A total of 100 AD patients, 54 patients with old-age diseases (17 cases of diabetes mellitus, 18 cases of hypertension, 15 cases of hyperlipemia and 4 cases of other endocrine diseases) and 46 healthy subjects were enrolled as old-age disease control group and healthy control group.Serum concentrations of sFas and sFasL were detected by enzyme-linked immuosorbent assay(ELISA). The AD patients' cognitive functions were evaluated by Clinical Dementia Rating Scale (CDR), mini-mental state examination(MMSE) and Hachinski ischemia score(HIS).

The levels of serum sFas and sFasL were significantly higher in AD group than in 2 control groups (P<0.01). As the disease aggravated, the serum levels of sFas and sFasL increased gradually. Serum sFas level was positively correlated with age, course of disease and the scores of MMSE, while it was negatively with the scores of HIS (r=0.856, 0.834, 0.799 and -0.714, P<0.01). Serum sFasL level was positively correlated with age and course of disease, while it was negatively with the scores of MMSE and HIS (r=0.863, 0.857, -0.801 and -0.745, P<0.01).

The abnormal levels of sFas and sFasL among AD patients may indicate being involved in the apoptosis pathological change, and the serum levels of sFas and sFasL might be related with the intelligent level and severity of cerebral ischemia.