title: Effect of intra-articular injection of hyaluronic acid in rheumatoid arthritis patients with knee osteoarthritis.
abstract: BACKGROUND
  Intra-articular injection of hyaluronic acid (HA) is a well-documented treatment for knee osteoarthritis (OA). One of the multifactorial mechanisms is that exogenous HA can stimulate endogenous HA production. HA can regulate the growth and function of chondrocytes by binding to CD44 receptors on the chondrocytes. Synovitis is often found in patients with rheumatoid arthritis (RA) and is supposed to result from CD44 activity. The aim of this study was to investigate the effect of intra-articular injection of HA in patients with RA combined with knee OA.
  
  
  METHODS
  Twenty RA patients with OA knees were enrolled; 11 patients were placed into a stage II group and 9 into a stage III group, in accordance with the Kellgren-Lawrence classification of knee OA. All patients received intra-articular injection of HA (ARTZ) once a week for 5 weeks, and were evaluated with the WOMAC index (including the pain, stiffness and physical function subscales) at baseline, week 5 and week 9. The Friedman test and Wilcoxon signed rank test with Bonferroni correction method were used for statistical analysis.
  
  
  RESULTS
  The effect of intra-articular injection of HA was significant at week 5 (p < 0.0167) and persisted to week 9 (p < 0.0167). This therapy was equally efficacious with stage II and stage III patients, with no difference between the 2 groups.
  
  
  CONCLUSIONS
  Intra-articular injection of HA was beneficial in patients with RA combined with knee OA.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taiwan, Republic of China. cl_chou@vghtpe.gov.tw
authors.forename: Chen-Liang
authors.initials: CL
authors.lastname: Chou
authors.forename: Han-Wen
authors.initials: HW
authors.lastname: Li
authors.forename: Si-Huei
authors.initials: SH
authors.lastname: Lee
authors.forename: Ko-Lun
authors.initials: KL
authors.lastname: Tsai
authors.forename: Hsiao-Yi
authors.initials: HY
authors.lastname: Ling
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis; D006820:Hyaluronic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D007270:Injections, Intra-Articular; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy*
chemical_list: C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid