Garrahy Ian, Forman Daniel, Swierczynski Sharon
Department of Medicine, Reading Hospital, Reading, PA, USA.
J Community Hosp Intern Med Perspect. 2019 Jun 19;9(3):226-229. doi: 10.1080/20009666.2019.1620092. eCollection 2019.
AL amyloidosis is due to deposition of protein derived from immunoglobulin light chain fragments. It is a systemic disorder in which deposition of plasma proteins can adversely affect function of the heart, liver, kidneys, and peripheral nerves. Deposition in the heart results in a decrease in the amplitude of the electrical activity of the heart and can be an early clue to the diagnosis. A 63-year-old male admitted for volume overload was found to have nephrotic range proteinuria, progressive renal insufficiency (Creatinine 4.0 increased from his baseline 0.9), and hypoalbuminemia. On exam, he had diffuse anasarca and peripheral neuropathy. A renal biopsy showed AL amyloidosis, lambda related, involving the glomeruli, interstitium, and arterial walls. Bone marrow biopsy showed 30% plasma cells with lambda light chain predominance. Serum free light chains were elevated. Lamda was 11.50 mg/dL and kappa was 5.12 mg/dL. In retrospective review of his chart, an EKG with low voltage and anterior pseudo-infarct pattern was first apparent on an admission for stroke two years prior. Echocardiogram showed mild concentric left ventricular hypertrophy. The patient was started on chemotherapy with Bortezomib. The differential of a low-voltage EKG includes many common pulmonary and chest wall (COPD, obesity) as well as pericardial diseases (effusions), but also important rarer infiltrative diseases including sarcoidosis and amyloidosis. Amyloidosis of the heart can cause progressive irreversible heart failure, but its progress can be altered if identified early. Physicians should consider amyloidosis when faced with a low-voltage EKG along with systemic symptoms including nephrotic range proteinuria, peripheral neuropathy, hepatosplenomegaly, and macroglossia.
AL型淀粉样变性是由于免疫球蛋白轻链片段衍生的蛋白质沉积所致。它是一种全身性疾病,血浆蛋白的沉积会对心脏、肝脏、肾脏和周围神经的功能产生不利影响。心脏中的沉积会导致心脏电活动幅度降低,这可能是诊断的早期线索。一名因容量超负荷入院的63岁男性被发现有肾病范围蛋白尿、进行性肾功能不全(肌酐从基线的0.9升至4.0)和低白蛋白血症。检查时,他有全身性水肿和周围神经病变。肾活检显示为与λ相关的AL型淀粉样变性,累及肾小球、间质和动脉壁。骨髓活检显示30%的浆细胞,以λ轻链为主。血清游离轻链升高。λ为11.50mg/dL,κ为5.12mg/dL。回顾他的病历,两年前因中风入院时首次出现低电压和前壁假性梗死图形的心电图。超声心动图显示轻度同心性左心室肥厚。患者开始接受硼替佐米化疗。低电压心电图的鉴别诊断包括许多常见的肺部和胸壁疾病(慢性阻塞性肺疾病、肥胖)以及心包疾病(积液),但也包括重要的罕见浸润性疾病,如结节病和淀粉样变性。心脏淀粉样变性可导致进行性不可逆心力衰竭,但如果早期发现,其进展可得到改变。当面对低电压心电图以及包括肾病范围蛋白尿、周围神经病变、肝脾肿大和巨舌等全身症状时,医生应考虑淀粉样变性。