Table 4.

Variations of B cell subset proportions after therapy with abatacept (ABA), and comparison with healthy controls. Except for p values, data are expressed as median (25th–75th percentile).

	Healthy Controls, n = 24	RA, n = 28,T0	RA, n = 28,T6	p, T0 vs T6	RA, n = 14, T6	RA, n = 14, T12	p, T6 vs T12
Naive B cells (% among CD19+ cells)	61.6 (53.6–69.8)	71.7 (64.4–83.5)	80.5^** (70.9–85.4)	NS	82.1 (71.7–86.8)	77.1^** (75.1–82.4)	NS
Memory B cells (% among CD19+ cells)	38.4 (30.2–46.4)	28.3^* (16.5–35.6)	16.1^*** (13.1–26.2)	NS	20.3 (14.1–30.5)	18.4^*** (17.0–23.3)	NS
Not switched memory B cells (% among CD19+ cells)	26.6 (19.4–33.5)	18.2^* (10.2–20.7)	13.4^*** (9.4–18.5)	NS	13.5 (11.2–18.6)	12.3^*** (7.0–14.7)	0.05
Post-switch memory B cells (% among CD19+ cells)	10.1 (7.1–12.2)	9.7 (5.7–12.9)	6.5^* (5.5–6.7)	0.03	6.6 (5.8–6.7)	5.7 (2.8–8.3)	NS

↵* p < 0.05 of controls;
↵** p < 0.01 of controls;
↵*** p < 0.001 of controls. NS: not significant; RA: rheumatoid arthritis; T0: first administration of ABA; T6: after 6 months of ABA treatment; T12: after 12 months of ABA treatment.