title: Periarticular bone gain at proximal interphalangeal joints and changes in bone turnover markers in response to tumor necrosis factor inhibitors in rheumatoid and psoriatic arthritis.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are characterized by periarticular bone erosion; periarticular bone formation is a feature in PsA. The effect of anti-tumor necrosis factor-α (TNF-α) on periarticular bone remodeling is unclear in both diseases. Our aim was to assess the response of bone turnover markers (BTM) and hand bone mineral density (BMD) to anti-TNF over 3 years in RA and PsA.
  
  
  METHODS
  We measured serum bone-specific alkaline phosphatase (bone ALP), procollagen type-I N-propeptide (PINP), intact osteocalcin, C-terminal cross-linking telopeptides (CTX-I), urinary N-terminal cross-linking telopeptide of type-I collagen (NTX-I), and free deoxypyridinoline crosslinks (fDPD) at baseline, 1, 12, and 36 months. BMD measurements (hands/spine/hip) were obtained at 3 timepoints.
  
  
  RESULTS
  We recruited 62 patients (RA 35; PsA 27). BTM correlated significantly with hand BMD but not with central BMD. Low hand BMD was associated with RA and increased BTM. Following anti-TNF therapy, hip BMD declined while spine and hand BMD were unchanged. Periarticular BMD at proximal interphalangeal (PIP) joints increased while it decreased at metacarpophalangeal joints. Bone ALP increased steadily and was always higher in PsA. PINP and intact osteocalcin increased to a lesser extent, but resorption markers did not change.
  
  
  CONCLUSIONS
  At baseline, hand BMD was inversely associated with BTM. Bone formation rather than resorption markers better showed the bone response to anti-TNF. Despite a lack of effect on central BMD, the modest effect of anti-TNF on PIP BMD may provide evidence that BTM reflect specifically bone remodeling activity at periarticular sites of inflammation in RA and PsA.
authors: Department of Rheumatology, the Metabolism Laboratory, St. Vincent's University Hospital, Dublin, Ireland.
authors: Agnes
authors: A
authors: Szentpetery
authors: Malachi J
authors: MJ
authors: McKenna
authors: Barbara F
authors: BF
authors: Murray
authors: Chin Teck
authors: CT
authors: Ng
authors: Jennifer J
authors: JJ
authors: Brady
authors: Michelle
authors: M
authors: Morrin
authors: Bea
authors: B
authors: Radovits
authors: Douglas J
authors: DJ
authors: Veale
authors: Oliver
authors: O
authors: Fitzgerald
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D000596:Amino Acids / Q000652:urine; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D015535:Arthritis, Psoriatic / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D015415:Biomarkers / Q000378:metabolism; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects* / Q000502:physiology; D024042:Collagen Type I / Q000378:metabolism; D005260:Female; D005384:Finger Joint / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007596:Joints / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000378:metabolism; D010146:Pain / Q000473:pathology / Q000503:physiopathology; D010147:Pain Measurement; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000378:metabolism; D011347:Procollagen / Q000097:blood; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000596:Amino Acids; D018501:Antirheumatic Agents; D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; D014409:Tumor Necrosis Factor-alpha; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; D015675:Osteocalcin; C036020:deoxypyridinoline; D000469:Alkaline Phosphatase
keywords: BONE TURNOVER MARKERS; HAND BONE MINERAL DENSITY; PERIARTICULAR BONE REMODELING; PSORIATIC ARTHRITIS; RHEUMATOID ARTHRITIS; TUMOR NECROSIS FACTOR INHIBITOR