| 1. |
- Matura, Mihaly, 1964, et al.
(författare)
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Not only oxidized R-(+)- but also S-(-)-limonene is a common cause of contact allergy in dermatitis patients in Europe.
- 2006
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Ingår i: Contact dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 55:5, s. 274-9
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Tidskriftsartikel (refereegranskat)abstract
- Limonene, one of the most often used fragrance terpenes in any kind of scented products, is prone to air-oxidation. The oxidation products formed have a considerable sensitizing potential. In previous patch test studies on consecutively tested dermatitis patients, oxidized R-limonene has been proven to be a good and frequent indicator of fragrance-related contact allergy. The current study extends these investigations to 6 European clinics of dermatology, where the oxidation mixture of both enantiomers of limonene (R and S) have been tested in 2411 dermatitis patients. Altogether, 63 out of 2411 patients tested (2.6%) reacted to 1 or both the oxidized limonene preparations. Only 2.3% reacted to the oxidized R-limonene and 2.0% to the oxidized S-limonene. In 57% of the cases, simultaneous reactions were observed to both oxidation mixtures. Concomitant reactions to the fragrance mix, colophonium, Myroxylon pereirae, and fragrance-related contact allergy were common in patients reacting to 1 or both the oxidized limonene enantiomers. Our study provides clinical evidence for the importance of oxidation products of limonene in contact allergy. It seems advisable to screen consecutive dermatitis patients with oxidized limonene 3% petrolatum, although this patch test material is not yet commercially available.
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| 2. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Linalool - a significant contact sensitizer after air exposure
- 2010
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 62:1, s. 32-41
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Tidskriftsartikel (refereegranskat)abstract
- Background: Linalool is a widely used fragrance terpene. Pure linalool is not allergenic or a very weak allergen, but autoxidizes on air exposure and the oxidation products can cause contact allergy. Oxidized (ox.) linalool has previously been patch tested at a concentration of 2.0% in petrolatum (pet.) in 1511 patients, and 1.3% positive patch test reactions were observed. Objective: To investigate the optimal patch test concentration for detection of contact allergy to ox. linalool. Methods: Four concentrations of ox. linalool (2.0%, 4.0%, 6.0%, 11.0% pet.) were tested in 3418 consecutive dermatitis patients. Results: Ox. linalool 2.0%, 4.0%, 6.0%, and 11.0% pet. detected positive patch test reactions in 0.83%, 3.2%, 5.3%, and 7.2% of the tested patients, respectively. The doubtful reactions increased with rising concentrations but relatively less, giving 5.1%, 6.4%, and 7.3% doubtful reactions, respectively, for ox. linalool 4.0%, 6.0%, and 11.0% pet. Few irritative reactions were seen. Conclusions: Raising the patch test concentration for ox. linalool gave a better detection of contact allergy, as many as 5-7% positive patch test reactions were detected. We suggest a patch test concentration of ox. linalool 6.0% pet. for future patch testing, giving a dose per unit area of 2.4 mg/cm(2) when 20 mg test substance is tested in small Finn Chambers (R).
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| 3. |
- Wahlkvist, H., et al.
(författare)
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The lipophilic hapten parthenolide induces interferon-gamma and interleukin-13 production by peripheral blood-derived CD8+ T cells from contact allergic subjects in vitro
- 2008
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 1365-2133 .- 0007-0963. ; 158:1, s. 70-77
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Tidskriftsartikel (refereegranskat)abstract
- Background Peripheral blood mononuclear cells (PBMC) from persons with contact allergy to nickel react in vitro predominantly with nickel-induced CD4+ T cell-mediated production of both T-cell type 1 and 2 cytokines. Objectives The aim of the present study was to investigate if the contact allergen parthenolide, a sesquiterpene lactone of lipophilic character, elicits an immune response which differs from that induced by water-soluble nickel ions. Patients and methods Ten allergic subjects with strong (n = 6), moderate (n = 2), or weak (n = 2) patch-test reactivity to parthenolide and five patch test-negative control subjects participated in the study. PBMC from the subjects were analysed for in vitro reactivity with parthenolide by an enzyme-linked immunospot (ELISpot) assay, measuring cytokine production at the single-cell level. Results The allergic group, but not the control group, responded to parthenolide with increased numbers of cells producing interferon (IFN)-gamma, interleukin (IL)-2, IL-4, IL-5 (P < 0.05 for all) and IL-13 (P < 0.01). The responses manifested by T-cell type 1 (IFN-gamma and IL-2) and type 2 (IL-4, IL-5 and IL-13) cytokines were positively correlated between cytokines. Subjects with a strong or moderate, but not weak or negative, patch-test reaction displayed detectable in vitro responses. In contrast to the CD4+ T cell-mediated peripheral reactivity induced by nickel, cell depletion experiments identified the parthenolide-reactive IFN-gamma- and IL-13-producing cells as CD8+ T cells. Conclusions The finding that the PBMC reactivity to parthenolide in humans involves a CD8+ T cell-mediated type 1 and 2 cytokine response warrants further studies on the relationship between the chemical nature of a hapten and the resulting immune response.
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| 4. |
- Masjedi, K., et al.
(författare)
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Is the variability of nickel patch test reactivity over time associated with fluctuations in the systemic T-cell reactivity to nickel?
- 2009
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 0007-0963 .- 1365-2133. ; 161:1, s. 102-109
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Tidskriftsartikel (refereegranskat)abstract
- Background Patch test reactivity to nickel varies over time. To what extent this variation is associated with fluctuations in the T-cell reactivity to nickel is not known. Objectives Our aim was to investigate the relationship between variation over time in the patch test and the systemic T-cell reactivity to nickel. Methods Patients (n = 15) with a history of contact allergy to nickel were subjected to three consecutive patch tests at 3-month intervals, utilizing NiSO4 at 10 concentrations ranging from 0.0032% to 12.5%. Prior to each patch test, blood mononuclear cells were analysed for T-cell reactivity to nickel by interleukin (IL)-4 and IL-13 enzyme-linked immunospot assay. Results Eleven patients reacted positively in all three patch tests, two patients reacted in one or two tests and two remained negative. All 13 positive patients displayed variability over time, in terms of the lowest dose of nickel to which they responded. Also the cytokine response to nickel varied over time but the patients' mean cytokine response was positively correlated with their mean patch test reactivity (r(s) = 0.70, P < 0.01 for IL-4; r(s) = 0.78, P < 0.001 for IL-13). However, although the changes over time in patch test reactivity and the cytokine responses to nickel displayed a similar pattern in many patients, there was no significant correlation between the individuals' variation over time in vivo and in vitro. Conclusions The overall magnitude of the T-cell reactivity to nickel and the patch test reactivity are closely associated but fluctuations in the systemic T-cell reactivity cannot be singled out as the major cause of longitudinal variability in nickel patch test reactivity.
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