title: Biochemical markers of bone turnover in seronegative spondylarthropathy: relationship to disease activity.
abstract: To investigate bone turnover in patients with seronegative spondylarthropathy, a bone formation marker, type 1 procollagen carboxy-terminal propeptide (P1CP), and resorption markers, the pyridinium cross-links of collagen [urinary free (f) PYR and DPYR], were measured. The median f-PYR, f-DPYR and P1CP (+/-interquartile range) were 15.8 (6.00) nmol/mmol creatinine, 3.8 (2.2) nmol/mmol creatinine and 101.5 (38) micrograms/1, respectively. There was a positive correlation between resorption markers and acute-phase reactants such as C-reactive protein (r = 0.42 for PYR, r = 0.42 for DPYR, P < 0.05), and a negative correlation observed between P1CP and the erythrocyte sedimentation rate (r = -0.64, P < 0.05). In the subgroup of patients with an elevated CRP concentration, the concentration of PYR and DPYR was significantly increased (f-PYR 25.7 vs 15.8 and f-DPYR 6.6 vs 3.8, P < 0.01 for f-PYR, P < 0.05 for f-DPYR). This study suggests than an elevation in acute-phase response in patients with seronegative spondylarthropathy is associated with increased concentration of bone resorption markers with a tendency for reduction in bone formation markers. This may represent uncoupling of bone formation and resorption, leading to bone loss in such patients.
authors.affiliation: Department of Rheumatology, Royal Liverpool University Hospital.
authors.forename: A G
authors.initials: AG
authors.lastname: MacDonald
authors.forename: G
authors.initials: G
authors.lastname: Birkinshaw
authors.forename: B
authors.initials: B
authors.lastname: Durham
authors.forename: R C
authors.initials: RC
authors.lastname: Bucknall
authors.forename: W D
authors.initials: WD
authors.lastname: Fraser
mesh_terms: D000210:Acute-Phase Reaction; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers; D001862:Bone Resorption / Q000503:physiopathology; D001842:Bone and Bones / Q000737:chemistry* / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011347:Procollagen / Q000378:metabolism; D012699:Serology; D013166:Spondylitis / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D003432:Cross-Linking Reagents; D011347:Procollagen; C015484:pyridinoline; C036020:deoxypyridinoline