In vitro lymphocyte proliferation as compared to patch test using gold, palladium and nickel

Area of Science:

• Immunology
• Dermatology
• Allergy Diagnostics

Background:

• Metal allergy diagnosis often relies on patch testing.
• In vitro lymphoproliferative assays like LTT and MELISA have been proposed as alternatives.
• Assessing the diagnostic accuracy of these in vitro methods is crucial.

Purpose of the Study:

• To compare the diagnostic performance of a conventional lymphocyte transformation test (LTT) against the MELISA (memory lymphocyte immunostimulation assay).
• To evaluate the sensitivity and specificity of both assays for diagnosing metal allergy.
• To determine the utility of these in vitro tests using patch testing as the reference standard.

Main Methods:

• 34 patients underwent patch testing for gold, palladium, and nickel sulfates.
• In vitro lymphocyte proliferation assays (LTT and MELISA) were performed using peripheral blood mononuclear cells.
• Sensitivity and specificity were calculated for both LTT and MELISA.

Main Results:

• No significant differences in sensitivity and specificity were observed between MELISA and conventional LTT.
• Sensitivity ranged from 55% to 95% for the tested assays.
• Specificity varied widely, ranging from 17% to 79%.

Conclusions:

• Both MELISA and conventional LTT demonstrated low specificity in diagnosing contact allergy to gold, palladium, and nickel.
• The high rate of false-positive results suggests these in vitro assays are not currently useful for clinical diagnosis.
• Further refinement of in vitro diagnostic methods for metal allergy is warranted.