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Updated: Mar 19, 2026
Humanized Mediator Release Assay as a Read-Out for Allergen Potency
Published on: June 29, 2021
Cross-reactivity between methylisothiazolinone, octylisothiazolinone and benzisothiazolinone using a modified local
J F Schwensen1, C Menné Bonefeld2, C Zachariae3
1National Allergy Research Centre, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Kildegårds Allé, 2900 Hellerup, Denmark.
Background:
In the light of the exceptionally high rates of contact allergy to the preservative methylisothiazolinone (MI), information about cross-reactivity between MI, octylisothiazolinone (OIT) and benzisothiazolinone (BIT) is needed.
Objectives:
To study cross-reactivity between MI and OIT, and between MI and BIT.
Methods:
Immune responses to MI, OIT and BIT were studied in vehicle and MI-sensitized female CBA mice by a modified local lymph node assay. The inflammatory response was measured by ear thickness, cell proliferation of CD4+ and CD8+ T cells, and CD19+ B cells in the auricular draining lymph nodes.
Results:
MI induced significant, strong, concentration-dependent immune responses in the draining lymph nodes following a sensitization phase of three consecutive days. Groups of MI-sensitized mice were challenged on day 23 with 0·4% MI, 0·7% OIT and 1·9% BIT - concentrations corresponding to their individual EC3 values. No statistically significant difference in proliferation of CD4+ and CD8+ T cells was observed between mice challenged with MI compared with mice challenged with BIT and OIT.
Conclusions:
The data indicate cross-reactivity between MI, OIT and BIT, when the potency of the chemical was taken into account in choice of challenge concentration. This means that MI-sensitized individuals may react to OIT and BIT if exposed to sufficient concentrations.
