Causal Relationship between Inflammatory Proteins and Alzheimer's Disease: A Two-Sample Bidirectional Mendelian...

Area of Science:

• Neuroscience
• Immunology
• Genetics

Background:

• Neuroinflammation is a key driver of neurodegeneration in Alzheimer's disease (AD).
• Protein aggregation in AD can exacerbate neuroinflammation and neurodegeneration.
• Understanding the causal relationship between inflammation and AD is crucial for developing new therapeutic strategies.

Purpose of the Study:

• To investigate the causal relationship between 91 inflammatory proteins and Alzheimer's disease (AD) using a bidirectional Mendelian randomization (MR) approach.
• To identify specific inflammatory proteins that may influence AD risk.
• To generate novel hypotheses regarding AD's pathological mechanisms.

Main Methods:

• Utilized a bidirectional two-sample MR approach.
• Selected independent genetic variants for 91 inflammatory proteins and AD from large genome-wide association studies.
• Employed various MR methods including inverse-variance-weighted (IVW) and sensitivity analyses to ensure robustness.

Main Results:

• Elevated levels of tumor necrosis factor-beta (TNF-β) were significantly associated with reduced AD risk (OR = 0.917, p = 0.006).
• Elevated levels of interleukin-6 (IL-6) were significantly associated with reduced AD risk (OR = 0.941, p = 0.009).
• No significant causal impact of AD on the levels of the 91 selected inflammatory proteins was observed.

Conclusions:

• Higher circulating levels of TNF-β and IL-6 appear to have a protective effect against the development of Alzheimer's disease.
• These findings highlight a potential therapeutic avenue targeting specific inflammatory pathways in AD prevention or treatment.