We studied the serum lipoprotein and apolipoprotein profiles in 44 patients with sporadic late-onset Alzheimer's dementia and 43 patients with vascular dementia. The levels of high-density lipoprotein (HDL) cholesterol were lower in both patient groups than in a control group. Apolipoprotein A I and A I1 levels have decreased in both the patient groups, especially in the vascular dementia group. The HDL-cholesterol levels correlated positively with the level of apolipoprotein A I, but not with the level of apolipoprotein A 11. The ratios of apolipoprotein A UA I1 have increased in both the patient groups. The apolipoprotein A I1 levels have disproportionally decreased in the patient groups. The serum apolipoprotein A I1 may involve the pathological process in the patients with senile dementia.

We investigated the immune-associated antigens of peripheral lymphocytes from 13 patients with Alzheimer's disease (AD) and 13 age-matched healthy control subjects using two-color analysis with flow cytometry. Four ratios of immune-related antigens, T/B lymphocytes, CD4/CD8, CD4/CD45R and CD4/HLA-DR, were compared for the AD and control groups. The T/B and CD4/CD8 ratios did not differ between the groups, the ratio of CD4+CD45R+ subset in the AD group was lower than the ratio in the control group, and the ratios of CD4+ CD45R- and CD4+HLA-DR+ subsets in the AD group were significantly higher. Further, in the AD group, the CD4+ CD45R+/CD4+ ratio was lower and the CD4+ CD45R- CD4+ ratio was higher than in the control group.

Vitamin B12 levels in the serum and the cerebrospinal fluid (CSF) were compared between patients with Alzheimer's disease (AD) and senile dementia of Alzheimer's type (SDAT) (AD group) and patients with multi-infarct dementia (MID group). The B12 levels in the serum and the CSF were 742 +/- 359 pg/ml and 28 +/- 7 pg/ml (mean +/- SD), respectively, in the AD group, and 962 +/- 254 pg/ml and 50 +/- 26 pg/ml, respectively, in the MID group. CSF B12 levels were significantly lower in the AD group than in the MID group, whereas the serum levels were not different. At the same time, the serum levels of almost all patients were within the normal range, whereas the CSF levels were 25 pg/ml or lower in 10 of 12 AD patients. Therefore, this low level in the CSF is considered to be a characteristic finding in the AD group.

No abstract

The interaction of various amyloid precursors and apolipoprotein E (apoE) is important for Congophilic amyloid formation. As for cerebral amyloidoses, although the correlation between amyloid beta protein (Abeta) and apoE in Alzheimer's disease (AD) has been clarified, the interaction of prion protein isoform (PrPsc) and apoE in several types of prion diseases (PDs) has not been examined in detail. ApoE colocalization has been confirmed in Congophilic PrPsc plaques, but to clarify the participation of apoE in the early stage of PDs, apoE deposition in immature lesions without Congophilic amyloid in PDs needs to be examined. In the present study two squirrel monkeys were inoculated with mouse PrPsc derived from sheep scrapie, and showed signs of severe spongiform degeneration. These lesions were immunohistochemically characterized as patchy perivacuolar and diffuse synaptic lesions without Congophilic amyloid. The central portion of the assemblies involving a few patchy perivacuolar lesions was detected by methenamine silver staining and appeared as a plaque-like lesion. ApoE was colocalized in all the plaque-like lesions and in half of the patchy perivacuolar lesions, but not in any diffuse synaptic lesions. These immunohistochemical characteristics indicated that apoE colocalization occurred in moderate mature lesions in PDs, and apoE might play an important role in the aggregation of PrPsc after a conformational change from cellular PrP isoform to PrPsc.