IgE cross reactivity between reindeer and bovine milk beta-lactoglobulins in cow's milk allergic patients.
BACKGROUND
Allergic reactions to cow's milk are common in small children. One of the main protein allergens found in cow's milk is beta-lactoglobulin (beta-Lg). Reindeer and bovine milk both contain related beta-Lg proteins, but the allergenicity of reindeer beta-Lg has not previously been studied. The purpose of this study was to analyze the immunological cross-reactivity of IgE antibodies from children with cow's milk allergy to reindeer and bovine beta-Lg.


METHODS
Sera from 17 children and a serum pool of 4 patients with elevated cow's milk-specific IgE were investigated. Beta-Lg from bovine and reindeer milk was isolated in native form and an enzyme-linked immunosorbent inhibition assay was developed. Bovine beta-Lg was used as a capturing antigen and the inhibiting effects of reindeer and bovine beta-Lg on the IgE binding were measured.


RESULTS
Cross-reactivity patterns of bovine milk beta-Lg specific IgE to reindeer beta-Lg varied among patients. In general, reindeer beta-Lg showed significantly lower inhibition (mean 43%) of IgE binding to the capturing antigen than did bovine beta-Lg (mean 89%). In some patients, even high concentrations of reindeer beta-Lg only partly eliminated the IgE binding to bovine beta-Lg.


CONCLUSIONS
The partial cross-reactivity of human anti-bovine IgE with reindeer beta-Lg suggests that it lacks important bovine epitopes and those that are recognized are only weakly bound.
Suutari
T J
TJ
Laboratory of Biotechnology, Kajaani University Consortium, University of Oulu, Sotkamo, Finland. tiina.suutari@oulu.fi
Valkonen
K H
KH
Karttunen
T J
TJ
Ehn
B M
BM
Ekstrand
B
B
Bengtsson
U
U
Virtanen
V
V
Nieminen
M
M
Kokkonen
J
J
D000818:Animals; D002417:Cattle; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000276:immunology*; D007223:Infant; D007782:Lactoglobulins / Q000276:immunology*; D008297:Male; D008892:Milk / Q000276:immunology*; D016269:Milk Hypersensitivity / Q000276:immunology*; D012053:Reindeer / Q000276:immunology*
D007782:Lactoglobulins; D007073:Immunoglobulin E