PET visualization of microglia in multiple sclerosis patients using [11C]PK11195.
Activated microglia are involved in the immune response of multiple sclerosis (MS). The peripheral benzodiazepine receptor (PBR) is expressed on microglia and up-regulated after neuronal injury. [11C]PK11195 is a positron emission tomography (PET) radioligand for the PBR. The objective of the present study was to investigate [11C]PK11195 imaging in MS patients and its additional value over magnetic resonance imaging (MRI) concerning the immuno-pathophysiological process. Seven healthy and 22 MS subjects were included. Semiquantitative [11C]PK11195 uptake values were assessed with normalization on cortical grey matter. Uptake in Gadolinium-lesions was significantly increased compared with normal white matter. Uptake in T2-lesions was generally decreased, suggesting a PBR down-regulation. However, uptake values increased whenever a clinical or MR-relapse was present, suggestive for a dynamic process with a transient PBR up-regulation. During disease progression, an increase of normal-appearing white matter (NAWM) uptake was found, propagating NAWM as the possible real burden of disease. In conclusion, [11C]PK11195 and PET are able to demonstrate inflammatory processes with microglial involvement in MS.
Debruyne
J C
JC
Department of Neurology, Ghent University Hospital, Ghent, Belgium. jan.debruyne@rug.ac.be
Versijpt
J
J
Van Laere
K J
KJ
De Vos
F
F
Keppens
J
J
Strijckmans
K
K
Achten
E
E
Slegers
G
G
Dierckx
R A
RA
Korf
J
J
De Reuck
J L
JL
D000328:Adult; D000367:Age Factors; D000970:Antineoplastic Agents / Q000378:metabolism / Q000627:therapeutic use; D001931:Brain Mapping; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000378:metabolism / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D017628:Microglia / Q000000981:diagnostic imaging / Q000378:metabolism*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D010296:Parietal Lobe / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D011869:Radioligand Assay / Q000379:methods; D012008:Recurrence; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D014055:Tomography, Emission-Computed / Q000379:methods*
D000970:Antineoplastic Agents; D007546:Isoquinolines; C037850:PK 11195