Cassava oral immunotherapy in cassava-latex allergy: A pilot study.

BACKGROUND

Cassava allergy is rare; however, because of the cross-reactivity of cassava with latex, it is clinically significant, affecting patient safety and quality of life. Oral immunotherapy (OIT) has been studied for use in patients with allergy to foods such as milk, egg, and peanut, but no studies have evaluated its use in patients with allergy to cassava.

OBJECTIVE

Our aim was to conduct a pilot study evaluating the feasibility, safety, and immunologic effects of a cassava OIT protocol in patients with IgE-mediated cassava and latex allergy.

METHODS

We conducted a prospective longitudinal study involving 5 patients. The OIT protocol included a hospital-based induction phase (weekly escalation until tolerance to 100 g of cooked cassava had been achieved) and a 6-month home-based maintenance phase. Skin prick test results and specific IgE/IgG4 levels in response to latex and its components were evaluated at baseline and after maintenance, as were the results of latex use tests after maintenance.

RESULTS

All 5 patients reached the 100-g target in induction (a 100% success rate). After 6 months, 3 patients (60%) maintained full desensitization, with the remaining 2 experiencing a reduction of tolerance to 10 g. Adverse reactions were mostly mild (oropharyngeal pruritus and cough) and managed with antihistamines; no epinephrine use was required. Skin prick test wheal sizes in response to cassava decreased after OIT. No significant changes in IgE and IgG4 levels in response to latex occurred. The results of latex use testing were negative in 3 of 4 patients tested.

CONCLUSION

This pilot study suggests that cassava OIT is a feasible and safe strategy for inducing desensitization in patients with casava allergy. We observed a suggestive signal of improved clinical tolerance to latex in some patients following therapy; however, the lack of a baseline latex challenge precludes definitive conclusions regarding cross-desensitization. These preliminary findings support the need for larger, controlled trials to confirm efficacy and further investigate this potential cross-reactive benefit.