Patterns of peanut ingestion in remission vs desensitized patients after completion of peanut oral immunotherapy at 3-years post-treatment
P. Loke1, 2, 3; W. Xiaofang1; M. Lloyd1; S. Ashley1, 2, 4; A. Chebar Lozinsky1; S. Rosser1, 2; J. Burns1; P. Quinn5, 6; M. O'sullivan7, 8, 9; M. Gold5, 6; F. Orsini1; ML. Tang1, 2, 4
1Murdoch Children's Research Institute, Parkville, Australia; 2The University of Melbourne, Parkville, Australia; 3Monash Children's Hospital, Clayton, Australia; 4The Royal Children's Hospital Melbourne, Parkville, Australia; 5Women’s and Children’s Hospital, North Adelaide, Australia; 6The University of Adelaide, Adelaide, Australia; 7Perth Children's Hospital, Nedlands, Australia; 8The University of Western Australia, Crawley, Australia; 9The Kids Research Institute Australia, Nedlands, Australia
Background

There is a paucity of long-term data following randomized control trials of oral immunotherapy (OIT). The probiotic peanut oral immunotherapy long-term study (PPOIT-003LT) is an extended follow-up study of participants who completed treatment with probiotic peanut OIT or peanut OIT. 

Method

After completing 18 months of treatment, remission participants consumed peanut ad libitum, and desensitized without remission (DWR) participants continued 2 peanuts daily. Peanut consumption and reactions were recorded prospectively via questionnaires and a mobile app, respectively. Outcomes at 3-years post-treatment are presented here.

Results

At 3-years post-treatment, 73% of eligible children (128/176) remained in the follow-up study. The majority of remission participants (n=53) were consuming moderate (47.2%) to large (20.8%) and very large (9.4%) amounts of peanut at 3-years post-treatment. Ingestion amounts remained consistent over time: 2-years post-treatment (moderate 50%, large 28.1%, very large 7.8%), 1-year post-treatment (moderate 53.8%, large 28.7%). Median frequency of ingestion was 1-2 times a week across all timepoints over the 3 years. At 3-years post-treatment, only 7.5% of remission participants were not eating peanut. In contrast, almost half (48.4%) of DWR participants (n=33) encountered difficulty in adherence to daily peanut ingestion, only 41.9% of DWR maintained daily ingestion at 3-year post-treatment and 16.1% had ceased peanut. The proportion of participants reporting reactions reduced over time for both groups (remission: 1st-year 27.5%, 2nd-year 15.9%, 3rd-year  11.3%; DWR 1st-year 57.9%, 2nd-year 36.8%, 3rd-year 27.3%). However, the proportion of DWR participants reporting reactions was consistently 2-3 fold higher than remission participants. In the third year of ad libitum consumption, remission participants had no moderate or severe reactions, and no rescue adrenaline injector usage. Conversely, amongst DWR participants, 16.7% and 11.1% of reactions were moderate or severe respectively, and 6.1% required rescue adrenaline injector usage.

Conclusion

At 3-years post-treatment, most remission participants continued ad libitum intake, and reported fewer and less severe reactions compared with DWR participants. Less than half of DWR participants adhered to daily peanut ingestion. Remission remains the preferred treatment outcome.