Correlation between quantitative in vivo and in vitro responses in nickel-allergic patients

Forty-three nickel-allergic patients (40 females and 3 males) participated in this study which was designed to elucidate the correlation between quantitative in vivo and in vitro responses. All were patch-tested with various concentrations of nickel-sulphate serial-diluted in water. The lowest concentration eliciting a cutaneous reaction (indicating the severity of the allergy) was recorded for each individual and compared with the in vitro lymphocyte response, using the lymphocyte transformation test. The best correlation coefficients obtained were 0.42 and 0.46, tested for linear and logarithmic correlation respectively. However, there were individuals who showed a weak cutaneous response and high lymphocyte reactivity. The converse situation was also found, however, indicating that other mechanisms than those mediated via lymphocytes may be of significance in the patch test response.