Repeat PET/CT Imaging in People With CAPS and Anakinra-Induced Amyloidosis Using an Amyloid-Reactive Peptide to Measure Changes in Organ-Specific Amyloid Load

Study Description: This is a phase 1 study to evaluate the feasibility of an investigational positron emission tomography (PET)/computed tomography (CT) radiotracer, 124I-AT-01, to screen for anakinra-induced amyloidosis in people with the cryopyrin-associated autoinflammatory syndromes (CAPS) (Muckle-Wells syndrome \[MWS\] or neonatal onset multisystem inflammatory disease \[NOMID\]), and to follow resolution of amyloidosis. This radiotracer binds to amyloid, so a PET/CT scan can show the presence and relative magnitude of amyloid. Participants aged 18 years and older who developed local skin or systemic amyloidosis as a result of anakinra treatment will be recruited. They will have a PET/CT scan with radiotracer 124I-AT-01 about once every 6 months for 2 years. Blood and urine will be collected for clinical safety analyses, but no specimen will be collected for research or storage purposes. The 124I-AT-01 PET/CT imaging is expected to be able to detect anakinra-induced amyloid in the skin and other organs (such as kidney, liver, and spleen). The percent change in quantitative uptake of 124I-AT-01 from baseline to each subsequent scan is expected to correlate with changes in clinical features related to load of amyloid in the body. Primary Objectives: 1. To screen participants with fixed skin thickening at the site of anakinra injection and/or biopsy-proven anakinra-induced amyloidosis of the skin for the presence of systemic amyloidosis, using 124I-AT-01 PET/CT imaging. 2. To measure changes in organ-specific uptake of 124I-AT-01 from baseline in participants with anakinra-induced amyloidosis (local or systemic) using PET/CT imaging. 3. To assess the safety profile of 124I-AT-01 in participants with CAPS. Primary Endpoints: Change in organ-specific 124I-AT-01 uptake from baseline PET/CT imaging to the follow-up PET/CT imaging every 6 months for 2 years. Frequency of CAPS disease flares after exposure to 124I-AT-01.