Nopparut Keawhanam. Development of a quantitative immunological test for detection of human IgE, IgG and IgG4 specific to house dust mite allergen . Master's Degree(Immunology). Mahidol University. : Mahidol University, 2007.
Development of a quantitative immunological test for detection of human IgE, IgG and IgG4 specific to house dust mite allergen
Abstract:
Allergic disease has increased as an important worldwide clinical problem. House dust
mite (HDM) has been shown to be one of the most important and ubiquitous allergens involving in
the pathogenesis of allergic disorders. The most dominant species that cause allergic disease are
Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df). Among several mite
allergens, Der p 1 and Der f 1 which are group 1 allergens of Dp and Df are strong immunogens
that can stimulate the specific IgE production in allergic patients. The immune response to mite
allergens have been studied in allergic disease and it has been found that IgE is regarded as the
most important specific antibody, but other antibodies such as IgG and IgG4 have been reported to
play some roles in allergic immune response.
In the present study, an indirect ELISA for detection of specific IgE, IgG and IgG4 in sera
of HDM allergic patients by using secretory antigen prepared from Dermatophagoides
pteronyssinus (Dp crude extract) was developed and evaluated. The advantages of secretory
antigens are that they are mimic antigens that contain high concentrations of group 1 allergens, As
demonstrated by SDS-PAGE and double antibody sandwich ELISAs, large amount of antigen
could be obtained relatively easily. The specific IgE, IgG and IgG4 in sera obtained from 47 house
dust mite allergic patients and 20 normal subjects were determined by the developed ELISA and
the results were evaluated by comparison with the reference method, CAP system. The results
showed 66% sensitivity and 90% specificity for specific IgE. For specific IgG, the calculated
sensitivity and specificity were 61% and 70.6%, respectively. For specific IgG4, the calculated
sensitivity and specificity were 83.3% and 70 %, respectively. There was a significant correlation
between specific IgE to Dp crude extract measured by CAP system and ELISA method (r = 0.688,
p<0.001). There were significant differences of the specific IgE and IgG4 antibodies between
the allergic group and the control group (p<0.05). Non significant differences in specific IgG
antibodies were found between the allergic group and the control group (p>0.05). Thus, the
developed ELISA will be useful for detection of a house dust mite specific antibody to patients’
sera.