title: Coll2-1, Coll2-1NO2 and myeloperoxidase serum levels in erosive and non-erosive osteoarthritis of the hands.
abstract: OBJECTIVE
  Erosive osteoarthritis of the hand (EHOA) is thought to be an aggressive variant of hand osteoarthritis (HOA) characterised by prominent local inflammation and radiographic aspects of bone erosions in interphalangeal (IP) joints. However, rare studies have until now investigated the value of biomarkers in these patients. Thus, we determined Coll2-1, a marker of type II collagen denaturation, its nitrated form (Coll2-1NO2) and myeloperoxidase (MPO) levels in serum of patients with EHOA vs non-EHOA and subsequently evaluated their relationships with disease indices of severity and activity.
  
  
  METHODS
  Coll2-1, Coll2-1NO2 and MPO were measured using specific immunoassays in 82 patients, 57 with EHOA, all females, median age 59 (41-74 yrs) and 20 with non-EHOA, all females, median age 55 (43-73 yrs), fulfilling the American College of Rheumatology (ACR) criteria for hand OA. EHOA was characterized by the presence of at least one central bone erosion on radiograph in the IP joints. Patients were also evaluated for disease duration, number of affected (swollen and painful or tender) joints, radiographic score (RS) by Kallman scale and high sensitivity C-reactive protein (hsCRP).
  
  
  RESULTS
  Serum levels of MPO were higher in EHOA (230.0 ± 152.1 ng/ml) than in non-EHOA (160.2 ± 111.5 ng/ml, P=0.037). Coll2-1NO2 levels trended towards an elevation in EHOA compared non-EHOA (0.40 ± 0.86 vs 0.22 ± 0.14 nmol/l, P=0.06), while Coll2-1 levels were not different. Correlations were found for disease duration and both MPO (R(2)=0.48, P=0.001) and Coll2-1NO2 (R(2)=0.73, P=0.01) after the splitting of the population in subgroups according to a cut off value above the 50th percentile. A correlation was found between hsCRP and MPO (R(2)=0.57, P=0.01).
  
  
  CONCLUSIONS
  This study clearly demonstrates an elevation of some serum biomarkers in EHOA, in comparison with non-EHOA. In particular, MPO, hsCRP and the ratio Coll2-1NO2/Coll2-1 discriminated the two subsets of hand osteoarthritis (HOA), and a trend was also observed for Coll2-1NO2. These data suggest that these biomarkers could be helpful for the diagnosis of EHOA.
authors.affiliation: Rheumatology Unit, Department of Clinical and Experimental Medicine, University of Padova, Italy. punzireu@unipd.it
authors.forename: L
authors.initials: L
authors.lastname: Punzi
authors.forename: R
authors.initials: R
authors.lastname: Ramonda
authors.forename: M
authors.initials: M
authors.lastname: Deberg
authors.forename: P
authors.initials: P
authors.lastname: Frallonardo
authors.forename: C
authors.initials: C
authors.lastname: Campana
authors.forename: E
authors.initials: E
authors.lastname: Musacchio
authors.forename: Y
authors.initials: Y
authors.lastname: Henrotin
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D024043:Collagen Type II / Q000097:blood*; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging; D050823:Hand Joints / Q000000981:diagnostic imaging; D006801:Humans; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood* / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging; D010446:Peptide Fragments / Q000097:blood*; D009195:Peroxidase / Q000097:blood*; D011859:Radiography; D012720:Severity of Illness Index; D013585:Synovitis / Q000097:blood / Q000209:etiology
chemical_list: D015415:Biomarkers; D024043:Collagen Type II; D010446:Peptide Fragments; C510280:collagen type II (108-116); C510281:collagen type II (108-116), (NO2)Tyr(111)-; D002097:C-Reactive Protein; D009195:Peroxidase