T and B lymphocytes in patients with nickel sensitivity

Peripheral blood mononuclear cells from altogether 45 nickel-sensitive patients and 37 controls were assayed for various T and B cell variables. All the patients, but none of the controls, fulfilled our in vitro criteria for a positive response to nickel sulphate (NiSO4). We report normal T and B lymphocyte counts, normal spontaneous plaque-forming cell (PFC) numbers, normal serum immunoglobulin levels, and no demonstrable specific cytotoxic T lymphocyte activity associated with nickel sensitivity. We could detect only a slight increase in the number of PFC and in the number of cytoplasmic immunoglobulin positive (cIg+) cells following stimulation of the patients' cells with NiSO4 for 6 days in culture. Apart from a transient increase in the [3H]thymidine uptake by patients' cells stimulated with NiSO4 in vitro, and a transient drop in the OKT4/OKT8 ratio, there were no major differences in the values of the above variables before and after in vivo challenge of 3 patients with NiSO4. Blood from only 2 of the latter 3 patients was tested in the DNA synthesis test. We conclude that apart from the DNA synthesis test, none of these tests is of any use as an aid to diagnosis in patients with nickel sensitivity. A careful attitude towards patch testing should be maintained.