Appendix is a priming site in the development of ulcerative colitis

Table 1 Characteristics of patients with ulcerative colitis and normal subjects

	A-Pan	A-Lt	A-Lt/Ap	I-Pan	I-Lt	Normal subjects
Number of patients	15	25	10	14	22	27
Sex (M/F)	7/8	12/13	6/4	9/5	11/11	12/15
Age (yr)
Mean	36.4	40.3	35.5	41.4	50.7	43.6
Range	11-69	22-76	18-64	17-78	23-73	16-65
Medications
None	7	11	9	1	2	27
SASP	2	7	0	5	11	0
5-ASA	2	5	1	1	3	0
PDN	1	0	0	0	1	0
SASP+PDN	3	2	0	3	4	0
5-ASA+PDN	0	0	0	4	1	0

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; PDN, prednisolone; SASP, salazosulfapyridine; 5-ASA, mesalazine.

Table 2 CD4/CD8 ratio in the colon (mean±SD)

	A-Pan	A-Lt	A-Lt/Ap	I-Pan	I-Lt	Controls
Rectum	2.3±2.0a	3.6±1.6b	4.9±2.2b	1.8±1.0a	2.4±2.0b	1.0±0.6
Transverse	1.5±0.7	1.1±0.4	1.8±0.4a	0.9±0.5	1.3±0.9	1.2±0.8
Appendix	3.2±1.3	3.5±1.3a	3.9±0.9a	2.9±1.9	2.6±1.4	2.6±1.1

^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.

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.