Specific humoral response to cows’ milk proteins and ovalbumin in children with atopic dermatitis

Abstract

Serum antibodies to four common food antigens, three cows' milk proteins (casein, alpha-lactalbumin and beta-lactoglobulin) and ovalbumin, were investigated in 21 children with atopic dermatitis (aged 3 months to 3 years) and in 15 age-matched healthy controls. Specific IgE was measured by radioallergosorbent test; an ELISA was developed to detect specific IgG, IgG subclasses and IgA. Specific IgE was found in 76% of patients, while antigen-directed IgG and IgA were present both in patients and healthy controls; IgG to ovalbumin and IgA to alpha-lactalbumin were significantly higher in children with atopic dermatitis. The analysis of the IgG subclass distribution showed different patterns of response, IgG1 and IgG4 being higher in patients (even though statistically significant only for ovalbumin), and IgG2 and IgG3 being lower in this group. The presence of food-specific IgE in the majority of atopic children and the different specific IgG subclass patterns observed in patients and controls may reflect an alteration in the immune response to dietary proteins in atopic dermatitis.

Patterns of immunoglobulin G responses to egg and peanut allergens are distinct: ovalbumin‐specific immunoglobulin responses are ubiquitous, but peanut‐specific immunoglobulin responses are up‐regulated in peanut allergy

“…The finding of significant IgG responses to OVA in all groups, including non‐allergics, supports the notion that IgG production can be a normal physiological response to frequently ingested proteins. Others have also reported the presence of IgG antibodies to dietary antigens, in particular egg and milk, in a large proportion of healthy subjects [25–27]. CPE‐specific IgG was also detected in all subjects in the study.…”

Significance of ovomucoid- and ovalbumin-specific IgE/IgG4 ratios in egg allergy

“…4,38 IgG production is a physiological response to ingested dietary antigens, which can be detected in a large proportion of tolerant subjects. [39][40][41][42][43] In our study, previous exposure to egg was reported in all subjects with positive IgG 4 to OVA and/or OVM. We found that 9 subjects (39.1%) with undetectable specific IgG 4 to both OVA and OVM had never been knowingly exposed to egg.…”

Food‐specific serumIgEandIgGreactivity in dogs with and without skin disease: lack of correlation between laboratories

“…Although homocytotropic/reaginic or complement‐fixing subclasses of IgG have been defined in dogs and other species, their significance in CAFR is not yet clear and, by way of comparison, evidence for a role of IgG subclasses in canine atopic dermatitis has been described as ‘at best, circumstantial’ . Conflicting data on IgG levels have been reported in studies of adverse reaction to cow's milk in humans; milk‐specific IgG1 and IgG4 in atopic children have been elevated in some studies, but IgG levels were comparable or reduced in relation to healthy control subjects in others . Development of tolerance in patients formerly reactive to cow's milk was associated with increasing levels of β‐lactoglobulin‐specific IgG4 in one study but not in another .…”