Panel Disdussion

3rd International Congress 3rd International of Nuclear Congress Medicine of Nuclear & 15th Medicine Iranian Annual & 15th Iranian Congress Annual of
Nuclear Congress Medicine of Nuclear Medicine
Shahid Beheshti Shahid Beheshti University University of Medical Sciences of Medical 19-21 Sciences May 201119-21 May 2011
Radiolabeled annexin V imaging: a useful technique for
determining apoptosis in multiple sclerosis
Majid Assadi 1 , Reza Nemati 2 , Iraj Nabipour 1 , Hooman Salimipour 2 ,
Abdullatif Amini 1
1 The Persian Gulf Nuclear Medicine Research Center
2 Department of Neurology
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,
it has been difficult to predict the prognosis of MS patients
undergoing an exacerbation from the cross-sectional area of the
contrast-enhanced lesions seen on MRI (or with FLARE MRI). The
edema assocaited with MS lesions creates confusion between changes
in extracellular fluid space and damage to the neuronal elements.
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. It is our
expectation that annexin will pass through the blood-brain-barrier at
the site of new lesions and localize at the site of stressed or damaged
neurons. The extent of localization should be proportional to the
extent of damage to the cellular elements of the brain. Thus, we
expect a much better correlation of annexin imaging to prognosis.
Based on this model, it might be good to image as soon as possible
after clinical presentation of an exacerbation to determine the extent
of neuronal involvement and then to do a follow up study about 14
days post treatment to determine response to therapeutic
intervention. Such studies should provide specific information on
severity and prognosis of the and on individual response to
treatment. We hypothesize that radiolabeled annexin V imaging is a
useful modality in the determination of apoptosis in MS and can
assess and monitor the effectiveness of neuroprotective and
immunomodulatory therapies on the clinical course of MS. It would
be productive to study MS patients with Tc-99m annexin V imaging.
Unfortunately, this cold kit is unavailable for human use in the world.
Keywords: Multiple sclerosis , phosphatidylserine
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