Hapten conjugation in the leucocyte migration inhibition test in allergic chromate eczema

We studied the in vitro conjugation of chromium salts and found that trivalent chromium binds to protein 10 times more strongly than hexavalent chromium. We also investigated the use of two different lymphocyte migration inhibition tests for the diagnosis of chromium allergy. The capillary method proved superior to the Clausen technique, and potassium dichromate was shown to be a better antigen than chromium chloride. The test results correlated well with standard patch tests and we recommend the capillary method for the investigation of difficult cases of suspected chromium allergy.