Contributions
Abstract: P1082
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: Thalamic volume is known to decrease in MS patients over time, and has been attributed to increased fatigue and decreased cognitive function. PK11195-PET is used to detect microglia/macrophage (MG/MΦ) activation by binding translocator protein (TSPO), a protein found on the outer mitochondrial membrane of MG/MΦ. PK uptake is known to be high within the thalamus of healthy controls (HC), and has also been described for the thalamus in MS patients. A comparison of PK uptake between HC and MS patients has yet to be obtained.
Objective: To determine thalamic [11C[PK11195 uptake in MS patients versus HC subjects.
Methods: Pharmacokinetic quantification was done using a segmented MRI, obtaining the thalamic volume for both hemispheres. PK11195-PET imaging was acquired cross-sectionally for 23 MS patients and 9 HC. PK uptake within the thalamus was quantified by volume of distribution (VT) calculation using image-derived input function. Thalamic VT was calculated in reference to each patient"s white matter, to consider physiologic variability, and Vt ratio (VTr) was obtained. VTr was analyzed based on age, gender, EDSS for MS pt, and analyzed for age for HC.
Results: The MS cohort consisted of 4 secondary progressive and 19 relapsing remitting patients. Mean age was 37.9 for MS patients, while mean age for HC was 49.5 years. VTr is higher in MS patients (mean VTr=1.28) compared to HC (mean VTr=1.23, p=0.01, paired T -test). Thalamic VTr was not associated with patients age, gender, disease duration or EDSS.
Conclusion: Our results show that VTr is increased in MS patients in comparison to HC. This finding is unrelated to disease characteristics and the reason remains speculative, since only small to medium amounts of MG/MΦ have been described in deep gray matter. However, given the known thalamic atrophy in MS, increased thalamic MG/MΦ activation might contribute to this observation.
Disclosure: UK - received a fellowship grant from biogen
YK - no disclosures
EM - no disclosures
NN - reports no disclosures.
JP- reports no disclosures.
TV - is a speaker for Teva Neuroscience, has received honoraria for advising Genzyme, and has received grant support from the National MS society, Biogen, and Mallinckrodt.
SG - has received honoraria for advertising Genentech and Teva Neuroscience and has received grant support from the National MS society, Biogen, Novartis Pharmaceuticals, Mallinckrodt, Genzyme and EMD Serono.
Abstract: P1082
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background: Thalamic volume is known to decrease in MS patients over time, and has been attributed to increased fatigue and decreased cognitive function. PK11195-PET is used to detect microglia/macrophage (MG/MΦ) activation by binding translocator protein (TSPO), a protein found on the outer mitochondrial membrane of MG/MΦ. PK uptake is known to be high within the thalamus of healthy controls (HC), and has also been described for the thalamus in MS patients. A comparison of PK uptake between HC and MS patients has yet to be obtained.
Objective: To determine thalamic [11C[PK11195 uptake in MS patients versus HC subjects.
Methods: Pharmacokinetic quantification was done using a segmented MRI, obtaining the thalamic volume for both hemispheres. PK11195-PET imaging was acquired cross-sectionally for 23 MS patients and 9 HC. PK uptake within the thalamus was quantified by volume of distribution (VT) calculation using image-derived input function. Thalamic VT was calculated in reference to each patient"s white matter, to consider physiologic variability, and Vt ratio (VTr) was obtained. VTr was analyzed based on age, gender, EDSS for MS pt, and analyzed for age for HC.
Results: The MS cohort consisted of 4 secondary progressive and 19 relapsing remitting patients. Mean age was 37.9 for MS patients, while mean age for HC was 49.5 years. VTr is higher in MS patients (mean VTr=1.28) compared to HC (mean VTr=1.23, p=0.01, paired T -test). Thalamic VTr was not associated with patients age, gender, disease duration or EDSS.
Conclusion: Our results show that VTr is increased in MS patients in comparison to HC. This finding is unrelated to disease characteristics and the reason remains speculative, since only small to medium amounts of MG/MΦ have been described in deep gray matter. However, given the known thalamic atrophy in MS, increased thalamic MG/MΦ activation might contribute to this observation.
Disclosure: UK - received a fellowship grant from biogen
YK - no disclosures
EM - no disclosures
NN - reports no disclosures.
JP- reports no disclosures.
TV - is a speaker for Teva Neuroscience, has received honoraria for advising Genzyme, and has received grant support from the National MS society, Biogen, and Mallinckrodt.
SG - has received honoraria for advertising Genentech and Teva Neuroscience and has received grant support from the National MS society, Biogen, Novartis Pharmaceuticals, Mallinckrodt, Genzyme and EMD Serono.