title: The effect of corticosteroid administration on soft-tissue inflammation associated with rhBMP-2 use in a rodent model of inflammation.
abstract: METHODS
  In vivo rodent model.
  
  
  OBJECTIVE
  Investigate the effect of systemic corticosteroid administration on soft-tissue inflammation after local delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2).
  
  
  BACKGROUND
  Corticosteroid use in cases of soft-tissue inflammation associated with the use of rhBMP-2 has been reported in clinical studies, but the effectiveness of its use and appropriate timing remain unclear.
  
  
  METHODS
  Absorbable collagen sponges were implanted with control or rhBMP-2 into the lumbar region of rats subcutaneously and intramuscularly. Four groups were studied: group I, control sponge only; group 2, BMP-2 sponge only; group III, BMP-2 sponge and preoperative intraperitoneal methylprednisolone (MPSS); group IV, BMP-2 sponge with MPSS given on day 2. Using magnetic resonance imaging, inflammation was assessed in terms of soft tissue edema volume at 0, 2, 4, and 7 days. Rats were sacrificed after 7 days for gross and histological analysis.
  
  
  RESULTS
  The peak mean intramuscular inflammatory volume occurred on day 2 in all groups. Group II (BMP-2 without MPSS) had a significantly higher peak mean inflammatory volume (405.46 mm) on day 2 than that of groups I (266 mm), III (278 mm), and IV (291 mm) (P = 0.001). No significant difference in intramuscular soft-tissue inflammation was observed between the control group and the groups receiving MPSS on day 0 or day 2 at any time point. No differences in the area of inflammatory cell infiltrate surrounding the sponge was observed histologically, after sacrificing them, in groups treated with BMP-2.
  
  
  CONCLUSIONS
  Systemic MPSS administration reduced soft tissue edema associated with rhBMP-2 as measured by magnetic resonance imaging, but no effect was observed on the histological area of inflammation. Further studies are required to elucidate if there is any benefit to the use of corticosteroid administration in reducing the area of inflammation associated with the use of rhBMP-2.
authors.affiliation: Orthopaedic Spine Department, Second Xiangya Hospital, Central South University, Chanhsha, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Tan
authors.forename: Scott R
authors.initials: SR
authors.lastname: Montgomery
authors.forename: Bayan G
authors.initials: BG
authors.lastname: Aghdasi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Inoue
authors.forename: Tuncay
authors.initials: T
authors.lastname: Kaner
authors.forename: Haijun
authors.initials: H
authors.lastname: Tian
authors.forename: Rodney
authors.initials: R
authors.lastname: Terrell
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Zhang
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Wang
authors.forename: Michael D
authors.initials: MD
authors.lastname: Daubs
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology; D055396:Bone Morphogenetic Protein 2 / Q000009:adverse effects*; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D004487:Edema / Q000139:chemically induced / Q000517:prevention & control; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000517:prevention & control*; D007274:Injections, Intraperitoneal; D008279:Magnetic Resonance Imaging; D008775:Methylprednisolone / Q000008:administration & dosage / Q000494:pharmacology*; D009132:Muscles / Q000187:drug effects* / Q000473:pathology; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000009:adverse effects; D015503:Surgical Sponges; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D008775:Methylprednisolone