lactoferrin and Synovitis

Antineutrophil cytoplasmic antibodies (ANCA) are present in several vasculitides and in other immunomediated diseases. The reported prevalence of ANCA in rheumatoid arthritis (RA) is variable. In addition, the presence of such autoantibodies has been poorly investigated in synovial fluid (SF). The objectives of this study were (1) to investigate the presence of ANCA both in the serum and in SF from patients with RA and other forms of synovitis (OS); (2) to analyze the reactivity of ANCA against isolated antigens proteinase 3 (PR3), myeloperoxidase (MPO) and lactoferrin (LF); and (3) to evaluate the clinical relevance of these autoantibodies.. Twenty-eight patients with RA, 13 with OS, and 17 with osteoarthritis (OA) of the knee joint were studied. No patient had clinical manifestations of vasculitis. SF and serum samples were investigated for the presence of ANCA by indirect immunofluorescence (IIF); the reactivity against PR3, MPO and LF was assessed by ELISA.. ANCA were detected by IIF in SF of 39.3% patients with RA, 38.5% with OS, and 5.9% with OA. With 2 exceptions, patients who had ANCA in SF showed positivity also in serum. The presence of both anti-MPO and anti-LF antibodies was found in 3 patients with RA and 1 with OA; a patient with RA showed antibodies only against LF and another one with RA only against MPO. No reactivity was found against PR3. In patients with RA ANCA were not associated with disease activity.. We found an increased incidence of ANCA both in SF and serum from patients with RA and OS. The pathogenic role and the clinical relevance of such autoantibodies in these diseases remain to be established.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Antinuclear; Arthritis, Rheumatoid; Demography; Disease Progression; Dose-Response Relationship, Immunologic; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique, Indirect; Humans; Joint Diseases; Lactoferrin; Male; Middle Aged; Peroxidase; Synovial Fluid; Synovitis

Cytidine deaminase (CD) is a cytoplasmatic enzyme present predominantly in polymorphonuclear cells (PMNC) in inflamed joints. Lactoferrin is situated in the secondary granules of PMNC and is released by secretory/phagocytic stimuli, whereas CD is released mainly upon cell lysis. To study the release of these molecules in arthritic conditions we measured CD and lactoferrin levels in synovial fluid (SF) drawn from patients with rheumatoid arthritis (RA), crystal pyrophosphate disease (CPPD), psoriatic arthropathy, reactive arthritis, spondylarthropathy, and osteoarthrosis. CD activity was highest in SF from RA and CPPD followed by psoriatic arthropathy, reactive arthritis and spondylarthropathy. Lactoferrin concentrations were highest in CPPD followed by RA, reactive arthritis, psoriatic arthropathy, and spondylarthropathy. Both CD and lactoferrin levels were low in osteoarthrosis SF. Although SF CD activity and lactoferrin levels correlated well in all diagnostic groups, the ratio between CD and lactoferrin was higher for RA, psoriatic arthropathy, and spondylarthropathy compared to reactive arthritis and CPPD. This suggests predominant release by PMNC lysis in the more chronic arthritis groups and more degranulation in the more episodic CPPD and reactive arthritis groups. CD activity and lactoferrin levels correlated significantly with SF cell counts in the RA and psoriatic arthropathy groups.

Topics: Arthritis, Psoriatic; Arthritis, Reactive; Arthritis, Rheumatoid; Cytidine Deaminase; Humans; Lactoferrin; Leukocyte Count; Neutrophils; Synovial Fluid; Synovitis