TY - JOUR
T1 - Immune Checkpoint Inhibitor-Associated Kelch-Like Protein-11 IgG Brainstem Encephalitis
AU - Aboseif, Albert
AU - Vorasoot, Nisa
AU - Pinto, Marcus V.
AU - Guo, Yong
AU - Hasan, Shemonti
AU - Zekeridou, Anastasia
AU - Chen, John J.
AU - Dubey, Divyanshu
PY - 2024/5/1
Y1 - 2024/5/1
N2 - OBJECTIVES: Kelch-like protein-11 (KLHL11)-IgG is associated with rhombencephalitis and seminoma. It has not previously been described as a neurologic immune checkpoint inhibitor (ICI)-related adverse event (nirAE) or in association with esophageal adenocarcinoma. METHODS: We describe a 61-year-old man with metastatic esophageal adenocarcinoma treated with folinic acid, fluorouracil, oxaliplatin (FOLFOX), and nivolumab, who subsequently developed diplopia, vertigo, and progressive gait ataxia after 8 weeks of treatment. RESULTS: Owing to a concern for ICI-associated myasthenia gravis, nivolumab was held and he was treated with prednisone and pyridostigmine. EMG showed no neuromuscular junction dysfunction, and acetylcholine-receptor antibodies were negative. Brain MRI was unrevealing. Murine brain tissue immunofluorescence assay revealed KLHL11-IgG in both serum and CSF, confirmed by cell-based assay. Tumor histopathology demonstrated poorly differentiated, highly proliferative adenocarcinoma with increased mitotic figures and cytoplasmic KLHL11 immunoreactivity. He was initiated on 6 months of cyclophosphamide in addition to FOLFOX for post-ICI-associated KLHL11-IgG rhombencephalitis. DISCUSSION: We report KLHL11-IgG rhombencephalitis associated with poorly differentiated esophageal cancer as a novel nirAE. Tumor staining revealed KLHL11 immunoreactivity, supporting a cancer-antigen-driven ICI-associated paraneoplastic syndrome. Recognition of novel nirAEs can expedite treatment and potentially prevent progressive neurologic disability.
AB - OBJECTIVES: Kelch-like protein-11 (KLHL11)-IgG is associated with rhombencephalitis and seminoma. It has not previously been described as a neurologic immune checkpoint inhibitor (ICI)-related adverse event (nirAE) or in association with esophageal adenocarcinoma. METHODS: We describe a 61-year-old man with metastatic esophageal adenocarcinoma treated with folinic acid, fluorouracil, oxaliplatin (FOLFOX), and nivolumab, who subsequently developed diplopia, vertigo, and progressive gait ataxia after 8 weeks of treatment. RESULTS: Owing to a concern for ICI-associated myasthenia gravis, nivolumab was held and he was treated with prednisone and pyridostigmine. EMG showed no neuromuscular junction dysfunction, and acetylcholine-receptor antibodies were negative. Brain MRI was unrevealing. Murine brain tissue immunofluorescence assay revealed KLHL11-IgG in both serum and CSF, confirmed by cell-based assay. Tumor histopathology demonstrated poorly differentiated, highly proliferative adenocarcinoma with increased mitotic figures and cytoplasmic KLHL11 immunoreactivity. He was initiated on 6 months of cyclophosphamide in addition to FOLFOX for post-ICI-associated KLHL11-IgG rhombencephalitis. DISCUSSION: We report KLHL11-IgG rhombencephalitis associated with poorly differentiated esophageal cancer as a novel nirAE. Tumor staining revealed KLHL11 immunoreactivity, supporting a cancer-antigen-driven ICI-associated paraneoplastic syndrome. Recognition of novel nirAEs can expedite treatment and potentially prevent progressive neurologic disability.
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U2 - 10.1212/NXI.0000000000200218
DO - 10.1212/NXI.0000000000200218
M3 - Article
C2 - 38484218
AN - SCOPUS:85187812483
SN - 2332-7812
VL - 11
SP - e200218
JO - Neurology(R) neuroimmunology & neuroinflammation
JF - Neurology(R) neuroimmunology & neuroinflammation
IS - 3
ER -