評估抗水通道蛋白4自體抗體在視神經脊髓炎的診斷效果

Evaluation the Performance of Aquaporin 4 Autoantibodies in Patients with Neuromyelitis Optica

視神經脊髓炎(Neuromyelitis optica，NMO)為一種罕見的中樞神經去髓鞘自體免疫疾病。最新臨床診斷標準需參考：腦、脊髓MRI影像及水通道蛋白4(water channel protein aquaporin-4,AQP4)自體抗體。初期或不典型的NMO可能會與多發性硬化症(multiple sclerosis，MS)誤判，若使用不恰當的藥物治療不但無效，還可能造成傷害。目前台灣尚無臨床檢驗室提供AQP4自體抗體定量服務，故本研究主要目的乃建立本土定量AQP4自體抗體之檢驗方法，並評估應用於診斷NMO的能力。本研究收集了13位NMO、27位MS患者及18位健康者之血清，以ELISA方式檢測抗體濃度，結果顯示診斷NMO的敏感度為84.6%，區別MS或健康者的專一性分別為77.8%、100%。本研究建立了本土偵測AQP4自體抗體之定量檢驗方法，並證實AQP4自體抗體確實能協助鑑別NMO及MS，避免NMO被誤判而錯誤治療。

Neuromyelitis optica (NMO) is a rare demyelinating autoimmunity disease of the central nervous system. Early discrimination NMO from multiple sclerosis (MS) is very important, because there are distinct treatments for each of these diseases. The current international diagnostic criteria of NMO include water channel protein aquaporin-4 autoantibody (anti-AQP4 Ab) seropositivestatus. To investigate the clinical utility of anti-AQP4 Ab for diagnosis of NMO, we assessed the sensitivity and specificity of the ELISA kit using the serum of 13 NMO patients, 27 MS patients, and 18 healthy individuals. Anti-AQP4 Ab seropositivity was 84.6 % for NMO. The specificity to discriminate between NMO and MS is 77.8 %, and the specificity to discriminate between NMO and healthy individuals is 100 %. Our study establishes a clinical test for anti-AQP4 Ab in Taiwan and confirms anti-AQP4 Ab is a valuable marker to differentiate NMO from MS.