The anticytokine neuropeptide alpha-melanocyte-stimulating hormone in synovial fluid of patients with rheumatic diseases: comparisons with other anticytokine molecules.
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.
Catania
A
A
Institute of Internal Medicine, Infectious Diseases, and Immunopathology, University of Milan, Italy.
Gerloni
V
V
Procaccia
S
S
Airaghi
L
L
Manfredi
M G
MG
Lomater
C
C
Grossi
L
L
Lipton
J M
JM
D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000521:alpha-MSH / Q000097:blood / Q000378:metabolism*
D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D000521:alpha-MSH