BIOLOGICAL VALIDATION AND TECHNICAL OPTIMIZATION OF AN EV PLASMA SMALL RNA BIOSIGNATURE TO DETECT PRESYMPTOMATIC CHANGES IN HUNTINGTON’S DISEASE

Huntington’s disease (HD) is a dominant genetic neurodegenerative disorder characterized by progressive brain cell loss and a constellation of cognitive, psychiatric, and motor disturbances. The investigation of biomarkers prior to clinical diagnosis is essential for monitoring disease progression. We have recently identified a small RNA (sRNA) biosignature in plasma extracellular vesicles (EVs) that is altered at presymptomatic stages in HD, highlighting its potential use as early biomarkers. The translational value of these findings requires the replication of the biosignature in additional biological samples and technical optimization for routine clinical use.
In our initial study, we used citrate tubes to extract plasma. Since EDTA is widely used in clinical practice, it is important to assess whether the candidate sRNAs show a similar pattern when using a different collection method. Here, we evaluated the HD sRNA biosignature in plasma EVs from novel samples collected in parallel in citrate and EDTA tubes, and assessed the consistency of our results when using lower starting plasma volumes.
Our results reveal no differences in the features and concentrations of EVs between citrate and EDTA samples. However, a clear effect of the type of anticoagulant was detected in the pattern of dysregulation of diverse candidate sRNA. In both conditions, significant alterations are still observed between control and HD mutation carriers at presymptomatic stages, highlighting the need to establish specific dysregulation patterns for each collection method. Importantly, the validation of the dysregulation of candidate sRNAs in this cohort stresses their potential use as early biomarkers in HD.