AAAAI Survey On Immunotherapy Practice Patterns Concerning Dosing, Dose-Adjustment After Missed Doses and Duration of Immunotherapy

Background: Several practical issues dealing with the exact application of allergen immunotherapy (AIT) among European and US allergists are not well known. Guidelines on AIT give recommendations and suggestions for only some of them. We present this unique survey with worldwide response.

Methods: The AAAAI immunotherapy committee conducted a web-based practice patterns survey (program: Survey Monkey) among all members in&outside US on dosing, dose-adjustment after missed doses and duration of AIT.

Results: 1201 Returned questionnaires (almost 25% response rate). 21% were non-US-Canada members.
Maintenance doses in USCan are (mean/median): Dermatophagoides farinae (Df) combined with Dermatophagoides pteronyssinus (Dpt): 2155/1000AU; Df solo 2484/1000AU. Dpt when combined with Df 1937/1000AU; Dpt solo: 2183/1000AU.Cat 3224/2000BAU. Grass 11,410/4000BAU. 57-65% of the dosing falls within the recommended Practice Parameters recommended ranges. Non-USCan allergists expressed maintenance doses in many different units making analysis impossible.
Dose-adjustment after missed doses is based on ‘time elapsed since the last applied dose’ by 77% of USCan and 58% of non-USCan allergists and on ‘time since missed scheduled dose’ by the rest. Doses are adjusted when a patient comes in more than 14 days/5 weeks after the last administration at build-up/maintenance by both USCan and non-USCan colleagues. The mostly followed dose-adjustment schedules after 1, 2, 3 missed doses are: Build-up: repeat last dose, reduce by one dose, reduce by two doses; maintenance: reduce by one dose, reduce by two doses, reduce by three doses. 26% uses a different approach reducing doses by a certain percentage or volume. AIT is restarted after a gap in build-up of >30 days and of >12 weeks during maintenance in both groups (median).
Outside USCan AIT is prescribed for 3yrs (Median).However, 75% of USCan allergists prescribes AIT for 5yrs. Main reasons why to continue AIT beyond 5yrs: ‘symptoms came back after stopping’ or ‘patient afraid to relapse’.

Conclusions:  these results show regional differences on some points (especially AIT duration) and they suggest in which direction to plan further research in two areas to establish universal dose-adjustment plans for missed applications and define the usefulness (or lack of..) of long-term AIT. Moreover, there is still room for improvement in the way AIT is dosed.