抗アクアポリン4抗体のほか複数の自己抗体をともなった視神経脊髄炎の1例

Abstract

We report a patient with optic neuropathy and longitudinally extensive myelitis associated with anti-aquaporin 4 (AQP4) antibody and other autoantibodies. An 89-year-old woman presented with progressive numbness and weakness of the extremities which had acutely developed. She also complained of neck pain and gait disturbance. The results of a general physical examination were unremarkable. Neurologic examination disclosed right optic atrophy, an absence of touch sensation, pain, and muscular weakness in all her extremities. Her deep tendon reflexes were decreased, and the Babinski sign was bilaterally positive. Immunoserologic study yielded positive titers for anti-nuclear antibody (ANA), anti-double-stranded DNA, anti-Sjögren syndrome (SS)-A, anti-SS-B, and anti-ribonucleoprotein (RNP) antibodies. A lumbar cerebrospinal fluid examination showed a protein concentration of 54 mg/dL, a glucose concentration of 50 mg/dL (simultaneous blood concentration, 140 mg/dL), and a cell count of 2/mm(3). Chest radiography revealed interstitial pneumonia. Magnetic resonance imaging (MRI) of the cervical spine showed spondylotic cervical canal stenosis with cord impingement. T2-weighted MR images demonstrated increased signal intensity extending from C2 to C6, while contrast enhancement was noted in T1-weighted MR images upon gadolinium-DTPA administration. We suspected longitudinally extensive myelitis associated with the autoimmune disorders systemic lupus erythematosus and Sjögren syndrome. After intravenous methylprednisolone administration, her neurologic abnormalities gradually decreased, while MRI no longer showed increased signal or contrast enhancement. Anti-AQP4 antibody titers were positive. We consider that this patient had a neuromyelitis optica (NMO) spectrum disorder which was associated with systemic autoimmune disease. The possibility of NMO should be considered in similar patients with autoimmune disease, and anti-AQP4 antibody should be assessed.