title: Increased oxidative stress biomarkers in the saliva of Down syndrome patients.
abstract: OBJECTIVE
  The DNA oxidation byproduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) is a well-known biomarker used to evaluate oxidative stress. We previously reported that the generation of reactive oxygen species (ROS) is increased in cultured gingival fibroblasts (GF) from patients with Down syndrome (DS). Thus, the aim of this study was to evaluate 8-OHdG as a marker of oxidative stress in saliva of DS patients.
  
  
  METHODS
  The study group consisted of DS patients (66 patients; age range 1-62 years) and systemically healthy control subjects (71 subjects; age range 4-58 years). Periodontal status was judged based on standard measurements of probing depth (PD) and gingival index (GI). The salivary levels of 8-OHdG were determined using an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The mean of PD and GI values were not significantly different between young (1-12 years) patients with DS (DS-1) and controls (C-1) or between adult (30-62 years) patients with DS (DS-2) and controls (C-2). There were statistically significant positive correlations between the salivary 8-OHdG levels and GI in the DS-1, DS-2 and C-2 groups, but not in the C-1. There were also statistically significant positive correlations between salivary 8-OHdG levels and PD in the DS-2 and C-2 groups, but not in the DS-1 or C-1 groups. The salivary levels of 8-OHdG of DS-1 and DS-2 groups were significantly higher than in the C-l and C-2 groups, respectively.
  
  
  CONCLUSIONS
  These results suggest that progressive oxidative stress occurred in DS patients. Oxidative stress may contribute to the clinical features of DS, particularly to the progressive periodontitis characteristic of early ageing.
authors.affiliation: Division of Dentistry for Special Patients, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Komatsu
authors.forename: Yoon
authors.initials: Y
authors.lastname: Duckyoung
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ito
authors.forename: Kenji
authors.initials: K
authors.lastname: Kurosawa
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Maehata
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kubodera
authors.forename: Masakazu
authors.initials: M
authors.lastname: Ikeda
authors.forename: Masaichi-Chang-il
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003839:Deoxyadenosines / Q000032:analysis*; D004314:Down Syndrome / Q000378:metabolism* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010519:Periodontium / Q000473:pathology*; D012463:Saliva / Q000378:metabolism*
chemical_list: C436623:8-hydroxy-2'-deoxyadenosine; D015415:Biomarkers; D003839:Deoxyadenosines
keywords: 8-OHdG; Down syndrome; Oxidative stress; Periodontal disease; Saliva