Effect on disease activity of ofatumumab in the treatment of glial fibrillary acidic protein astrocytopathy and 18F-DPA714 PET/MRI imaging assessment.

A 49-year-old male with Glial Fibrillary Acidic Protein Astrocytopathy (GFAP-A) presented with progressive cognitive decline, visual hallucinations, and bowel/bladder incontinence. Brain MRI revealed extensive white matter hyperintensities on T2-FLAIR sequences. After suboptimal response to first-line treatments including corticosteroids and intravenous immunoglobulin (IVIg), the patient was initiated on Ofatumumab (OFA) therapy. Treatment response was systematically monitored through validated clinical assessment tools (MMSE, MoCA, mRS, and CASE) and advanced neuroimaging, including conventional MRI and 18F-DPA714 PET. Following OFA treatment, the patient demonstrated marked clinical improvement and radiological resolution. Notably, 18F-DPA714 PET imaging captured dynamic changes in neuroinflammation and revealed distinct patterns not apparent on conventional MRI. This case demonstrates the potential effect on disease activity and safety of OFA in GFAP-A treatment while highlighting the value of 18F-DPA714 PET as an innovative tool for monitoring neuroinflammation and therapeutic response. To our knowledge, this represents the first comprehensive multimodal assessment using 18F-DPA714 PET/MRI in a GFAP-A patient treated with ofatumumab.