Radiolabeled annexin V imaging: a useful technique for determining apoptosis in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that involves myelin, oligodendrocytes and axons and culminates in consecutive neuronal death and progressive neurologic disability. Based on magnetic resonance imaging (MRI), neuroaxonal loss in MS results in brain atrophy and has a strong correlation with neurological disability. The newer MR imaging tools seem to be sensitive biomarkers for measuring the pathogenetic processes associated with disease activity and progression. However, they are unable to detect apoptosis in neurodegenerative diseases. Annexin V has a high affinity for phosphatidylserine (PS) that presents on the outer surface of the plasma membrane early on during the onset of apoptosis. Radiolabeled annexin V imaging may reveal the initiation and degree of neuronal apoptosis. We propose that radiolabeled annexin V imaging is a useful modality in determining apoptosis in MS and can assess and monitor the effectiveness of neuroprotective and immunomodulatory therapies on the clinical course of MS.