title: Concentrations of circulating matrix metalloproteinase 9 inversely correlate with autoimmune antibodies to double stranded DNA: implications for monitoring disease activity in systemic lupus erythematosus.
abstract: OBJECTIVE
  To compare circulating matrix metalloproteinase (MMP) concentrations with antibodies to single and double stranded DNA (ssDNA and dsDNA) to determine their relation in inflammatory arthritic diseases, such as systemic lupus erythematosus (SLE).
  
  
  METHODS
  Fibroblast MMP-2 and neutrophil MMP-9 were resolved by gelatin zymography and measured by densitometry. Anti-ssDNA and anti-dsDNA were determined by enzyme immunoassay and samples grouped on antibody content as follows: low anti-ssDNA/low anti-dsDNA antibodies (group 1); high anti-ssDNA/low anti-dsDNA antibodies (group 2); and high anti-ssDNA/high anti-dsDNA antibodies (group 3).
  
  
  RESULTS
  Group 3 samples contained significantly lower amounts of MMP-9 when compared with group 1 samples. Higher molecular weight MMP-9 forms (130 and 225 kDa) were virtually absent. Group 2 samples contained intermediate MMP-9 concentrations. Fibroblast MMP-2 was unchanged in all groups. Mean complement C3 and C4 concentrations showed a consistent, but variably significant, decrease with increasing anti-ssDNA and anti-dsDNA antibodies. The mean erythrocyte sedimentation rate was raised in all patient groups.
  
  
  CONCLUSIONS
  Neutrophil MMP-9, an inflammatory marker, inversely correlates with anti-dsDNA antibodies, which are a specific marker for SLE, and may be important in monitoring disease activity during antibody deposition in tissues.
authors.affiliation: Department of Laboratory Medicine, School of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA. makowski@nso1.uchc.edu
authors.forename: G S
authors.initials: GS
authors.lastname: Makowski
authors.forename: M L
authors.initials: ML
authors.lastname: Ramsby
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004247:DNA / Q000276:immunology*; D004277:DNA, Single-Stranded / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008970:Molecular Weight; D009504:Neutrophils / Q000201:enzymology*
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers; D004277:DNA, Single-Stranded; D004247:DNA; D020780:Matrix Metalloproteinase 9