Table 2.

Changes in DAS28, IgM RF, ACPA concentrations, and peripheral CD19+ B cell numbers during subsequent cycles of ritximab. Values are mean ± SD. Statistically significant differences are indicated in bold type.

	Baseline	Day 15	After 6 Months	After 12 Months	After 18 Months	After 24 Months
DAS28, n = 77	5.36 ± 0.34	—	4.07 ± 0.39	3.99 ± 0.43	3.58 ± 0.36	3.43 ± 0.31
DAS28, n = 77	5.36 ± 0.34		p = 0.01	p = 0.004	p < 0.001	p < 0.001
IgM RF, U/ml, n = 77	198.9 ± 110.3	116.6 ± 62.0	93.5 ± 57.5	44.7 ± 21.4	28.6 ± 13.7	21.1 ± 7.9
IgM RF, U/ml, n = 77	198.9 ± 110.3	p = 0.115	p < 0.001	p < 0.001	p < 0.001	p < 0.001
ACPA U/ml, n = 77	574.2 ± 303.0	473.5 ± 259.6	449.1 ± 248.6	421.7 ± 233.2	244.9 ± 132.5	168.3 ± 99.2
ACPA U/ml, n = 77	574.2 ± 303.0	p = 0.119	p = 0.096	p = 0.003	p = 0.011	p = 0.001
CD19+ B cell number, g/l, n = 50	0.234 ± 0.067	0.104 ± 0.043	0.026 ± 0.016	0.016 ± 0.010	0.006 ± 0.004	0.0013 ± 0.0005
CD19+ B cell number, g/l, n = 50	0.234 ± 0.067	p = 0.007	p < 0.001	p < 0.001	p < 0.001	p = 0.012

DAS28: 28-joint Disease Activity Score; RF: rheumatoid factor; ACPA: anticitrullinated protein antibodies.