title: Time course of total and food specific IgE antibodies (Rast Fx5) in the developing allergic child.
abstract: OBJECTIVE
  To analyze the evolution of total and food specific IgE (Rast Fx5) titers in the course of food allergy in children.
  
  
  METHODS
  925 children, mean age 8.9 + 9.1 years (15 days-18 years), 455 girls and 470 boys, investigated for food allergy in year 1997, underwent serum samples assay for total IgE and of Rast Fx5, Cap System, Pharmacia & Upjohn Diagnostics AB, Uppsala, Sweden, a mix test detecting specific IgE to 6 major food allergens in children, cow's milk proteins (CMP), egg white, peanut, soy, wheat and fish and analyzed as a function of reference values by age.
  
  
  RESULTS
  Total IgE titers increased significantly with age, r0.22, p0.0001. The percentage of children with a total IgE level above normal range first increased with age, from 10.3 % at 0-6 months, reaching 38.2 % at 1-2 years and peaking at 56.9% at 4-6 years, then leveled off, 48.1% at 8-12 years (ns vs 4-6 years) and 41.3% above 12 years (ns). Detectable Rast Fx5 increased in a parallel manner until age 4-6 years and then exhibited a progressive decrease from age 6-8 years, differing significantly from total IgE: 31.9% vs 52.9%, p0.01 (6-8 years), 32.2% vs 48.1%, p0.03 (8-12 years), 21.8% vs 41.3%, p0.05 (> 12 years).
  
  
  CONCLUSIONS
  In these outpatient children investigated for food allergy, the increase with age of the percentage of high total IgE contrasted with the progressive decrease of Rast Fx5 from age 4-6 yr. This biological finding correlates timely with the clinical spontaneous decrease of food allergy in the developing child.
authors.affiliation: Department of Pediatrics, Neonatology, Pediatric Gastroenterology & Nutrition Unit, Hôpital Cochin-Saint Vincent de Paul, Paris, France. kalach.nicolas@ghicl.net
authors.forename: Nicolas
authors.initials: N
authors.lastname: Kalach
authors.forename: Pascale
authors.initials: P
authors.lastname: Soulaines
authors.forename: Sylvie
authors.initials: S
authors.lastname: Guerin
authors.forename: Delphine
authors.initials: D
authors.lastname: de Boissieu
authors.forename: Christophe
authors.initials: C
authors.lastname: Dupont
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D021181:Egg Hypersensitivity / Q000097:blood / Q000276:immunology; D005260:Female; D005396:Fish Products; D005512:Food Hypersensitivity / Q000097:blood* / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016269:Milk Hypersensitivity / Q000097:blood / Q000276:immunology; D021183:Peanut Hypersensitivity / Q000276:immunology; D011852:Radioallergosorbent Test; D013025:Glycine max / Q000276:immunology; D013997:Time Factors; D021182:Wheat Hypersensitivity / Q000276:immunology
chemical_list: D007073:Immunoglobulin E