Contamination of probiotic preparations with milk allergens can cause anaphylaxis in children with cow's milk allergy

Abstract

To the Editor: Cow's milk allergy (CMA) is one of the most common food allergies in infants. Most patients outgrow CMA by the age of 5 years; however, some patients have persistent allergy.1Sicherer S.H. Sampson H.A. Food allergy.J Allergy Clin Immunol. 2006; 117: S470-S475Abstract Full Text Full Text PDF PubMed Scopus (607) Google Scholar Probiotics are live microorganisms, isolated first in the intestinal flora of healthy children.2FAO/WHO Evaluation of health and nutritional properties of powder milk and live lactic acid bacteria. Food and Agriculture Organization of the United Nations and World Health Organization Expert Consultation Report, Cordoba, Argentina2001Google Scholar Probiotics include lactic acid producing bacteria of Lactobacillus, Bifidobacterium, and Streptococcus species. Escherichia coli subspecies and yeasts like Saccharomyces species may also demonstrate probiotic activity. Demonstration of health benefits, safety, and absence of transfer of antibiotic resistance between probiotics and pathogens led to the probiotic concept. Probiotics open new therapeutic possibilities for the management of atopic diseases.3Majamaa H. Isolauri E. Probiotics: a novel approach in the management of food allergy.J Allergy Clin Immunol. 1997; 99: 179-185Abstract Full Text Full Text PDF PubMed Scopus (803) Google Scholar, 4Kalliomaki M. Salminen S. Poussa T. Arvilommi H. Isolauri E. Probiotics and prevention of atopic disease: 4-year follow-up of a randomized placebo-controlled trial.Lancet. 2003; 361: 1869-1871Abstract Full Text Full Text PDF PubMed Scopus (1049) Google Scholar, 5Prescott S.L. Dunstan J.A. Hale J. Breckler L. Lehmann H. Weston S. et al.Clinical effects of probiotics are associated with increased interferon-γ responses in very young children with atopic dermatitis.Clin Exp Allergy. 2005; 35: 1557-1564Crossref PubMed Scopus (115) Google Scholar, 6Viljanen M. Savilahti E. Haahtela T. Juntunen-Backman K. Korpela R. Poussa T. et al.Probiotics in the treatment of atopic eczema/dermatitis syndrome in infants: a double-blind placebo-controlled trial.Allergy. 2005; 60: 494-500Crossref PubMed Scopus (377) Google Scholar, 7Sistek D. Kelly R. Wickens K. Stanley T. Fitzharris P. Crane J. Is the effect of probiotics on atopic dermatitis confined to food sensitized children?.Clin Exp Allergy. 2006; 36: 629-633Crossref PubMed Scopus (144) Google Scholar, 8Bjorksten B. Sepp E. Julge K. Voor T. Mikelsaar M. Allergy development and the intestinal microflora during the first year of life.J Allergy Clin Immunol. 2001; 108: 516-520Abstract Full Text Full Text PDF PubMed Scopus (970) Google Scholar Randomized placebo-controlled trials show a reduction of the severity of atopic dermatitis because of mother and/or infant supplementation with Lactobacillus.4Kalliomaki M. Salminen S. Poussa T. Arvilommi H. Isolauri E. Probiotics and prevention of atopic disease: 4-year follow-up of a randomized placebo-controlled trial.Lancet. 2003; 361: 1869-1871Abstract Full Text Full Text PDF PubMed Scopus (1049) Google Scholar, 5Prescott S.L. Dunstan J.A. Hale J. Breckler L. Lehmann H. Weston S. et al.Clinical effects of probiotics are associated with increased interferon-γ responses in very young children with atopic dermatitis.Clin Exp Allergy. 2005; 35: 1557-1564Crossref PubMed Scopus (115) Google Scholar, 6Viljanen M. Savilahti E. Haahtela T. Juntunen-Backman K. Korpela R. Poussa T. et al.Probiotics in the treatment of atopic eczema/dermatitis syndrome in infants: a double-blind placebo-controlled trial.Allergy. 