Long-term efficacy of sublingual immunotherapy with Dermatophagoides Farianae Drops in children with allergic asthma sensitized to dust mites

Abstract

To observe the efficacy of sublingual immunotherapy (SLIT) in children with allergic asthma during the treatment and 1 year after the treatment. This is an open and retrospective study; 80 children with mild-moderate allergic asthma between 4 and 14 years of age were chosen from the Department of Respiratory Medicine, Nanjing Children's Hospital Affiliated to Nanjing Medical University from May to August, 2009. All children were sensitized to Dermatophagoides Farianae and/or Dermatophagoides Pteronyssinus and have received anti-asthma drug therapy for 3 months (baseline). Thirty-nine children in SLIT group underwent 2-year SLIT and combined with anti-asthma drug, these children were then followed up for 1 year. Forty-one children in drug group only received anti-asthma drug and were followed up for 3 years. The scores of asthma symptom, scores of asthma medication and the number of discontinuation of anti-asthma drug were compared between the SLIT group and drug group for the baseline, end of the 2nd year and 3rd year treatment. The frequency of acute attack of asthma was also compared between the two groups for 1 year before the treatment and the 3rd year treatment. (1) At baseline, the asthma symptom scores, the medication scores and the frequency of acute attack of asthma in 1 year before the treatment of the two groups showed no significant difference. (2) After 2-year SLIT, the daytime asthma symptom scores of SLIT group were lower than the drug group (0.18 ± 0.06,0.93 ± 0.12,Z = -4.873, P < 0.05), the night asthma symptom scores of the two groups showed no significant difference. One year after SLIT, the daytime and night asthma symptom scores of SLIT group were both lower than those of the drug group (daytime SLIT group vs. Drug group: 0.18 ± 0.06 vs. 1.46 ± 0.72,Z = -5.082, P < 0.05;night SLIT group vs. Drug group: 0.05 ± 0.04 vs. 0.66 ± 0.14,Z = -4.019, P < 0.05). (3) At the end of SLIT and 1 year after SLIT, the medication scores of SLIT group were both lower than those of the drug group (End of SLIT SLIT group vs. Drug group: 0.31 ± 0.07 vs. 0.75 ± 0.12,Z = -2.813, P < 0.05;1 year after SLIT SLIT group vs. Drug group: 0.17 ± 0.06 vs. 0.87 ± 0.17,Z = -4.106, P < 0.05), the number of discontinuation of anti-asthma drug of SLIT group were both more than the drug group (End of SLIT SLIT group vs. Drug group: 20 vs. 10,χ(2) = 6.167, P < 0.05;1 year after SLIT SLIT group vs. Drug group: 29 vs.13,χ(2) = 14.581, P < 0.05).(4) In the 3rd year, the frequency of acute attack of asthma in SLIT group was significantly lower than that of drug group (0.69 ± 1.20, 1.20 ± 1.44,Z = -1.968, P < 0.05) . SLIT can significantly improve the symptoms of asthma, reduce the use of anti-asthma drug and reduce the frequency of the acute attack of asthma. Meanwhile, the efficacy could still maintain 1 year after the SLIT treatment.