Study On The Relationship Between Dermatophagoides And Atopic Dermatitis And CDNA Cloning Of Major Allergen Ermatophagoides Farinae (Der F1 And Der F2)

Dust mites, which include Dermatophagoides pteronyssinus and Dermatophagoides farinae, are the most important allergens in allergic diseases and almost ubiquitous. Atopic dermatitis (AD) is also known as atopic eczema, which is a chronic, inflammatory, recurrent and pruritus skin disease characterized by elevated serum IgE. It is well known that the most of allergens in AD were from the environment and the dust mites are the major one.The study included two parts, one was analyzing the relationship between AD and dust mites, which was the retrospective study of AD patients by analyzing the inhaling allergens and dust-mite-special IgE, the other was cDNA cloning and sequencing of Dermatophagoides farinae major allergens of Der fl and Derf2, including section one and section two.Objectives: To explore the relationship between house dust mite and atopic dermatitis (AD). And to clone and analyze the cDNA of major allergen Der fl and Der f2 of Dermatophagoides farinae inChina. This would lay a foundation for Der f1 and Der f2 proteins expression, and further for the diagnosis and therapy of house dust mite allergic diseases. Method: A Retrospective study was employed to analyzed the major inhaling allergens and dust mites specialized IgE in AD patients.The total RNA of Dermatophagoides farinae was extracted by Trizol. The cDNA of Der fl and Der f2 was amplified with RT-PCR, then were cloned into the vector pMD18-T Simple and sequenced.. Results: The retrospective study showed that the inhaling allergens of AD patients in north China were similar. The commonest allergens were house dust mite, mixed inhaling allergens, house dirt, respectively. The serum Dermatophagoides pteronyssinus and Dermatophagoides farinae special IgE of AD patients are significantly higher than that of the controls (p<0.05) .Two segments with 361 bases of Der fl were determined. Compared the sequence homology with the published Der fl (AB034946) on Genebank, one was 100% at the nucleotide level, the other was 99.7% at the nucleotide level with two different bases . Just the same, the two segments with 436 bases of Der f2 were determined. Compared the sequence homology with the published Der f2(D10448 )on Genebank, one was 98.6% at the nucleotide level with six different bases. The other one was 99.7% at the nucleotide level with two different basesConclusion: The house dust mites were associated with atopic dermatitis. The gene sequences of Der fl and Der f2 of the house dust mite showed polymorphism, which indicated that the allergens of Dermatophagoides farinae be multiple and the therapy of allergic diseases be complicated.