Zifan Liu1, Qingmei Huang2,3, Huijuan Li4, Wei Qiu4, Baikeng Chen2,3, Jie Luo5, Huacai Yang2,3, Tianni Liu2,3, Si Liu2,3, Huiming Xu2,3, Youming Long2,3, Cong Gao2,3. 1. Department of Neurology, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. 2. Department of Neurology, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. 3. Institute of Neuroscience and Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Guangzhou, China. 4. Department of Neurology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. 5. First Affiliated Hospital of Shanxi Medical University, Taiyuan, China.
Abstract
OBJECTIVE: The aim of this study was to evaluate the positive rate of serum glutamic acid decarboxylase (GAD) autoantibody in patients with myelitis and to describe the clinical findings in patients with positive GAD antibody. METHODS: Serum samples were collected from 390 patients with myelitis, including 210 patients positive for aquaporin 4 (AQP4) antibody and 180 patients negative for AQP4. GAD65 antibody was measured by an indirect immunofluorescence assay. RESULTS: Only 1 serum and cerebral spinal fluid sample from 390 patients (0.26%) was positive for anti-GAD antibodies. The patient was a female with relapsing myelitis and a thymic mass. Thymic resection was undertaken, and pathological examination revealed a benign thymic cyst. Extensive infiltration of lymphocytes positive for CD3, CD4, CD8 and CD20 was found. Immunohistochemistry showed positive expression of GAD65 in the cyst. CONCLUSIONS: Although serum GAD65 antibodies were present in a patient, it is not recommended to routinely screen for GAD65 antibodies in patients with myelitis because of their rare occurrence. However, screening for GAD65 antibodies should be considered in patients who have been diagnosed with cancer or a thymic abnormality.
OBJECTIVE: The aim of this study was to evaluate the positive rate of serum glutamic acid decarboxylase (GAD) autoantibody in patients with myelitis and to describe the clinical findings in patients with positive GAD antibody. METHODS: Serum samples were collected from 390 patients with myelitis, including 210 patients positive for aquaporin 4 (AQP4) antibody and 180 patients negative for AQP4. GAD65 antibody was measured by an indirect immunofluorescence assay. RESULTS: Only 1 serum and cerebral spinal fluid sample from 390 patients (0.26%) was positive for anti-GAD antibodies. The patient was a female with relapsing myelitis and a thymic mass. Thymic resection was undertaken, and pathological examination revealed a benign thymic cyst. Extensive infiltration of lymphocytes positive for CD3, CD4, CD8 and CD20 was found. Immunohistochemistry showed positive expression of GAD65 in the cyst. CONCLUSIONS: Although serum GAD65 antibodies were present in a patient, it is not recommended to routinely screen for GAD65 antibodies in patients with myelitis because of their rare occurrence. However, screening for GAD65 antibodies should be considered in patients who have been diagnosed with cancer or a thymic abnormality.