Altered β-Amyloid Precursor Protein Isoforms in Mexican Alzheimer’s Disease Patients

Objective: To determine the β-amyloid precursor protein (βAPP) isoforms ratio as a risk factor for Alzheimer’s Disease and to assess its relationship with demographic and genetic variables of the disease. Methods: Blood samples from 26 patients fulfilling NINCDS-ADRDA diagnostic criteria for AD and 46 healthy control subjects were collected for Western blotting for βAPP. A ratio of βAPP isoforms, in optical densities, between the upper band (130 Kd) and the lower bands (106–110 Kd) was obtained. Odds ratios were obtained to determine risk factor of this component. Results: βAPP ratio on AD subjects was lower than that of control subjects: 0.3662 ± 0.1891 vs. 0.6769 ± 0.1021 (mean ± SD, p<0.05). A low βAPP ratio (<0.6) showed an OR of 4.63 (95% CI 1.45 ± 15.33). When onset of disease was taken into account, a βAPP ratio on EOAD subjects of 0.3965 ± 0.1916 was found vs. 0.3445 ± 0.1965 on LOAD subjects (p>0.05). Conclusions: Altered βAPP isoforms is a high risk factor for Alzheimer’s disease, although it has no influence on the time of onset of the disease.