Detection of a kappa-casein-specific lymphocyte response in milk-responsive atopic dermatitis.
BACKGROUND
Bovine casein leads to an expansion of lymphocytes expressing the cutaneous lymphocyte antigen and to specific lymphocyte proliferation in a subgroup of patients with milk-responsive atopic dermatitis (AD). The casein fraction is composed of different proteins with defined and completely different sequences.


OBJECTIVE
To define the stimulatory capacity of the major casein protein (alpha, beta and kappa) in lymphocyte proliferation assays with cells from milk-allergic and non-allergic individuals.


METHODS
Proliferative responses of peripheral blood mononuclear cells to lipopolysaccharide-depleted casein subfractions were measured by thymidine incorporation. Lymphocytes from milk-responsive patients with AD were compared with cells from non-responsive patients with AD and to non-atopic individuals. Atopic individuals with immediate symptoms following consumption of cow's milk were included as positive controls. Casein-specific T-cell clones (TCC) from four patients with milk-responsive AD were restimulated with unfractionated casein and kappa-casein.


RESULTS
Higher proliferative responses to unfractionated casein and alpha-, beta- and kappa-casein were observed in milk-responsive patients compared with non-responders. Unfractionated casein and kappa-casein discriminated best between the milk-responsive patients with AD and non-responders. Twenty-five of 31 TCG from patients with milk-responsive AD reacted to the mixed casein preparation and kappa-casein.


CONCLUSIONS
A pronounced kappa-casein-specific T-cell-mediated immune response is found in the blood of many patients with a history of milk-related exacerbation of AD.
Werfel
T
T
Department of Dermatology, Medical School Hannover, Germany.
Ahlers
G
G
Schmidt
P
P
Boeker
M
M
Kapp
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002364:Caseins / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000276:immunology*; D006020:Glycopeptides / Q000494:pharmacology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D007223:Infant; D008213:Lymphocyte Activation / Q000187:drug effects; D008875:Middle Aged; D016269:Milk Hypersensitivity / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D002364:Caseins; D006020:Glycopeptides; C020251:kappa-casein glycomacropeptide