Translocator Protein and Inflammation After Traumatic Brain Injury
- People with traumatic brain injury (TBI) often have inflammation in the brain. A protein called the translocator protein (TSPO) is often present with inflammation. Researchers want to see if a radioactive chemical known as [11C]PBR28 can be used to study TSPO and inflammation in the brain of people with TBI.
- To test whether [11C]PBR28 can be used to study changes in the brain after a traumatic brain injury.
- Individuals at least 18 years of age who have had TBI and have had a brain scan that shows signs of inflammation.
- Healthy volunteers at least 18 years of age.
- Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected.
- All participants will have two brain scans during an outpatient visit. A magnetic resonance imaging scan will study brain activity. A positron emission tomography (PET) scan will use [11C]PBR28 to look for signs of TSPO and brain inflammation.
- Participants with TBI will have two PET scans within 10 days of the head injury, and a PET scan around 90 days after the injury. They may also have MRI scans under this or another study. Tests of thinking, memory, and concentration will be used to study the effects of the injury and inflammation
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||PET Imaging of Translocator Protein in Subjects With Traumatic Brain Injury|
- Binding of [(11)C]PBR28.
- Neurocognitive assessment scores and clinical evaluations
|Study Start Date:||January 2012|
|Estimated Study Completion Date:||May 2015|
Objective: Brain damage following traumatic injury (TBI) results from both direct (eg, mechanical injury to the brain and vasculature) and indirect mechanisms (eg, secondary mechanisms such as inflammation). While CT and MRI can help visualize the result of inflammatory processes in the brain-for instance, the development of cerebral edema-neither method can be used to document active inflammation itself. The translocator protein (TSPO), which is highly expressed in microglia and reactive astrocytes, has been used as a biomarker in positron emission tomography (PET) to identify active inflammatory processes. Recently, our laboratory developed [(11)C]PBR28, a new PET ligand that images TSPO with high levels of specific binding. We have successfully used [(11)C]PBR28 to investigate a number of brain disorders such as epilepsy, multiple sclerosis, and HIV infection with minor cognitive motor disorder, and are detecting neuroinflammation. The current protocol aims to explore whether [(11)C]PBR28 PET imaging can show changes in subjects with TBI who have shown MRI abnormalities.
Study population: Twenty TBI subjects who have exhibited MRI abnormalities consistent with TBI and who are enrolled in one of two protocols-"Evaluation, Pathogenesis, and Outcome of Subjects with or Suspected Traumatic Brain Injury" (10-N-N122, PI Latour) or "Evaluation and Diagnosis of Potential Research Subjects with Traumatic Brain Injury (TBI), (11-NR-0084, PI: Raymond Dionne)-will be studied. In addition 20 healthy age-matched volunteers will be studied.
Design: This is an exploratory study to determine whether [(11)C]PBR28 can detect the increased TSPO associated with neuroinflammation by scanning subjects who have shown MRI abnormalities. Subjects with TBI will have up to three [(11)C]PBR28 PET scans, approximately matching the study time-points of the MRI scans performed in 10-N-N122; one to two PET scans will be performed within approximately 10 days of head injury, and a third PET scan will be performed approximately 90 days after injury. In addition to MRI data, clinical information obtained in 10-N-N122 and 11-NR-0084 will be used to evaluate the utility of the PET data in order to better understand the pathology of TBI.
Outcome Measures: In this exploratory study to investigate the ability of [(11)C]PBR28 PET to detect increases in TSPO, the primary goal will be to measure the magnitude and variance of any increases observed in [11C]PBR28 binding in areas of inflammation following TBI. Those data may be used to design future studies with a larger sample size.
|Contact: Holly Giesen||(301) firstname.lastname@example.org|
|Contact: Masahiro Fujita, M.D.||(301) email@example.com|
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike||Recruiting|
|Bethesda, Maryland, United States, 20892|
|Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL) 800-411-1222 ext TTY8664111010 firstname.lastname@example.org|
|Principal Investigator:||Masahiro Fujita, M.D.||National Institute of Mental Health (NIMH)|