A trial of adding Lactobacillus johnsonii EM1 to levocetirizine for treatment of perennial allergic rhinitis in children aged 7-12 years

Supplementary consumption of probiotics may temporarily alter the intestinal microflora of infants and children, thereby preventing and treating allergic disorders.To compare the clinical efficacy of levocetirizine with that of levocetirizine plus Lactobacillus johnsonii EM1 (Lj EM1) for treating perennial allergic rhinitis (PAR) in children.Sixty-three children aged 7-12 years fulfilled the entry criteria for the study and had moderate to severe PAR of at least 1 year's duration. The treatment followed a randomized, open-label crossover design: all subjects were randomized to 2 crossover treatment regimens of levocetirizine with Lj EM1 (group 1) or levocetirizine alone (group 2) for 12 weeks; subsequently, treatments were reversed for a further 12 weeks. The effects of the 2 regimens were compared using the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and the total symptom score (TSS) from diary cards. The parameters evaluated were nasal peak expiratory flow rate (nPEFR), FVC, FEV1, serum immunoglobulin E (IgE), mite-specific IgE, eosinophilic cationic protein (ECP), resistin, blood eosinophils, eosinophil percentage in nasal smears, IL-4, IL-10, interferon-γ (IFN-γ), and transforming growth factor-β (TGF-β).After the first 12 weeks of treatment, TSS in both groups had improved progressively compared with that in the run-in period. Both groups had improved TSS at weeks 4, 8, and 12 (P0.05), and group 1 was more efficacious than group 2 at week 4 (P=0.014), week 8 (P=0.011), and week 12 (P0.009). During the second 12-week period, group 2 showed continual and progressive improvement, while group 1 did not. The PRQLQ scores were significantly decreased in both groups (P0.05), but there was no statistically significant difference between the 2 groups (P=0.446). The eosinophil percentage in nasal smears decreased in both groups compared with that in the run-in period, and significant differences were detected in groups 2 and 1at 16 and 24 weeks of treatment, respectively (P0.05). Both groups showed significant improvement in nPEFR at weeks 4, 8, 12, 16, and 24 (P0.01), and the treatment for group 1 appeared to be more efficacious than that for group 2 at weeks 12, 16, and 20 (P0.05). FVC and FEV1 were improved in both groups at weeks 8 through 24 (P0.05), but there was no significant difference between the 2 groups. In cytokine measurements, IFN-γ and IL-10 increased significantly and IL-4 decreased significantly in both groups, while elevation of TGF-β was seen only in group 1 at 12 weeks (P0.001). However, the difference in TGF-β disappeared after 24 weeks treatment. There was no difference in serum resistin levels. No serious adverse events were recorded in either treatment group.The 24-week, 2-phase, crossover treatment program showed that levocetirizine plus Lj EM1 was more effective for PAR than levocetirizine and that this difference persisted for at least 3 months after discontinuation of Lj EM1.