Los genes TAP y EMP2 en el asma alérgica

Abstract

Patients with mite-induced allergic asthma (AA) present strong IgE-response to mite allergens. Thus, immunogenetic study of this response could help in the understanding of allergic disease etiology. AA is a common disease in the Tropics, Blomia tropicalis and Dermatophagoides pteronyssinus being the principal causative agents. An association between HLA class II genes and IgE-response to mite allergens in AA patients from the prevalent ethnic mulatto group in Cartagena, a Caribbean city, has already been described (by these authors), the main vector being Blomia tropicalis. TAP and LMP genes play an important part in antigen processing but their possible role in AA pathogenesis has not been well-documented. In this study, the role of TAP and LMP2 polymorphism in the control of specific IgE-response to mite allergens has been evaluated in two groups, consisting of 96 unrelated asthmatic patients with IgE-response to mite allergens and 97 non-allergic controls belonging to the mulatto ethnic group. TAPl and TAP2 were typed by PCRISSO; LMP2 was typed by PCRIRFLP. Each alleles' frequency in AA patients and controls was: TAPO1 O1 : 52.6-56.2%; TAPO2011 : 35.9-34.9%; TAP*O301: 5.2-3.8%; TAP*0401: 6.3-4.7%; TAP2A: 31.5-30.5%; TAP2B: 44.3-46.6%; TAP2C: 16.5-1 8.0%; TAP 2H: 7.7-4.9%; LMP2*HI H: 6.7-1 0.4%; LMP2'RR: 42.7-44.8%; LMP2*RH: 50.6-44.8%. There was no significant statistical difference in allele distribution between the two groups studied. In addition, no linkage disequilibrium between the HLA DRBl allele and TAP and LMP2 genes was found. These findings suggest that TAP and LMP genes are not primarily involved in AA genetic susceptibility.