State-of-the-art immunosuppressive therapies, though efficient in the treatment of rheumatic inflammatory disorders, in most cases do not provide a cure. Complete immunablation and the associated deletion of the reactive immunological memory followed by reconstitution of the "healthy" immune system from stem cells results in a therapy-free remission in many patients suffering from rheumatic diseases. Chronically activated T helper (Th) lymphocytes seem to play a critical role in this reactive pathogenic memory. We have shown that the transcription factor twist1 is specifically expressed in chronically activated, inflammatory Th cells. Twist1 as a biomarker for such Th cells enables the identification and elucidation of the role of Th cells in chronic inflammation and opens new therapeutic options for the targeted manipulation of the pathogenic, reactive memory, such as the targeted deletion of twist1 expressing pathogenic Th cells.