Objective: To compare the efficacy and safety of a 6-week cluster schedule of specific immunotherapy with that of a 14-week conventional schedule for the treatment of subjects with persistent allergic rhinitis (AR).
Methods: The trial was a prospective and randomized study involving 80 patients with persistent AR, who were allergic to Dermatophagoides pteronyssinus. While 40 patients were randomly assigned to the cluster schedule reaching the maintenance dose within 6 weeks, the other 40 patients were randomly assigned to the conventional schedule reaching the maintenance dose within 14 weeks. Symptom scores and medication scores were used to evaluate the clinical efficacy. Serum specific IgG4 level was examined to mark immunologic change, adverse reactions were recorded during the treatment.
Results: Cluster group achieved clinical efficacy (reducing symptom scores and medication score) and increasing serum specific IgG4 sooner (after 6 weeks treatment). During the incremental dose phase, there were 6 systemic adverse reactions (1.12% of all injection) in 3 patients in cluster group and there were 5 systemic adverse reactions (0.85% of all injection) in 3 patients in conventional group. No severe systemic reactions occurred in both group. There was no difference between the 2 groups in frequency or type of systemic reaction (χ(2) = 0.333, P > 0.05).
Conclusion: The cluster schedule is a safe alternative to the conventional schedule with the advantage of achieving clinical efficacy sooner.