Yamaguchi Tomohisa, Matsunaga Akiko, Ikawa Masamichi, Shirafuji Norimichi, Nishino Ichizo, Hamano Tadanori
Department of Neurology, University of Fukui Hospital.
Rinsho Shinkeigaku. 2017 Mar 28;57(3):118-123. doi: 10.5692/clinicalneurol.cn-000982. Epub 2017 Feb 22.
A 49-year-old woman presented with progressive muscle weakness of the limbs and dysphagia. Her past and family medical history were unremarkable and she did not take statins or any other medications. Laboratory tests showed that serum levels of creatine kinase were elevated (13,565 IU/l) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies were detected in the serum. Other autoantibodies to the nuclear (ANA), RNP, aminoacyl-tRNA synthetases (ARS), and signal recognition particle (SRP) were negative. Pathological analysis of the left biceps muscle revealed minimal lymphocytic infiltration into the muscle fibers together with many necrotic and regenerated fibers, which corresponded to necrotizing myopathy. Abdominal CT and upper gastrointestinal endoscopy showed an advanced gastric cancer with lymph node metastasis. The patient was subsequently diagnosed with anti-HMGCR antibody-positive paraneoplastic necrotizing myopathy associated with advanced gastric cancer. The patient underwent radical surgery to remove the cancer and was initially treated with oral prednisolone and intravenous methylprednisolone pulse therapy; however, her symptoms worsened and she became bedridden. After an additional treatment with intravenous immunoglobulin (IVIg), she showed noticeable improvements in muscle strength and dysphagia and became ambulatory. This case and recent case-series studies suggest that anti-HMGCR antibody-positive necrotizing myopathy may be included in paraneoplastic syndrome and that physicians should screen for malignant tumors in patients with anti-HMGCR antibody-positive necrotizing myopathy. Moreover, IVIg can be a useful therapy in patients with anti-HMGCR antibody-positive paraneoplastic necrotizing myopathy who show refractoriness to tumor resection and corticosteroid therapies.
一名49岁女性因四肢进行性肌无力和吞咽困难就诊。她的既往病史和家族病史均无异常，未服用他汀类药物或其他任何药物。实验室检查显示血清肌酸激酶水平升高（13565 IU/L），血清中检测到抗3-羟基-3-甲基戊二酰辅酶A还原酶（HMGCR）抗体。其他针对核（ANA）、核糖核蛋白（RNP）、氨酰tRNA合成酶（ARS）和信号识别颗粒（SRP）的自身抗体均为阴性。左肱二头肌的病理分析显示，肌纤维有少量淋巴细胞浸润，同时存在许多坏死和再生纤维，符合坏死性肌病。腹部CT和上消化道内镜检查显示晚期胃癌伴淋巴结转移。该患者随后被诊断为与晚期胃癌相关的抗HMGCR抗体阳性副肿瘤性坏死性肌病。患者接受了根治性手术切除肿瘤，最初接受口服泼尼松龙和静脉注射甲泼尼龙冲击治疗；然而，她的症状恶化，卧床不起。在接受静脉注射免疫球蛋白（IVIg）额外治疗后，她的肌肉力量和吞咽困难有明显改善，并能够行走。该病例及近期的病例系列研究表明，抗HMGCR抗体阳性坏死性肌病可能属于副肿瘤综合征，医生应在抗HMGCR抗体阳性坏死性肌病患者中筛查恶性肿瘤。此外，IVIg对于对抗肿瘤切除和皮质类固醇治疗无效的抗HMGCR抗体阳性副肿瘤性坏死性肌病患者可能是一种有效的治疗方法。
