Autoantibodies against matrix metalloproteinase-1 in patients with localized scleroderma.
BACKGROUND
Localized scleroderma (LSc) is characterized by cutaneous fibrosis and various autoantibodies.


OBJECTIVE
To determine the presence or levels of antibodies (Abs) against matrix metalloproteinase (MMP)-1 and their clinical relevance in LSc.


METHODS
Anti-MMP-1 Ab was examined by ELISA (Enzyme-Linked ImmunoSorbent Assay) and immunoblotting using human recombinant MMP-1. MMP-1 collagenase activity was determined using biotinylated collagen as substrate and the amount of cleaved biotinylated fragments of collagen by MMP-1 was measured by ELISA.


RESULTS
LSc patients exhibited significantly elevated IgG anti-MMP-1 Ab levels relative to normal controls at similar level of patients with systemic sclerosis (SSc). However, IgG anti-MMP-1 Ab levels were comparable among the 3 LSc subgroups: morphea, linear scleroderma, and generalized morphea. When absorbance values higher than the mean+2S.D. of normal controls were considered positive, IgG or IgM anti-MMP-1 Ab was found in 46% and 49% of total LSc patients and SSc patients, respectively. Anti-MMP-1 Ab was detected most frequently in morphea patients (60%), followed by linear scleroderma patients (47%) and then generalized morphea patients (25%). LSc patients positive for IgG anti-MMP-1 Ab had elevated levels of IgG anti-single-stranded DNA Ab, IgG anti-nucleosome Ab, and shorter disease duration relative to those negative. The presence of anti-MMP-1 Ab in LSc patients was confirmed by immunoblotting. IgG isolated from LSc patients' sera positive for IgG anti-MMP-1 Ab by ELISA inhibited MMP-1 collagenase activity.


CONCLUSIONS
These results suggest that anti-MMP-1 autoantibody is a novel autoantibody in LSc.
Department of Dermatology, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, Japan.
Saori
S
Tomimura
Fumihide
F
Ogawa
Yohei
Y
Iwata
Kazuhiro
K
Komura
Toshihide
T
Hara
Eiji
E
Muroi
Motoi
M
Takenaka
Kazuhiro
K
Shimizu
Minoru
M
Hasegawa
Manabu
M
Fujimoto
Shinichi
S
Sato
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015151:Immunoblotting; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D012594:Scleroderma, Localized / Q000276:immunology* / Q000378:metabolism
D001323:Autoantibodies; D011994:Recombinant Proteins; D020781:Matrix Metalloproteinase 1