lactoferrin and Arthritis--Psoriatic

We determined the occurrence of antineutrophil cytoplasmic antibodies (ANCAs) and their specificities in 77 rheumatoid arthritis (RA) patients and compared them with 25 patients with psoriatic arthritis (Pso), 19 with drug-induced lupus erythematosus (DI-LE) and 11 with systemic lupus erythematosus (SLE). Thirty-two percent of RA patients had positive indirect immunofluorescence (IIF) stains (P or atypical ANCA). Twenty-nine per cent of patients with rheumatoid vasculitis (RAV), 48% with long-standing RA (LSRA) and 20% with early RA (Ely RA) had positive ANCAs compared with 4% of Pso patients, 47% of DI-LE patients and 45% of SLE patients. Western blotting (with polymorphonuclear cell extracts or alpha-granules) and alpha-granule enzyme-linked immunosorbent assay (ELISA) yielded variable results and proved unhelpful for characterizing the specificities of ANCAs. ELISAs based on commercial purified lactoferrin (LF), myeloperoxidase (MPO), human elastase (HLE) and cathepsin G (CG) showed that anti-HLE antibody was the most prevalent (14%) antibody in RA, followed by anti-MPO antibody and anti-LF antibody (10% each). Statistical analysis of antibody prevalence by clinical presentation showed that LSRA patients were more likely to have anti-HLE antibody and that DI-LE patients were more likely to have anti-CG antibody compared with the other patient groups. In lupus patients serial ELISA titration of ANCAs (LF and MPO) was found to be reliable for predicting the outcome. The overall incidence of ANCAs in RA patients was 33% by IIF.

Topics: Antibodies, Anti-Idiotypic; Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Psoriatic; Arthritis, Rheumatoid; Autoantibodies; Biomarkers; Humans; Immunoglobulin G; Lactoferrin; Lupus Erythematosus, Systemic; Pancreatic Elastase; Peroxidase; Time Factors

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