Anti-Ma2 Antibody Paraneoplastic Cerebellar Degeneration Associated with Renal Cell Carcinoma: A Case Report. (P8-11.013)

Abstract

<h3>Objective:</h3> To highlight a unique case of Anti-Ma2 antibody paraneoplastic cerebellar degeneration (PCD) associated with renal cell carcinoma (RCC). <h3>Background:</h3> Paraneoplastic neurologic syndromes are a group of immune mediated disorders with a multitude of presentations. PCD is a rare presentation of a rapidly progressive ataxia associated with a variety of antibodies. In 0.5–1% of patients, anti-Ma2 antibody has been known to cause PCD in the setting of neoplasms. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 70-year-old male presented with three-month history of progressive gait difficulty, poor balance and recurrent falls. He had a history of metastatic RCC for which he underwent a total left nephrectomy, radiation therapy and chemotherapy with nivolumab and axitinib. Initial evaluation noted end-gaze nystagmus, limb dysmetria, truncal ataxia and wide-based gait. Chemotherapy was discontinued at the onset of symptoms. Work-up demonstrated cerebellar atrophy and cerebrospinal fluid (CSF) studies revealed mildly elevated protein and oligoclonal bands. He was hospitalized one month later for rapidly worsening ataxia. Repeat serum and CSF studies were positive for anti-Ma2 antibodies. He underwent 5 sessions of plasmapheresis with minimal improvement. Despite treatment, disease continued to progress with patient becoming wheelchair bound. Further treatment with immunotherapies were discussed, but patient elected to pursue palliative care. <h3>Conclusions:</h3> Anti-Ma2 antibodies have been well characterized in PCD in the setting of neoplasms. Immune checkpoint inhibitors (ICI) have also been associated with anti-Ma2 antibodies, causing immune related adverse events including encephalitis and cranial neuropathies. Nivolumab has been reported with cerebellar ataxia in the absence of anti-Ma2 antibodies with symptoms starting shortly after the initiation of therapy. However, symptoms improved after discontinuation of nivolumab and treatment with steroids. In our case, symptoms started almost one year after the initiation of ICI and patient continued to decline even after discontinuation of ICI. This presentation demonstrates a unique case of anti-Ma2 antibody PCD associated with RCC. <b>Disclosure:</b> Dr. Zahra has nothing to disclose. Dr. Ahmed has nothing to disclose. Dr. Sivakumar has nothing to disclose. Dr. Urrea-Mendoza has nothing to disclose. Dr. Veerappan has nothing to disclose.