I was interested to read the letter on “Rheumatoid arthritis associated with ulcerative colitis” by Boyer et al published recently in theAnnals,1 and would like to make the following comments. Studies in patients with established Crohn's disease (CD) have generally supported the predominance of Th1 responses.2 ,3 In ulcerative colitis, although enhanced humoral immunity has been described, evidence for classical Th2 predominance remains to be demonstrated. On the other hand, it …