title: Elevated erythrocyte sedimentation rate and high-sensitivity C-reactive protein in osteoarthritis of the knee: relationship with clinical findings and radiographic severity.
abstract: OBJECTIVE
  We assessed erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration in knee osteoarthritis and non-knee osteoarthritis. In addition, we investigated potential relationship between the levels of erythrocyte sedimentation rate and high-sensitivity C-reactive protein with clinical findings and radiographic severity.
  
  
  METHODS
  We compared erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration between 104 patients with knee osteoarthritis (knee osteoarthritis group; 25 males, 79 females; mean age, 73 y) and 50 patients without knee osteoarthritis (non-knee osteoarthritis group; 16 males, 34 females; mean age, 64 y) excluding any patients with comorbid joint osteoarthritis, rheumatoid arthritis, malignant tumours or inflammatory diseases. In the knee osteoarthritis group, we assessed whether erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration differed in clinical features and Kellgren-Lawrence (KL) grades.
  
  
  RESULTS
  Erythrocyte sedimentation rate and high-sensitivity C-reactive protein were significantly higher in the knee osteoarthritis group than in the non-knee osteoarthritis group (P = 0.0013 and 0.00010, respectively). In the knee osteoarthritis group, erythrocyte sedimentation rate was significantly elevated in patients with tenderness and patellar ballottement (P = 0.032 and 0.038, respectively), and high-sensitivity C-reactive protein concentration was significantly elevated in patients with tenderness, swelling and patellar ballottement (P = 0.0042, 0.00030 and 0.019, respectively). Erythrocyte sedimentation rate in KL-I was lower than erythrocyte sedimentation rate in KL-III and -IV (P = 0.012 and 0.037, respectively). Erythrocyte sedimentation rate in KL-II did not significantly differ from erythrocyte sedimentation rate in the other groups. High-sensitivity C-reactive protein concentration was lower in grade I than in KL-II, -III and -IV (P = 0.044, 0.0085 and 0.049, respectively).
  
  
  CONCLUSIONS
  Erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration were higher in patients with knee osteoarthritis and were related to clinical features. In knee osteoarthritis, high-sensitivity C-reactive protein concentration may increase in early-stage KL-II.
authors.affiliation: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan mitsuruhanada@gmail.com.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Hanada
authors.affiliation: Joint Center, Jyuzen Memorial Hospital, Hamamatsu, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Furuhashi
authors.affiliation: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koyama
authors.affiliation: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Matsuyama
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood* / Q000000981:diagnostic imaging
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: Kellgren-Lawrence grade; Knee osteoarthritis; erythrocyte sedimentation rate; high-sensitivity C-reactive protein