Biomarker profiling in elderly patients with acute hip fracture: modulation by prophylactic dosage of enoxaparin

Abstract

Hip fracture (HF) is common in the elderly and associated with a high risk of venous thromboembolism. Activation of inflammation and coagulation results in generation of various biomarkers. This study is designed to identify biomarkers in elderly HF patients using protein chip array methods. Plasma samples from elderly patients included in a randomized HF study comparing enoxaparin (40 mg o.d.s.c.) and UFH (5000 IU b.i.d.s.c.) were collected prior to and at 1, 3, 5 and 7 days post‐surgery. 37 samples were analyzed using surface enhanced laser desorption ionization‐time of flight mass spectroscopy to identify biomarkers with molecular weights <150 kDa. Plasma from 29 healthy volunteers and pooled plasma from total knee/hip replacement (TKR/THR) patients containing an 11.9 kDa biomarker were used as quality controls. In healthy individuals, no unique peaks were noted in comparison to normal human plasma. 8.1% of plasmas obtained prior to HF surgery exhibited unique biomarkers. On day 1 post‐surgery, 83% showed a distinct peak at 11.9 kDa. On day 3, 94% patients showed the presence of this biomarker at its strongest intensity. 55% showed this biomarker on day 5 and 12.5% on day 7. Consistent with earlier findings, these results demonstrate that HF in the elderly is associated with generation of a unique biomarker at 11.9 kDa. Unlike the TKR/THR patients, the elderly HF patients exhibited sustained generation of this marker.