Increased Frequencies of Switched Memory B Cells and Plasmablasts in Peripheral Blood from Patients with ANCA-Associated Vasculitis

Table 2

Frequencies of B cells and subsets in patients with AAV and HBD.

Phenotype	Patients (AAV) ()	HBD ()	value
B cells (% of lymphocytes)	5.13 (3.15-8.98)	8.33 (5.98-11.6)	<0.0001
B cells (10^6/L)^a	26.5 (15.2-69.4)
B cell subsets
Naive (% of B cells)	47.8 (33.4-60.3)	56.7 (47.9-67.0)	0.0002
Naive (10^6/L)	12.1 (4.49-33.9)
Preswitch memory (% of B cells)	6.32 (3.63-10.1)	7.00 (4.65-10.2)	ns
Preswitch memory (10^6/L)	1.86 (0.818-4.28)
Switched memory (% of B cells)	22.3 (14.0-31.1)	16.5 (11.4-21.8)	0.0013
Switched memory (10^6/L)	5.78 (2.98-11.2)
Exhausted memory (% of B cells)	21.2 (14.1-25.9)	17.4 (12.0-21.6)	0.0006
Exhausted memory (10^6/L)	5.30 (2.69-15.1)
Transitional (% of B cells)	0.695 (0.0700-3.17)	4.44 (2.83-6.18)	<0.0001
Transitional (10^6/L)	0.278 (0.0107-1.29)
Plasmablasts (% of B cells)	0.885 (0.390-1.87)	0.320 (0.160-0.613)	<0.0001
Plasmablasts (10^6/L)	0.293 (0.138-0.587)
Activated B cells and subsets
CD95^+ B cells (% of B cells)	20.6 (12.3-33.1)	10.3 (7.24-15.5)	<0.0001
CD95^+ B cells (10^6/L)	5.48 (3.24-11.2)
CD95^+ naive (% of naive)	3.38 (1.49-7.24)	1.02 (0.575-1.71)	<0.0001
CD95^+ naive (10^6/L)	0.427 (0.194-0.833)
CD95^+ preswitch memory (% of preswitch memory)	23.0 (16.4-38.7)	13.5 (9.07-19.8)	<0.0001
CD95^+ preswitch memory (10^6/L)	0.355 (0.190-0.892)
CD95^+ switched memory (% of switched memory)	59.7 (51.2-73.0)	44.6 (36.0-51.9)	<0.0001
CD95^+ switched memory (10^6/L)	3.15 (1.70-6.66)
CD95^+ exhausted memory (% of exhausted memory)	25.2 (15.0-35.0)	14.0 (8.38-18.2)	<0.0001
CD95^+ exhausted memory (10^6/L)	1.27 (0.667-2.78)

Frequencies of B cells (CD19⁺ lymphocytes) and subsets analyzed in patients and healthy controls using flow cytometry. The Mann-Whitney test was used to calculate the level of significance. Data are presented with medians and interquartile ranges. AAV: antineutrophil cytoplasmic autoantibody- (ANCA-) associated vasculitis; HBD: healthy blood donors; ns: not significant. ^a equals 101 for absolute values.