Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, Graz, A-8036, Austria.
Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria.
ESC Heart Fail. 2021 Aug;8(4):3397-3402. doi: 10.1002/ehf2.13381. Epub 2021 May 7.
Amyloid light chain (AL) cardiomyopathy is the most malignant specific cardiomyopathy. According to international recommendations, it should be ruled out non-invasively using the serum free light chain (FLC) ratio and immunofixation electrophoresis in both serum and urine. Here, we report on a 69-year-old female patient with new-onset heart failure with mid-range ejection fraction. Cardiac imaging was highly suggestive of cardiac amyloidosis. Amyloid scintigraphy showed faint myocardial tracer uptake according to Perugini Score 1, but immunofixation was negative and the FLC ratio was normal, despite a slight increase in lambda FLCs. Endomyocardial biopsy revealed advanced myocardial lambda immunoglobulin light chain deposition. Clinically relevant extracardiac amyloid organ infiltration could not be detected. Conclusively, non-invasive testing can in rare cases fail to exclude isolated AL amyloid cardiomyopathy. We suggest that even slight increases in serum lambda or kappa FLCs should be considered abnormal in suspected cardiac amyloidosis if non-invasive testing delivers discrepant results.
轻链淀粉样变心肌病是最恶性的特异性心肌病。根据国际建议，应使用血清游离轻链（FLC）比值以及血清和尿液中的免疫固定电泳来进行非侵入性排除。在此，我们报告了一位 69 岁女性新诊断的心力衰竭伴中等射血分数患者。心脏影像学高度提示心脏淀粉样变性。根据 Perugini 评分 1，淀粉样闪烁扫描显示心肌示踪剂摄取微弱，但免疫固定电泳为阴性，FLC 比值正常，尽管 lambda FLC 略有增加。心内膜心肌活检显示晚期心肌 lambda 免疫球蛋白轻链沉积。临床相关的心脏外器官淀粉样浸润未被检测到。总之，在罕见情况下，非侵入性检查可能无法排除孤立的 AL 淀粉样变心肌病。我们建议，如果非侵入性检查结果不一致，即使血清 lambda 或 kappa FLC 略有增加，也应被视为可疑心脏淀粉样变性中的异常。
