<prompt> The main cytokine, involved in erythema nodosum leprosum ENL reaction is-lnterleukin - 2Interferon - gammaTumor necrosis factor - alphaMacrophage colony stimulating factor  <response>: The main cytokines responsible for type 2 leprosy reactions are interleukin 1 and tumour necrosis factor alpha. iadvl textbook of dermatology, page 2049 