Assessment of the sensitizing potential of textile disperse dyes and some of their metabolites by the loose-fit coculture-based sensitization assay (LCSA)

Abstract

Certain textile disperse dyes are known to cause allergic reactions of the human skin. Here, we examined 8 disperse dyes and 7 products of azo-cleavage of these dyes in an in vitro assay. We used the loose-fit coculture-based sensitization assay (LCSA) of primary human keratinocytes and of allogenic dendritic cell-related cells for combined testing of the sensitizing and irritative properties of these substances. The obtained data were compared to data generated in a modified version of the local lymph node assay by our working group. Disperse Blue 1 (DB1), p-nitroaniline (pNA) and p-aminoacetanilide (AAA) showed no sensitizing potential under our experimental conditions. Disperse Blue 124 (DB124), Disperse Yellow 3 (DY3), Disperse Orange 37/76 (DO37), Disperse Blue 106 (DB106), Disperse Red 1 (DR1), 2-amino-p-cresol (ApC), Disperse Orange 3 (DO3) and 2,6-dichloro-4-nitroaniline (DCh) were categorized as extreme sensitizers. Para-phenylenediamine (pPD) was categorized as strong sensitizer, and 2-amino-5-nitrothiazole (ANT) and 2-(N-ethylanilino)-ethanol (EAE) as weak sensitizers. All dyes, except for DB1, and ApC turned out to be strong irritants. DB1, ANT and DCh showed only weak irritative potential. PPD, pNA, EAE and AAA did not show any irritative effect at the concentration range tested. These results correlate with data derived from the modified version of LLNA and human data. Therefore, the LCSA represents a suitable test system to simultaneously analyse two crucial properties of substances relevant for allergy induction.

Patch Testing with a Textile Dye Mix in Two Concentrations – A Multicentre Study by the Swedish Contact Dermatitis Research Group

“…The majority of the irritant patch test reactions were reported from 2 of the participating clinics, both using Finn Chambers ® . It is known that several of the DDs used in the TDMs are not only very strong sensitisers but also have a strong irritative potential (14). In the present study, however, the TDM tested at the concentration 8.0% did not give a higher frequency of irritant reactions compared to testing with the mix at the lower concentration.…”

Sensitizing capacity of Disperse Orange 1 and its potential metabolites from azo reduction and their cross‐reactivity pattern

“…In our study, 4‐nitroaniline at an equimolar concentration to Disperse Orange 1 did not show sensitizing capacity. This finding confirms results from other studies , where 4‐nitroaniline was found to be a non‐sensitizer even when a higher concentration was used for sensitization in the GPMT .…”

“…Sonnenburg et al. examined several disperse dyes and products from azo cleavage of these dyes in the loose‐fit co‐culture‐based sensitization assay of primary human keratinocytes and of allogenic dendritic cell‐related cells . In this assay, 4‐nitroaniline and 4‐aminoacetanilide showed no sensitizing potential, whereas Disperse Yellow 3 and 2‐amino‐ p ‐cresol were categorized as extreme sensitizers.…”

Immune-competent in vitro co-culture models as an approach for skin sensitisation assessment

“…Loose-fit Co-culture-based Sensitization Assay (LCSA): 48h treatment CD86 DCrc expression and cell viability by flow cytometry (Schreiner et al, 2007); (Schreiner et al, 2008); (Wanner and Schreiner, 2008); (Wanner et al, 2010); (Sonnenburg et al, 2012); (Sonnenburg et al, 2015); (Frohwein et al, 2016); (Frombach et al, 2017) Primary KC + PBMC with addition of cytokines cocktail after co-culture for 48h in serum free condition LCSA-ly: 48h treatment CD44, CD119, CD124 and IL-23R lymphocyte cell expression and cell viability by flow cytometry, extracellular release of IL-4, IFN-ɣ and IL-17 by ELISA (Frombach et al, 2018) NCTC2544 KC cell line + THP-1 cell line 24h treatment CD86, CD54, CCR7 and IL-8 co-culture expression by RT-qPCR (Meloni et al, 2010) HaCaT KC cell line + moDC 2 treatment protocols: either 1h treatment of HaCaT cell line, removal of treatment and co-culture with DC for 20h or 1h treatment of HaCaT cell line, removal of treatment, post-incubation for 20h and conditioned supernatant in contact with DC for 20h CD83 and CD86 moDC cell expression by flow cytometry (Matjeka et al, 2012) HaCaT KC cell line + primary dermal fibroblasts + MUTZ-LC 48h treatment Cell viability (Alamar Blue test), extracellular release of 27 cytokines using bio-plex assay and of IL-8 by ELISA (Lee et al, 2018) ELISA: enzyme-linked immunosorbent assay; moDC: monocytes-derived dendritic cell; MUTZ-LC: MUTZ-3 acute myeloid leukemia cell line differentiated into LC; PBMC: peripheral blood mononuclear cell; PI: propidium iodide…”