LBP and synovitis: Patients with serological evidence of arthritis, joint pain but no synovitis (pre-RA), displayed significantly increased levels of LPS, a trend to raised levels of LBP, and moderately elevated I-FABP levels compared to healthy controls, although patients showing early undifferentiated clinical arthritis (early RA) displayed significantly raised levels of LBP and moderately elevated LPS and I-FABP levels compared to healthy controls (HC).