Discussion
This study retrospectively analyzed real-world experiences of OIT for CN
and peanut allergies. The findings reveal a notable lower incidence of
adverse reactions in the CN group, coupled with a high success rate in
reaching maintenance. Adverse reactions were generally mild to moderate,
with severe reactions primarily occurring in the peanut group. Notably,
a substantial proportion of patients who underwent a second OFC
demonstrated desensitization, especially in the CN group.
Ensuring safety during OIT is a significant concern, considering the
known risk of severe adverse reactions, particularly during the
up-dosing phase17 12. In our study,
we observed a low frequency and severity of adverse reactions in
patients undergoing CN OIT. In contrast, the NUT Cracker study reported
a high incidence of side effects (88%) with 18% of patients requiring
adrenaline use18. Another study on CN OIT in preschool
children recorded no severe reactions, but 70.7% experienced mild
reactions19. Our CN group had an even lower rate of
mild to moderate adverse effects (33%) with no episodes of anaphylaxis,
possibly due, in part, to the low sIgE levels in our study population.
In contrast, the peanut group exhibited a significantly higher rate of
side effects, with 13% of patients experiencing anaphylaxis and 63%
encountering any side effect. The increased likelihood of severe
allergic reactions during peanut OIT, compared to strict avoidance, has
been reported in other studies,23 17underscoring the importance of thorough discussions with families to
assess the risk-benefit ratio. As reported in previous studies, moderate
or severe reactions were associated with higher sIgE
levels,24 25 explaining our finding
of higher rates of adverse reactions in the peanut group, with greater
safety observed in those with lower IgE levels.
In our patients, we did not validate previous findings that associated
the severity of adverse effects during OIT up-dosing with the presence
of co-existing asthma or allergic rhinitis.2627 However, patients with asthma or other food
allergies took significantly longer to reach the maintenance phase. It
remains unclear whether this slower progress was intentional for safety
reasons, as 70% of asthmatic patients had seasonal symptoms, or if
other factors influenced the time required to reach maintenance. This
suggests the possibility that seasonal triggers may have contributed to
a deceleration during the up-dosing phase, especially during pollen
season. Patients undergoing CN OIT reached their maintenance dose
quicker, which might be attributed to the significantly lower mean
starting dose in the peanut group.
A small proportion (5%) of children discontinued peanut OIT due to
aversion to taste, a phenomenon not observed in the CN group, suggesting
a potentially better tolerance for the taste of cashews. The
introduction of a standardized peanut OIT product may enhance treatment
compliance12. The rate of desensitization in CN OIT
was high (88%), in line with existing data1819. In contrast, the desensitization rate in the
peanut group was lower (69%). However, all patients who didn’t pass the
second OFC had mild to moderate reactions and increased their individual
reactive dose, indicating partial desensitization.11
Consistent with other studies, a substantial number of patients in the
peanut group experienced an initial increase in sIgE
levels28 29, with some showing
persistent high levels even after years of therapy. This complexity in
sIgE dynamics makes it challenging to rely on IgE levels for prognostic
purposes.
This study has several limitations, including its retrospective design,
potential biases, and missing immunological data. The heterogeneity in
starting and up-dosing protocols further complicates therapy duration
comparisons. The open OFC format may introduce bias, and the relatively
small sample size of patients undergoing a second OFC after the
maintenance phase limits statistical power and generalizability. Further
evaluations, especially considering the association of low nut-specific
IgE with a higher remission rate, may offer additional insights into the
study population.15 30 To optimize
and standardize CN OIT, prospective studies are needed to evaluate
safety, feasibility, and long-term outcomes, enhancing the effectiveness
and reliability of this treatment.
In conclusion, CN OIT shows promise as a treatment option, demonstrating
a lower rate of severe reactions compared to peanut OIT and good
feasibility with low dropout rates. However, careful consideration of
immunological parameters and other allergic diseases is crucial when
informing families and planning therapy. Further prospective studies
will help enhance the safety and effectiveness of OIT as a treatment
option for cashew nut allergic children.