Effects of leukotriene receptor antagonists on peripheral eosinophil counts and serum IgE levels in children with food allergy.

Background: Although the efficacy of leukotriene receptor antagonists (LTRAs) for bronchial asthma is already established, their effect on food allergy remains unclear.

Objective: To investigate the efficacy of LTRAs in children with food allergy.

Methods: This retrospective study examined 65 children with food allergy who were aged between 3 and 36 months (mean 14 ± 9.6 months) from 2005 to 2008. Thirty-two children were treated as a dietary control group by avoiding any antigenic foods to which they had previously experienced adverse reactions. The remaining 33 children, designated the LTRA group, were treated with pranlukast (7 mg/kg bodyweight/day) in addition to maintaining dietary control. Clinical symptoms and laboratory data before and after 1 year of treatment were compared between the groups.

Results: Allergic symptoms improved in both the dietary controlled and LTRA groups, and there was no significant difference observed in the clinical parameters examined between the groups after the 1-year trial. Peripheral eosinophil count, serum IgE, interleukin (IL)-4, IL-5, IL-6, and eosinophil cationic protein (ECP) levels in children with food allergy were above standardized values in both groups. Although both the dietary controlled and LTRA groups showed a decreased eosinophil count (-273 ± 232 vs -595 ± 295/μL; p < 0.05 and p < 0.001, respectively), only children treated with LTRA showed a significant decrease in serum IgE (-73.5 ± 115 IU/mL; p < 0.01); conversely, the control group exhibited a significant increase in serum IgE (+159 ± 138 IU/mL; p < 0.01). Furthermore, the LTRA group also showed a significant decrease in serum IL-4 (54.5 ± 31.0 to 27.3 ± 10.1 pg/mL), IL-5 (6.7 ± 5.2 to 5.0 ± 0.4 pg/mL), and ECP (45.4 ± 15.0 to 15.0 ± 9.8 μg/L) levels (p < 0.05 for each).

Conclusion: Early intervention with LTRAs may be effective in regulating eosinophil count and serum IgE, IL-4, IL-5, and ECP levels. These data support the potential effectiveness of LTRAs in young children with food allergy to prevent further allergic development.