. 2001 Nov 8;4(2):117–125. doi: 10.1186/ar391

Table 4.

Cytokine concentrations in supernatants of rheumatoid arthritis synovial fibroblast (RA-SFB) cultures (pg/ml)

		RA-SFB

Cytokine	Detection limit of the ELISA (pg/ml)	First passage (n = 3)	Tenth passage (n = 3)
IL-1β	5	Not detectable	Not detectable
IL-6	5	15,800 ± 2110	790.0 ± 35.6^*
IL-10	1.5	35.7 ± 34.2^b	9.0 ± 7.5^b
IL-15	1	Not detectable	Not detectable
IL-18	94	Not detectable	Not detectable
TNF-α	1.7	22.1 ± 1.1	15.1 ± 0.7^*

^bCytokine detected in only one of three samples. ^*P ≤ 0.05 in comparison with first-passage RA-SFB.