a method for diagnosis of immunologically - mediated conditions such as allergic conditions , autoimmune diseases and immunological deficiency , and of assessing immunological reactivity associated with conditions such as viral infections , cancer , aids , tissue transplantation and the like . the method comprises : taking a sample from a subject suspected to be manifesting an abnormal immunological reaction ; isolating leukocytes from subject and a control ; measuring the level of expression of a transcription factor in unstimulated leukocytes ; stimulating the leukocytes by exposure to a stimulus ; measuring the level of expression of a transcription factor in stimulated leukocytes ; comparing results of stimulated and unstimulated leukocytes from subject and control ; a significant difference in expression between the subject and control is indicative of an abnormal immunological reaction .