title: Association of serum levels of aggrecan ARGS, NITEGE fragments and radiologic knee osteoarthritis in Tunisian patients.
abstract: OBJECTIVE
  Proteolytic degradation of aggrecan is a hallmark of the pathology of osteoarthritis. The aim of this study was to develop enzyme-linked immunosorbent assay (ELISA) to quantify the serum levels of specific aggrecan fragments generated by aggrecanases-mediated cleavage. We investigated the relationships between these two aggrecan degradations fragments and urinary CTX-II levels.
  
  
  METHODS
  The competitive ELISAs employ a polyclonal antibody raised against the aggrecan fragments containing two neoepitopes NITEGE(373)and (374)ARGSVI. We measured serum levels of ARGSV and NITEGE in 125 women with knee osteoarthritis (mean±SD age of 53.6±7.6 years, mean±SD disease duration of 3.6±3.8 years), and 57 women age-matched controls.
  
  
  RESULTS
  Aggrecan neoepitopes assays showed an intra- and inter-assay imprecision (CV) lower than 20% for both tests and good linearity. Median serum ARGSVI (by 18%; P=0.002), and NITEGE (36.4%; P<0.001) levels were significantly decreased in patients with knee osteoarthritis compared with controls. Minimal joint space width was negatively correlated with ARGSVI (r=-0.368, P=0.04) and NITEGE (r=-0.274, P=0.038) in knee osteoarthritis patients. Median urinary CTX-II levels were significantly increased by 39.5% (P=0.001) in knee OA patients compared with controls.
  
  
  CONCLUSIONS
  Markers of degradation aggrecan were analyzed for the first time in an African osteoarthritis population. These markers can be used to monitor aggrecanase activity in human joint disease. Their combination with CTX-II can improve clinical investigation of patients with osteoarthritis patients.
authors.affiliation: Department of Biochemistry, Charles-Nicolle Hospital, boulevard 9-Avril-1938, Tunis, Tunisia. kalaie79@yahoo.fr
authors.forename: Eya
authors.initials: E
authors.lastname: Kalai
authors.forename: Afef
authors.initials: A
authors.lastname: Bahlous
authors.forename: Nadine
authors.initials: N
authors.lastname: Charni
authors.forename: Kahena
authors.initials: K
authors.lastname: Bouzid
authors.forename: Hela
authors.initials: H
authors.lastname: Sahli
authors.forename: Lilia
authors.initials: L
authors.lastname: Laadhar
authors.forename: Mouna
authors.initials: M
authors.lastname: Chelly
authors.forename: Hatem
authors.initials: H
authors.lastname: Rajhi
authors.forename: Bechir
authors.initials: B
authors.lastname: Zouari
authors.forename: Sondes
authors.initials: S
authors.lastname: Makni
authors.forename: Jaouida
authors.initials: J
authors.lastname: Abdelmoula
authors.forename: Slaheddine
authors.initials: S
authors.lastname: Sallemi
authors.forename: Patrick
authors.initials: P
authors.lastname: Garnero
mesh_terms: D000328:Adult; D000368:Aged; D053674:Aggrecans / Q000097:blood*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D024042:Collagen Type I / Q000652:urine; D024043:Collagen Type II / Q000652:urine; D010450:Endopeptidases / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000208:ethnology / Q000378:metabolism; D010446:Peptide Fragments / Q000097:blood*; D010455:Peptides / Q000652:urine; D011859:Radiography; D014416:Tunisia
chemical_list: D053674:Aggrecans; D015415:Biomarkers; D024042:Collagen Type I; D024043:Collagen Type II; D010446:Peptide Fragments; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D010450:Endopeptidases; C083641:aggrecanase