Ishikawa Hidehiro, Taniguchi Akira, Ii Yuichiro, Higuchi Osamu, Matsuo Hidenori, Nakane Shunya, Asahi Masaru, Niwa Atsushi, Tomimoto Hidekazu
Department of Neurology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
Department of Neurology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
Neuromuscul Disord. 2017 Oct;27(10):914-917. doi: 10.1016/j.nmd.2017.06.001. Epub 2017 Jun 3.
We describe two cases of myasthenia gravis (MG) with double seropositivity for acetylcholine receptor (AChR) and low-density lipoprotein receptor-related protein 4 (LRP4) antibodies (AChR/LRP4-MG) with invasive thymoma. Both cases showed myasthenic weakness, which was restricted to the ocular muscles for >5 months from onset, and then unprovoked severe clinical deterioration supervened with predominant bulbar symptoms. The patients responded adequately to therapeutic intervention. Serum AChR antibody levels at post-intervention were markedly decreased, whereas LRP4 antibodies were almost unchanged in case 1 and slightly decreased in case 2. Although our results suggest that patients with AChR/LRP4-MG are likely to present with more severe symptoms than those with LRP4-MG, none of the previously reported cases had thymomas. Coexistence of autoantibodies may reflect breakdown of self-tolerance caused by invasive thymomas. The main cause affecting symptoms of MG in our cases was probably AChR antibodies, and anti-LRP4 antibodies might have been an exacerbating factor.
我们描述了两例重症肌无力（MG）患者，其乙酰胆碱受体（AChR）和低密度脂蛋白受体相关蛋白4（LRP4）抗体呈双重血清阳性（AChR/LRP4-MG），并伴有侵袭性胸腺瘤。两例患者均表现为肌无力，起病后眼肌受累超过5个月，随后出现无诱因的严重临床恶化，主要表现为延髓症状。患者对治疗干预反应良好。干预后血清AChR抗体水平明显降低，而LRP4抗体在病例1中几乎未变，在病例2中略有下降。虽然我们的结果表明，AChR/LRP4-MG患者可能比LRP4-MG患者表现出更严重的症状，但之前报道的病例均无胸腺瘤。自身抗体的共存可能反映了侵袭性胸腺瘤导致的自身耐受破坏。在我们的病例中，影响MG症状的主要原因可能是AChR抗体，而抗LRP4抗体可能是一个加重因素。
