Evaluation of lymphocyte transformation tests as compared with patch tests in nickel allergy diagnosis

Abstract

In the patch tests, 2 of 50 controls and 18 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to Ni. In the LTTs, 2 of 50 controls and 26 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to NiSO 2.5 × 10 m, and 2 of 50 controls and 17 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to NiSO 1 × 10 m. Sixteen of the 18 history-positive and patch test-positive patients (i.e. 88% sensitivity) were also LTT-positive, in contrast to only 2 positive LTT reactors within the 48 PT and history negative individuals (i.e. 96% specificity). [Correction added on 16 February 2017, after first online publication: The preceding sentence has been edited for language and this has been amended in this version.] CONCLUSION: Performing the LTT with optimized stimulating conditions might be a useful additional tool for the diagnosis of Ni allergy if non-sensitized controls are included.

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

“…In other studies using peripheral blood samples taken from patients with contact allergy, blood sampling has tended to be conducted before patch testing, as the authors were concerned that exposure to contact allergen might activate the cells. 15,39 Alternatively, donors have been drawn from a pool of previously patch testpositive or patch test-negative individuals. 40 Given that significant differences were found between the phenotype of the healthy control population and that of the nickel-positive and PPD-positive donors in our study, particularly with respect to increases in the proportions of naïve CD4 + and CD8 hi cells, it is possible that the observed differences were attributable to cellular recruitment of skin-homing lymphocytes to the patch test site.…”

“…There is considerable interest in developing such in vitro measures of allergen-specific responses in order to supplement, or perhaps even to replace, patch testing when there are concerns about severe reactions or unintended sensitization. [8][9][10][11][12][13][14][15] In the absence of cytokine supplements (IL-2 or IL-7, for example) 11,39 being used to enhance proliferative responses, the overall positive rate for nickel was 17 of 31, which is lower than the rate found in many other reported studies (16/18; 62/74; and 13/14), 15,39,40 although it is similar to the frequency of 13 of 19 reported in 2013 by Pacheco et al for patients referred by local orthopaedists for evaluation for possible nickel sensitization who were patch test-positive. 45 The reasons for this lower share of positivity in our study are not clear, although it is noted that minor technical differences in the lymphocyte transformation test protocol can have marked effects, such as the use of autologous serum, 46 or the length of time in culture (5 days vs 6 or 7 days).…”

“…[2][3][4][5][6][7] One important tool for the characterization of human T cell responses to contact allergens is the lymphocyte transformation test, in which the proliferation of cultured T lymphocytes induced by contact allergens, or by contact allergens conjugated with proteins, is measured. [8][9][10][11][12][13][14][15] Experience with the lymphocyte transformation test has been predominantly with metals, and in particular nickel, although somewhat variable results have also been reported with certain organic contact allergens, including: 2,4-dinitrochlorobenzene, 9 methylisothiazolinone (MI), 7 and p-phenylenediamine (PPD). 11,12 In the present investigations, the lymphocyte transformation test was used to explore further the characteristics of T lymphocyte responses to nickel (as nickel sulfate), and to PPD, which is a proven contact allergen in hair dyes and henna tattoos 1,16 (delivered in culture as a hapten-protein conjugate).…”

New attempts to improve in vitro diagnosis of contact allergy are still far from regular clinical practice

“…Nevertheless, the diagnosis of ACD based on these in vitro tests is still far from current practice. Contrary to patch testing, in vitro tests evaluate a single allergen at a time, few laboratories have facilities to perform them and there are difficulties in standardization, specificity and sensitivity of the techniques …”

“…Contrary to patch testing, in vitro tests evaluate a single allergen at a time, few laboratories have facilities to perform them and there are difficulties in standardization, specificity and sensitivity of the techniques. 1 Characteristics of the chemical and the pathways it activates during sensitization or elicitation and patient's immune status/ concomitant diseases, like atopic dermatitis, may influence the sensitivity and specificity. Circulating T cells that specifically proliferate in vitro when exposed to cutaneous haptens belong to different phenotypes and produce different cytokines.…”