Lymphocyte stimulation by trivalent and hexavalent chromium compounds in patients with chromium sensitivity. An aid...

Peripheral blood lymphocytes from 31 patients with a positive patch test to potassium dichromate (K2Cr2O7) and from 24 healthy controls were stimulated with various concentrations of chromium chloride (CrCl3) and/or chromium basic sulphate (Cr4(SO4)5(OH)2), sodium chromate (Na2CrO4) or K2Cr2O7 on various days of culture. Both trivalent and hexavalent chromium compounds could induce lymphocyte transformation, as measured by increased DNA synthesis. The response occurred in the T-enriched population and was monocyte dependent. Lymphocytes from 11 of these patients could not be stimulated with the chromium compounds in vitro, whereas the in vivo serial dilution test (SDT) was positive in 4 and negative in 7 of them. Lymphocytes from 2 patients with a negative in vivo SDT showed a positive response in vitro. The strength of the in vivo SDT results did not correlate well with the height of in vitro responses. The DNA synthesis test seems to be a reliable in vitro method to aid in the diagnosis of chromium sensitivity.