The aim of this study was to determine if the anticytokine neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) occurs, along with interleukin 1 receptor antagonist (IL-1ra) and soluble tumor necrosis factor receptor (sTNFr), in synovial fluid of patients with rheumatoid arthritis (RA), juvenile chronic arthritis (JCA), or osteoarthritis. The data show that alpha-MSH does occur in the synovial fluid and its concentrations are greater in patients with RA than in those with osteoarthritis. Synovial fluid concentrations of IL-1ra and sTNFr were likewise greater in RA. Further, concentrations of alpha-MSH, IL-1-ra, and sTNFr were greater in patients with polyarticular/systemic-onset JCA than in those with pauciarticular disease, that is in patients with greater joint inflammation. Concentrations of alpha-MSH were greater in synovial fluid than in plasma in a substantial proportion of patients, suggesting local production of the peptide; this is the first indication that the anticytokine molecule alpha-MSH is produced within a site of inflammation. Further, it appears that local production of alpha-MSH is induced particularly in those arthritic joints that have more intense inflammatory reactions. This finding, combined with previous evidence of the marked anti-inflammatory activity of alpha-MSH, suggests that the peptide acts locally to modulate proinflammatory influences in rheumatic diseases.

Arthritis, Rheumatoid↗

PubMedDate not supplied

ELISA determined IgM, IgG and IgA rheumatoid factors in rheumatoid arthritis and in other connective tissue diseases.

We used an adaptation of an enzyme-linked immunoadsorbent assay (ELISA) to determine serum levels of IgM, IgG and IgA rheumatoid factors (RF) in 50 patients with classic or definite rheumatoid arthritis (RA) according to the ARA criteria, balanced for positive or negative-routine Latex-RF reaction. A control group of 50 young normal subjects and a reference group of 44 patients with other connective tissue diseases (OCTD) were also studied. We confirmed the high sensibility of the method, together with its good specificity and reproducibility. For the IgM RF a very significant correlation was found between ELISA results and Latex-RF titration (p less than 0.001). Many Latex-RF negative RA patients had high ELISA levels of IgM RF, suggesting that this assay reveals, at least in part, hidden or non-agglutinating IgM RF. Among the OCTD group only some SLE cases, mainly Latex-RF positive, had enhanced IgM RF on ELISA. Considered quantitatively, IgG RF did not play a significant diagnostic role for RA (p greater than 0.05), because they were also found, with widely dispersed values, in normal subjects, and because the mean increase in RA patients was relatively small. Interestingly, IgA RF were above the normal range in many RA patients, both Latex-RF positive or negative. The mean values differed significantly from those of controls (p less than 0.005), and a correlation was observed between IgA RF levels and IgA containing immune-complexes. Normal IgA RF values were observed in SLE patients, even if Latex-RF positive, suggesting that their increase in RA patients is not the mere expression of a polyclonal B cell activation.

Arthritis, Rheumatoid↗

PubMedDate not supplied