Effect of Avoidance on Peanut Allergy after Early Peanut Consumption
George Du Toit, Peter H Sayre, Graham Roberts, Michelle L Sever, Kaitie Lawson, Henry T Bahnson, Helen A Brough, Alexandra F Santos, Kristina M Harris, Suzana Radulovic, Monica Basting, Victor Turcanu, Marshall Plaut, Gideon Lack, Immune Tolerance Network LEAP-On Study Team, Susan Chan, Adam Fox, Mable Abraham, Muhsinah Adam, Louise Coverdale, Claire Duncan, Helen Fisher, Amy Nixon, Una O'Dwyer-Leeson, Victoria Offord, Aine Sheridan, Fiona Watson, Natalie Witham, Kathryn Cockerell, Mary Feeney, Gail Harland, Tiffany Miller, Charlotte Stedman, Catherine Clarke, Richard Cleaver, Gemma Deutsch, Alicia Parr, Natalia Becares, Matthew Crossley, Natalia do Couto Francisco, Kerry Richards, Ewa Pietraszewicz, Alick Stephens, Asha Sudra, Rianne Wester, Alastair Wilson, Celine Wu, Jenna Heath, Kathryn Hersee, Devi Patkunam, Adam Asare, Eduard Chani, Judith Evind, Noha Lim, Audrey Plough, Don Whitehouse, Margarita Gomez Lorenzo, Joy Laurienzo Panza, Maya Barton, Susan McCachren, Travis Mason, George Du Toit, Peter H Sayre, Graham Roberts, Michelle L Sever, Kaitie Lawson, Henry T Bahnson, Helen A Brough, Alexandra F Santos, Kristina M Harris, Suzana Radulovic, Monica Basting, Victor Turcanu, Marshall Plaut, Gideon Lack, Immune Tolerance Network LEAP-On Study Team, Susan Chan, Adam Fox, Mable Abraham, Muhsinah Adam, Louise Coverdale, Claire Duncan, Helen Fisher, Amy Nixon, Una O'Dwyer-Leeson, Victoria Offord, Aine Sheridan, Fiona Watson, Natalie Witham, Kathryn Cockerell, Mary Feeney, Gail Harland, Tiffany Miller, Charlotte Stedman, Catherine Clarke, Richard Cleaver, Gemma Deutsch, Alicia Parr, Natalia Becares, Matthew Crossley, Natalia do Couto Francisco, Kerry Richards, Ewa Pietraszewicz, Alick Stephens, Asha Sudra, Rianne Wester, Alastair Wilson, Celine Wu, Jenna Heath, Kathryn Hersee, Devi Patkunam, Adam Asare, Eduard Chani, Judith Evind, Noha Lim, Audrey Plough, Don Whitehouse, Margarita Gomez Lorenzo, Joy Laurienzo Panza, Maya Barton, Susan McCachren, Travis Mason
Abstract
Background: In a randomized trial, the early introduction of peanuts in infants at high risk for allergy was shown to prevent peanut allergy. In this follow-up study, we investigated whether the rate of peanut allergy remained low after 12 months of peanut avoidance among participants who had consumed peanuts during the primary trial (peanut-consumption group), as compared with those who had avoided peanuts (peanut-avoidance group).
Methods: At the end of the primary trial, we instructed all the participants to avoid peanuts for 12 months. The primary outcome was the percentage of participants with peanut allergy at the end of the 12-month period, when the participants were 72 months of age.
Results: We enrolled 556 of 628 eligible participants (88.5%) from the primary trial; 550 participants (98.9%) had complete primary-outcome data. The rate of adherence to avoidance in the follow-up study was high (90.4% in the peanut-avoidance group and 69.3% in the peanut-consumption group). Peanut allergy at 72 months was significantly more prevalent among participants in the peanut-avoidance group than among those in the peanut-consumption group (18.6% [52 of 280 participants] vs. 4.8% [13 of 270], P<0.001). Three new cases of allergy developed in each group, but after 12 months of avoidance there was no significant increase in the prevalence of allergy among participants in the consumption group (3.6% [10 of 274 participants] at 60 months and 4.8% [13 of 270] at 72 months, P=0.25). Fewer participants in the peanut-consumption group than in the peanut-avoidance group had high levels of Ara h2 (a component of peanut protein)-specific IgE and peanut-specific IgE; in addition, participants in the peanut-consumption group continued to have a higher level of peanut-specific IgG4 and a higher peanut-specific IgG4:IgE ratio.
Conclusions: Among children at high risk for allergy in whom peanuts had been introduced in the first year of life and continued until 5 years of age, a 12-month period of peanut avoidance was not associated with an increase in the prevalence of peanut allergy. Longer-term effects are not known. (Funded by the National Institute of Allergy and Infectious Diseases and others; LEAP-On ClinicalTrials.gov number, NCT01366846.).
Source: PubMed