New PET tracer aims to light up inflammation in joint and muscle diseases

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* INCLUSION CRITERIA: Healthy subjects * Aged 18 years or older. * Willing and able to complete all study procedures. * Able to provide informed consent. * Healthy based on medical history, physical examination, and laboratory testing. * Enrolled in protocol 01-M-0254 The Evaluation of Participants with Mood and Anxiety Disorders and Healthy Volunteers or 17-M-0181 Recruitment and Characterization of Healthy Research Volunteers for National Institute of Mental Health (NIMH) Intramural Studies. * Be age and sex-matched with patient groups for the 15 subjects in the Phase 2. RA patients * Aged 18 years or older. * Willing and able to complete all study procedures. * Able to provide informed consent. * Have been given a diagnosis of RA based on the published criteria (Aletaha et al., 2010). * Have moderate to severe symptoms, as defined by a Disease Activity Score in 28 joints with erythrocyte sedimentation rate (DAS28-ESR) score \>3.2, but RA patients may be in remission for the repeat scan in phase 4. IIM patients * Aged 18 years or older * Willing and able to complete all study procedures. * Able to provide informed consent. * Meets Bohan and Peter criteria ((Bohan and Peter, 1975a, b) for probable or definite dermatomyositis (DM) or polymyositis (PM), or * Meets criteria for inclusion body myositis (IBM) as defined by Lloyd et al.: 1) finger flexor or quadriceps weakness, and 2) endomysial inflammation, and 3) either invasion of non-necrotic muscle fibers or rimmed vacuoles. Axial Spondyloarthritis (AxSpA) patients * Aged 18 years or older. * Willing and able to complete all study procedures. * Able to provide informed consent. * Have been given a diagnosis of AxSpA based on Assessment of Spondylo-Arthritis International Society (ASAS) criteria AxSpA. EXCLUSION CRITERIA: 1. Common for all participants * Because non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX-2, subjects should not have taken NSAIDs or willow bark tea for two weeks prior to the PET scan. * For Phase 2, 3 and 4 \*contraindications to taking COX-2 inhibitors that, in the opinion of the investigators, have the potential to affect the results or the safety of the participant. These may include: * History of hypersensitivity reaction to COX inhibitors or History of aspirin- or NSAID-induced asthma * History of upper or lower gastrointestinal bleeding, gastritis, peptic ulcer disease * History of uncontrolled gastroesophageal reflux disease (GERD), but not medically controlled GERD * Coagulation disorder * Thrombocytopenia * Glucose-6-phosphate dehydrogenase (G6PD) deficiency * History of gout * History of hepatic or renal impairment * History of cardiovascular disease or presence of cardiovascular risk factors such as uncontrolled or poorly controlled hypertension * Current use of probenecid * Patients clinically in remission or who have low disease activity * Positive HIV infection * Any other history of severe medical illness or injury with the potential to affect study data interpretation or to be any medical contraindication to the procedures performed in the study, including active infection and untreated malignancy. * Unable to travel to NIH * Recent exposure to radiation related to research (e.g., PET from other research) that, when combined with this study, would be above the allowable limits. * Inability to lie flat on camera bed for at least two hours, including claustrophobia and overweight greater than the maximum for the scanner (500 lb.). * Pregnancy or breastfeeding. * Participants must not have substance use disorder or alcohol use disorder. However, alcohol or cannabis use by themselves are not exclusion criteria, unless that use affects the function of daily life. * NIMH employees or an NIH employee who is a subordinate/relative/co-worker of the investigators. * These criteria will not be applied to the two healthy volunteers participating in the Phase 1 of this study\*. 2. Healthy subjects * Clinically significant laboratory abnormalities based on tests performed under screening protocol 01-M-0254 or 17-M-0181. 3. AxSpA and IIM patients * Unable to have an MRI scan (e.g., pacemakers or other implanted electrical devices, brain stimulators, dental implants, aneurysm clips (metal clips on the wall of a large artery), metallic prostheses (including metal pins and rods, heart valves, and cochlear implants), permanent eyeliner, implanted delivery pumps, or shrapnel fragments, metal fragments in the eye).