EPIDERMAL GROWTH-FACTOR RECEPTOR EXPRESSION IN DEMENTED ELDERLY - LOCALIZATION TO VASCULAR ENDOTHELIAL-CELLS OF BRAIN, PITUITARY AND SKIN

We have previously demonstrated that expression of epidermal growth fa ctor receptor (EGFR) was upregulated on vascular endothelial cells fro m brains of patients with dementia but not in brains from non-demented patients. The present study used a monoclonal antibody against EGFR t o examine its expression in pituitary gland, scalp, abdominal skin and brain of 29 patients with and without various dementias and neurologi cal deficits, as well as normal aged controls. Of 20 clinically dement ed patients examined postmortem, 15 exhibited EGFR immunoreactivity (I R) on brain and peripheral vascular endothelial cells. Examination of nine non-demented patients revealed only 1 patient with EGFR-IR. EGFR- IR was expressed on all blood vessels, regardless of size or location within the tissue examined. Ultrastructural analysis of EGFR revealed that in pituitary, like brain, the receptor was restricted to the lume nal cell surface of vascular endothelial cells. In all cases of EGFR-I R there was an absolute correlation between central nervous system and peripheral expression; if there was EGFR-IR in brain vessels it was p resent in skin. If there was no staining in brain there was no periphe ral skin vessel staining; and vice versa. Increased EGFR expression ma y indicate proliferative or regenerative changes in the vasculature of affected patients and may provide a biological marker supporting the diagnosis of dementia by analysis of skin biopsy.