Increased TIA1-expressing intraepithelial lymphocytes in cow's milk protein intolerance.
BACKGROUND
Although a high level of intraepithelial lymphocytes (IELs) has been demonstrated in intestinal biopsies from children with cow's milk protein intolerance (CMPI), the properties of IELs in food-sensitive enteropathies remain unclear. In the present study, we analyzed the cytotoxic potential of IELs in CMPI, using a monoclonal antibody directed against the cytotoxic granule-associated protein TIA1.


METHODS
The study included 18 duodenal biopsies from 10 children previously diagnosed with CMPI and on a cow's milk-free diet of various duration. Six normal duodenal biopsies from children free of food intolerance served as controls. Immunostaining of formalin-fixed tissues was used to determine in the intraepithelial compartment (1) the number of TIA1-expressing cells per 100 epithelial cells, (2) the number of IELs per 100 epithelial cells, (3) the ratio of TIA1-expressing IELs (TIA1/IEL ratio).


RESULTS
In CMPI, the number of IELs and TIA1-positive cells, as well as the TIA1/IEL ratio was significantly increased compared with controls. Moreover, a negative correlation between the TIA1/IEL ratio and the duration of the diet was observed.


CONCLUSIONS
These results suggest that the recruitment of IELs with cytotoxic potential is increased in CMPI, and that IEL-mediated cytotoxicity could be involved in the pathogenesis of the disease.
Hankard
G F
GF
Service d'Anatomie Pathologique et de Gastroenterologie Pédiatrique, Hôpital Robert Debré, Paris, France.
Matarazzo
P
P
Duong
J P
JP
Mougenot
J F
JF
Navarro
J
J
Cézard
J P
JP
Peuchmaur
M
M
D000911:Antibodies, Monoclonal / Q000276:immunology; D001706:Biopsy; D002675:Child, Preschool; D004386:Duodenum / Q000276:immunology / Q000473:pathology*; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D017493:Leukocyte Common Antigens / Q000276:immunology; D008297:Male; D008565:Membrane Proteins / Q000276:immunology*; D016269:Milk Hypersensitivity / Q000276:immunology / Q000473:pathology*; D008894:Milk Proteins / Q000009:adverse effects*; D039102:Poly(A)-Binding Proteins; D011506:Proteins; D016601:RNA-Binding Proteins / Q000276:immunology*; D000074019:T-Cell Intracellular Antigen-1; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D008894:Milk Proteins; D039102:Poly(A)-Binding Proteins; D011506:Proteins; D016601:RNA-Binding Proteins; D000074019:T-Cell Intracellular Antigen-1; C071558:TIA1 protein, human; D016179:Granulocyte Colony-Stimulating Factor; D017493:Leukocyte Common Antigens