Bactericidal/permeability increasing protein and proinflammatory cytokinesin synovial fluid of psoriatic arthritis

Objective Bactericidal/permeability increasing protein (BPI) is a leukocyte product e xerting antibacterial activity Its production may be stimulated by cytokine s, mainly Tumor Necrosis Factor (TNF)alpha. We studied BPI in the synovial fluid (SF) of psoriatic arthritis (PsA), a disease suspected to be influenc ed by infections agents. Methods The levels of BPI and various indices of SF inflammation, including cytokin es and its receptors, were determined in the SF of 18 patients with PsA and compared with those of 12 patients with rheumatoid arthritis (RA) and 9 wi th osteoarthtoid (OA). Results The lowest SF levels of BPI were found in PsA (145.3 +/- 97.3 ng/ml), signi ficantly lower than in RA (307.7 +/- 42.8 ng/ml, p = 0.0001) and similar to those in OA (151.1 +/- 52.4 ng/ml). Furthermore, only in PsA, and not in t he RA and OA subgroups correlations were observed between BPI and the indic es considered, including TNF alpha (r = 0.746, p = 0.0004). Conclusion Due to its relationship with local inflammation, SF BPI may play a role in the pathogenesis of arthropathies, in particular PsA.