Effect of Lactobacillus rhamnosus GG on rBet v1 and rMal d1 specific IgA in the saliva of patients with birch pollen allergy

Abstract

Lactobacillus rhamnosus GG (LGG) has demonstrated promising results in the treatment and prevention of atopic eczema. To study the effects of LGG on the oral immune response in adolescents and adults with birch pollen allergy combined with oral allergy syndrome. Patients received either LGG (n = 19) or a placebo (n = 19) for 5.5 months (from February 8 to August 6, 1999), starting 2.5 months before the birch pollen season. An oral apple challenge test was performed before, during, and after the pollen season. Saliva samples were collected before and after the challenges, and serum samples were collected before the challenges. Total IgA, IgG, and IgM and rBet v1 and rMal dl specific IgA, IgG, IgG1, and IgG4 levels were measured from saliva with an enzyme-linked immunosorbent assay (ELISA). Serum rBet v1 specific IgE ELISA and birch radioallergosorbent testing were performed. After 5.5 months, rBet v1 and rMal dl specific IgA levels had increased from baseline in the LGG compared with the placebo group (delta rBet v1 IgA, 0.319 vs. -0.136 relative units; P = .02; delta rMal d1 IgA, 0.097 vs -0.117, P = .02). rBet v1 specific IgE serum levels did not differ between the groups. In the LGG group, rBet v1 specific IgE levels correlated positively with stimulated total IgA (P = .04) and IgG (P = .003) in saliva. In the placebo group, rBet vl specific IgE levels correlated negatively with stimulated rBet v1 and rMal d1 IgA levels (P = .009 for both) and IgG (P = .02 and P = .03, respectively). LGG showed immunostimulating effects on oral mucosa seen as increased allergen specific IgA levels in saliva.