A cross-sectional study on cerebrospinal fluid biomarker levels in cognitively normal elderly subjects with or without a family history of Alzheimer's disease.

Background: Cerebrospinal fluid (CSF) biomarkers reflect changes in the brain, and contribute to early screening. Maternal inheritance is putatively stronger than paternal inheritance for late-onset Alzheimer's disease (LOAD).

Methods: Clinical data of 162 cognitively normal subjects were reviewed. A standard questionnaire was used to identify LOAD family history. Mini-mental state examination (MMSE) was used to evaluate cognition. CSF Aβ1-40, Aβ1-42, total and phosphorylated tau were measured using ELISA.

Aims: To compare biomarkers in cognitively normal elderly subjects with versus without LOAD family history.

Results: Among the 162 subjects, 38 and 60 had LOAD family history on paternal and maternal sides, respectively. The remaining 60 subjects had no family history. No difference was noted in age, gender, education level, MMSE score, and memory impairment complaint in the three groups. Aβ42 and the Aβ42/40 ratio were lower than in subjects with a maternal history than in subjects with a paternal history or without family history (P < 0.05 in both). Phosphorylated and total tau did not differ among the three groups.

Conclusion: Offspring with a family history of LOAD on the maternal side have lower Aβ42 and Aβ42/40 ratio in the CSF, and maybe at higher risk for developing AD.