The standard assay for the detection of
chromium sensitization, the patch test, does not allow discrimination between patients with and without clinical symptoms of
allergy.
OBJECTIVE: RESULTS: Sensitized individuals with an
allergy displayed significantly higher lymphocyte transformation test (LTT) responses than sensitized volunteers without
allergy and controls (P<0.05 and P<0.01, respectively). 12.5 microg/mL of
chromium chloride and 50 ng/mL of
potassium dichromate were found to be optimal to discriminate between sensitized individuals with and without
allergy. Combining the results of
chromium chloride and
potassium dichromate LTT, a positive reaction to at least one of the stimuli was highly predictive of
allergy [sensitization with vs. without
allergy: Odds ratio (OR)=6.4, P=0.004; sensitization with
allergy vs. controls: OR=11.5, P<0.0001]. On the contrary, IFN-gamma,
IL-2,
IL-4,
IL-10, and
IL-12 production to the ELISpot, patch test results, sensitization against other metals, and atopy score did not significantly discriminate between sensitization with and without
allergy. However, IFN-gamma responses towards
chromium chloride were significantly correlated with the strength of patch test reactivity (r=0.49, P=0.002). By IFN-gamma ELISpot, the average precursor cell frequency reactive to trivalent
chromium could be defined as 26, 15, and 11 : 10(6) in volunteers with sensitization and
allergy, with sensitization without
allergy, and controls, respectively.
CONCLUSIONS: