Article

Microarray and allergenic activity assessment of milk allergens.

Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria.
Clinical & Experimental Allergy (impact factor: 5.03). 12/2010; 40(12):1809-18. DOI:10.1111/j.1365-2222.2010.03602.x pp.1809-18
Source: PubMed

ABSTRACT Cow's milk is one of the most common causes of food allergy affecting approximately 2.5% of infants in the first years of their life. However, only limited information regarding the allergenic activity of individual cow's milk allergens is available.
To analyse the frequency of IgE reactivity and to determine the allergenic activity of individual cow's milk allergens.
A nitrocellulose-based microarray, based on purified natural and recombinant cow's milk allergens was used to determine IgE reactivity profiles using sera from 78 cow's milk-sensitized individuals of varying ages. The allergenic activity of the individual allergens was tested using patients' sera for loading rat basophil leukaemia cells (RBL) expressing the α-chain of the human receptor FcεRI.
Using the microarray and the RBL assay, cow's milk allergens were assessed for frequency of IgE recognition and allergenic activity. Moreover, the RBL assay allowed distinguishing individuals without or with mild clinical reactions from those with severe systemic or gastrointestinal symptoms as well as persons who grew out cow's milk allergy from those who did not.
Component-resolved testing using milk allergen microarrays and RBL assays seems to provide useful additional diagnostic information and may represent a basis for future forms of prophylactic and therapeutic strategies for cow's milk allergy.

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    Article: Tolerability of a fully maturated cheese in cow's milk allergic children: biochemical, immunochemical, and clinical aspects.
    Claudia Alessandri, Stefano Sforza, Paola Palazzo, Francesca Lambertini, Sara Paolella, Danila Zennaro, Chiara Rafaiani, Rosetta Ferrara, Maria Livia Bernardi, Mario Santoro, Sara Zuzzi, Ivana Giangrieco, Arnaldo Dossena, Adriano Mari
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    ABSTRACT: 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. 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. 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. 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.
    PLoS ONE 01/2012; 7(7):e40945. · 4.09 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

78 cow's milk-sensitized individuals
 
allergenic activity
 
Component-resolved testing
 
Cow's milk
 
cow's milk allergens
 
cow's milk allergy
 
distinguishing individuals
 
human receptor FcεRI
 
IgE reactivity profiles
 
individual allergens
 
individual cow's milk allergens
 
limited information
 
loading rat basophil leukaemia cells
 
mild clinical reactions
 
milk allergen microarrays
 
patients' sera
 
RBL assay
 
RBL assays
 
recombinant cow's milk allergens
 
useful additional diagnostic information