Table 2.

Baseline cytokine levels in ankylosing spondylitis patients and healthy controls

	Ankylosing spondylitis (n = 86)			Healthy controls (n = 47)
Cytokine	Active-AS	Control-AS	p valuea		p valueb	p valuec
	(BASDAI ≥4; n = 47)	(BASDAI <4; n = 39)
IL-17A (pg/ml)	1.62 (1.06–2.98)	1.57 (1.04–2.17)	0.45	1.57 (1.04–2.17)	0.48	0.90
IL-22 (ng/ml)	0.00 (0.00–0.00)	0.00 (0.00–0.00)	0.68	0.00 (0.00–0.00)	0.47	0.78
IL-23 (ng/ml)	0.08 (0.04–0.17)	0.03 (0.01–0.08)	<0.001	0.02 (0.00–0.05)	<0.001	0.57
PGE2 (pg/ml)	19.46 (5.41–102.58)	7.67 (3.96–24.73)	0.008	7.66 (3.30–30.32)	0.02	0.99

All values are expressed as the median (25–75 % interquartile range)

^aActive-AS vs. control-AS

^bActive-AS vs. healthy controls

^cControl-AS vs. healthy controls

AS ankylosing spondylitis, BASDAI Bath Ankylosing Spondylitis Disease Activity Index, IL interleukin, PGE2 prostaglandin E2