BACKGROUND: A conventional lymphocyte transformation test (LTT) was compared to the commercially available MELISA (memory lymphocyte immunostimulation assay), a lymphoproliferative assay that has been suggested to be a valuable instrument for the diagnosis of metal allergy. Sensitivity and specificity of the two assays were calculated using a patch test as a reference method. METHODS: 34 patients were patch-tested for gold sodium thiosulfate, palladium chloride and nickel sulfate, and the lymphocyte proliferation to these metals was tested in vitro using mononuclear cells from peripheral blood. RESULTS: No significant differences regarding sensitivity and specificity were found between MELISA and conventional LTT. The sensitivity varied between 55 and 95% and the specificity between 17 and 79%. CONCLUSIONS: The low specificity of the two in vitro assays suggests that they are not useful for diagnosis of contact allergy to the metals gold, palladium and nickel, since a large number of false-positive results will be obtained.
BACKGROUND: A conventional lymphocyte transformation test (LTT) was compared to the commercially available MELISA (memory lymphocyte immunostimulation assay), a lymphoproliferative assay that has been suggested to be a valuable instrument for the diagnosis of metalallergy. Sensitivity and specificity of the two assays were calculated using a patch test as a reference method. METHODS: 34 patients were patch-tested for gold sodium thiosulfate, palladium chloride and nickel sulfate, and the lymphocyte proliferation to these metals was tested in vitro using mononuclear cells from peripheral blood. RESULTS: No significant differences regarding sensitivity and specificity were found between MELISA and conventional LTT. The sensitivity varied between 55 and 95% and the specificity between 17 and 79%. CONCLUSIONS: The low specificity of the two in vitro assays suggests that they are not useful for diagnosis of contact allergy to the metals gold, palladium and nickel, since a large number of false-positive results will be obtained.
Authors: Nadim James Hallab; Marco Caicedo; Rachel Epstein; Kyron McAllister; Joshua J Jacobs Journal: J Biomed Mater Res A Date: 2010-02 Impact factor: 4.396