散发性迟发性线虫肌病(SLONM)是一种可治疗或致命的肌病。SLONM的诊断仍然具有挑战性,尚未达成治疗共识。这里,我们报道了中国队列中SLONM的临床病理特征和长期随访数据.
我们对临床进行了回顾性评估,病理性,以及1986年3月至2021年4月在我们的神经肌肉中心诊断的17例SLONM患者的治疗结果。在SLONM的肌肉活检中使用针对5种Z-盘相关蛋白的抗体进行免疫组织化学(IHC),以鉴定潜在的病理标记,以帮助诊断。相比之下,我们还对选择性II型纤维萎缩患者进行了肌肉IHC(n=22),神经性萎缩(n=22),线粒体肌病(n=5),免疫介导的坏死性肌病(n=5),和正常对照(n=5)。
大多数患者表现出不对称的肢体肌肉无力(71%,12/17)和颈部伸肌无力(53%,9/17).对11例患者进行了免疫固定电泳,其中4例被鉴定为意义不明的单克隆丙种球蛋白病(MGUS)。来自16例患者的EMG表现出肌病模式,其中69%(11/16)具有自发活动。肌肉MRI显示脊柱旁优先受累,臀小肌和中肌,半膜,和比目鱼肌.使用抗α-肌动蛋白抗体(100%,17/17),抗肌动蛋白抗体(94%,16/17),抗结蛋白抗体(94%,16/17),抗α-B晶状体蛋白抗体(65%,11/17),和抗端黄素抗体(18%,3/17)具有各种阳性率。值得注意的是,抗α-肌动蛋白IHC显示强阳性染色百分比最高(77%,13/17),是唯一没有负面结果的人。3/4MGUS患者在自体干细胞移植(ASCT)后有中度改善;6/7无MGUS患者也取得了良好的结果。包括3例完全恢复的患者,他们接受了泼尼松和另一种免疫抑制剂的联合治疗。
SLONM是一种用ASCT或传统免疫疗法治疗的肌病,特别是与类固醇和免疫抑制剂联合使用时。抗α-肌动蛋白免疫染色是识别杆状纤维的最可靠的病理标记,对于未确诊的非坏死性肌病的成年患者应常规进行。
Sporadic late-onset nemaline myopathy (SLONM) is a treatable or otherwise fatal myopathy. Diagnosis of SLONM is still challenging, and no therapeutic consensus has been achieved. Here, we reported the clinicopathologic features and long-term follow-up data of SLONM in a Chinese cohort.
We performed a retrospective evaluation of clinical, pathologic, and treatment outcomes of 17 patients with SLONM diagnosed between March 1986 and April 2021 at our neuromuscular center. Immunohistochemistry (IHC) with antibodies against 5 Z-disc-associated proteins was performed in the muscle biopsies of SLONM to identify a potential pathologic marker in aid of diagnosis. In comparison, we also performed muscle IHC in patients with selective type II fiber atrophy (n = 22), neurogenic atrophy (n = 22), mitochondrial myopathy (n = 5), immune-mediated necrotizing myopathy (n = 5), and normal controls (n = 5).
Most of the patients exhibited asymmetric limb muscles weakness (71%, 12/17) and neck extensor weakness (53%, 9/17). Immunofixation electrophoresis was performed in 11 patients, and 4 of them were identified with monoclonal gammopathy of undetermined significance (MGUS). EMG from 16 patients demonstrated a myopathic pattern with spontaneous activities in 69% (11/16) of them. Muscle MRI showed preferential involvement of paraspinal, gluteus minimus and medius, semimembranosus, and soleus muscles. Suspected nemaline bodies on modified Gomori trichrome were confirmed by IHC using anti-α-actinin antibody (100%, 17/17), anti-myotilin antibody (94%, 16/17), anti-desmin antibody (94%, 16/17), anti-α-B crystallin antibody (65%, 11/17), and anti-telethonin antibody (18%, 3/17) with various positive rates. Notably, anti-α-actinin IHC showed the highest percentage of strongly positive staining (77%, 13/17), being the only one without negative results. Moderate improvement following autologous stem cell transplantation (ASCT) was noted in 3/4 patients with MGUS; favorable outcomes were also achieved in 6/7 patients without MGUS, including 3 patients with complete recovery who were given a combined treatment of prednisone and another immunosuppressant.
SLONM is a treatable myopathy with ASCT or traditional immunotherapy, especially when combined with steroids and immunosuppressants. Anti-α-actinin immunostaining is the most reliable pathologic marker to identify rod-bearing fibers, and it should be performed routinely in adult patients with undiagnosed nonnecrotic myopathies.