Leon T. Van Den Broeke, Astrid Gräslund, Per H. Larsson, J. Lars G. Nilsson, Jan E. Wahlberg, Annika Scheynius, Ann-Therese Karlberg
DOI: 10.1080/000155598433395

A possible free radical mechanism in metal allergy was investigated in peripheral blood mononuclear cell (PBMC) cultures from 6 subjects, contact allergic to Ni2+ and Co2+ and 6 control individuals. Ni2+ and Co2+-mediated free radical generation was studied with electron spin resonance spectroscopy. The immune response was characterized by cellular [methyl-3H]thymidine uptake and interferon- γ (IFN- γ ) production. Ni2+ and Co2+ (10-50 μM) significantly increased lymphocyte proliferation and IFN- γ production in PBMC cultures from contact allergic subjects in comparison with cultures from controls. Inhibition of Co2+-mediated free radical generation by ascorbic acid did not influence cellular [methyl-3H]thymidine uptake and IFN- γ production. Detectable amounts of free radicals were not obtained with Ni2+. We therefore conclude that it is unlikely that free radicals are involved in contact allergy to Ni2+ and Co2+.