Measurement of IgE and IgG subclass antibodies to whole body antigen and two major allergens (Der fI & Der fII) of Dermatophagoides farinae in normal subjects and asthmatics

Abstract

House dust mites have been known as the most important allergen in respiratory allergic diseases. Among several mite allergens, group I and group II antigens were recognized as major allergens. We measured specific IgE and IgG subclass antibodies against whole body antigen (WBA) and two major allergens of Dermatophagoides farinae (Der fI and Der fII) in sera from 66 adults with asthma (asthma group) and 34 normal subjects (healthy group) by ELISA. The mean O.D. values of WBA-specific IgE and IgG subclass antibodies in 100 studied sera were significantly higher than those of the two major allergens (p<0.001) and the level of Der fII- IgG1, IgG4 and IgE were higher than those of Der fI but IgG2 of Der fI was higher than that of Der fII (p< 0.001). The level of IgG4 of WBA were significantly higher in the atopic group than in the nonatopic group (1.280 ± 0.634 v.s. 0.8290 ± 0.388, p< 0.001), but the WBA- IgG1, IgG2, IgG3 were not different between the two groups. Among IgG subclass antibodies of Der fI, IgG2 was significantly higher in the nonatopic group than in the atopic group (1.7770 ± 0.255 v.s. 1.636 ± 0.390, p< 0.05) but there were no differences in IgG1, IgG3, and IgG4. Among IgG subclass antibodies of Der fII, IgG2 (1.534 ± 0.380 v.s. 1.3010 ± .431, p< 0.05) and IgG4 (1.09650 ± .567 v.s. 0.708 ± 0.146, p< 0.001) were significantly higher in the atopic group than in the nonatopic group. IgE antibodies to WBA, Der fI and Der fII were significantly higher in the atopic group (p< 0.001). There were significant correlationships between the levels of IgE and IgG4 of WBA (r = 0.60), Der fI (r = 0.33) and Der fII (r = 0.72). Even though there were no differences in the levels of allergen specific IgE and IgG subclass antibodies between nonatopic healthy and nonatopic asthmatic groups, the number of sera with prominent level of IgG2 of WBA were more common in the nonatopic asthmatic group (69% in nonatopic asthma group v.s. 28% in nonatopic healthy group, X2-test, p< 0.01).