preference toward a thelper type 1 response in patients with coronary spastic angina background coronary artery spasm plays an important role in the pathogenesis of ischemic heart diseases such as unstable angina ua and acute myocardial infarction nitric oxide no plays an important role in coronary artery spasm we previously reported a deficiency in no activity in the spasm arteries of patients with coronary spastic angina csa others have reported that no influences the immune response therefore we investigated the balance between thelper type 1 th1 and 2 th2 responses in patients with csa by evaluating the frequencies of interferon ifngammaproducing t cells and interleukin il4producing t cells in the peripheral blood of such patientsmethods and results peripheral blood mononuclear cells were collected from 50 consecutive patients with csa 23 consecutive patients with ua 36 patients with stable angina sa and 21 patients with chest pain syndrome cps cytokineproducing cd4 t cells were quantified by 3color flow cytometry after stimulation with phorbol myristate acetate and ionomycin ua and csa were associated with a significant increase in the frequency of cd4 t cells that produced ifngamma whereas these conditions caused no significant difference in the frequency of cd4 t cells that produced il4 culturing with an no donor compound for 24 hours before stimulation inhibited the increase in the frequency of cd4 t cells that produced ifngammaconclusions we demonstrated that there was a preference toward the th1type response in patients with csa and that t cells showed a reduced th1type response after being treated with no