Prevalence and Clinical Relevance of IgE Sensitization to Profilin in Childhood: A Multicenter Study

BACKGROUND: Little is known about the prevalence and clinical relevance of hypersensitivity to the plant panallergen profilin in children. OBJECTIVES: The present study aimed to investigate prevalence, risk factors and clinical relevance of profilin sensitization in a large cohort of Italian children of different ages living in different geographic areas. METHODS: Children with pollen allergy enrolled by 16 pediatric outpatient clinics sited in three main geographic areas of Italy were studied. SPT were carried out with commercial pollen extracts and a commercial purified date palm pollen profilin. IgE specific for allergenic pollen molecules, Phl p 12 (grass profilin) and Pru p 3 (peach lipid transfer protein) were tested by ImmunoCAP FEIA. RESULTS: IgE to Phl p 12 (≥0.35 kU/l) was observed in 296 of the 1,271 participants (23%), including 17 of the 108 (16%) preschool children. Profilin SPT was positive (≥3 mm) in 320/1,271 (25%) participants. The two diagnostic methods were concordant in 1,151 (91%, p < 0.0001) cases. Phl p 12 IgE prevalence declined from northern to southern Italy and was directly associated with IgE to Phl p 1 and/or Phl p 5 and Ole e 1. Among children with IgE to Phl p 12, OAS was provoked by kiwi, melon, watermelon, banana, apricot and cucumber. CONCLUSIONS: Profilin sensitization is very frequent among pollen-allergic children, occurs at a very young age and contributes to the development of childhood OAS with a typical pattern of offending foods. Pediatricians should always consider IgE sensitization to profilin while examining pollen-allergic children, even if they are at preschool age.