allergies were not detected by microarray in only seven of the 67 patients with EoE. Controls with pollen allergy showed sensitisation to different groups of pollen proteins without significant differences. In EoE patients with response to some allergens, the predominant allergens were grasses group 1 and, in particular, nCyn d 1 (Cynodon dactylon) or Bermuda grass pollen in 59.5%, followed by lipid transfer proteins (LTP) of peach (19.40%), hazelnut (17.91%) and Artemisia (19.40%). CONCLUSIONS: In patients with EoE, sensitisation to plant foods and pollen is important. The proteins most frequently involved are nCyn d 1 and lipid transfer proteins, hazelnuts and walnuts. After one year of an array-guided exclusion diet and pollen-specific immunotherapy in the case of high levels of response, patients with EoE showed preliminary significant improvements.

Frequencies of HLA-A24 and HLA-DR4-DQ8 are increased and that of HLA-B blank is decreased in chronic toxic oil syndrome.

The cause of toxic oil syndrome (TOS) has not yet been definitively determined, but some genetic susceptibility factors (certain HLA antigens and female sex) have been identified in 236 patients. Similarities with genetic factors for scleroderma and hydralazine-induced lupus (i.e. in TOS female sex and HLA-A24, Pcorrected = 0.00001 and DR4, Pcorrected = 0.04, respectively) may provide a clue to the responsible xenobiotic and its pathogenesis, and may also help in understanding the basis of the related eosinophilia-myalgia syndrome associated with tryptophan ingestion. In this paper it is also established that a human class I antigen (HLA-A24) and, independently, an HLA class II haplotype (DR4-DQ8, Pcorrected = 0.04) and arginine 52 in the alpha-DQ chains (Pcorrected = 0.03) are associated with TOS susceptibility, similarly to insulin-dependent diabetes. This further supports the classification of TOS as an autoimmune disease. Also, the increased frequency of a particular set of low-frequency HLA class I antigens in chronic TOS patients (i.e. B27, B37, B38 and B49) and the probable decrease in the frequency of HLA-B homozygotes in surviving patients (Pcorrected = 0.008) may provide an objective model to explain the maintenance of the HLA polymorphism: less frequent HLA alleles may be more advantageous in the event of unexpected human contact with unusual xenobiotics (not only microbes); however, other mechanisms working together to preserve and generate HLA polymorphism may coexist.