Arthur J Dalton | PubMed Health

PubMed2005

Increased serum neopterin levels in adults with Down syndrome.

We quantitated serum neopterin levels in Down syndrome (DS), normal controls, Alzheimer's disease, multiple sclerosis and other neurological diseases. We then analyzed the relationships with age, sex, apolipoprotein E (Apo E) phenotype, and amyloid beta protein 1-40 (Abeta40) and 1-42 (Abeta42) levels. Neopterin levels were higher in DS than all other groups. Levels in young DS (< 40 years of age) and old DS (> 41 years) were similar. There was no significant correlation between neopterin levels and age, sex, Apo E phenotype, and Abeta40 or Abeta42 levels in DS. This lack of correlation between neopterin and Abeta levels suggests that the higher neopterin concentrations in DS group reflect inflammatory cell activation rather than AD neuropathology.

Adult↗

PubMed2003

Relation between apolipoprotein E genotype, hepatitis B virus status, and thyroid status in a sample of older persons with Down syndrome.

Dementia of the Alzheimer type (DAT) is common in older persons with Down syndrome (DS). There are three common alleles of the apolipoprotein E (ApoE) gene (Sigma 2, Sigma 3, and Sigma 4) resulting in three different isoforms (E2, E3, and E4) and six different genotypes (2,2; 2,3; 2,4; 3,3; 3,4; and 4,4). Sigma 4 is a risk factor for DAT whereas Sigma 2 appears prophylactic. As hepatitis B virus (HBV) infection and hypothyroidism also are common in DS, we evaluated associations between ApoE type, HBV status, and thyroid status in a sample of older persons with DS (n = 55; mean age, 44.3 +/- 10.8 years) using chi-squared analysis. Participants were classified as E2 (2,2 or 2,3), E3 (3,3), or E4 (3,4 or 4,4); positive for markers of HBV infection in the present or past (i.e., total HBcAb+ and/or HBsAg+ with or without infectivity, defined as HBV+) or negative for markers of HBV infection (defined as HBV-) and, currently receiving thyroid hormone supplement (defined as "hypothyroidism") or having normal thyroid function. The majority of the HBV+ were currently HBcAb+ and HBsAb+, but not HBsAg+. In females, there was an ApoE allele effect on thyroid status (P < or = 0.01), E2 being negatively (P < or = 0.01) and E4 being positively (P < or = 0.05) associated with "hypothyroidism". There was no evidence for an ApoE allele effect on thyroid status in males. There was no evidence for an ApoE allele effect on HBV status, or for an HBV status effect on thyroid status. As thyroid status can affect cognitive function, ApoE allele effects in DAT may, in part, be thyroid effects.

Adult↗

PubMed2003

Plasma amyloid beta protein 1-42 levels are increased in old Down Syndrome but not in young Down Syndrome.

Plasma amyloid beta protein 1-40 (Abeta40) and Abeta42 levels were quantitated from 28 young Down syndrome (DS) (20-40 years old), 28 age-matched controls, 32 old DS (41-65 years old) and 32 age-matched controls in a sandwich enzyme-linked immunosorbent assay. Abeta40 levels were higher in young DS and old DS than controls. Abeta42 levels in young DS and controls were similar, however Abeta42 levels were higher in old DS than controls or young DS. The higher Abeta42 levels in old DS suggests that Abeta42 is selectively increased in plasma concurrently with the development of Alzheimer disease neuropathology.

Adult↗