Background Ankylosing spondylitis (AS) is characterized by osteoproliferation, which can be seen as an enhanced reparative response to inflammation, mechanical stress or micro-damage. Male sex is a risk factor for the disease and for the osteoproliferation.
Hepatocyte growth factor (HGF), initially known as a mitogen for hepatocytes, is an important factor for regeneration and repair in many tissues. HGF is produced by osteoblasts, has receptors on osteoblasts and osteoclasts and stimulates both cell types.
Objectives To compare levels of serum HGF in AS patients with healthy controls and to explore the association with disease activity, osteoproliferation and bone density.
Methods Serum from AS patients (modified NY-criteria) and healthy controls was analyzed for HGF with ELISA (Quantikine R&DSystems). Disease activity was assessed by BASDAI, ASDAS, ESR and CRP, back-mobility with BASMI, syndesmophyte formation with mSASSS and BMD with DXA of femoral neck.
Results 204 AS patients (87 women/117 men; age 50±13 years; symptom duration 24±13 years; BASDAI 3.6±2.1; ASDAS-CRP 2.4±0.9) and 80 sex and age-matched controls were included.
HGF was significantly higher in the AS patients compared with the controls (1556±452 vs. 1450±527 pg/ml; p=0.024). HGF correlated with age in the male AS patients (rS=0.316 p=0.001) but not in the female patients nor in controls of both sexes. In the AS men HGF also correlated with ESR (rS=0.380 p<0.001), CRP (rS=0.304 p=0.001), BASMI (rS=0.323 p<0.001), mSASSS (rS=0.302 p=0.001) and BMD of femoral neck (rS= -0.211 p=0.022), but in the female patients only with ESR. HGF was significantly higher in male smokers (p=0.005), although there was no age-difference in male smokers and non-smokers. In multiple linear regression age, CRP, and smoking were all independently associated with HGF.
Conclusions Known risk factors for osteoproliferation in AS were independently associated with serum HGF. HGF could be a negative prognostic biomarker, especially for the male AS patients. Further prospective studies are warranted.
Disclosure of Interest None declared