2005; 60: 494-500Crossref PubMed Scopus (377) Google Scholar, 7Sistek D. Kelly R. Wickens K. Stanley T. Fitzharris P. Crane J. Is the effect of probiotics on atopic dermatitis confined to food sensitized children?.Clin Exp Allergy. 2006; 36: 629-633Crossref PubMed Scopus (144) Google Scholar Probiotics could be beneficial in atopic dermatitis associated with food allergy.3Majamaa H. Isolauri E. Probiotics: a novel approach in the management of food allergy.J Allergy Clin Immunol. 1997; 99: 179-185Abstract Full Text Full Text PDF PubMed Scopus (803) Google Scholar, 6Viljanen M. Savilahti E. Haahtela T. Juntunen-Backman K. Korpela R. Poussa T. et al.Probiotics in the treatment of atopic eczema/dermatitis syndrome in infants: a double-blind placebo-controlled trial.Allergy. 2005; 60: 494-500Crossref PubMed Scopus (377) Google Scholar, 7Sistek D. Kelly R. Wickens K. Stanley T. Fitzharris P. Crane J. Is the effect of probiotics on atopic dermatitis confined to food sensitized children?.Clin Exp Allergy. 2006; 36: 629-633Crossref PubMed Scopus (144) Google Scholar Recently, we reported the case of an infant with CMA who presented anaphylaxis, including generalized urticaria and laryngeal edema, 15 minutes after ingestion of Bacilor (Lyocentre Laboratories, Aurillac, France), a probiotic preparation prescribed for E coli gastroenteritis.9Moneret-Vautrin D.A. Morisset M. Cordebar V. Codreanu F. Kanny G. Probiotics may be unsafe in infants allergic to cow's milk.Allergy. 2006; 61: 507-508Crossref PubMed Scopus (30) Google Scholar Skin prick tests (SPTs) to milk and Bacilor were positive, and the specific cow's milk (CM) IgE value was 49 kU/L. We questioned whether most common probiotic preparations used in France (Bacilor; Imgalt [Jaldes, Gigean, France]; Ditopy [Ducray Laboratories, Boulogne, France]) contain CM allergens. Bacilor is approved by regulatory agencies for additional treatment of acute diarrhea and contains Lactobacillus rhamnosus. Imgalt is supplied as a food supplement and contains Bifidobacterium bifidum and Bifidobacterium longum, as well as Lactobacillus acidophilus, rhamnosus, and casei. Ditopy is a food supplement containing Lactobacillus acidophilus and rhamnosus. Manufacturers indicated that Bacilor and Imgalt were grown on lactoserum proteins and casein-containing media, whereas Ditopy was grown in the presence of hydrolyzed soy proteins. This study includes 10 children with CMA, the clinical characteristics of whom are shown in Table I. Parents and children were informed of its purpose and agreed to participate. SPTs were performed with an infant formula based on CM proteins (O-LAC; Mead Johnson Nutritionals, Rueil-Malmaison, France) and the 3 probiotics prepared at 1 g/mL with sterile physiological saline solution, all purchased from a local pharmacy.Table IClinical data for patients with CMAWheal diameter of skin prick tests (mm)SexAge (y)SymptomsIgE CM (kU/L)CRD CM (mL)CodeineO-LACBacilorImgaltDitopyM1.0U, AO, AD100ND3.09.07.06.01.5M1.3U, AD7.2ND3.515.510.56.00.0M1.5U, AD21.86.83.014.010.03.00.0M2.0U, Vo2.5∗IgE to casein.2.54.05.02.51.50.0M4.0U, AO, AD5.7ND3.510.53.04.00.5M5.0U, A, AD16.86.83.54.04.52.51.5M6.0U, A16.720.03.010.05.05.00.0F0.5U1.5Positive LC2.06.01.51.00.0F1.5AD0.6∗IgE to casein.ND2.57.53.50.00.0F10.0AS2.560.03.09.54.54.00.0Means ± SEMs—3.3 ± 0.9—21.5 ± 11.5—3.1 ± 0.29.1 ± 1.25.2 ± 1.03.3 ± 0.70.4 ± 0.2CRD, Cumulative reactive dose of CM; M, male; F, female; U, urticaria; AO, angioedema; AD, atopic dermatitis; ND, not determined; Vo, vomiting; A, asthma; LC, labial challenge; AS, anaphylactic shock.