Dermatophagoides pteronyssinus cluster immunotherapy. A controlled trial of safety and clinical efficacy

We designed a cluster schedule of immunotherapy for patients allergic to Dermatophagoides pteronyssinus to reach the maximal recommended dose in 7 weeks. We compared its safety and clinical efficacy with those of a conventional schedule in a controlled trial. Sixty-three patients were randomized as follows: 29 were treated with the cluster schedule, 15 with a conventional schedule and 19 without immunotherapy. A standardized extract was used. Clinical efficacy was measured by visual analog scale, clinical severity score, symptom/medication diary cards and control of peak expiratory flow (PEF) in asthmatic patients, before immunotherapy (T0), on reaching the maintenance phase (T1), and after 6 (T2), 12 (T3) and 18 months of maintenance (T4). The safety of immunotherapy was found to be good. Visual analog scale improved significantly at T4 in the cluster and conventional schedules, and clinical severity score also improved from T1 in these schedules. Diary cards improved from T1 in the cluster schedule and from T2 in the conventional schedule in asthmatic patients. Significant improvements in diary cards in rhinitis patients and PEF were found only in the cluster schedule. There were no changes in the group without immunotherapy. In conclusion, our cluster schedule showed as good tolerance and clinical efficacy as the conventional schedule in patients allergic to D. pteronyssinus. These clinical improvements did not appear in the group without immunotherapy.