Diagnostic utility of the basophil activation test in natto-induced hypersensitivity

Risa Fukuda, Takeshi Ouchi, Yasuhiko Asahina, Chihiro Shiiya, Sakiko Takeuchi, Fumiyo Yasuda-Sekiguchi, Hisato Iriki, Michiyoshi Kouno, Shinichi Takahashi, Akiko Tanikawa, Masayuki Amagai, Hayato Takahashi

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Background: Natto (fermented soybeans)-induced hypersensitivity is characterized by delayed symptom onset that hampers diagnosis. We aimed to clarify the clinical utility of the basophil activation test (BAT) in the diagnosis of natto-induced hypersensitivity. Methods: Five patients with a history of anaphylaxis and chronic urticaria suspected of natto-induced hypersensitivity and seven with chronic spontaneous urticaria clinically unrelated to natto were enrolled in the patient and control groups, respectively. The BAT was performed with two incubation times, 15 min and 1 h, in combination with various concentrations of natto-mucilage extract. Results: In controls, CD203c levels in basophils remained low in the 15-min incubation but were significantly increased in the 1-h incubation. In the patient group, in the 15-min condition, basophil CD203c was significantly upregulated by natto mucilage but not by soybean vs controls (P = 0.001). Low concentrations of natto mucilage were sufficient to upregulate basophil CD203c in the anaphylaxis cases, but high concentrations were required to induce the same effect in the urticaria cases. Finally, the dose-dependent pattern of the BAT results differed significantly between the anaphylaxis and urticaria cases (P = 0.006). Thus, a strong background reaction was observed in the BAT with 1 h incubation; 15 min of incubation was sufficient to identify patients with natto-induced hypersensitivity and may distinguish the clinical phenotype of natto-induced hypersensitivity, i.e., anaphylaxis or urticaria. Conclusions: The BAT with a 15-min incubation period is useful in diagnosing natto-induced hypersensitivity.

Original languageEnglish
Pages (from-to)125-130
Number of pages6
JournalAllergology International
Issue number1
Publication statusPublished - 2022 Jan


  • Anaphylaxis
  • Basophil activation test
  • Natto-induced hypersensitivity
  • Poly γ-glutamic acid
  • Urticaria

ASJC Scopus subject areas

  • Immunology and Allergy


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