Relationship Between HLA-DRB1 Alleles Polymorphism And Susceptibility To Bronchial Asthma And The Levels Of IL-4,IFN-Gamma In Peripheral Blood

OBJECTIVE To investigate whether susceptibility or resistance to asthma associated with HLA-DRB1 alleles among the Han people in Shandong province . Observe the levels of IL-4> IFN-gamma in peripheral blood of asthmatic patients and analyze the relationship between the susceptible HLA-DRB1 gene and the levels of IL-4 , IFN-gamma .METHODS Firstly, 50 asthmatic patients in acute episode (the asthmatic group) were selected and 60 healthy volunteers (the control group) were selected. The serum were obtained from above groups, Sequence-specific primer polymerase chain reaction (PCR-SSP) was used to gene frequencies of HLA-DRB1 genes. Sandwich ELISA was used to examine IL-4 and IFN- γ levels in above-mentioned serum samples. The results were analysed statistically.RESULTS ( 1 ) There was significantly increased gene frequency of alleles HLA-DRBl*1301/1302 in asthmatics compared with normal controls(15% vs 4.1% , P<0.01),and RR was 4.13 respectively. (2) In asthmatic group, IL-4 level was significantly higher than that of the normal control group (118.47 ±28.45ng/L vs 92.32 ±14.43ng/L, P<0.01) and IFN-γ level was significantly lower than that of the remission asthma group (74.50±14.25ng/L vs 85.52±13.14ng/L, P<0.01). There were obviously negative correlation between the levels of IL-4, IFN- γ in peripheral blood of asthmatic patients (r=-0.336, P<0.01) . (3) There were no significantly statistical difference between the levels of IL-4 , IFN- γ in peripheral blood of individuals carrying HLA-DRBl*1301/1302 and no carrying HLA-DRBl*1301/1302 in asthmatic patients (119.53 ±17.38 ng/Lvs 118.26±20.49ng/L, 73.58 ±15.62 ng/Lvs 77.83 ±14.76 ng/L,P>0.05) .CONCLUSIONS (1) Alleles HLA-DRB1*1301/1302 is significantly implicated in their susceptibility to asthma. (2 ) The serum IL-4 is overproduced and IFN- γ production is impaired in allergy asthma, the imbalance of IL-4/IFN-γ is a key factor of asthmatic attack. (3) The levels of IL-4 , IFN- γ in peripheral blood are no significantly difference between individuals carrying HLA-DRBl*1301/1302 and no carrying HLA-DRB1*1301/1302 in asthmatic patients. It indicates that allele HLA-DRB1*1301/1302 is only related with some allergens and there are many genes have a modulating effect in asthma.