Heterogeneity of brain gene expression in Alzheimer's disease

We have examined the expression of several genes whose transcripts have increased levels in Alzheimer's disease and have found heterogeneity in these levels in different patients with this condition. The level of expression of these genes was compared to different clinical and pathological aspects of the disease. A case with markedly elevated alpha 1-antichymotrypsin mRNA levels demonstrated prominent neuronal accumulation of this protein. Many of the neurons which demonstrated alpha 1-antichymotrypsin staining did not have neurofibrillary tangles, and vice versa. This suggests that alpha 1-antichymotrypsin staining might identify a different facet of the pathology of Alzheimer's disease than does neurofibrillary tangle staining and may provide new information in the study of this condition.