∗ IgE to casein. Open table in a new tab CRD, Cumulative reactive dose of CM; M, male; F, female; U, urticaria; AO, angioedema; AD, atopic dermatitis; ND, not determined; Vo, vomiting; A, asthma; LC, labial challenge; AS, anaphylactic shock. Skin prick tests to CM infant formula were positive (≥75% of positive control codeine wheal diameter) in all patients, with a mean wheal diameter of 9.1 ± 3.0 mm. SPTs to Bacilor, Imgalt, and Ditopy were positive in 10, 7, and 0 out of 10 children, respectively (Table I). The mean SPT diameters were 5.2 mm ± 1.0 mm, 3.3 mm ± 0.7 mm, and 0.4 mm ± 0.2 mm with Bacilor, Imgalt, and Ditopy, respectively. Representative skin tests are shown in this article's Fig E1 in the Online Repository at www.jacionline.org. Coomassie blue staining of O-LAC showed protein bands corresponding to casein isoforms (20-30 kDa), β-lactoglobulin (BLG; 18 kDa) and α-lactalbumin (14 kDa; Fig 1, A). The migration rate of purified bovine BLG matches that of infant formula BLG. A protein with a similar migration pattern was clearly visible in Bacilor and was found in trace amounts in Imgalt. The immunoblot with polyclonal anti-BLG IgG confirmed the presence of BLG in CM formula as well as in Bacilor and Imgalt, but not in Ditopy (Fig 1, B). The signal obtained with Imgalt was lower than that of Bacilor, consistent with the results obtained by direct gel staining (Fig 1, A). Dot blotting experiments revealed strong positive signals with only Bacilor and Imgalt, whereas Ditopy remained negative (Fig 1, C, row a). Immuno-competition using increasing concentrations of purified BLG confirmed that Bacilor contained more BLG than Imgalt (Fig 1, C, rows b and c). The allergenicity of BLG contaminating Bacilor and Imgalt was demonstrated by binding of IgE from 2 patients with CMA (Fig 1, D, row a). No binding was observed with 2 control sera (Fig 1, D, row b). Thus, probiotic-contaminating BLG contains linear epitopes that bind human IgE from patients with CMA. Here, we show that 2 out 3 probiotics used widely in France contain significant amounts of BLG. CMP contamination appears quantitatively highest in Bacilor, relatively lower in Imgalt, and not detectable in Ditopy. Results of SPTs correlate with biochemical testing: SPT diameters were greater for Bacilor than for Imgalt, and were not different between SPTs of negative controls and those obtained with Ditopy. It must be emphasized here that we have tested only 1 lot of products available to patients in pharmacies; hence, lot to lot variation in allergen content remains possible. Our results indicate that prescription of probiotics can be unsafe in severe food allergies because of residual allergens contained in the culture medium. Although we have observed only a single case of severe reaction after probiotic ingestion in the context of acute gastroenteritis and CMA, we feel that the severity of this reaction justifies caution and awareness. Serious efforts should be made by probiotic providers to establish production procedures that effectively eliminate food allergens from probiotic culture media, to evaluate the residual allergen content in their preparations, and finally to indicate on the label the characteristics of the culture medium. Currently, no such measures are in place. Nevertheless, we are convinced that the therapeutic potential of probiotics remains promising if appropriate regulatory procedures for informative labeling are set in place. Download .pdf (.05 MB) Help with pdf files Online Repository