Table 1

Cytokine and neuropeptide concentrations in synovial fluid

Substance

Early RA (pg/ml)

Long-standing RA (pg/ml)

P

Controls (pg/ml)

Cytokine

TNF-α

8.0^a

7.0^c

ns

nm

(1.0–47)

(1.0–24)

IL-6

5100^b

3100^d

<0.05

nd^f

(4500–8000)

(1300–3900)

MCP-1

1200^b

1500^d

ns

620^f

(810–1800)

(1200–3000)

Neuropeptide

BN/GRP

31^a

17^c

<0.05

nd^g

(21–39)

(7.0–23)

CGRP

580^b

450^d

ns

nd^f

(160–1500)

(230–960)

NPY

190^b

260^e

ns

180^f

(65–320)

(170–500)

SP

48^a

58^c

ns

nd^g

(36–80)

(42–77)

VIP

150^b

300^d

ns

nm

(40–200)

(55–630)

Concentrations were measured by ELISA and RIA in synovial fluid from the knee joints of patients with RA and in healthy control subjects. Values are medians (and Q₁–Q₃). P relates to long-standing RA versus early RA (Mann–Whitney test). ^an = 7; ^bn = 6; ^cn = 28; ^dn = 23; ^en = 25; ^fn = 2; ^gn = 10. BN/GRP, bombesin/gastrin-releasing peptide; CGRP, calcitonin-gene-related peptide; MCP-1, monocyte chemoattractant protein-1; nd, not detectable; nm, not measured; NPY, neuropeptide Y; ns, not significant; RA, rheumatoid arthritis; SP, substance P; TNF, tumour necrosis factor; VIP, vasoactive intestinal peptide.

Grimsholm et al. Arthritis Research & Therapy 2005 7:R416   doi:10.1186/ar1503