Abnormal lgG4 Antibody Response to Aeroallergens in Allergic Patients

Abstract

Various studies have suggested the involvement of immunoglobulin G4 (IgG4) antibodies (Ab) in the physiopathology of allergic disorders. Recently, an abnormal IgG4 Ab production in response to immunization has been reported in some atopic patients. Thus, in order to evidence in allergic patients, a potential abnormal IgG4 Ab response to aeroallergens following natural exposure, we compared, in 34 patients sensitive to Dermatophagoides pteronyssinus and in 16 healthy subjects, the IgG4 Ab response to D. pteronyssinus, grass pollen and cat dander, using a solid-phase radioimmunoassay. Since some patients were also sensitive to grass pollen and/or to cat dander, we analyzed, in all patients, the IgG4 Ab responses both towards the allergen(s) they were sensitive to (sensitizing allergen) or not (unrelated allergen). The results showed that 90% of the patients produced levels of antisensitizing allergen(s) IgG4 Ab significantly higher than the controls; this IgG4 Ab response was correlated with the corresponding specific IgE Ab level. In addition, among these patients, around 40% presented high levels of IgG4 Ab to the unrelated allergen(s). Thus, in allergic patients, while specific IgE Ab define the nature of the sensitizing allergen, the presence of IgG4 Ab directed against various allergens seems in relation with an abnormal isotype regulation associated with atopic disorders.

Maternal Influence on IgG Subclass Antibodies to Bet v 1 during the First 18 Months of Life as Detected with a Sensitive ELISA

“…35] antibodies to D.pteronyssinus are higher in atopic individu als, while the IgGI antibody titres arc similar to those found in nonatopics [34]. Furthermore, grass pollen specific IgG4 antibody titres are higher in atopic than nonatopic individu als [34][35][36], whereas the levels of IgGI antibodies have been reported to be similar [34] or higher [36], Higher IgG4 binding activity to cat dander have been reported in atopic as compared to nonatopic individuals [35]. In a recent Swedish study [37], Bet v 1-specific IgGI and lgG4 re sponses were detected by immunoblotting more frequently in birch pollen allergic than in normal individuals, support ing our findings in cord serum.…”

Detection of specific antibody isotypes and subtypes before and after treatment of American visceral leishmaniasis

“…It is interesting to note that both antibodies are produced by the activation of IL-4 (37,38), which is a cytokine present in active AVL (3,4). Some investigators have found in humans that parasite-specific IgG4 levels correlate with parasite-specific IgE levels (43,44).…”

IgG1, IgG4 and IgE Antibody Reactivity to Mutant Forms of the Major Dust Mite Allergen Lep d 2 among Atopic and Nonatopic Subjects Naturally Exposed to <i>Lepidoglyphus destructor</i>

“…It is considered that immunotherapy gives a rise in mainly the IgG1 and IgG4 subclasses and that the magnitude, the ratio or kinetic appearance between the two isotypes may predict the outcome of treatment [5, 22]. The few studies on natural exposures suggest a similar pattern [23, 24]or perhaps more IgG4-restricted response to aeroallergen extracts among atopics as compared to nonatopics [25, 26, 27, 28]. Our data with recombinant Lep d 2(wt) are in agreement with the latter studies and the levels of IgG4 and IgE clearly correlated as previously reported in some studies [28]but not others [25].…”

“…The few studies on natural exposures suggest a similar pattern [23, 24]or perhaps more IgG4-restricted response to aeroallergen extracts among atopics as compared to nonatopics [25, 26, 27, 28]. Our data with recombinant Lep d 2(wt) are in agreement with the latter studies and the levels of IgG4 and IgE clearly correlated as previously reported in some studies [28]but not others [25]. It is noteworthy that among the farmers it is only those sensitized to L. destructor who develop IgG4 Ab despite an expected similar level of exposure to dust mite allergen among all farmers [2].…”