Cerebrospinal fluid S100B is elevated in the earlier stages of Alzheimer'sdisease

Postmortem demonstration of increased expression of biologically active S10 0B in Alzheimer's disease (AD) and its relation to progression of neuropath ological changes across the cortical regions suggests involvement of this a strocytic cytokine in the pathophysiology of AD. The hypothesis that the ov erexpression of S100B in Alzheimer brain is related to the progression of c linical symptoms was addressed in living persons by measuring S100B concent rations in cerebrospinal fluid (CSF) from AD patients with a broad range of clinical dementia severity and from healthy older persons. The effect of n ormal aging on CSF S100B concentrations also was estimated. CSF S100B did n ot differ between all 68 AD subjects (0.98 +/- 0.09 ng/ml (mean +/- S.E.M.) ) and 25 healthy older subjects (0.81 +/- 0.13 ng/ml). When AD subjects wer e divided into mild/moderate stage and advanced stage clinical dementia sev erity by the established Clinical Dementia Rating Scale (CDR) criteria, S10 0B was significantly higher in the 46 mild/moderate stage AD subjects (1.17 +/-0.11 ng/ml) than in either the 22 advanced stage AD subjects (0.60 +/- 0.12 ng/ml) or the healthy older subjects. Consistent with higher CSF S100B in mild to moderate AD, there was a significant correlation among all AD s ubjects between CSF S100B and cognitive status as measured by the Mini Ment al State Exam (MMSE) score. CSF S100B did not differ between healthy older subjects and healthy young subjects. These results suggest increased CNS ex pression of S100B in the earlier stages of AD, and are consistent with a ro le for S100B in the initiation and/or facilitation of neuritic plaque forma tion in AD brain. (C) 2001 Published by Elsevier Science Ltd.