Beyond Pain: A Pilot Study of Neurodegenerative and Mitochondrial Pathway Alterations in Sickle Cell Disease Using Platelet Proteomics

Background: Sickle cell disease (SCD) is a systemic disorder marked by chronic pain and neurocognitive deficits, yet the molecular drivers of these neurocognitive features remain poorly defined. Platelets, central to inflammation and vascular homeostasis, may reflect broad pathophysiologic processes in SCD. Methods: We performed high-resolution mass spectrometry on ultra-purified platelets from 16 adults with SCD and moderate to severe pain (self-reported ≥ 3/10 in the past year), identifying 4196 proteins, of which 1046 were significant (FDR < 0.05). Unsupervised clustering was used to stratify individuals into high- and low-pain phenotypes. Results: Contrary to expectations, canonical pain pathways were not enriched. Instead, significant alterations were observed in neurodegeneration, mitochondrial metabolism, ATP regulation, mitophagy, and tRNA aminoacylation pathways between high- and low-pain phenotypes. High-pain individuals exhibited elevated levels of proteins involved in proteostasis and neurodegenerative disease processes, whereas low-pain individuals showed increased expression of proteins linked to mitochondrial integrity, neuroprotection, and reduced oxidative stress. Protein-protein interaction networks revealed tightly connected clusters within neurodegenerative and central nervous system-related pathways. Disease association analysis ranked neurodegenerative and mitochondrial pathways above traditional hematologic and nociceptive mechanisms. Conclusions: These findings suggest that platelet proteomics may serve as a peripheral window into PNS or CNS vulnerability and cognitive risk in SCD. The enrichment of tRNA aminoacylation and mitochondrial regulation pathways underscores the metabolic complexity of SCD and highlights novel targets for biomarker development and therapeutic intervention.