Eosinophilia in infants with food protein-induced enterocolitis syndrome in Japan.
BACKGROUND
Many Japanese infants with food protein-induced enterocolitis syndrome (FPIES) show eosinophilia, which has been thought to be a characteristic of food protein-induced proctocolitis (FPIP).


METHODS
To elucidate the characteristics of eosinophilia in Japanese FPIES patients, 113 infants with non-IgE-mediated gastrointestinal food allergy due to cow's milk were enrolled and classified into FPIES (n = 94) and FPIP (n = 19).


RESULTS
The percentage of peripheral blood eosinophils (Eo) was increased in most FPIES patients (median, 7.5%), which was comparable with that in FPIP patients (9.0%). Among FPIES patients, Eo was the highest in patients who had vomiting, bloody stool, and diarrhea simultaneously (12.9%) and lowest in patients with diarrhea alone (3.2%). Eo showed a significant positive correlation with the incidence of vomiting (Cramer's V = 0.31, p < 0.005) and bloody stool (Cramer's V = 0.34, p < 0.0005). A significant difference was found in Eo between early- (≤10 days, n = 56) and late-onset (>10 days, n = 38) FPIES (median, 9.8% vs. 5.4%; p < 0.005). IL-5 production by peripheral blood T cells stimulated with cow's milk protein in early-onset FPIES was significantly higher than that in late-onset FPIES (67.7 pg/mL vs. 12.5 pg/mL, p < 0.01), and showed a significant positive correlation with Eo (rs = 0.60, p < 0.01).


CONCLUSIONS
This study demonstrated two types of eosinophilia in Japanese FPIES infants: conspicuous and mild eosinophilia in early- and late-onset FPIES patients, respectively. Conspicuous eosinophilia in early-onset FPIES is suggested to be caused by abnormally high IL-5 production.
Department of Allergy and Clinical Immunology, Shizuoka Children's Hospital, Shizuoka, Japan. Electronic address: mitsuaki-kimura@i.shizuoka-pho.jp.
Mitsuaki
M
Kimura
Department of Allergy and Clinical Immunology, Shizuoka Children's Hospital, Shizuoka, Japan.
Masaki
M
Shimomura
Department of Allergy and Clinical Immunology, Shizuoka Children's Hospital, Shizuoka, Japan.
Hideaki
H
Morishita
Department of Allergy and Clinical Immunology, Shizuoka Children's Hospital, Shizuoka, Japan.
Takaaki
T
Meguro
Department of Allergy and Clinical Immunology, Shizuoka Children's Hospital, Shizuoka, Japan.
Shiro
S
Seto
D017668:Age of Onset; D016207:Cytokines / Q000096:biosynthesis; D004760:Enterocolitis / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D004802:Eosinophilia / Q000150:complications*; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D010641:Phenotype; D013577:Syndrome
D016207:Cytokines
Eosinophilia; Food protein-induced enterocolitis syndrome; Food protein-induced proctocolitis; Infants; Interleukin-5