AMYLOID-BETA PROTEIN-PRECURSOR WITH KUNITZ-TYPE PROTEASE INHIBITOR DOMAINS (APPI) IN CEREBROSPINAL-FLUID AND APPI MESSENGER-RNAS IN CULTURED SKIN FIBROBLASTS OF PATIENTS WITH ALZHEIMERS-DISEASE

We studied amyloid beta protein precursor with Kunitz-type protease in hibitor domains (APPI) concentration in cerebrospinal fluid (CSF) and APPI mRNA in skin fibroblast in Alzheimer's disease (AD). The subjects consisted of AD, cerebrovaseular dementia (VD) and age-matched contro ls. We measured the APPI concentration in the CSF by the trypsin antib ody sandwich ELISA. APPI mRNA mas examined by the RT-PCR technique. Th e CSF APPI concentration in AD was significantly higher than that of V D and controls. The CSF APPI concentration in AD was high in the initi al stage of dementia and decreased during the course. The expression o f APPI mRNA in skin fibroblasts in AD was also significantly higher th an that of VD and controls. These results suggest that measurements of APPI levels in CSF and APPI mRNA in skin fibroblasts may be useful fo r early diagnosis of AD.