Phadia’s nGal D4 test makes it possible to detect in the blood IgE (antibodies) responsible for allergic reactions to the lysozyme in egg whites. Lysozyme is sometimes used as a preservative known as E1105 in food products (old cheeses including cheddar, wine) and pharmaceuticals. The interpretation chart accompanying the result expresses the likelihood of an allergic reaction specific to egg white lysozyme, but not necessarily the severity of the reaction. Case history (age, symptoms, relation to meals or medication, etc.) and clinical examination by the physician are essential for a reliable interpretation of the results.
An anti-nGal d4 IgE result of less than 0.35 kilounits per litre (< 0.35 kU/L) indicates that the individual is not likely to have a sensitivity to egg white lysozyme, but it does not COMPLETELY ELMINATE THIS POSSIBILITY. When the result is negative for nGal d1, a positive result for nGal d4 indicates a risk of allergic reaction possibly limited to raw or lightly cooked eggs and certain foods and pharmaceutical preparations. Both negative and positive results of molecular egg white allergen tests should be interpreted according to clinical manifestations. The double-blind oral food challenge remains the definitive technique for confirming any food allergy including raw or cooked egg.