TOMM40 alterations in Alzheimer's disease over a 2-year follow-up period.

We previously reported TOMM40 to be significantly down-regulated in whole blood of Alzheimer's disease (AD) subjects at baseline and after one-year. In this longitudinal follow-up study of TOMM40 expression up to 2 years, we performed 6-monthly assessments for the first year and 2nd year blood sampling on 27 probable AD subjects compared with age- and gender-matched controls. TOMM40 gene expression remained significantly lower in AD patients at all time-points compared to controls, supported by confirmatory RT-PCR results. Our findings of consistently lower TOMM40 expression on longitudinal 2-year sampling support its potential role as a diagnostic blood AD biomarker.