Appendix is a priming site in the development of ulcerative colitis

Table 3 Activated T cells in the colon (mean±SD, %)

	A-Pan	A-Lt	A-Lt/Ap	I-Pan	I-Lt	Controls
CD4+CD69+ T cells
Rectum	27.8±4.6a	23.2±5.0	24.0±7.6	24.5±6.2	28.2±8.6	23.1±4.1
Transverse	25.0±5.7	20.4±7.8	23.4±4.3	21.5±7.3	22.1±6.2	21.0±9.1
Appendix	26.6±3.0b	28.0±7.0b	26.0±4.0a	28.9±3.9b	25.4±7.3a	19.6±4.1
CD4+HLA-DR+ T cells
Rectum	15.2±6.2a	10.1±3.8	7.3±2.4	11.6±4.1	11.1±6.0	8.6±4.7
Transverse	13.2±5.0	7.9±4.0	9.1±4.9	14.9±6.7	9.5±3.7	9.5±5.3
Appendix	8.9±2.4	9.9±4.1	9.9±2.4	12.6±2.8	10.9±4.3	8.8±3.6

^aP<0.05,

^bP<0.01 vs controls. A-Pan, active pancolitis; A-Lt, active left-sided colitis; A-Lt/Ap, active left-sided colitis with appendiceal involvement; I-Pan, inactive pancolitis; I-Lt, inactive left-sided colitis.