Abstract
Asthma is an inflammatory disease with a strong genetic predisposition. There is a strong relationship between the immune response to several antigens, and specific HLA-DQ/DR haplotype. Objectives: The aim of this study was to determine the HLA class II (DRB1 and DQB1) phenotypic frequencies in atopic and non-atopic members of asthmatic family pedigrees and to analyze the relationship between these phenotypes and any type of asthma. Patients and methods: A series of 41 asthmatic individuals from 20 asthmatic family pedigrees assigned either to the atopic (24AA) or to the non-atopic (17-NAA) groups were studied and compared with 15 healthy age and sex matched controls. HLA class II DRB1 and DQB1 typing were done to all patients and controls using polymerase chain reaction (PCR) technique. Results: The comparison between the AA and NAA groups of patients revealed an increase in DRB1 alleles( 01, 103, 15, 16, 17, 18+, 04, 07, 09, 10, 11, 12,13.1,14.2, 53) and in DQB1 alleles (2,3(8), 3(7), 3(8,9), 2,3(7,9) 4) while DRB1 alleles (08,13.3,13.4,14.1,14.3,14.4,52,51) and DQB1 alleles (5,6,2) were reduced, but none of these tendencies was statistically significant. Also analysis of the AA group and NAA group versus controls showed no statistical significant findings. Conclusion: Although there are some differences in HLA phenotypic distribution in asthma patients, no definitive HLA association could be established with atopic or non atopic asthma in the population studied. Nonetheless, although HLA by itself may not determine the asthma process, this does not exclude its involvement with other genetic systems which may be implicated in the susceptibility to this disease.