Neuronal cyclooxygenase 2 expression in the hippocampal formation as a function of the clinical progression of Alzheimer disease

Background: Prior studies have shown that. cyclooxygenase 2 (COX-2), an enz yme involved in inflammatory mechanisms and neuronal activities, is up-regu lated in the brain with Alzheimer disease (AD) and may represent a therapeu tic target for anti-inflammatory treatments. Objective: To explore COX-2 expression in the brain as a function of clinic al progression of early AD. Design and Main Outcome Measures: Using semi-quantitative immunocytochemist ry, we analyzed COX-2 protein content in the hippocampal formation in 54 po st-mortem brain specimens from patients with normal or impaired cognitive s tatus. Setting and Patients: Postmortem study of nursing home residents. Results: The immunointensity of COX-2 signal in the CA3 and CA2 but not CA1 subdivisions of the pyramidal layers of the hippocampal formation of the A D brain increased as the disease progressed from questionable to mild clini cal dementia as assessed by Clinical Dementia Rating. COX-2 signal was incr eased in all 3 regions examined among cases characterized by severe dementi a. Conclusion: Neuronal COX-2 content in subsets of hippocampal pyramidal neur ons may be an indicator of progression of dementia in early AD.