Table 1. Clinical and laboratory characteristics of study subjects.

		pSS patients (n=97)				Healthy controls (n=100)			Reference range	P
	n	Mean±SD	Median	Min-Max	n	Mean±SD	Median	Min-Max
Age (year)		54±2								0.140
Sex						51±1				0.359
Male	12				17
Female	85				83
WBC count (x109/L)		5.3±2.5				6.1±1.2			4-10	0.003
IgA (g/L)			2.71	2.00-3.77					0.82-4.53
IgM (g/L)			1.33	0.84-1.90					0.46-3.04
IgG (g/L)			16.85	12.45-24.13					7.51-15.60
C3 (g/L)			0.83	0.70-1.02					0.79-1.52
C4 (g/L)			0.18	0.15-0.21					0.16-0.38
RF (U/ml)			20	11-73					0-20
ESR (mm/h)			38	16-74					1-20
CRP (mg/L)			2.92	1.28-7.23					0-10
ALT (U/L)			16	11-24			16	14-24	0-40	0.355
AST (U/L)			21	17-28			20	17-24	0-35	0.136
ANA
+	75
-	22
Anti-SSA
+	72
-	25
Anti-SSB
+	45
-	52
ACA
+	9
-	88
ESSDAI			5	3-8
pSS: Primary Sjögren’s syndrome; SD: Standard deviation; Min: Minimum; Max: Maximum; WBC: White blood cell; Ig: Immunoglobulin; C: Complement component; RF: Rheumatoid factor; ESR: Erythrocyte sedimentation rate; CRP: C-reactive protein; ALT: Alanine aminotransaminase; AST: Aspartate aminotransferase; ANA: Antinuclear antibodies; Anti-SSA: Anti-Sjögren’s syndrome type A antibody; Anti-SSB: Anti-Sjögren’s syndrome type B antibody; ACA: Anti-centromere antibodies; ESSDAI: The European League Against Rheumatism Sjögren’s syndrome disease activity index.