McKeon, Andrew

Purpose of review To describe a recently characterized autoimmune, inflammatory central nervous system (CNS) disorder known as autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy. Recent findings Affected patients present with symptoms of one or more of meningitis (headache and neck ache), encephalitis (delirium, tremor, seizures, or psychiatric symptoms), and myelitis (sensory symptoms and weakness). Optic disc papillitis (blurred vision) is common. CNS inflammation is evident in characteristic T1 postgadolinium enhancement of GFAP-enriched CNS regions, and lymphocytic cerebrospinal fluid (CSF) white cell count elevation. CSF is more reliable than serum for GFAP-immunoglobulin G (IgG) testing. Ovarian teratoma commonly coexists, particularly among patients with accompanying N-methyl-D-aspartate receptor or aquaporin-4 autoimmunity. Parainfectious autoimmunity is suspected in some other patients, though the culprit organism is rarely verified. Pathophysiologic relevance of T cells is underscored by neuropathology and cases of dysregulated T-cell function (HIV or checkpoint inhibitor cancer therapy). Corticosteroid-responsiveness is a hallmark of the disease. Relapses occur in approximately 20% of patients, necessitating transition to a steroid-sparing drug. Reported outcomes vary, though in the authors’ experience, early and sustained intervention usually portends recovery. Summary Autoimmune GFAP astrocytopathy is a treatable autoimmune CNS disease diagnosable by GFAP-IgG testing in CSF. This disease presents opportunities to explore novel mechanisms of CNS autoimmunity and inflammation.

11559 Background: Paraneoplastic neurologic disease (PND) is an aberrant immune-mediated response against the nervous system triggered by occult malignancy. Given the rarity of this disease, a paucity of data exists describing breast cancer (BC)-related PND; thus, we sought to further examine this specific population of patients. Methods: Using an institution specific clinical search tool, we identified all patients at our institution from 1997-2016 with a diagnosis of BC-related PND, verified by an international expert. Retrospective review was used to record tumor and treatment factors associated with PND and BC. A descriptive analysis was performed of the characteristics associated with BC-related PND. Results: BC-related PND was diagnosed in 58 female patients. Average age at BC diagnosis was 54.0±10.3 years. Most had invasive cancer of Stage II or higher [Stage 0 (10.3%), I (10.3%), II (44.8%), III (13.8%), IV (6.9%), unknown (13.8%)]. Most patients were hormone receptor (HR)+ (63.8%), while 4 (6.9%) were HR-, and 17 (29.3%) were unknown. Of the 34 patients where Her2/neu (Her2) data was available, 7 (20.6%) were Her2+ and 27 (79.4%) were Her2-. The majority (62.1%) had neurological symptoms prior to BC, 5.2% were concurrent, and 32.7% developed PND after initial BC. The interquartile range for time from PND to BC diagnosis was -8.5 to 10.5 months. Of the 58 patients, 29 (50%) had autoantibodies detected: Purkinje Cell Cytoplasmic Autoantibody Type-1 (PCA-1[anti-Yo]) (10), amphiphysin-IgG (n = 9), Anti-Neuronal Nuclear Autoantibody Type-2 (ANNA-2[anti-Ri]) (n = 5), and other (n = 5). The most common syndromes were cerebellar ataxia (n = 14), myelopathy (n = 11), and myopathy (n = 11). Immunotherapy was used for PND in 53 of 58 (91.4%) patients; benefit from immunotherapy was assessed as complete 0 (0%), robust 11 (20.8%), mild to moderate 28 (52.8%), none 9 (17%), and indeterminate 5 (9.4%). Conclusions: BC-related PND is rare, with only 58 cases over 20 years at a large academic institution. Paraneoplastic symptoms often present prior to BC diagnosis and BC characteristics are typical of the general population. Over 75% of patients benefit from immunotherapy. These data may provide helpful information to providers treating this population of patients.