title: Elevated plasma levels of TIMP-1 in patients with rotator cuff tear.
abstract: OBJECTIVE
  Extracellular matrix remodeling is altered in rotator cuff tears, partly due to altered expression of matrix metalloproteinases (MMPs) and their inhibitors. It is unclear whether this altered expression can be traced as changes in plasma protein levels. We measured the plasma levels of MMPs and their tissue inhibitors (TIMPs) in patients with rotator cuff tears and related changes in the pattern of MMP and TIMP levels to the extent of the rotator cuff tear.
  
  
  METHODS
  Blood samples were collected from 17 patients, median age 61 (39-77) years, with sonographically verified rotator cuff tears (partial- or full-thickness). These were compared with 16 age- and sex-matched control individuals with sonographically intact rotator cuffs. Plasma levels of MMPs and TIMPs were measured simultaneously using Luminex technology and ELISA.
  
  
  RESULTS
  The plasma levels of TIMP-1 were elevated in patients with rotator cuff tears, especially in those with full-thickness tears. The levels of TIMP-1, TIMP-3, and MMP-9 were higher in patients with full-thickness tears than in those with partial-thickness tears, but only the TIMP-1 levels were significantly different from those in the controls.
  
  
  CONCLUSIONS
  The observed elevation of TIMP-1 in plasma might reflect local pathological processes in or around the rotator cuff, or a genetic predisposition in these patients. That the levels of TIMP-1 and of certain MMPs were found to differ significantly between partial and full-thickness tears may reflect the extent of the lesion or different etiology and pathomechanisms.
authors.affiliation: Institution for Clinical and Experimental Medicine and Sports Medicine, Faculty of Health Sciences, Linköping University, Sweden. hanna.bjornsson.hallgren@lio.se
authors.forename: Hanna C Björnsson
authors.initials: HC
authors.lastname: Hallgren
authors.forename: Pernilla
authors.initials: P
authors.lastname: Eliasson
authors.forename: Per
authors.initials: P
authors.lastname: Aspenberg
authors.forename: Lars E
authors.initials: LE
authors.lastname: Adolfsson
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D020782:Matrix Metalloproteinases / Q000097:blood; D008875:Middle Aged; D017006:Rotator Cuff / Q000000981:diagnostic imaging; D000070636:Rotator Cuff Injuries; D013708:Tendon Injuries / Q000097:blood* / Q000000981:diagnostic imaging; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood*; D019714:Tissue Inhibitor of Metalloproteinases / Q000097:blood; D014463:Ultrasonography
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D019714:Tissue Inhibitor of Metalloproteinases; D020782:Matrix Metalloproteinases