Table 1 Characteristics of the lymphocyte population and subpopulations, B cell activating factor (BAFF) receptor expression and serum BAFF level in patients with primary Sjögren's syndrome, systemic lupus erythematosus and controls.
| pSS (n = 20) | SLE (n = 19) | Controls (n = 15) | p Value (SLE vs controls) | p Value (pSS vs controls) | p Value (pSS vs SLE) | |
|---|---|---|---|---|---|---|
| Leucocyte number | 6150 (2400–9570) | 5845 (3100–14 810) | 7390 (4290–15 300) | 0.16 | 0.1 | 0.89 |
| Lymphocyte number | 1333 (200–2500) | 1460 (800–3140) | 2390 (830–3400) | 0.006 | 0.002 | 0.49 |
| B cell number | 123 (37–570) | 206 (67–597) | 221 (64–1462) | 0.58 | 0.04 | 0.016 |
| Memory B cell number | 8.2 (1.7–54.1) | 16 (3.2–36.1) | 42 (20–529) | 0.003 | <0.001 | 0.11 |
| Memory B cell frequency | 7.3 (4.5–26) | 8.3 (2.7–19.7) | 24.4 (8.6–43.3) | 0.001 | 0.001 | 0.99 |
| T cell number | 974 (143–1810) | 962 (228–2402) | 1838 (1090–2698) | 0.001 | <0.001 | 0.86 |
| Frequency of BAFF‐R+ T cells | 0.2 (0.05–0.8) | 0.3 (0.05–0.65) | 0.15 (0.1–0.6) | 0.19 | 0.68 | 0.37 |
| BAFF‐R+ T cell number | 1.6 (0.6–11) | 2.6 (0.3–7.5) | 2.4 (0–10.8) | 0.13 | 0.1 | 0.42 |
| BAFF‐R MFI on B cells | 7.8 (4.2–14.8) | 9.5 (3.2–16.1) | 10.6 (5.6–16.5) | 0.19 | 0.001 | 0.14 |
| BAFF‐R MFI on CD27− B cells | 8.1 (4.1–15.8) | 9.7(3.2–16.1) | 10.9 (5.8–16.8) | 0.14 | <0.001 | 0.09 |
| BAFF‐R MFI on CD27+ B cells | 6.6 (4.1–12.3) | 9.7 (3.7–16.2) | 10.0 (5.3–17.9) | 0.36 | 0.001 | 0.06 |
| BAFF‐R MFI on T cells | 7.2 (3.3–12.9) | 8.1 (3.4–16.1) | 9.7 (3.4–15.3) | 0.06 | 0.002 | 0.3 |
| Serum BAFF level (ng/ml) | 1.2 (0.8–2.2) | 0.9 (0.3–5.0) | NA | NA | NA | 0.33 |
BAFF, B cell activating factor; BAFF‐R, BAFF receptor; MFI, mean fluorescence intensity; NA, not available; pSS, primary Sjögren's syndrome; SLE, systemic lupus erythematosus.
Values are shown as median (range).
Absolute numbers of cells are expressed as number of cells/mm3; frequencies are expressed in percentages.