To date, SU has been studied as a binary outcome after an arbitrary period of avoidance. Characteristics about the duration of SU and the desensitization effect have not been well described.
METHODS:
Fifty-five subjects ages 1-11 years were enrolled in an open-label study of peanut SLIT using a maintenance dose of 4 mg. After 48 months of therapy, a 5000 mg DBPCFC was performed to assess for desensitization. A randomly selected period between 1-17 weeks of avoidance was then assigned to each subject after which an identical DBPCFC was performed to assess for SU.
RESULTS:
Forty-seven subjects completed the DBPCFC after 48 months of treatment with a median successfully consumed dose (SCD) of 0 mg (0-425 mg) prior to treatment and 2900 mg (100-5000 mg) after 48 months. Peanut IgE levels dropped significantly over the treatment period: Median 84.7 kU/L (0.3-1804) at entry, to 11.2 kU/L (0.05-970) after 48 months.
Thirty subjects completed the randomly assigned post-avoidance DBPCFC demonstrating an estimated decrease in SCD of 111 mg/week of avoidance. Only one subject demonstrated a decrease in SCD below 300 mg after avoidance (100 mg was tolerated at 48 months and at 1 week post avoidance)
CONCLUSIONS:
Long-term treatment with peanut SLIT successfully desensitizes subjects to a median dose well above that expected in an accidental exposure. Our novel assessment of SU demonstrates a steady decrease in SCD over time but at a slower rate than expected with the majority of subjects maintaining a clinically significant SCD even after 17 weeks of avoidance.