Format

Send to

Choose Destination
Clin Exp Allergy. 1998 Jul;28(7):824-33.

Anti-betalactoglobulin IgG antibodies bind to a specific profile of epitopes when patients are allergic to cow's milk proteins.

Author information

1
Immunology Department, Centre Hospitalier Universitaire Brugmann-HUDERF, Université Libre de Bruxelles, Brussels, Belgium.

Abstract

BACKGROUND:

We demonstrated recently that mite-allergic patients differed from healthy controls in the specificity of their IgG antibodies towards mite antigens.

OBJECTIVE:

The present study investigates whether these discriminatory IgG responses could be associated with the expression and the evolution of clinical manifestations in allergy to cow's milk proteins.

METHODS:

Antibody specificity was evaluated by comparing IgG-binding to native bovine beta-lactoglobulin (nBLG) and its products of pepsin hydrolysis (dBLG) using a solid-phase enzyme-linked immunosorbent assay (ELISA). Antibody specificity was further investigated in competitive ELISA using streptavidin-biotin technology with purified IgG fractions from selected subjects and specific mouse monoclonals raised against BLG.

RESULTS:

IgG antibodies from CM-intolerant or allergic sera (n=222) showed a higher degree of binding to nBLG than to dBLG, while control sera showed similar levels to both nBLG and dBLG (n=99 children/65 adults). Sera from symptomatic patients, wether or not they contained IgE antibodies, demonstrated group-segregating capacities to compete with pooled purified IgG from each clinical class, and with selected murine anti-nBLG monoclonal antibodies for binding to n- and dBLG. Furthermore, this inhibitory capacity shifted dramatically in a small subset (n=14) of children as they developed CM-tolerance.

CONCLUSIONS:

The IgG responses to BLG of CM-intolerant or allergic patients are very different from those of healthy controls, being characterized not only by increased titres but also similar patterns of modified specificity, including a marked preference for conformational epitopes. Cross-competition experiments confirmed that the restricted specificity was clinically associated, appearing as an immunological signature, which allowed almost complete discrimination between patient groups. This phenomenon is a particularly promising diagnostic feature in this category of young patients where conventional tests usually only document the status of sensitization.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center