title: Combined effect of tnf-α polymorphisms and hypoxia on steroid-induced osteonecrosis of femoral head.
abstract: OBJECTIVE
  Tumor necrosis factor (TNF)-α is a proinflammatory cytokine, some studies reported that TNF-α gene plays important role in the pathogenesis of SONFH. And the polymorphisms of TNF-α were presented as risk factors for steroid-induced osteonecrosis of the femoral head (SONFH). Meanwhile, various environment factors involve in the pathogenesis of SONFH. Our study aimed to investigate the interaction effect of TNF-α polymorphisms and hypoxia factor on SONFH.
  
  
  METHODS
  120 patients with SONFH and 100 healthy people, matched with the cases on age and sex, participated in this study. DNA was extracted from all participants. According to previous studies, genotyping of TNF-α polymorphisms (rs1800629, rs1799964 and rs1800630) was tested with the method of PCR-RDB (Reverse Dot Blot). Environmental factors were also chose. Logistic regression analysis was used to analyze the interaction between TNF-α polymorphisms and environment factors on SONFH.
  
  
  RESULTS
  The polymorphisms of rs1800629 and rs1800630 were significantly associated with SONFH (OR: 3.70, 9.93). Patients with hypoxia history were found higher (65.00%) compared with the healthy controls (43.00%). For the person with hypoxic history, GG and AG+AA genotypes of rs1800629 could increase their risk to suffer SONFH (OR: 2.12, 3.78). If the patients with the variant genotypes of rs1800630 experienced hypoxia state, then the risk for SONFH increased 2.41 folds.
  
  
  CONCLUSIONS
  We concluded that the onset of SONFH was influenced by TNF-α and hypoxia history. There existed strong interaction between TNF-α and hypoxia history.
authors.affiliation: Department of Orthopedics, 307 Hospital of PLA 8 Fengtaidongda Road, Beijing, People's Republic of China.
authors.forename: Yaosheng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, 307 Hospital of PLA 8 Fengtaidongda Road, Beijing, People's Republic of China.
authors.forename: Weihao
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Department of Orthopedics, 307 Hospital of PLA 8 Fengtaidongda Road, Beijing, People's Republic of China.
authors.forename: Shubin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, 307 Hospital of PLA 8 Fengtaidongda Road, Beijing, People's Republic of China.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Su
authors.affiliation: Statistics Room, Capital Medical University Affiliated Beijing Friendship Hospital 95 Xuanwu District Yongan Road, Beijing, People's Republic of China.
authors.forename: Shiguo
authors.initials: S
authors.lastname: Zhou
mesh_terms: D000328:Adult; D005260:Female; D005271:Femur Head Necrosis / Q000209:etiology*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D005938:Glucocorticoids / Q000009:adverse effects*; D006801:Humans; D000860:Hypoxia / Q000150:complications* / Q000235:genetics; D008297:Male; D008775:Methylprednisolone / Q000009:adverse effects; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D005938:Glucocorticoids; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D008775:Methylprednisolone
keywords: TNF-α; hypoxia; osteonecrosis of the femoral head; polymorphism; steroid