title: Mitochondrial DNA haplogroups and serum levels of proteolytic enzymes in patients with osteoarthritis.
abstract: OBJECTIVE
  To analyse the influence of mitochondrial DNA haplogroups, as well as the radiographic grade, on serum levels of proteolytic enzymes in patients with osteoarthritis (OA).
  
  
  METHODS
  Serum levels of metalloproteinase-1 (MMP-1), MMP-3, MMP-13, myeloperoxidase and cathepsin K were analysed in 73 patients with OA and 77 healthy controls carrying the haplogroups J, U and H, by ELISA. Knee and hip radiographs were classified according to Kellgren and Lawrence (K/L) scoring from grade 0 to grade IV. Non-parametric and multiple regression analyses were performed to test the effects of clinical variables, including gender, age, smoking status, diagnosis, haplogroups and radiological K/L grade on serum levels of these enzymes.
  
  
  RESULTS
  A significant influence of the haplogroups on the serum levels of MMP-3 and MMP-13 was detected (p=0.027 and p=0.035, respectively). Patients with OA with haplogroup H showed higher serum levels of MMP-3 than healthy controls. Serum levels of MMP-13 were significantly higher in patients with OA (p<0.001), and carriers of the haplogroup J showed lower levels than H carriers. Besides, levels of MMP-13 were proportionally higher in radiological groups B (K/L grade II and III) and C (K/L grade IV) than in group A (K/L grade 0 and I) (p=0.005).
  
  
  CONCLUSIONS
  This study shows that haplogroups have a significant influence on serum levels of MMP-3 and MMP-13. The influence of the haplogroups on serum levels of MMP-3 is clearly dependent on the diagnosis, whereas the influence of the haplogroups on serum levels of MMP-13 is independent of diagnosis.
authors.affiliation: Osteoarticular and Aging Research Laboratory, Biomedical Research Center, Complejo Hospitalario Universitario A Coruña, 15006-A Coruña, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Rego-Pérez
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Moreno
authors.forename: M
authors.initials: M
authors.lastname: Deberg
authors.forename: S
authors.initials: S
authors.lastname: Pértega
authors.forename: C
authors.initials: C
authors.lastname: Fernández-López
authors.forename: N
authors.initials: N
authors.lastname: Oreiro
authors.forename: Y
authors.initials: Y
authors.lastname: Henrotin
authors.forename: F J
authors.initials: FJ
authors.lastname: Blanco
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000097:blood; D019278:Matrix Metalloproteinase 3 / Q000097:blood; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000201:enzymology / Q000235:genetics*; D020370:Osteoarthritis, Knee / Q000201:enzymology / Q000235:genetics*; D010447:Peptide Hydrolases / Q000097:blood*
chemical_list: D015415:Biomarkers; D004272:DNA, Mitochondrial; D010447:Peptide Hydrolases; D053509:Matrix Metalloproteinase 13; D019278:Matrix Metalloproteinase 3