SUMMARY
# Viral and Post-Infectious Mechanisms in ALS — Experiment Design
## Background and Rationale
This experiment directly addresses ALS Knowledge Gap #15 (Score: 27/40): "What role do viral and post-infectious mechanisms play in a subset of sporadic ALS?" This represents a critical but understudied area in ALS pathogenesis, as while approximately 90% of ALS cases are sporadic with unknown etiology, emerging evidence suggests viral infections may trigger or accelerate neurodegeneration in a substant
METHODOLOGY NOTES
1. **Patient Recruitment and Stratification**: Recruit 300 participants across three cohorts: ALS patients (n=150), neurologically healthy controls (n=75), and patients with other neurodegenerative diseases (n=75). Stratify ALS patients by disease duration (<2 years vs ≥2 years), progression rate (fast vs slow), and family history. 2. **Comprehensive Viral Screening**: Collect blood, CSF, and saliva samples at baseline, 6, and 12 months. Screen for active and past infections using multiplex PCR panels targeting neurotropic viruses (EBV, CMV, HSV-1/2, HHV-6, enterovirus, influenza A/B). Perform viral load quantification and serological testing (IgG/IgM titers). 3. **Immunological Profiling**: Analyze inflammatory markers (IL-1β, TNF-α, IL-6, interferon-γ) via ELISA and multiplex cytokine panels. Measure complement activation (C3a, C5a) and autoantibody profiles against neuronal antigens. Conduct flow cytometry to assess T-cell activation states and regulatory T-cell populations. 4. **Mo