A laboratory test based on determination of cytokine profiles: a promising assay to identify exposition to contact allergens and predict the clinical outcome in occupational allergic contact dermatitis

Abstract

BackgroundPara-phenylenediamine (PPD) is the main allergen causing adverse reactions to hair dyes and a frequent cause of occupational-related skin sensitization among hairdressers and beauticians. The immunologic mechanism of the disease relies on the production of inflammatory cytokines by allergen-specific T cells, while regulatory T cells are thought to down-modulate the allergic response. This study was aimed at investigating the expression of effector or regulatory cytokines in exposed subjects in order to verify whether different cytokine profiles might predict distinct clinical outcomes. Peripheral blood mononuclear cells (PBMC) from 21 subjects occupationally exposed or not (10) to PPD were kept in short term cultures in the presence of optimized concentrations of NiSO4 × 6H2O or PPD. The production of IFN-γ and IL-10 elicited by antigens were analyzed by the ELISpot assay.ResultsThe presence of IFN-γ responses toward PPD was significantly correlated with a positive patch test (P = 0.002) and allergic symptoms, while IL10 responses were invariably found in PPD-exposed but clinically asymptomatic subjects with negative patch testing. We found concordance between the different cytokine profiles and patch test results. No false-positive results were found for the different cytokine profiles induced by PPD, resulting in 100% specificity. The sensitivity of the test was 87.5% (95% CI 65.9-100.0) with an overall test accuracy of 93.3%. Although larger prospective-retrospective studies are necessary to validate the predictive potential of the test, the negative and positive predicted values for PPD in this study were NPV = 87.5% and PPV = 100%, respectively.ConclusionsThese data indicate that distinct cytokine profiles are associated with different clinical manifestations. The test, which is based on a simple and rapid profiling of cytokine responses by T lymphocytes against allergens, has proven to be a promising laboratory tool, useful for both the identification of previous contact with allergens and the etiologic diagnosis of contact allergies as well as capable of predicting the clinical outcome (development of an allergic or tolerant response).

T lymphocyte phenotype of contact‐allergic patients: experience with nickel and p‐phenylenediamine

“…Given the level of sensitivity, the number of false negatives, and interlaboratory variation, the lymphocyte transformation test seems very unlikely to be a replacement for patch testing, but does have the advantages that additional endpoints such as the identity of the proliferating cells (CD4 or CD8) or the nature of cytokine production can be incorporated to improve mechanistic understanding. 7,47,48 In addition to sensitization being associated with changes in the profile of naïve and effector/central memory and EMRA cells, we also observed that, particularly for extremely allergic individuals, the Treg frequency was decreased, as was the CD4 + /CD8 hi ratio, whereas CLA expression was increased. These findings appeared to be a feature of sensitization to each of the three different allergens, despite the fact that they have very different chemistries.…”

“…Cytokine expression profiling, including the ratio of IL-5 to IL-8 production 47 or the secretion of interferon-γ, are being explored currently. 48 Experience with PPD is rather more variable, with some groups reporting vigorous proliferative responses to free PPD (6 of 9 +++ patch test donors; 7 of 8 ++ or +++ patch test donors; and 10 of 11 donors said to have a strong history of sensitization to PPD). 11,12,24 However, other studies found that free PPD stimulated proliferative responses in a minority of donors (1/6), despite them having ++ or +++ scores in patch tests, 49 or that 0 of 9 sensitized donors reacted positively to free PPD, although 7 of 9 responded to the metabolite Brandowski's base.…”

Serum Biomarkers of Allergic Contact Dermatitis: A Pilot Study

“…Enzymatic assays have also shown promise as diagnostic tools for ACD [10,11,12]. In particular, an ELISpot assay, which can detect serum levels of IL-4, IL-5, IL-10, IL-13, and IFN-γ, was developed for ACD diagnostics [13]. …”

Cytokines Profile in Experimental Contact Allergic Dermatitis and Use of Nanoencapsulated Preparations

“…Pathogenesis of allergic contact dermatitis includes sensitization (or induction) and elicitation (or efferent) phases, which are innate (opposite to contact irritant dermatitis) [20]. It is established at present that cytokines are crucial in inflammation, including immuneinvolved dermatitis [21][22][23].…”

“…The Th1 cells release of pro-inflammatory cytokines includes il-1α, il-1β, il-8, il-13, tnf-α, and granulocyte-macrophage colony-stimulating factor (GM-CSF). They increase the vascular permeability and cause swelling and redness associated with inflammation and immunologic reactions in skin exposed to irritants, also affect the proliferation and differentiation of keratinocytes and mediators of cellular infiltration [3,21,22].…”