title: Tolerability of a fully maturated cheese in cow's milk allergic children: biochemical, immunochemical, and clinical aspects.
abstract: BACKGROUND
  From patients' reports and our preliminary observations, a fully maturated cheese (Parmigiano-Reggiano; PR) seems to be well tolerated by a subset of cow's milk (CM) allergic patients.
  
  
  OBJECTIVE
  To biochemically and immunologically characterize PR samples at different maturation stage and to verify PR tolerability in CM allergic children. Seventy patients, with suspected CM allergy, were enrolled. IgE to CM, α-lactalbumin (ALA), β-lactoglobulin (BLG) and caseins (CAS) were tested using ImmunoCAP, ISAC103 and skin prick test. Patients underwent a double-blind, placebo-controlled food challenge with CM, and an open food challenge with 36 months-maturated PR. Extracts obtained from PR samples were biochemically analyzed in order to determine protein and peptide contents. Pepsin and trypsin-chymotrypsin-pepsin simulated digestions were applied to PR extracts. Each PR extract was investigated by IgE Single Point Highest Inhibition Achievable assay (SPHIAa). The efficiency analysis was carried out using CM and PR oral challenges as gold standards.
  
  
  RESULTS
  The IgE binding to milk allergens was 100% inhibited by almost all PR preparations; the only difference was for CAS, mainly α(S1)-CAS. Sixteen patients sensitized to CM tolerated both CM and PR; 29 patients tolerated PR only; 21 patients, reacted to both CM and PR, whereas 4 patients reactive to CM refused to ingest PR. ROC analysis showed that the absence of IgE to BLG measured by ISAC could be a good marker of PR tolerance. The SPHIAa using digested PR preparations showed a marked effect on IgE binding to CAS and almost none on ALA and BLG.
  
  
  CONCLUSIONS
  58% of patients clinically reactive to CM tolerated fully maturated PR. The preliminary digestion of CAS induced by PR maturation process, facilitating a further loss of allergenic reactivity during gut digestion, might explain the tolerance. This hypothesis seems to work when no IgE sensitization to ISAC BLG is detected.
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy.
authors: Claudia
authors: C
authors: Alessandri
authors: Stefano
authors: S
authors: Sforza
authors: Paola
authors: P
authors: Palazzo
authors: Francesca
authors: F
authors: Lambertini
authors: Sara
authors: S
authors: Paolella
authors: Danila
authors: D
authors: Zennaro
authors: Chiara
authors: C
authors: Rafaiani
authors: Rosetta
authors: R
authors: Ferrara
authors: Maria Livia
authors: ML
authors: Bernardi
authors: Mario
authors: M
authors: Santoro
authors: Sara
authors: S
authors: Zuzzi
authors: Ivana
authors: I
authors: Giangrieco
authors: Arnaldo
authors: A
authors: Dossena
authors: Adriano
authors: A
authors: Mari
mesh_terms: D000293:Adolescent; D000818:Animals; D002364:Caseins / Q000378:metabolism; D002417:Cattle; D002611:Cheese; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D007223:Infant; D007768:Lactalbumin / Q000378:metabolism; D007782:Lactoglobulins / Q000378:metabolism; D016269:Milk Hypersensitivity / Q000276:immunology* / Q000378:metabolism
chemical_list: D002364:Caseins; D007782:Lactoglobulins; D007073:Immunoglobulin E; D007768:Lactalbumin