Detection of Oxidative Stress Marker in Saliva of Down Syndrome

Objectives: The 8-hydroxy-2'-deoxyguanosine (8-OHdG) was well known a biomarker to evaluate oxidative stress in neurodegenerative disease such as Alzheimer disease or early aging. It has been reported that 8-OHdG was a useful biomarker for assessing oxidative stress-induced disease, including periodontitis. Down syndrome (DS) displays early aging and early periodontitis. We had reported that the generation of reactive oxygen species (ROS) increased in cultured gingival fibroblasts (GF) from DS. Thus, the aim of this study was to evaluate 8-OHdG as oxidative stress in saliva from DS.

Methods: The study group consisted of DS patients aged 1 year to 39 years and systemically healthy subjects (control) aged 4 years to 45 years. Informed consent was obtained and care was taken to ensure that none of these individuals were under any medication. The levels of periodontal status were judged from standard measurements of probing depth (PD), gingival index (GI). The salivary levels of 8-OHdG were determined using an enzyme-linked immunosorbent assay.

Results: The mean values of clinical indices, PD and GI, were not significantly different between young (<13 years) patients with DS (DS-1) and controls (C-1), adults (30 years to 45 years) patients with DS (DS-2) and controls (C-2). The salivary levels of 8-OHdG in DS -1 and DS-2 were significantly higher than those in C-l and C-2.

Conclusions: These results suggested that the progressive oxidative stress occurred in DS. The high oxidative stress of DS may lead to clinical features of DS, especially early aging including rapidly progressive periodontitis.