Long-Term Clinical Landscapes of Spinal Hypertrophic Pachymeningitis With Anti-Neutrophil Cytoplasmic Antibody–Associated Vasculitis

BACKGROUND AND OBJECTIVES: Spinal hypertrophic pachymeningitis (HP) is an extremely rare disorder characterized by the thickening of the spinal dura mater, which harbors distinct repertoires of immune cells due to the unique partitioning of the arachnoid blood-CSF barrier. The objectives were to identify the pathogenesis and therapeutic strategies for spinal HP. METHODS: This retrospective cohort study analyzed the clinical and pathologic profiles of patients with idiopathic/immune-mediated HP including spinal HP. RESULTS: cranial HP (1, 2, 6, 8, 9, and 10), but also has unique clinical features (3, 4, 5, 7, and 11). DISCUSSION: spinal HP, as an organ-threatening disease, should be positioned as having unique characteristics, whether limited to the CNS or as part of a generalized form in ANCA-associated vasculitis.