Decreased serum CXCL12/SDF-1 concentrations may reflect disease severity of non-traumatic osteonecrosis of femoral head

Abstract

Objective: The current study was performed to investigate the potential association of serum CXCL12 with disease severity in non-traumatic ONFH.

Methods: This study enrolled 182 patients with non-traumatic ONFH and 182 age- and gender-matched healthy controls. The CXCL12 levels in serum were measured by enzyme-linked immunosorbent assay. Meanwhile, serum levels of procollagen type I (PINP) and Interleukin-33(IL-33) were also detected. The radiographic severity was determined by FICAT grade. Clinical severity was evaluated by visual analogue scale (VAS), Harris Hip Score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Among the non-traumatic ONFH, 90 patients ONFH received total hip arthroplasty, the localization and expression of the CXCL12 protein and mRNA were detected by immunohistochemistry, Western blot analysis, RT-PCR and in necrotic area and adjacent non-necrotic area from lesioned femoral neck from ONFH patients and healthy femoral head from femoral neck fracture patients. Receiver operating characteristic (ROC) curve analysis was carried out to confirm the diagnostic value serum CXCL12, PINP and IL-33 with regard to the FICAT grade.

Results: Serum CXCL12 levels were significantly lower in non-traumatic ONFH patients compared with healthy controls. CXCL12 mRNA and protein expressions were both significantly decreased in necrotic area in comparison with non-necrotic area and healthy femoral head. Serum CXCL12 concentrations were drastically reduced in patients with FICAT stage 4 compared with stage 3, and CXCL12 concentrations in patients with stage 3 were markedly lower than stage 2. Serum CXCL12 levels were negatively related to FICAT grading. In addition, Serum CXCL12 concentrations were also negatively related to VAS, WOMAC scores and positively correlated with HHS scores. Meanwhile, serum CXCL12 levels were positively correlated with serum PINP and negatively correlated with IL-33 levels. ROC curve analysis implicated that decrease CXCL12 in serum may act as a favorable marker for FICAT grade.

Conclusions: Decreased serum CXCL12 concentrations may reflect disease severity of non-traumatic ONFH.

Keywords: Chemokine (C-X-C motif) ligand 12; Disease severity; Osteonecrosis of the femoral head; Stromal cell derived factor 1.