Contamination of Probiotic Preparations With Milk Allergen Can Cause Anaphylaxis in Cow's Milk Allergic Patients

Can Cause Anaphylaxis in Cow's Milk Allergic Patients M. Morisset, T. T. Lee, C. M. N. Astier, D. A. Moneret-Vautrin, V. Cordebar, E. Beaudouin, F. Codreanu, B. E. Bihain, G. Kanny; University Hospital, Nancy, FRANCE, Laboratory of Molecular Medicine and Therapeutics, Vandoeuvre-Les-Nancy, FRANCE, INPL, Vandoeuvre-Les-Nancy, FRANCE, Laboratory of Molecular Medicine and Therapeutics, Nancy, FRANCE. RATIONALE: A randomized placebo control trial demonstrated that probiotics (Lactobacillus rhamnosus) are effective in prevention of early childhood atopic disease. Anaphylaxis occurring immediately after ingestion of Lactobacillus casei rhamnosus prescribed for infectious diarrhoea in a cow’s milk allergic patient was recently reported. This study aimed to search for contamination of probiotics with milk allergen(s). METHODS: Ten cow’s milk allergic (CMA) children were tested by prick-tests with 3 probiotic preparations: Bacilor , Imgalt and Ditopy . All 3 products were further screened by Western, dot blotting and immuno-competition experiments using anti-b-lactoglobulin (BLG) IgG. Allergenic potential of BLG was tested using IgE isolated from CMA patients’ sera in Western and dot blotting. RESULTS: Prick-tests to Bacilor , Imgalt and Ditopy were positive in 10, 7 and 0 out of 10 CMA patients, respectively. Western and immuno-competition experiments with BLG showed that Bacilor and Imgalt , but not Ditopy , contain detectable amounts of BLG that bound to IgE of CMA patients. On a semi-quantitative basis, Bacilor contains relatively more BLG than Imgalt . CONCLUSIONS: Although probiotics have been shown to be useful for the management of atopic diseases, the contamination of some preparations with milk proteins can have adverse effects for CMA patients. The potential allergen content of probiotics should be considered prior to their use in atopic dermatitis regarding its association with food allergy. Allergen content in probiotics should be systematically tested prior to their use in atopic patients and should also be labelled to inform consumers of their food allergen content.